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-// Written in the D programming language.
-
-/**
- * Contains the elementary mathematical functions (powers, roots,
- * and trigonometric functions), and low-level floating-point operations.
- * Mathematical special functions are available in $(D std.mathspecial).
- *
-$(SCRIPT inhibitQuickIndex = 1;)
-
-$(DIVC quickindex,
-$(BOOKTABLE ,
-$(TR $(TH Category) $(TH Members) )
-$(TR $(TDNW Constants) $(TD
- $(MYREF E) $(MYREF PI) $(MYREF PI_2) $(MYREF PI_4) $(MYREF M_1_PI)
- $(MYREF M_2_PI) $(MYREF M_2_SQRTPI) $(MYREF LN10) $(MYREF LN2)
- $(MYREF LOG2) $(MYREF LOG2E) $(MYREF LOG2T) $(MYREF LOG10E)
- $(MYREF SQRT2) $(MYREF SQRT1_2)
-))
-$(TR $(TDNW Classics) $(TD
- $(MYREF abs) $(MYREF fabs) $(MYREF sqrt) $(MYREF cbrt) $(MYREF hypot)
- $(MYREF poly) $(MYREF nextPow2) $(MYREF truncPow2)
-))
-$(TR $(TDNW Trigonometry) $(TD
- $(MYREF sin) $(MYREF cos) $(MYREF tan) $(MYREF asin) $(MYREF acos)
- $(MYREF atan) $(MYREF atan2) $(MYREF sinh) $(MYREF cosh) $(MYREF tanh)
- $(MYREF asinh) $(MYREF acosh) $(MYREF atanh) $(MYREF expi)
-))
-$(TR $(TDNW Rounding) $(TD
- $(MYREF ceil) $(MYREF floor) $(MYREF round) $(MYREF lround)
- $(MYREF trunc) $(MYREF rint) $(MYREF lrint) $(MYREF nearbyint)
- $(MYREF rndtol) $(MYREF quantize)
-))
-$(TR $(TDNW Exponentiation & Logarithms) $(TD
- $(MYREF pow) $(MYREF exp) $(MYREF exp2) $(MYREF expm1) $(MYREF ldexp)
- $(MYREF frexp) $(MYREF log) $(MYREF log2) $(MYREF log10) $(MYREF logb)
- $(MYREF ilogb) $(MYREF log1p) $(MYREF scalbn)
-))
-$(TR $(TDNW Modulus) $(TD
- $(MYREF fmod) $(MYREF modf) $(MYREF remainder)
-))
-$(TR $(TDNW Floating-point operations) $(TD
- $(MYREF approxEqual) $(MYREF feqrel) $(MYREF fdim) $(MYREF fmax)
- $(MYREF fmin) $(MYREF fma) $(MYREF nextDown) $(MYREF nextUp)
- $(MYREF nextafter) $(MYREF NaN) $(MYREF getNaNPayload)
- $(MYREF cmp)
-))
-$(TR $(TDNW Introspection) $(TD
- $(MYREF isFinite) $(MYREF isIdentical) $(MYREF isInfinity) $(MYREF isNaN)
- $(MYREF isNormal) $(MYREF isSubnormal) $(MYREF signbit) $(MYREF sgn)
- $(MYREF copysign) $(MYREF isPowerOf2)
-))
-$(TR $(TDNW Complex Numbers) $(TD
- $(MYREF abs) $(MYREF conj) $(MYREF sin) $(MYREF cos) $(MYREF expi)
-))
-$(TR $(TDNW Hardware Control) $(TD
- $(MYREF IeeeFlags) $(MYREF FloatingPointControl)
-))
-)
-)
-
- * The functionality closely follows the IEEE754-2008 standard for
- * floating-point arithmetic, including the use of camelCase names rather
- * than C99-style lower case names. All of these functions behave correctly
- * when presented with an infinity or NaN.
- *
- * The following IEEE 'real' formats are currently supported:
- * $(UL
- * $(LI 64 bit Big-endian 'double' (eg PowerPC))
- * $(LI 128 bit Big-endian 'quadruple' (eg SPARC))
- * $(LI 64 bit Little-endian 'double' (eg x86-SSE2))
- * $(LI 80 bit Little-endian, with implied bit 'real80' (eg x87, Itanium))
- * $(LI 128 bit Little-endian 'quadruple' (not implemented on any known processor!))
- * $(LI Non-IEEE 128 bit Big-endian 'doubledouble' (eg PowerPC) has partial support)
- * )
- * Unlike C, there is no global 'errno' variable. Consequently, almost all of
- * these functions are pure nothrow.
- *
- * Status:
- * The semantics and names of feqrel and approxEqual will be revised.
- *
- * Macros:
- * TABLE_SV = <table border="1" cellpadding="4" cellspacing="0">
- * <caption>Special Values</caption>
- * $0</table>
- * SVH = $(TR $(TH $1) $(TH $2))
- * SV = $(TR $(TD $1) $(TD $2))
- * TH3 = $(TR $(TH $1) $(TH $2) $(TH $3))
- * TD3 = $(TR $(TD $1) $(TD $2) $(TD $3))
- * TABLE_DOMRG = <table border="1" cellpadding="4" cellspacing="0">
- * $(SVH Domain X, Range Y)
- $(SV $1, $2)
- * </table>
- * DOMAIN=$1
- * RANGE=$1
-
- * NAN = $(RED NAN)
- * SUP = <span style="vertical-align:super;font-size:smaller">$0</span>
- * GAMMA = &#915;
- * THETA = &theta;
- * INTEGRAL = &#8747;
- * INTEGRATE = $(BIG &#8747;<sub>$(SMALL $1)</sub><sup>$2</sup>)
- * POWER = $1<sup>$2</sup>
- * SUB = $1<sub>$2</sub>
- * BIGSUM = $(BIG &Sigma; <sup>$2</sup><sub>$(SMALL $1)</sub>)
- * CHOOSE = $(BIG &#40;) <sup>$(SMALL $1)</sup><sub>$(SMALL $2)</sub> $(BIG &#41;)
- * PLUSMN = &plusmn;
- * INFIN = &infin;
- * PLUSMNINF = &plusmn;&infin;
- * PI = &pi;
- * LT = &lt;
- * GT = &gt;
- * SQRT = &radic;
- * HALF = &frac12;
- *
- * Copyright: Copyright Digital Mars 2000 - 2011.
- * D implementations of tan, atan, atan2, exp, expm1, exp2, log, log10, log1p,
- * log2, floor, ceil and lrint functions are based on the CEPHES math library,
- * which is Copyright (C) 2001 Stephen L. Moshier $(LT)steve@moshier.net$(GT)
- * and are incorporated herein by permission of the author. The author
- * reserves the right to distribute this material elsewhere under different
- * copying permissions. These modifications are distributed here under
- * the following terms:
- * License: $(HTTP www.boost.org/LICENSE_1_0.txt, Boost License 1.0).
- * Authors: $(HTTP digitalmars.com, Walter Bright), Don Clugston,
- * Conversion of CEPHES math library to D by Iain Buclaw and David Nadlinger
- * Source: $(PHOBOSSRC std/_math.d)
- */
-
-/* NOTE: This file has been patched from the original DMD distribution to
- * work with the GDC compiler.
- */
-module std.math;
-
-version (Win64)
-{
- version (D_InlineAsm_X86_64)
- version = Win64_DMD_InlineAsm;
-}
-
-static import core.math;
-static import core.stdc.math;
-static import core.stdc.fenv;
-import std.traits; // CommonType, isFloatingPoint, isIntegral, isSigned, isUnsigned, Largest, Unqual
-
-version (LDC)
-{
- import ldc.intrinsics;
-}
-
-version (DigitalMars)
-{
- version = INLINE_YL2X; // x87 has opcodes for these
-}
-
-version (X86) version = X86_Any;
-version (X86_64) version = X86_Any;
-version (PPC) version = PPC_Any;
-version (PPC64) version = PPC_Any;
-version (MIPS32) version = MIPS_Any;
-version (MIPS64) version = MIPS_Any;
-version (AArch64) version = ARM_Any;
-version (ARM) version = ARM_Any;
-version (S390) version = IBMZ_Any;
-version (SPARC) version = SPARC_Any;
-version (SPARC64) version = SPARC_Any;
-version (SystemZ) version = IBMZ_Any;
-version (RISCV32) version = RISCV_Any;
-version (RISCV64) version = RISCV_Any;
-
-version (D_InlineAsm_X86) version = InlineAsm_X86_Any;
-version (D_InlineAsm_X86_64) version = InlineAsm_X86_Any;
-
-version (InlineAsm_X86_Any) version = InlineAsm_X87;
-version (InlineAsm_X87)
-{
- static assert(real.mant_dig == 64);
- version (CRuntime_Microsoft) version = InlineAsm_X87_MSVC;
-}
-
-version (X86_64) version = StaticallyHaveSSE;
-version (X86) version (OSX) version = StaticallyHaveSSE;
-
-version (StaticallyHaveSSE)
-{
- private enum bool haveSSE = true;
-}
-else version (X86)
-{
- static import core.cpuid;
- private alias haveSSE = core.cpuid.sse;
-}
-
-version (D_SoftFloat)
-{
- // Some soft float implementations may support IEEE floating flags.
- // The implementation here supports hardware flags only and is so currently
- // only available for supported targets.
-}
-else version (X86_Any) version = IeeeFlagsSupport;
-else version (PPC_Any) version = IeeeFlagsSupport;
-else version (RISCV_Any) version = IeeeFlagsSupport;
-else version (MIPS_Any) version = IeeeFlagsSupport;
-else version (ARM_Any) version = IeeeFlagsSupport;
-
-// Struct FloatingPointControl is only available if hardware FP units are available.
-version (D_HardFloat)
-{
- // FloatingPointControl.clearExceptions() depends on version IeeeFlagsSupport
- version (IeeeFlagsSupport) version = FloatingPointControlSupport;
-}
-
-version (GNU)
-{
- // The compiler can unexpectedly rearrange floating point operations and
- // access to the floating point status flags when optimizing. This means
- // ieeeFlags tests cannot be reliably checked in optimized code.
- // See https://github.com/ldc-developers/ldc/issues/888
-}
-else
-{
- version = IeeeFlagsUnittest;
- version = FloatingPointControlUnittest;
-}
-
-version (unittest)
-{
- import core.stdc.stdio; // : sprintf;
-
- static if (real.sizeof > double.sizeof)
- enum uint useDigits = 16;
- else
- enum uint useDigits = 15;
-
- /******************************************
- * Compare floating point numbers to n decimal digits of precision.
- * Returns:
- * 1 match
- * 0 nomatch
- */
-
- private bool equalsDigit(real x, real y, uint ndigits)
- {
- if (signbit(x) != signbit(y))
- return 0;
-
- if (isInfinity(x) && isInfinity(y))
- return 1;
- if (isInfinity(x) || isInfinity(y))
- return 0;
-
- if (isNaN(x) && isNaN(y))
- return 1;
- if (isNaN(x) || isNaN(y))
- return 0;
-
- char[30] bufx;
- char[30] bufy;
- assert(ndigits < bufx.length);
-
- int ix;
- int iy;
- version (CRuntime_Microsoft)
- alias real_t = double;
- else
- alias real_t = real;
- ix = sprintf(bufx.ptr, is(real_t == real) ? "%.*Lg" : "%.*g", ndigits, cast(real_t) x);
- iy = sprintf(bufy.ptr, is(real_t == real) ? "%.*Lg" : "%.*g", ndigits, cast(real_t) y);
- assert(ix < bufx.length && ix > 0);
- assert(ix < bufy.length && ix > 0);
-
- return bufx[0 .. ix] == bufy[0 .. iy];
- }
-}
-
-
-
-package:
-// The following IEEE 'real' formats are currently supported.
-version (LittleEndian)
-{
- static assert(real.mant_dig == 53 || real.mant_dig == 64
- || real.mant_dig == 113,
- "Only 64-bit, 80-bit, and 128-bit reals"~
- " are supported for LittleEndian CPUs");
-}
-else
-{
- static assert(real.mant_dig == 53 || real.mant_dig == 106
- || real.mant_dig == 113,
- "Only 64-bit and 128-bit reals are supported for BigEndian CPUs."~
- " double-double reals have partial support");
-}
-
-// Underlying format exposed through floatTraits
-enum RealFormat
-{
- ieeeHalf,
- ieeeSingle,
- ieeeDouble,
- ieeeExtended, // x87 80-bit real
- ieeeExtended53, // x87 real rounded to precision of double.
- ibmExtended, // IBM 128-bit extended
- ieeeQuadruple,
-}
-
-// Constants used for extracting the components of the representation.
-// They supplement the built-in floating point properties.
-template floatTraits(T)
-{
- // EXPMASK is a ushort mask to select the exponent portion (without sign)
- // EXPSHIFT is the number of bits the exponent is left-shifted by in its ushort
- // EXPBIAS is the exponent bias - 1 (exp == EXPBIAS yields ×2^-1).
- // EXPPOS_SHORT is the index of the exponent when represented as a ushort array.
- // SIGNPOS_BYTE is the index of the sign when represented as a ubyte array.
- // RECIP_EPSILON is the value such that (smallest_subnormal) * RECIP_EPSILON == T.min_normal
- enum T RECIP_EPSILON = (1/T.epsilon);
- static if (T.mant_dig == 24)
- {
- // Single precision float
- enum ushort EXPMASK = 0x7F80;
- enum ushort EXPSHIFT = 7;
- enum ushort EXPBIAS = 0x3F00;
- enum uint EXPMASK_INT = 0x7F80_0000;
- enum uint MANTISSAMASK_INT = 0x007F_FFFF;
- enum realFormat = RealFormat.ieeeSingle;
- version (LittleEndian)
- {
- enum EXPPOS_SHORT = 1;
- enum SIGNPOS_BYTE = 3;
- }
- else
- {
- enum EXPPOS_SHORT = 0;
- enum SIGNPOS_BYTE = 0;
- }
- }
- else static if (T.mant_dig == 53)
- {
- static if (T.sizeof == 8)
- {
- // Double precision float, or real == double
- enum ushort EXPMASK = 0x7FF0;
- enum ushort EXPSHIFT = 4;
- enum ushort EXPBIAS = 0x3FE0;
- enum uint EXPMASK_INT = 0x7FF0_0000;
- enum uint MANTISSAMASK_INT = 0x000F_FFFF; // for the MSB only
- enum realFormat = RealFormat.ieeeDouble;
- version (LittleEndian)
- {
- enum EXPPOS_SHORT = 3;
- enum SIGNPOS_BYTE = 7;
- }
- else
- {
- enum EXPPOS_SHORT = 0;
- enum SIGNPOS_BYTE = 0;
- }
- }
- else static if (T.sizeof == 12)
- {
- // Intel extended real80 rounded to double
- enum ushort EXPMASK = 0x7FFF;
- enum ushort EXPSHIFT = 0;
- enum ushort EXPBIAS = 0x3FFE;
- enum realFormat = RealFormat.ieeeExtended53;
- version (LittleEndian)
- {
- enum EXPPOS_SHORT = 4;
- enum SIGNPOS_BYTE = 9;
- }
- else
- {
- enum EXPPOS_SHORT = 0;
- enum SIGNPOS_BYTE = 0;
- }
- }
- else
- static assert(false, "No traits support for " ~ T.stringof);
- }
- else static if (T.mant_dig == 64)
- {
- // Intel extended real80
- enum ushort EXPMASK = 0x7FFF;
- enum ushort EXPSHIFT = 0;
- enum ushort EXPBIAS = 0x3FFE;
- enum realFormat = RealFormat.ieeeExtended;
- version (LittleEndian)
- {
- enum EXPPOS_SHORT = 4;
- enum SIGNPOS_BYTE = 9;
- }
- else
- {
- enum EXPPOS_SHORT = 0;
- enum SIGNPOS_BYTE = 0;
- }
- }
- else static if (T.mant_dig == 113)
- {
- // Quadruple precision float
- enum ushort EXPMASK = 0x7FFF;
- enum ushort EXPSHIFT = 0;
- enum ushort EXPBIAS = 0x3FFE;
- enum realFormat = RealFormat.ieeeQuadruple;
- version (LittleEndian)
- {
- enum EXPPOS_SHORT = 7;
- enum SIGNPOS_BYTE = 15;
- }
- else
- {
- enum EXPPOS_SHORT = 0;
- enum SIGNPOS_BYTE = 0;
- }
- }
- else static if (T.mant_dig == 106)
- {
- // IBM Extended doubledouble
- enum ushort EXPMASK = 0x7FF0;
- enum ushort EXPSHIFT = 4;
- enum realFormat = RealFormat.ibmExtended;
-
- // For IBM doubledouble the larger magnitude double comes first.
- // It's really a double[2] and arrays don't index differently
- // between little and big-endian targets.
- enum DOUBLEPAIR_MSB = 0;
- enum DOUBLEPAIR_LSB = 1;
-
- // The exponent/sign byte is for most significant part.
- version (LittleEndian)
- {
- enum EXPPOS_SHORT = 3;
- enum SIGNPOS_BYTE = 7;
- }
- else
- {
- enum EXPPOS_SHORT = 0;
- enum SIGNPOS_BYTE = 0;
- }
- }
- else
- static assert(false, "No traits support for " ~ T.stringof);
-}
-
-// These apply to all floating-point types
-version (LittleEndian)
-{
- enum MANTISSA_LSB = 0;
- enum MANTISSA_MSB = 1;
-}
-else
-{
- enum MANTISSA_LSB = 1;
- enum MANTISSA_MSB = 0;
-}
-
-// Common code for math implementations.
-
-// Helper for floor/ceil
-T floorImpl(T)(const T x) @trusted pure nothrow @nogc
-{
- alias F = floatTraits!(T);
- // Take care not to trigger library calls from the compiler,
- // while ensuring that we don't get defeated by some optimizers.
- union floatBits
- {
- T rv;
- ushort[T.sizeof/2] vu;
-
- // Other kinds of extractors for real formats.
- static if (F.realFormat == RealFormat.ieeeSingle)
- int vi;
- }
- floatBits y = void;
- y.rv = x;
-
- // Find the exponent (power of 2)
- // Do this by shifting the raw value so that the exponent lies in the low bits,
- // then mask out the sign bit, and subtract the bias.
- static if (F.realFormat == RealFormat.ieeeSingle)
- {
- int exp = ((y.vi >> (T.mant_dig - 1)) & 0xff) - 0x7f;
- }
- else static if (F.realFormat == RealFormat.ieeeDouble)
- {
- int exp = ((y.vu[F.EXPPOS_SHORT] >> 4) & 0x7ff) - 0x3ff;
-
- version (LittleEndian)
- int pos = 0;
- else
- int pos = 3;
- }
- else static if (F.realFormat == RealFormat.ieeeExtended ||
- F.realFormat == RealFormat.ieeeExtended53)
- {
- int exp = (y.vu[F.EXPPOS_SHORT] & 0x7fff) - 0x3fff;
-
- version (LittleEndian)
- int pos = 0;
- else
- int pos = 4;
- }
- else static if (F.realFormat == RealFormat.ieeeQuadruple)
- {
- int exp = (y.vu[F.EXPPOS_SHORT] & 0x7fff) - 0x3fff;
-
- version (LittleEndian)
- int pos = 0;
- else
- int pos = 7;
- }
- else
- static assert(false, "Not implemented for this architecture");
-
- if (exp < 0)
- {
- if (x < 0.0)
- return -1.0;
- else
- return 0.0;
- }
-
- static if (F.realFormat == RealFormat.ieeeSingle)
- {
- if (exp < (T.mant_dig - 1))
- {
- // Clear all bits representing the fraction part.
- const uint fraction_mask = F.MANTISSAMASK_INT >> exp;
-
- if ((y.vi & fraction_mask) != 0)
- {
- // If 'x' is negative, then first substract 1.0 from the value.
- if (y.vi < 0)
- y.vi += 0x00800000 >> exp;
- y.vi &= ~fraction_mask;
- }
- }
- }
- else
- {
- static if (F.realFormat == RealFormat.ieeeExtended53)
- exp = (T.mant_dig + 11 - 1) - exp; // mant_dig is really 64
- else
- exp = (T.mant_dig - 1) - exp;
-
- // Zero 16 bits at a time.
- while (exp >= 16)
- {
- version (LittleEndian)
- y.vu[pos++] = 0;
- else
- y.vu[pos--] = 0;
- exp -= 16;
- }
-
- // Clear the remaining bits.
- if (exp > 0)
- y.vu[pos] &= 0xffff ^ ((1 << exp) - 1);
-
- if ((x < 0.0) && (x != y.rv))
- y.rv -= 1.0;
- }
-
- return y.rv;
-}
-
-public:
-
-// Values obtained from Wolfram Alpha. 116 bits ought to be enough for anybody.
-// Wolfram Alpha LLC. 2011. Wolfram|Alpha. http://www.wolframalpha.com/input/?i=e+in+base+16 (access July 6, 2011).
-enum real E = 0x1.5bf0a8b1457695355fb8ac404e7a8p+1L; /** e = 2.718281... */
-enum real LOG2T = 0x1.a934f0979a3715fc9257edfe9b5fbp+1L; /** $(SUB log, 2)10 = 3.321928... */
-enum real LOG2E = 0x1.71547652b82fe1777d0ffda0d23a8p+0L; /** $(SUB log, 2)e = 1.442695... */
-enum real LOG2 = 0x1.34413509f79fef311f12b35816f92p-2L; /** $(SUB log, 10)2 = 0.301029... */
-enum real LOG10E = 0x1.bcb7b1526e50e32a6ab7555f5a67cp-2L; /** $(SUB log, 10)e = 0.434294... */
-enum real LN2 = 0x1.62e42fefa39ef35793c7673007e5fp-1L; /** ln 2 = 0.693147... */
-enum real LN10 = 0x1.26bb1bbb5551582dd4adac5705a61p+1L; /** ln 10 = 2.302585... */
-enum real PI = 0x1.921fb54442d18469898cc51701b84p+1L; /** $(_PI) = 3.141592... */
-enum real PI_2 = PI/2; /** $(PI) / 2 = 1.570796... */
-enum real PI_4 = PI/4; /** $(PI) / 4 = 0.785398... */
-enum real M_1_PI = 0x1.45f306dc9c882a53f84eafa3ea69cp-2L; /** 1 / $(PI) = 0.318309... */
-enum real M_2_PI = 2*M_1_PI; /** 2 / $(PI) = 0.636619... */
-enum real M_2_SQRTPI = 0x1.20dd750429b6d11ae3a914fed7fd8p+0L; /** 2 / $(SQRT)$(PI) = 1.128379... */
-enum real SQRT2 = 0x1.6a09e667f3bcc908b2fb1366ea958p+0L; /** $(SQRT)2 = 1.414213... */
-enum real SQRT1_2 = SQRT2/2; /** $(SQRT)$(HALF) = 0.707106... */
-// Note: Make sure the magic numbers in compiler backend for x87 match these.
-
-
-/***********************************
- * Calculates the absolute value of a number
- *
- * Params:
- * Num = (template parameter) type of number
- * x = real number value
- * z = complex number value
- * y = imaginary number value
- *
- * Returns:
- * The absolute value of the number. If floating-point or integral,
- * the return type will be the same as the input; if complex or
- * imaginary, the returned value will be the corresponding floating
- * point type.
- *
- * For complex numbers, abs(z) = sqrt( $(POWER z.re, 2) + $(POWER z.im, 2) )
- * = hypot(z.re, z.im).
- */
-Num abs(Num)(Num x) @safe pure nothrow
-if (is(typeof(Num.init >= 0)) && is(typeof(-Num.init)) &&
- !(is(Num* : const(ifloat*)) || is(Num* : const(idouble*))
- || is(Num* : const(ireal*))))
-{
- static if (isFloatingPoint!(Num))
- return fabs(x);
- else
- return x >= 0 ? x : -x;
-}
-
-/// ditto
-auto abs(Num)(Num z) @safe pure nothrow @nogc
-if (is(Num* : const(cfloat*)) || is(Num* : const(cdouble*))
- || is(Num* : const(creal*)))
-{
- return hypot(z.re, z.im);
-}
-
-/// ditto
-auto abs(Num)(Num y) @safe pure nothrow @nogc
-if (is(Num* : const(ifloat*)) || is(Num* : const(idouble*))
- || is(Num* : const(ireal*)))
-{
- return fabs(y.im);
-}
-
-/// ditto
-@safe pure nothrow @nogc unittest
-{
- assert(isIdentical(abs(-0.0L), 0.0L));
- assert(isNaN(abs(real.nan)));
- assert(abs(-real.infinity) == real.infinity);
- assert(abs(-3.2Li) == 3.2L);
- assert(abs(71.6Li) == 71.6L);
- assert(abs(-56) == 56);
- assert(abs(2321312L) == 2321312L);
- assert(abs(-1L+1i) == sqrt(2.0L));
-}
-
-@safe pure nothrow @nogc unittest
-{
- import std.meta : AliasSeq;
- foreach (T; AliasSeq!(float, double, real))
- {
- T f = 3;
- assert(abs(f) == f);
- assert(abs(-f) == f);
- }
- foreach (T; AliasSeq!(cfloat, cdouble, creal))
- {
- T f = -12+3i;
- assert(abs(f) == hypot(f.re, f.im));
- assert(abs(-f) == hypot(f.re, f.im));
- }
-}
-
-/***********************************
- * Complex conjugate
- *
- * conj(x + iy) = x - iy
- *
- * Note that z * conj(z) = $(POWER z.re, 2) - $(POWER z.im, 2)
- * is always a real number
- */
-auto conj(Num)(Num z) @safe pure nothrow @nogc
-if (is(Num* : const(cfloat*)) || is(Num* : const(cdouble*))
- || is(Num* : const(creal*)))
-{
- //FIXME
- //Issue 14206
- static if (is(Num* : const(cdouble*)))
- return cast(cdouble) conj(cast(creal) z);
- else
- return z.re - z.im*1fi;
-}
-
-/** ditto */
-auto conj(Num)(Num y) @safe pure nothrow @nogc
-if (is(Num* : const(ifloat*)) || is(Num* : const(idouble*))
- || is(Num* : const(ireal*)))
-{
- return -y;
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- creal c = 7 + 3Li;
- assert(conj(c) == 7-3Li);
- ireal z = -3.2Li;
- assert(conj(z) == -z);
-}
-//Issue 14206
-@safe pure nothrow @nogc unittest
-{
- cdouble c = 7 + 3i;
- assert(conj(c) == 7-3i);
- idouble z = -3.2i;
- assert(conj(z) == -z);
-}
-//Issue 14206
-@safe pure nothrow @nogc unittest
-{
- cfloat c = 7f + 3fi;
- assert(conj(c) == 7f-3fi);
- ifloat z = -3.2fi;
- assert(conj(z) == -z);
-}
-
-/***********************************
- * Returns cosine of x. x is in radians.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH cos(x)) $(TH invalid?))
- * $(TR $(TD $(NAN)) $(TD $(NAN)) $(TD yes) )
- * $(TR $(TD $(PLUSMN)$(INFIN)) $(TD $(NAN)) $(TD yes) )
- * )
- * Bugs:
- * Results are undefined if |x| >= $(POWER 2,64).
- */
-
-real cos(real x) @safe pure nothrow @nogc { pragma(inline, true); return core.math.cos(x); }
-//FIXME
-///ditto
-double cos(double x) @safe pure nothrow @nogc { return cos(cast(real) x); }
-//FIXME
-///ditto
-float cos(float x) @safe pure nothrow @nogc { return cos(cast(real) x); }
-
-@safe unittest
-{
- real function(real) pcos = &cos;
- assert(pcos != null);
-}
-
-/***********************************
- * Returns $(HTTP en.wikipedia.org/wiki/Sine, sine) of x. x is in $(HTTP en.wikipedia.org/wiki/Radian, radians).
- *
- * $(TABLE_SV
- * $(TH3 x , sin(x) , invalid?)
- * $(TD3 $(NAN) , $(NAN) , yes )
- * $(TD3 $(PLUSMN)0.0, $(PLUSMN)0.0, no )
- * $(TD3 $(PLUSMNINF), $(NAN) , yes )
- * )
- *
- * Params:
- * x = angle in radians (not degrees)
- * Returns:
- * sine of x
- * See_Also:
- * $(MYREF cos), $(MYREF tan), $(MYREF asin)
- * Bugs:
- * Results are undefined if |x| >= $(POWER 2,64).
- */
-
-real sin(real x) @safe pure nothrow @nogc { pragma(inline, true); return core.math.sin(x); }
-//FIXME
-///ditto
-double sin(double x) @safe pure nothrow @nogc { return sin(cast(real) x); }
-//FIXME
-///ditto
-float sin(float x) @safe pure nothrow @nogc { return sin(cast(real) x); }
-
-///
-@safe unittest
-{
- import std.math : sin, PI;
- import std.stdio : writefln;
-
- void someFunc()
- {
- real x = 30.0;
- auto result = sin(x * (PI / 180)); // convert degrees to radians
- writefln("The sine of %s degrees is %s", x, result);
- }
-}
-
-@safe unittest
-{
- real function(real) psin = &sin;
- assert(psin != null);
-}
-
-/***********************************
- * Returns sine for complex and imaginary arguments.
- *
- * sin(z) = sin(z.re)*cosh(z.im) + cos(z.re)*sinh(z.im)i
- *
- * If both sin($(THETA)) and cos($(THETA)) are required,
- * it is most efficient to use expi($(THETA)).
- */
-creal sin(creal z) @safe pure nothrow @nogc
-{
- const creal cs = expi(z.re);
- const creal csh = coshisinh(z.im);
- return cs.im * csh.re + cs.re * csh.im * 1i;
-}
-
-/** ditto */
-ireal sin(ireal y) @safe pure nothrow @nogc
-{
- return cosh(y.im)*1i;
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert(sin(0.0+0.0i) == 0.0);
- assert(sin(2.0+0.0i) == sin(2.0L) );
-}
-
-/***********************************
- * cosine, complex and imaginary
- *
- * cos(z) = cos(z.re)*cosh(z.im) - sin(z.re)*sinh(z.im)i
- */
-creal cos(creal z) @safe pure nothrow @nogc
-{
- const creal cs = expi(z.re);
- const creal csh = coshisinh(z.im);
- return cs.re * csh.re - cs.im * csh.im * 1i;
-}
-
-/** ditto */
-real cos(ireal y) @safe pure nothrow @nogc
-{
- return cosh(y.im);
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert(cos(0.0+0.0i)==1.0);
- assert(cos(1.3L+0.0i)==cos(1.3L));
- assert(cos(5.2Li)== cosh(5.2L));
-}
-
-/****************************************************************************
- * Returns tangent of x. x is in radians.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH tan(x)) $(TH invalid?))
- * $(TR $(TD $(NAN)) $(TD $(NAN)) $(TD yes))
- * $(TR $(TD $(PLUSMN)0.0) $(TD $(PLUSMN)0.0) $(TD no))
- * $(TR $(TD $(PLUSMNINF)) $(TD $(NAN)) $(TD yes))
- * )
- */
-
-real tan(real x) @trusted pure nothrow @nogc
-{
- version (D_InlineAsm_X86)
- {
- asm pure nothrow @nogc
- {
- fld x[EBP] ; // load theta
- fxam ; // test for oddball values
- fstsw AX ;
- sahf ;
- jc trigerr ; // x is NAN, infinity, or empty
- // 387's can handle subnormals
-SC18: fptan ;
- fstsw AX ;
- sahf ;
- jnp Clear1 ; // C2 = 1 (x is out of range)
-
- // Do argument reduction to bring x into range
- fldpi ;
- fxch ;
-SC17: fprem1 ;
- fstsw AX ;
- sahf ;
- jp SC17 ;
- fstp ST(1) ; // remove pi from stack
- jmp SC18 ;
-
-trigerr:
- jnp Lret ; // if theta is NAN, return theta
- fstp ST(0) ; // dump theta
- }
- return real.nan;
-
-Clear1: asm pure nothrow @nogc{
- fstp ST(0) ; // dump X, which is always 1
- }
-
-Lret: {}
- }
- else version (D_InlineAsm_X86_64)
- {
- version (Win64)
- {
- asm pure nothrow @nogc
- {
- fld real ptr [RCX] ; // load theta
- }
- }
- else
- {
- asm pure nothrow @nogc
- {
- fld x[RBP] ; // load theta
- }
- }
- asm pure nothrow @nogc
- {
- fxam ; // test for oddball values
- fstsw AX ;
- test AH,1 ;
- jnz trigerr ; // x is NAN, infinity, or empty
- // 387's can handle subnormals
-SC18: fptan ;
- fstsw AX ;
- test AH,4 ;
- jz Clear1 ; // C2 = 1 (x is out of range)
-
- // Do argument reduction to bring x into range
- fldpi ;
- fxch ;
-SC17: fprem1 ;
- fstsw AX ;
- test AH,4 ;
- jnz SC17 ;
- fstp ST(1) ; // remove pi from stack
- jmp SC18 ;
-
-trigerr:
- test AH,4 ;
- jz Lret ; // if theta is NAN, return theta
- fstp ST(0) ; // dump theta
- }
- return real.nan;
-
-Clear1: asm pure nothrow @nogc{
- fstp ST(0) ; // dump X, which is always 1
- }
-
-Lret: {}
- }
- else
- {
- // Coefficients for tan(x) and PI/4 split into three parts.
- static if (floatTraits!real.realFormat == RealFormat.ieeeQuadruple)
- {
- static immutable real[6] P = [
- 2.883414728874239697964612246732416606301E10L,
- -2.307030822693734879744223131873392503321E9L,
- 5.160188250214037865511600561074819366815E7L,
- -4.249691853501233575668486667664718192660E5L,
- 1.272297782199996882828849455156962260810E3L,
- -9.889929415807650724957118893791829849557E-1L
- ];
- static immutable real[7] Q = [
- 8.650244186622719093893836740197250197602E10L,
- -4.152206921457208101480801635640958361612E10L,
- 2.758476078803232151774723646710890525496E9L,
- -5.733709132766856723608447733926138506824E7L,
- 4.529422062441341616231663543669583527923E5L,
- -1.317243702830553658702531997959756728291E3L,
- 1.0
- ];
-
- enum real P1 =
- 7.853981633974483067550664827649598009884357452392578125E-1L;
- enum real P2 =
- 2.8605943630549158983813312792950660807511260829685741796657E-18L;
- enum real P3 =
- 2.1679525325309452561992610065108379921905808E-35L;
- }
- else
- {
- static immutable real[3] P = [
- -1.7956525197648487798769E7L,
- 1.1535166483858741613983E6L,
- -1.3093693918138377764608E4L,
- ];
- static immutable real[5] Q = [
- -5.3869575592945462988123E7L,
- 2.5008380182335791583922E7L,
- -1.3208923444021096744731E6L,
- 1.3681296347069295467845E4L,
- 1.0000000000000000000000E0L,
- ];
-
- enum real P1 = 7.853981554508209228515625E-1L;
- enum real P2 = 7.946627356147928367136046290398E-9L;
- enum real P3 = 3.061616997868382943065164830688E-17L;
- }
-
- // Special cases.
- if (x == 0.0 || isNaN(x))
- return x;
- if (isInfinity(x))
- return real.nan;
-
- // Make argument positive but save the sign.
- bool sign = false;
- if (signbit(x))
- {
- sign = true;
- x = -x;
- }
-
- // Compute x mod PI/4.
- real y = floor(x / PI_4);
- // Strip high bits of integer part.
- real z = ldexp(y, -4);
- // Compute y - 16 * (y / 16).
- z = y - ldexp(floor(z), 4);
-
- // Integer and fraction part modulo one octant.
- int j = cast(int)(z);
-
- // Map zeros and singularities to origin.
- if (j & 1)
- {
- j += 1;
- y += 1.0;
- }
-
- z = ((x - y * P1) - y * P2) - y * P3;
- const real zz = z * z;
-
- if (zz > 1.0e-20L)
- y = z + z * (zz * poly(zz, P) / poly(zz, Q));
- else
- y = z;
-
- if (j & 2)
- y = -1.0 / y;
-
- return (sign) ? -y : y;
- }
-}
-
-@safe nothrow @nogc unittest
-{
- static real[2][] vals = // angle,tan
- [
- [ 0, 0],
- [ .5, .5463024898],
- [ 1, 1.557407725],
- [ 1.5, 14.10141995],
- [ 2, -2.185039863],
- [ 2.5,-.7470222972],
- [ 3, -.1425465431],
- [ 3.5, .3745856402],
- [ 4, 1.157821282],
- [ 4.5, 4.637332055],
- [ 5, -3.380515006],
- [ 5.5,-.9955840522],
- [ 6, -.2910061914],
- [ 6.5, .2202772003],
- [ 10, .6483608275],
-
- // special angles
- [ PI_4, 1],
- //[ PI_2, real.infinity], // PI_2 is not _exactly_ pi/2.
- [ 3*PI_4, -1],
- [ PI, 0],
- [ 5*PI_4, 1],
- //[ 3*PI_2, -real.infinity],
- [ 7*PI_4, -1],
- [ 2*PI, 0],
- ];
- int i;
-
- for (i = 0; i < vals.length; i++)
- {
- real x = vals[i][0];
- real r = vals[i][1];
- real t = tan(x);
-
- //printf("tan(%Lg) = %Lg, should be %Lg\n", x, t, r);
- assert(approxEqual(r, t));
-
- x = -x;
- r = -r;
- t = tan(x);
- //printf("tan(%Lg) = %Lg, should be %Lg\n", x, t, r);
- assert(approxEqual(r, t));
- }
- // overflow
- assert(isNaN(tan(real.infinity)));
- assert(isNaN(tan(-real.infinity)));
- // NaN propagation
- assert(isIdentical( tan(NaN(0x0123L)), NaN(0x0123L) ));
-}
-
-@system unittest
-{
- assert(equalsDigit(tan(PI / 3), std.math.sqrt(3.0), useDigits));
-}
-
-/***************
- * Calculates the arc cosine of x,
- * returning a value ranging from 0 to $(PI).
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH acos(x)) $(TH invalid?))
- * $(TR $(TD $(GT)1.0) $(TD $(NAN)) $(TD yes))
- * $(TR $(TD $(LT)-1.0) $(TD $(NAN)) $(TD yes))
- * $(TR $(TD $(NAN)) $(TD $(NAN)) $(TD yes))
- * )
- */
-real acos(real x) @safe pure nothrow @nogc
-{
- return atan2(sqrt(1-x*x), x);
-}
-
-/// ditto
-double acos(double x) @safe pure nothrow @nogc { return acos(cast(real) x); }
-
-/// ditto
-float acos(float x) @safe pure nothrow @nogc { return acos(cast(real) x); }
-
-@system unittest
-{
- assert(equalsDigit(acos(0.5), std.math.PI / 3, useDigits));
-}
-
-/***************
- * Calculates the arc sine of x,
- * returning a value ranging from -$(PI)/2 to $(PI)/2.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH asin(x)) $(TH invalid?))
- * $(TR $(TD $(PLUSMN)0.0) $(TD $(PLUSMN)0.0) $(TD no))
- * $(TR $(TD $(GT)1.0) $(TD $(NAN)) $(TD yes))
- * $(TR $(TD $(LT)-1.0) $(TD $(NAN)) $(TD yes))
- * )
- */
-real asin(real x) @safe pure nothrow @nogc
-{
- return atan2(x, sqrt(1-x*x));
-}
-
-/// ditto
-double asin(double x) @safe pure nothrow @nogc { return asin(cast(real) x); }
-
-/// ditto
-float asin(float x) @safe pure nothrow @nogc { return asin(cast(real) x); }
-
-@system unittest
-{
- assert(asin(0.5).approxEqual(PI / 6));
-}
-
-/***************
- * Calculates the arc tangent of x,
- * returning a value ranging from -$(PI)/2 to $(PI)/2.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH atan(x)) $(TH invalid?))
- * $(TR $(TD $(PLUSMN)0.0) $(TD $(PLUSMN)0.0) $(TD no))
- * $(TR $(TD $(PLUSMN)$(INFIN)) $(TD $(NAN)) $(TD yes))
- * )
- */
-real atan(real x) @safe pure nothrow @nogc
-{
- version (InlineAsm_X86_Any)
- {
- return atan2(x, 1.0L);
- }
- else
- {
- // Coefficients for atan(x)
- static if (floatTraits!real.realFormat == RealFormat.ieeeQuadruple)
- {
- static immutable real[9] P = [
- -6.880597774405940432145577545328795037141E2L,
- -2.514829758941713674909996882101723647996E3L,
- -3.696264445691821235400930243493001671932E3L,
- -2.792272753241044941703278827346430350236E3L,
- -1.148164399808514330375280133523543970854E3L,
- -2.497759878476618348858065206895055957104E2L,
- -2.548067867495502632615671450650071218995E1L,
- -8.768423468036849091777415076702113400070E-1L,
- -6.635810778635296712545011270011752799963E-4L
- ];
- static immutable real[9] Q = [
- 2.064179332321782129643673263598686441900E3L,
- 8.782996876218210302516194604424986107121E3L,
- 1.547394317752562611786521896296215170819E4L,
- 1.458510242529987155225086911411015961174E4L,
- 7.928572347062145288093560392463784743935E3L,
- 2.494680540950601626662048893678584497900E3L,
- 4.308348370818927353321556740027020068897E2L,
- 3.566239794444800849656497338030115886153E1L,
- 1.0
- ];
- }
- else
- {
- static immutable real[5] P = [
- -5.0894116899623603312185E1L,
- -9.9988763777265819915721E1L,
- -6.3976888655834347413154E1L,
- -1.4683508633175792446076E1L,
- -8.6863818178092187535440E-1L,
- ];
- static immutable real[6] Q = [
- 1.5268235069887081006606E2L,
- 3.9157570175111990631099E2L,
- 3.6144079386152023162701E2L,
- 1.4399096122250781605352E2L,
- 2.2981886733594175366172E1L,
- 1.0000000000000000000000E0L,
- ];
- }
-
- // tan(PI/8)
- enum real TAN_PI_8 = 0.414213562373095048801688724209698078569672L;
- // tan(3 * PI/8)
- enum real TAN3_PI_8 = 2.414213562373095048801688724209698078569672L;
-
- // Special cases.
- if (x == 0.0)
- return x;
- if (isInfinity(x))
- return copysign(PI_2, x);
-
- // Make argument positive but save the sign.
- bool sign = false;
- if (signbit(x))
- {
- sign = true;
- x = -x;
- }
-
- // Range reduction.
- real y;
- if (x > TAN3_PI_8)
- {
- y = PI_2;
- x = -(1.0 / x);
- }
- else if (x > TAN_PI_8)
- {
- y = PI_4;
- x = (x - 1.0)/(x + 1.0);
- }
- else
- y = 0.0;
-
- // Rational form in x^^2.
- const real z = x * x;
- y = y + (poly(z, P) / poly(z, Q)) * z * x + x;
-
- return (sign) ? -y : y;
- }
-}
-
-/// ditto
-double atan(double x) @safe pure nothrow @nogc { return atan(cast(real) x); }
-
-/// ditto
-float atan(float x) @safe pure nothrow @nogc { return atan(cast(real) x); }
-
-@system unittest
-{
- assert(equalsDigit(atan(std.math.sqrt(3.0)), PI / 3, useDigits));
-}
-
-/***************
- * Calculates the arc tangent of y / x,
- * returning a value ranging from -$(PI) to $(PI).
- *
- * $(TABLE_SV
- * $(TR $(TH y) $(TH x) $(TH atan(y, x)))
- * $(TR $(TD $(NAN)) $(TD anything) $(TD $(NAN)) )
- * $(TR $(TD anything) $(TD $(NAN)) $(TD $(NAN)) )
- * $(TR $(TD $(PLUSMN)0.0) $(TD $(GT)0.0) $(TD $(PLUSMN)0.0) )
- * $(TR $(TD $(PLUSMN)0.0) $(TD +0.0) $(TD $(PLUSMN)0.0) )
- * $(TR $(TD $(PLUSMN)0.0) $(TD $(LT)0.0) $(TD $(PLUSMN)$(PI)))
- * $(TR $(TD $(PLUSMN)0.0) $(TD -0.0) $(TD $(PLUSMN)$(PI)))
- * $(TR $(TD $(GT)0.0) $(TD $(PLUSMN)0.0) $(TD $(PI)/2) )
- * $(TR $(TD $(LT)0.0) $(TD $(PLUSMN)0.0) $(TD -$(PI)/2) )
- * $(TR $(TD $(GT)0.0) $(TD $(INFIN)) $(TD $(PLUSMN)0.0) )
- * $(TR $(TD $(PLUSMN)$(INFIN)) $(TD anything) $(TD $(PLUSMN)$(PI)/2))
- * $(TR $(TD $(GT)0.0) $(TD -$(INFIN)) $(TD $(PLUSMN)$(PI)) )
- * $(TR $(TD $(PLUSMN)$(INFIN)) $(TD $(INFIN)) $(TD $(PLUSMN)$(PI)/4))
- * $(TR $(TD $(PLUSMN)$(INFIN)) $(TD -$(INFIN)) $(TD $(PLUSMN)3$(PI)/4))
- * )
- */
-real atan2(real y, real x) @trusted pure nothrow @nogc
-{
- version (InlineAsm_X86_Any)
- {
- version (Win64)
- {
- asm pure nothrow @nogc {
- naked;
- fld real ptr [RDX]; // y
- fld real ptr [RCX]; // x
- fpatan;
- ret;
- }
- }
- else
- {
- asm pure nothrow @nogc {
- fld y;
- fld x;
- fpatan;
- }
- }
- }
- else
- {
- // Special cases.
- if (isNaN(x) || isNaN(y))
- return real.nan;
- if (y == 0.0)
- {
- if (x >= 0 && !signbit(x))
- return copysign(0, y);
- else
- return copysign(PI, y);
- }
- if (x == 0.0)
- return copysign(PI_2, y);
- if (isInfinity(x))
- {
- if (signbit(x))
- {
- if (isInfinity(y))
- return copysign(3*PI_4, y);
- else
- return copysign(PI, y);
- }
- else
- {
- if (isInfinity(y))
- return copysign(PI_4, y);
- else
- return copysign(0.0, y);
- }
- }
- if (isInfinity(y))
- return copysign(PI_2, y);
-
- // Call atan and determine the quadrant.
- real z = atan(y / x);
-
- if (signbit(x))
- {
- if (signbit(y))
- z = z - PI;
- else
- z = z + PI;
- }
-
- if (z == 0.0)
- return copysign(z, y);
-
- return z;
- }
-}
-
-/// ditto
-double atan2(double y, double x) @safe pure nothrow @nogc
-{
- return atan2(cast(real) y, cast(real) x);
-}
-
-/// ditto
-float atan2(float y, float x) @safe pure nothrow @nogc
-{
- return atan2(cast(real) y, cast(real) x);
-}
-
-@system unittest
-{
- assert(atan2(1.0, sqrt(3.0)).approxEqual(PI / 6));
-}
-
-/***********************************
- * Calculates the hyperbolic cosine of x.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH cosh(x)) $(TH invalid?))
- * $(TR $(TD $(PLUSMN)$(INFIN)) $(TD $(PLUSMN)0.0) $(TD no) )
- * )
- */
-real cosh(real x) @safe pure nothrow @nogc
-{
- // cosh = (exp(x)+exp(-x))/2.
- // The naive implementation works correctly.
- const real y = exp(x);
- return (y + 1.0/y) * 0.5;
-}
-
-/// ditto
-double cosh(double x) @safe pure nothrow @nogc { return cosh(cast(real) x); }
-
-/// ditto
-float cosh(float x) @safe pure nothrow @nogc { return cosh(cast(real) x); }
-
-@system unittest
-{
- assert(equalsDigit(cosh(1.0), (E + 1.0 / E) / 2, useDigits));
-}
-
-/***********************************
- * Calculates the hyperbolic sine of x.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH sinh(x)) $(TH invalid?))
- * $(TR $(TD $(PLUSMN)0.0) $(TD $(PLUSMN)0.0) $(TD no))
- * $(TR $(TD $(PLUSMN)$(INFIN)) $(TD $(PLUSMN)$(INFIN)) $(TD no))
- * )
- */
-real sinh(real x) @safe pure nothrow @nogc
-{
- // sinh(x) = (exp(x)-exp(-x))/2;
- // Very large arguments could cause an overflow, but
- // the maximum value of x for which exp(x) + exp(-x)) != exp(x)
- // is x = 0.5 * (real.mant_dig) * LN2. // = 22.1807 for real80.
- if (fabs(x) > real.mant_dig * LN2)
- {
- return copysign(0.5 * exp(fabs(x)), x);
- }
-
- const real y = expm1(x);
- return 0.5 * y / (y+1) * (y+2);
-}
-
-/// ditto
-double sinh(double x) @safe pure nothrow @nogc { return sinh(cast(real) x); }
-
-/// ditto
-float sinh(float x) @safe pure nothrow @nogc { return sinh(cast(real) x); }
-
-@system unittest
-{
- assert(sinh(1.0).approxEqual((E - 1.0 / E) / 2));
-}
-
-/***********************************
- * Calculates the hyperbolic tangent of x.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH tanh(x)) $(TH invalid?))
- * $(TR $(TD $(PLUSMN)0.0) $(TD $(PLUSMN)0.0) $(TD no) )
- * $(TR $(TD $(PLUSMN)$(INFIN)) $(TD $(PLUSMN)1.0) $(TD no))
- * )
- */
-real tanh(real x) @safe pure nothrow @nogc
-{
- // tanh(x) = (exp(x) - exp(-x))/(exp(x)+exp(-x))
- if (fabs(x) > real.mant_dig * LN2)
- {
- return copysign(1, x);
- }
-
- const real y = expm1(2*x);
- return y / (y + 2);
-}
-
-/// ditto
-double tanh(double x) @safe pure nothrow @nogc { return tanh(cast(real) x); }
-
-/// ditto
-float tanh(float x) @safe pure nothrow @nogc { return tanh(cast(real) x); }
-
-@system unittest
-{
- assert(equalsDigit(tanh(1.0), sinh(1.0) / cosh(1.0), 15));
-}
-
-package:
-
-/* Returns cosh(x) + I * sinh(x)
- * Only one call to exp() is performed.
- */
-creal coshisinh(real x) @safe pure nothrow @nogc
-{
- // See comments for cosh, sinh.
- if (fabs(x) > real.mant_dig * LN2)
- {
- const real y = exp(fabs(x));
- return y * 0.5 + 0.5i * copysign(y, x);
- }
- else
- {
- const real y = expm1(x);
- return (y + 1.0 + 1.0/(y + 1.0)) * 0.5 + 0.5i * y / (y+1) * (y+2);
- }
-}
-
-@safe pure nothrow @nogc unittest
-{
- creal c = coshisinh(3.0L);
- assert(c.re == cosh(3.0L));
- assert(c.im == sinh(3.0L));
-}
-
-public:
-
-/***********************************
- * Calculates the inverse hyperbolic cosine of x.
- *
- * Mathematically, acosh(x) = log(x + sqrt( x*x - 1))
- *
- * $(TABLE_DOMRG
- * $(DOMAIN 1..$(INFIN)),
- * $(RANGE 0..$(INFIN))
- * )
- *
- * $(TABLE_SV
- * $(SVH x, acosh(x) )
- * $(SV $(NAN), $(NAN) )
- * $(SV $(LT)1, $(NAN) )
- * $(SV 1, 0 )
- * $(SV +$(INFIN),+$(INFIN))
- * )
- */
-real acosh(real x) @safe pure nothrow @nogc
-{
- if (x > 1/real.epsilon)
- return LN2 + log(x);
- else
- return log(x + sqrt(x*x - 1));
-}
-
-/// ditto
-double acosh(double x) @safe pure nothrow @nogc { return acosh(cast(real) x); }
-
-/// ditto
-float acosh(float x) @safe pure nothrow @nogc { return acosh(cast(real) x); }
-
-
-@system unittest
-{
- assert(isNaN(acosh(0.9)));
- assert(isNaN(acosh(real.nan)));
- assert(acosh(1.0)==0.0);
- assert(acosh(real.infinity) == real.infinity);
- assert(isNaN(acosh(0.5)));
- assert(equalsDigit(acosh(cosh(3.0)), 3, useDigits));
-}
-
-/***********************************
- * Calculates the inverse hyperbolic sine of x.
- *
- * Mathematically,
- * ---------------
- * asinh(x) = log( x + sqrt( x*x + 1 )) // if x >= +0
- * asinh(x) = -log(-x + sqrt( x*x + 1 )) // if x <= -0
- * -------------
- *
- * $(TABLE_SV
- * $(SVH x, asinh(x) )
- * $(SV $(NAN), $(NAN) )
- * $(SV $(PLUSMN)0, $(PLUSMN)0 )
- * $(SV $(PLUSMN)$(INFIN),$(PLUSMN)$(INFIN))
- * )
- */
-real asinh(real x) @safe pure nothrow @nogc
-{
- return (fabs(x) > 1 / real.epsilon)
- // beyond this point, x*x + 1 == x*x
- ? copysign(LN2 + log(fabs(x)), x)
- // sqrt(x*x + 1) == 1 + x * x / ( 1 + sqrt(x*x + 1) )
- : copysign(log1p(fabs(x) + x*x / (1 + sqrt(x*x + 1)) ), x);
-}
-
-/// ditto
-double asinh(double x) @safe pure nothrow @nogc { return asinh(cast(real) x); }
-
-/// ditto
-float asinh(float x) @safe pure nothrow @nogc { return asinh(cast(real) x); }
-
-@system unittest
-{
- assert(isIdentical(asinh(0.0), 0.0));
- assert(isIdentical(asinh(-0.0), -0.0));
- assert(asinh(real.infinity) == real.infinity);
- assert(asinh(-real.infinity) == -real.infinity);
- assert(isNaN(asinh(real.nan)));
- assert(equalsDigit(asinh(sinh(3.0)), 3, useDigits));
-}
-
-/***********************************
- * Calculates the inverse hyperbolic tangent of x,
- * returning a value from ranging from -1 to 1.
- *
- * Mathematically, atanh(x) = log( (1+x)/(1-x) ) / 2
- *
- * $(TABLE_DOMRG
- * $(DOMAIN -$(INFIN)..$(INFIN)),
- * $(RANGE -1 .. 1)
- * )
- * $(BR)
- * $(TABLE_SV
- * $(SVH x, acosh(x) )
- * $(SV $(NAN), $(NAN) )
- * $(SV $(PLUSMN)0, $(PLUSMN)0)
- * $(SV -$(INFIN), -0)
- * )
- */
-real atanh(real x) @safe pure nothrow @nogc
-{
- // log( (1+x)/(1-x) ) == log ( 1 + (2*x)/(1-x) )
- return 0.5 * log1p( 2 * x / (1 - x) );
-}
-
-/// ditto
-double atanh(double x) @safe pure nothrow @nogc { return atanh(cast(real) x); }
-
-/// ditto
-float atanh(float x) @safe pure nothrow @nogc { return atanh(cast(real) x); }
-
-
-@system unittest
-{
- assert(isIdentical(atanh(0.0), 0.0));
- assert(isIdentical(atanh(-0.0),-0.0));
- assert(isNaN(atanh(real.nan)));
- assert(isNaN(atanh(-real.infinity)));
- assert(atanh(0.0) == 0);
- assert(equalsDigit(atanh(tanh(0.5L)), 0.5, useDigits));
-}
-
-/*****************************************
- * Returns x rounded to a long value using the current rounding mode.
- * If the integer value of x is
- * greater than long.max, the result is
- * indeterminate.
- */
-long rndtol(real x) @nogc @safe pure nothrow { pragma(inline, true); return core.math.rndtol(x); }
-//FIXME
-///ditto
-long rndtol(double x) @safe pure nothrow @nogc { return rndtol(cast(real) x); }
-//FIXME
-///ditto
-long rndtol(float x) @safe pure nothrow @nogc { return rndtol(cast(real) x); }
-
-@safe unittest
-{
- long function(real) prndtol = &rndtol;
- assert(prndtol != null);
-}
-
-/*****************************************
- * Returns x rounded to a long value using the FE_TONEAREST rounding mode.
- * If the integer value of x is
- * greater than long.max, the result is
- * indeterminate.
- */
-extern (C) real rndtonl(real x);
-
-/***************************************
- * Compute square root of x.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH sqrt(x)) $(TH invalid?))
- * $(TR $(TD -0.0) $(TD -0.0) $(TD no))
- * $(TR $(TD $(LT)0.0) $(TD $(NAN)) $(TD yes))
- * $(TR $(TD +$(INFIN)) $(TD +$(INFIN)) $(TD no))
- * )
- */
-float sqrt(float x) @nogc @safe pure nothrow { pragma(inline, true); return core.math.sqrt(x); }
-
-/// ditto
-double sqrt(double x) @nogc @safe pure nothrow { pragma(inline, true); return core.math.sqrt(x); }
-
-/// ditto
-real sqrt(real x) @nogc @safe pure nothrow { pragma(inline, true); return core.math.sqrt(x); }
-
-@safe pure nothrow @nogc unittest
-{
- //ctfe
- enum ZX80 = sqrt(7.0f);
- enum ZX81 = sqrt(7.0);
- enum ZX82 = sqrt(7.0L);
-
- assert(isNaN(sqrt(-1.0f)));
- assert(isNaN(sqrt(-1.0)));
- assert(isNaN(sqrt(-1.0L)));
-}
-
-@safe unittest
-{
- float function(float) psqrtf = &sqrt;
- assert(psqrtf != null);
- double function(double) psqrtd = &sqrt;
- assert(psqrtd != null);
- real function(real) psqrtr = &sqrt;
- assert(psqrtr != null);
-}
-
-creal sqrt(creal z) @nogc @safe pure nothrow
-{
- creal c;
- real x,y,w,r;
-
- if (z == 0)
- {
- c = 0 + 0i;
- }
- else
- {
- const real z_re = z.re;
- const real z_im = z.im;
-
- x = fabs(z_re);
- y = fabs(z_im);
- if (x >= y)
- {
- r = y / x;
- w = sqrt(x) * sqrt(0.5 * (1 + sqrt(1 + r * r)));
- }
- else
- {
- r = x / y;
- w = sqrt(y) * sqrt(0.5 * (r + sqrt(1 + r * r)));
- }
-
- if (z_re >= 0)
- {
- c = w + (z_im / (w + w)) * 1.0i;
- }
- else
- {
- if (z_im < 0)
- w = -w;
- c = z_im / (w + w) + w * 1.0i;
- }
- }
- return c;
-}
-
-/**
- * Calculates e$(SUPERSCRIPT x).
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH e$(SUPERSCRIPT x)) )
- * $(TR $(TD +$(INFIN)) $(TD +$(INFIN)) )
- * $(TR $(TD -$(INFIN)) $(TD +0.0) )
- * $(TR $(TD $(NAN)) $(TD $(NAN)) )
- * )
- */
-real exp(real x) @trusted pure nothrow @nogc
-{
- version (D_InlineAsm_X86)
- {
- // e^^x = 2^^(LOG2E*x)
- // (This is valid because the overflow & underflow limits for exp
- // and exp2 are so similar).
- return exp2(LOG2E*x);
- }
- else version (D_InlineAsm_X86_64)
- {
- // e^^x = 2^^(LOG2E*x)
- // (This is valid because the overflow & underflow limits for exp
- // and exp2 are so similar).
- return exp2(LOG2E*x);
- }
- else
- {
- alias F = floatTraits!real;
- static if (F.realFormat == RealFormat.ieeeDouble)
- {
- // Coefficients for exp(x)
- static immutable real[3] P = [
- 9.99999999999999999910E-1L,
- 3.02994407707441961300E-2L,
- 1.26177193074810590878E-4L,
- ];
- static immutable real[4] Q = [
- 2.00000000000000000009E0L,
- 2.27265548208155028766E-1L,
- 2.52448340349684104192E-3L,
- 3.00198505138664455042E-6L,
- ];
-
- // C1 + C2 = LN2.
- enum real C1 = 6.93145751953125E-1;
- enum real C2 = 1.42860682030941723212E-6;
-
- // Overflow and Underflow limits.
- enum real OF = 7.09782712893383996732E2; // ln((1-2^-53) * 2^1024)
- enum real UF = -7.451332191019412076235E2; // ln(2^-1075)
- }
- else static if (F.realFormat == RealFormat.ieeeExtended ||
- F.realFormat == RealFormat.ieeeExtended53)
- {
- // Coefficients for exp(x)
- static immutable real[3] P = [
- 9.9999999999999999991025E-1L,
- 3.0299440770744196129956E-2L,
- 1.2617719307481059087798E-4L,
- ];
- static immutable real[4] Q = [
- 2.0000000000000000000897E0L,
- 2.2726554820815502876593E-1L,
- 2.5244834034968410419224E-3L,
- 3.0019850513866445504159E-6L,
- ];
-
- // C1 + C2 = LN2.
- enum real C1 = 6.9314575195312500000000E-1L;
- enum real C2 = 1.4286068203094172321215E-6L;
-
- // Overflow and Underflow limits.
- enum real OF = 1.1356523406294143949492E4L; // ln((1-2^-64) * 2^16384)
- enum real UF = -1.13994985314888605586758E4L; // ln(2^-16446)
- }
- else static if (F.realFormat == RealFormat.ieeeQuadruple)
- {
- // Coefficients for exp(x) - 1
- static immutable real[5] P = [
- 9.999999999999999999999999999999999998502E-1L,
- 3.508710990737834361215404761139478627390E-2L,
- 2.708775201978218837374512615596512792224E-4L,
- 6.141506007208645008909088812338454698548E-7L,
- 3.279723985560247033712687707263393506266E-10L
- ];
- static immutable real[6] Q = [
- 2.000000000000000000000000000000000000150E0,
- 2.368408864814233538909747618894558968880E-1L,
- 3.611828913847589925056132680618007270344E-3L,
- 1.504792651814944826817779302637284053660E-5L,
- 1.771372078166251484503904874657985291164E-8L,
- 2.980756652081995192255342779918052538681E-12L
- ];
-
- // C1 + C2 = LN2.
- enum real C1 = 6.93145751953125E-1L;
- enum real C2 = 1.428606820309417232121458176568075500134E-6L;
-
- // Overflow and Underflow limits.
- enum real OF = 1.135583025911358400418251384584930671458833e4L;
- enum real UF = -1.143276959615573793352782661133116431383730e4L;
- }
- else
- static assert(0, "Not implemented for this architecture");
-
- // Special cases. Raises an overflow or underflow flag accordingly,
- // except in the case for CTFE, where there are no hardware controls.
- if (isNaN(x))
- return x;
- if (x > OF)
- return real.infinity;
- if (x < UF)
- return 0.0;
-
- // Express: e^^x = e^^g * 2^^n
- // = e^^g * e^^(n * LOG2E)
- // = e^^(g + n * LOG2E)
- int n = cast(int) floor(LOG2E * x + 0.5);
- x -= n * C1;
- x -= n * C2;
-
- // Rational approximation for exponential of the fractional part:
- // e^^x = 1 + 2x P(x^^2) / (Q(x^^2) - P(x^^2))
- const real xx = x * x;
- const real px = x * poly(xx, P);
- x = px / (poly(xx, Q) - px);
- x = 1.0 + ldexp(x, 1);
-
- // Scale by power of 2.
- x = ldexp(x, n);
-
- return x;
- }
-}
-
-/// ditto
-double exp(double x) @safe pure nothrow @nogc { return exp(cast(real) x); }
-
-/// ditto
-float exp(float x) @safe pure nothrow @nogc { return exp(cast(real) x); }
-
-@system unittest
-{
- assert(exp(3.0).feqrel(E * E * E) > 16);
-}
-
-/**
- * Calculates the value of the natural logarithm base (e)
- * raised to the power of x, minus 1.
- *
- * For very small x, expm1(x) is more accurate
- * than exp(x)-1.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH e$(SUPERSCRIPT x)-1) )
- * $(TR $(TD $(PLUSMN)0.0) $(TD $(PLUSMN)0.0) )
- * $(TR $(TD +$(INFIN)) $(TD +$(INFIN)) )
- * $(TR $(TD -$(INFIN)) $(TD -1.0) )
- * $(TR $(TD $(NAN)) $(TD $(NAN)) )
- * )
- */
-real expm1(real x) @trusted pure nothrow @nogc
-{
- version (D_InlineAsm_X86)
- {
- enum PARAMSIZE = (real.sizeof+3)&(0xFFFF_FFFC); // always a multiple of 4
- asm pure nothrow @nogc
- {
- /* expm1() for x87 80-bit reals, IEEE754-2008 conformant.
- * Author: Don Clugston.
- *
- * expm1(x) = 2^^(rndint(y))* 2^^(y-rndint(y)) - 1 where y = LN2*x.
- * = 2rndy * 2ym1 + 2rndy - 1, where 2rndy = 2^^(rndint(y))
- * and 2ym1 = (2^^(y-rndint(y))-1).
- * If 2rndy < 0.5*real.epsilon, result is -1.
- * Implementation is otherwise the same as for exp2()
- */
- naked;
- fld real ptr [ESP+4] ; // x
- mov AX, [ESP+4+8]; // AX = exponent and sign
- sub ESP, 12+8; // Create scratch space on the stack
- // [ESP,ESP+2] = scratchint
- // [ESP+4..+6, +8..+10, +10] = scratchreal
- // set scratchreal mantissa = 1.0
- mov dword ptr [ESP+8], 0;
- mov dword ptr [ESP+8+4], 0x80000000;
- and AX, 0x7FFF; // drop sign bit
- cmp AX, 0x401D; // avoid InvalidException in fist
- jae L_extreme;
- fldl2e;
- fmulp ST(1), ST; // y = x*log2(e)
- fist dword ptr [ESP]; // scratchint = rndint(y)
- fisub dword ptr [ESP]; // y - rndint(y)
- // and now set scratchreal exponent
- mov EAX, [ESP];
- add EAX, 0x3fff;
- jle short L_largenegative;
- cmp EAX,0x8000;
- jge short L_largepositive;
- mov [ESP+8+8],AX;
- f2xm1; // 2ym1 = 2^^(y-rndint(y)) -1
- fld real ptr [ESP+8] ; // 2rndy = 2^^rndint(y)
- fmul ST(1), ST; // ST=2rndy, ST(1)=2rndy*2ym1
- fld1;
- fsubp ST(1), ST; // ST = 2rndy-1, ST(1) = 2rndy * 2ym1 - 1
- faddp ST(1), ST; // ST = 2rndy * 2ym1 + 2rndy - 1
- add ESP,12+8;
- ret PARAMSIZE;
-
-L_extreme: // Extreme exponent. X is very large positive, very
- // large negative, infinity, or NaN.
- fxam;
- fstsw AX;
- test AX, 0x0400; // NaN_or_zero, but we already know x != 0
- jz L_was_nan; // if x is NaN, returns x
- test AX, 0x0200;
- jnz L_largenegative;
-L_largepositive:
- // Set scratchreal = real.max.
- // squaring it will create infinity, and set overflow flag.
- mov word ptr [ESP+8+8], 0x7FFE;
- fstp ST(0);
- fld real ptr [ESP+8]; // load scratchreal
- fmul ST(0), ST; // square it, to create havoc!
-L_was_nan:
- add ESP,12+8;
- ret PARAMSIZE;
-L_largenegative:
- fstp ST(0);
- fld1;
- fchs; // return -1. Underflow flag is not set.
- add ESP,12+8;
- ret PARAMSIZE;
- }
- }
- else version (D_InlineAsm_X86_64)
- {
- asm pure nothrow @nogc
- {
- naked;
- }
- version (Win64)
- {
- asm pure nothrow @nogc
- {
- fld real ptr [RCX]; // x
- mov AX,[RCX+8]; // AX = exponent and sign
- }
- }
- else
- {
- asm pure nothrow @nogc
- {
- fld real ptr [RSP+8]; // x
- mov AX,[RSP+8+8]; // AX = exponent and sign
- }
- }
- asm pure nothrow @nogc
- {
- /* expm1() for x87 80-bit reals, IEEE754-2008 conformant.
- * Author: Don Clugston.
- *
- * expm1(x) = 2^(rndint(y))* 2^(y-rndint(y)) - 1 where y = LN2*x.
- * = 2rndy * 2ym1 + 2rndy - 1, where 2rndy = 2^(rndint(y))
- * and 2ym1 = (2^(y-rndint(y))-1).
- * If 2rndy < 0.5*real.epsilon, result is -1.
- * Implementation is otherwise the same as for exp2()
- */
- sub RSP, 24; // Create scratch space on the stack
- // [RSP,RSP+2] = scratchint
- // [RSP+4..+6, +8..+10, +10] = scratchreal
- // set scratchreal mantissa = 1.0
- mov dword ptr [RSP+8], 0;
- mov dword ptr [RSP+8+4], 0x80000000;
- and AX, 0x7FFF; // drop sign bit
- cmp AX, 0x401D; // avoid InvalidException in fist
- jae L_extreme;
- fldl2e;
- fmul ; // y = x*log2(e)
- fist dword ptr [RSP]; // scratchint = rndint(y)
- fisub dword ptr [RSP]; // y - rndint(y)
- // and now set scratchreal exponent
- mov EAX, [RSP];
- add EAX, 0x3fff;
- jle short L_largenegative;
- cmp EAX,0x8000;
- jge short L_largepositive;
- mov [RSP+8+8],AX;
- f2xm1; // 2^(y-rndint(y)) -1
- fld real ptr [RSP+8] ; // 2^rndint(y)
- fmul ST(1), ST;
- fld1;
- fsubp ST(1), ST;
- fadd;
- add RSP,24;
- ret;
-
-L_extreme: // Extreme exponent. X is very large positive, very
- // large negative, infinity, or NaN.
- fxam;
- fstsw AX;
- test AX, 0x0400; // NaN_or_zero, but we already know x != 0
- jz L_was_nan; // if x is NaN, returns x
- test AX, 0x0200;
- jnz L_largenegative;
-L_largepositive:
- // Set scratchreal = real.max.
- // squaring it will create infinity, and set overflow flag.
- mov word ptr [RSP+8+8], 0x7FFE;
- fstp ST(0);
- fld real ptr [RSP+8]; // load scratchreal
- fmul ST(0), ST; // square it, to create havoc!
-L_was_nan:
- add RSP,24;
- ret;
-
-L_largenegative:
- fstp ST(0);
- fld1;
- fchs; // return -1. Underflow flag is not set.
- add RSP,24;
- ret;
- }
- }
- else
- {
- // Coefficients for exp(x) - 1 and overflow/underflow limits.
- static if (floatTraits!real.realFormat == RealFormat.ieeeQuadruple)
- {
- static immutable real[8] P = [
- 2.943520915569954073888921213330863757240E8L,
- -5.722847283900608941516165725053359168840E7L,
- 8.944630806357575461578107295909719817253E6L,
- -7.212432713558031519943281748462837065308E5L,
- 4.578962475841642634225390068461943438441E4L,
- -1.716772506388927649032068540558788106762E3L,
- 4.401308817383362136048032038528753151144E1L,
- -4.888737542888633647784737721812546636240E-1L
- ];
-
- static immutable real[9] Q = [
- 1.766112549341972444333352727998584753865E9L,
- -7.848989743695296475743081255027098295771E8L,
- 1.615869009634292424463780387327037251069E8L,
- -2.019684072836541751428967854947019415698E7L,
- 1.682912729190313538934190635536631941751E6L,
- -9.615511549171441430850103489315371768998E4L,
- 3.697714952261803935521187272204485251835E3L,
- -8.802340681794263968892934703309274564037E1L,
- 1.0
- ];
-
- enum real OF = 1.1356523406294143949491931077970764891253E4L;
- enum real UF = -1.143276959615573793352782661133116431383730e4L;
- }
- else
- {
- static immutable real[5] P = [
- -1.586135578666346600772998894928250240826E4L,
- 2.642771505685952966904660652518429479531E3L,
- -3.423199068835684263987132888286791620673E2L,
- 1.800826371455042224581246202420972737840E1L,
- -5.238523121205561042771939008061958820811E-1L,
- ];
- static immutable real[6] Q = [
- -9.516813471998079611319047060563358064497E4L,
- 3.964866271411091674556850458227710004570E4L,
- -7.207678383830091850230366618190187434796E3L,
- 7.206038318724600171970199625081491823079E2L,
- -4.002027679107076077238836622982900945173E1L,
- 1.0
- ];
-
- enum real OF = 1.1356523406294143949492E4L;
- enum real UF = -4.5054566736396445112120088E1L;
- }
-
-
- // C1 + C2 = LN2.
- enum real C1 = 6.9314575195312500000000E-1L;
- enum real C2 = 1.428606820309417232121458176568075500134E-6L;
-
- // Special cases. Raises an overflow flag, except in the case
- // for CTFE, where there are no hardware controls.
- if (x > OF)
- return real.infinity;
- if (x == 0.0)
- return x;
- if (x < UF)
- return -1.0;
-
- // Express x = LN2 (n + remainder), remainder not exceeding 1/2.
- int n = cast(int) floor(0.5 + x / LN2);
- x -= n * C1;
- x -= n * C2;
-
- // Rational approximation:
- // exp(x) - 1 = x + 0.5 x^^2 + x^^3 P(x) / Q(x)
- real px = x * poly(x, P);
- real qx = poly(x, Q);
- const real xx = x * x;
- qx = x + (0.5 * xx + xx * px / qx);
-
- // We have qx = exp(remainder LN2) - 1, so:
- // exp(x) - 1 = 2^^n (qx + 1) - 1 = 2^^n qx + 2^^n - 1.
- px = ldexp(1.0, n);
- x = px * qx + (px - 1.0);
-
- return x;
- }
-}
-
-
-
-/**
- * Calculates 2$(SUPERSCRIPT x).
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH exp2(x)) )
- * $(TR $(TD +$(INFIN)) $(TD +$(INFIN)) )
- * $(TR $(TD -$(INFIN)) $(TD +0.0) )
- * $(TR $(TD $(NAN)) $(TD $(NAN)) )
- * )
- */
-pragma(inline, true)
-real exp2(real x) @nogc @trusted pure nothrow
-{
- version (InlineAsm_X86_Any)
- {
- if (!__ctfe)
- return exp2Asm(x);
- else
- return exp2Impl(x);
- }
- else
- {
- return exp2Impl(x);
- }
-}
-
-version (InlineAsm_X86_Any)
-private real exp2Asm(real x) @nogc @trusted pure nothrow
-{
- version (D_InlineAsm_X86)
- {
- enum PARAMSIZE = (real.sizeof+3)&(0xFFFF_FFFC); // always a multiple of 4
-
- asm pure nothrow @nogc
- {
- /* exp2() for x87 80-bit reals, IEEE754-2008 conformant.
- * Author: Don Clugston.
- *
- * exp2(x) = 2^^(rndint(x))* 2^^(y-rndint(x))
- * The trick for high performance is to avoid the fscale(28cycles on core2),
- * frndint(19 cycles), leaving f2xm1(19 cycles) as the only slow instruction.
- *
- * We can do frndint by using fist. BUT we can't use it for huge numbers,
- * because it will set the Invalid Operation flag if overflow or NaN occurs.
- * Fortunately, whenever this happens the result would be zero or infinity.
- *
- * We can perform fscale by directly poking into the exponent. BUT this doesn't
- * work for the (very rare) cases where the result is subnormal. So we fall back
- * to the slow method in that case.
- */
- naked;
- fld real ptr [ESP+4] ; // x
- mov AX, [ESP+4+8]; // AX = exponent and sign
- sub ESP, 12+8; // Create scratch space on the stack
- // [ESP,ESP+2] = scratchint
- // [ESP+4..+6, +8..+10, +10] = scratchreal
- // set scratchreal mantissa = 1.0
- mov dword ptr [ESP+8], 0;
- mov dword ptr [ESP+8+4], 0x80000000;
- and AX, 0x7FFF; // drop sign bit
- cmp AX, 0x401D; // avoid InvalidException in fist
- jae L_extreme;
- fist dword ptr [ESP]; // scratchint = rndint(x)
- fisub dword ptr [ESP]; // x - rndint(x)
- // and now set scratchreal exponent
- mov EAX, [ESP];
- add EAX, 0x3fff;
- jle short L_subnormal;
- cmp EAX,0x8000;
- jge short L_overflow;
- mov [ESP+8+8],AX;
-L_normal:
- f2xm1;
- fld1;
- faddp ST(1), ST; // 2^^(x-rndint(x))
- fld real ptr [ESP+8] ; // 2^^rndint(x)
- add ESP,12+8;
- fmulp ST(1), ST;
- ret PARAMSIZE;
-
-L_subnormal:
- // Result will be subnormal.
- // In this rare case, the simple poking method doesn't work.
- // The speed doesn't matter, so use the slow fscale method.
- fild dword ptr [ESP]; // scratchint
- fld1;
- fscale;
- fstp real ptr [ESP+8]; // scratchreal = 2^^scratchint
- fstp ST(0); // drop scratchint
- jmp L_normal;
-
-L_extreme: // Extreme exponent. X is very large positive, very
- // large negative, infinity, or NaN.
- fxam;
- fstsw AX;
- test AX, 0x0400; // NaN_or_zero, but we already know x != 0
- jz L_was_nan; // if x is NaN, returns x
- // set scratchreal = real.min_normal
- // squaring it will return 0, setting underflow flag
- mov word ptr [ESP+8+8], 1;
- test AX, 0x0200;
- jnz L_waslargenegative;
-L_overflow:
- // Set scratchreal = real.max.
- // squaring it will create infinity, and set overflow flag.
- mov word ptr [ESP+8+8], 0x7FFE;
-L_waslargenegative:
- fstp ST(0);
- fld real ptr [ESP+8]; // load scratchreal
- fmul ST(0), ST; // square it, to create havoc!
-L_was_nan:
- add ESP,12+8;
- ret PARAMSIZE;
- }
- }
- else version (D_InlineAsm_X86_64)
- {
- asm pure nothrow @nogc
- {
- naked;
- }
- version (Win64)
- {
- asm pure nothrow @nogc
- {
- fld real ptr [RCX]; // x
- mov AX,[RCX+8]; // AX = exponent and sign
- }
- }
- else
- {
- asm pure nothrow @nogc
- {
- fld real ptr [RSP+8]; // x
- mov AX,[RSP+8+8]; // AX = exponent and sign
- }
- }
- asm pure nothrow @nogc
- {
- /* exp2() for x87 80-bit reals, IEEE754-2008 conformant.
- * Author: Don Clugston.
- *
- * exp2(x) = 2^(rndint(x))* 2^(y-rndint(x))
- * The trick for high performance is to avoid the fscale(28cycles on core2),
- * frndint(19 cycles), leaving f2xm1(19 cycles) as the only slow instruction.
- *
- * We can do frndint by using fist. BUT we can't use it for huge numbers,
- * because it will set the Invalid Operation flag is overflow or NaN occurs.
- * Fortunately, whenever this happens the result would be zero or infinity.
- *
- * We can perform fscale by directly poking into the exponent. BUT this doesn't
- * work for the (very rare) cases where the result is subnormal. So we fall back
- * to the slow method in that case.
- */
- sub RSP, 24; // Create scratch space on the stack
- // [RSP,RSP+2] = scratchint
- // [RSP+4..+6, +8..+10, +10] = scratchreal
- // set scratchreal mantissa = 1.0
- mov dword ptr [RSP+8], 0;
- mov dword ptr [RSP+8+4], 0x80000000;
- and AX, 0x7FFF; // drop sign bit
- cmp AX, 0x401D; // avoid InvalidException in fist
- jae L_extreme;
- fist dword ptr [RSP]; // scratchint = rndint(x)
- fisub dword ptr [RSP]; // x - rndint(x)
- // and now set scratchreal exponent
- mov EAX, [RSP];
- add EAX, 0x3fff;
- jle short L_subnormal;
- cmp EAX,0x8000;
- jge short L_overflow;
- mov [RSP+8+8],AX;
-L_normal:
- f2xm1;
- fld1;
- fadd; // 2^(x-rndint(x))
- fld real ptr [RSP+8] ; // 2^rndint(x)
- add RSP,24;
- fmulp ST(1), ST;
- ret;
-
-L_subnormal:
- // Result will be subnormal.
- // In this rare case, the simple poking method doesn't work.
- // The speed doesn't matter, so use the slow fscale method.
- fild dword ptr [RSP]; // scratchint
- fld1;
- fscale;
- fstp real ptr [RSP+8]; // scratchreal = 2^scratchint
- fstp ST(0); // drop scratchint
- jmp L_normal;
-
-L_extreme: // Extreme exponent. X is very large positive, very
- // large negative, infinity, or NaN.
- fxam;
- fstsw AX;
- test AX, 0x0400; // NaN_or_zero, but we already know x != 0
- jz L_was_nan; // if x is NaN, returns x
- // set scratchreal = real.min
- // squaring it will return 0, setting underflow flag
- mov word ptr [RSP+8+8], 1;
- test AX, 0x0200;
- jnz L_waslargenegative;
-L_overflow:
- // Set scratchreal = real.max.
- // squaring it will create infinity, and set overflow flag.
- mov word ptr [RSP+8+8], 0x7FFE;
-L_waslargenegative:
- fstp ST(0);
- fld real ptr [RSP+8]; // load scratchreal
- fmul ST(0), ST; // square it, to create havoc!
-L_was_nan:
- add RSP,24;
- ret;
- }
- }
- else
- static assert(0);
-}
-
-private real exp2Impl(real x) @nogc @trusted pure nothrow
-{
- // Coefficients for exp2(x)
- static if (floatTraits!real.realFormat == RealFormat.ieeeQuadruple)
- {
- static immutable real[5] P = [
- 9.079594442980146270952372234833529694788E12L,
- 1.530625323728429161131811299626419117557E11L,
- 5.677513871931844661829755443994214173883E8L,
- 6.185032670011643762127954396427045467506E5L,
- 1.587171580015525194694938306936721666031E2L
- ];
-
- static immutable real[6] Q = [
- 2.619817175234089411411070339065679229869E13L,
- 1.490560994263653042761789432690793026977E12L,
- 1.092141473886177435056423606755843616331E10L,
- 2.186249607051644894762167991800811827835E7L,
- 1.236602014442099053716561665053645270207E4L,
- 1.0
- ];
- }
- else
- {
- static immutable real[3] P = [
- 2.0803843631901852422887E6L,
- 3.0286971917562792508623E4L,
- 6.0614853552242266094567E1L,
- ];
- static immutable real[4] Q = [
- 6.0027204078348487957118E6L,
- 3.2772515434906797273099E5L,
- 1.7492876999891839021063E3L,
- 1.0000000000000000000000E0L,
- ];
- }
-
- // Overflow and Underflow limits.
- enum real OF = 16_384.0L;
- enum real UF = -16_382.0L;
-
- // Special cases. Raises an overflow or underflow flag accordingly,
- // except in the case for CTFE, where there are no hardware controls.
- if (isNaN(x))
- return x;
- if (x > OF)
- return real.infinity;
- if (x < UF)
- return 0.0;
-
- // Separate into integer and fractional parts.
- int n = cast(int) floor(x + 0.5);
- x -= n;
-
- // Rational approximation:
- // exp2(x) = 1.0 + 2x P(x^^2) / (Q(x^^2) - P(x^^2))
- const real xx = x * x;
- const real px = x * poly(xx, P);
- x = px / (poly(xx, Q) - px);
- x = 1.0 + ldexp(x, 1);
-
- // Scale by power of 2.
- x = ldexp(x, n);
-
- return x;
-}
-
-///
-@safe unittest
-{
- assert(feqrel(exp2(0.5L), SQRT2) >= real.mant_dig -1);
- assert(exp2(8.0L) == 256.0);
- assert(exp2(-9.0L)== 1.0L/512.0);
-}
-
-@safe unittest
-{
- version (CRuntime_Microsoft) {} else // aexp2/exp2f/exp2l not implemented
- {
- assert( core.stdc.math.exp2f(0.0f) == 1 );
- assert( core.stdc.math.exp2 (0.0) == 1 );
- assert( core.stdc.math.exp2l(0.0L) == 1 );
- }
-}
-
-@system unittest
-{
- version (FloatingPointControlSupport)
- {
- FloatingPointControl ctrl;
- if (FloatingPointControl.hasExceptionTraps)
- ctrl.disableExceptions(FloatingPointControl.allExceptions);
- ctrl.rounding = FloatingPointControl.roundToNearest;
- }
-
- enum realFormat = floatTraits!real.realFormat;
- static if (realFormat == RealFormat.ieeeQuadruple)
- {
- static immutable real[2][] exptestpoints =
- [ // x exp(x)
- [ 1.0L, E ],
- [ 0.5L, 0x1.a61298e1e069bc972dfefab6df34p+0L ],
- [ 3.0L, E*E*E ],
- [ 0x1.6p+13L, 0x1.6e509d45728655cdb4840542acb5p+16250L ], // near overflow
- [ 0x1.7p+13L, real.infinity ], // close overflow
- [ 0x1p+80L, real.infinity ], // far overflow
- [ real.infinity, real.infinity ],
- [-0x1.18p+13L, 0x1.5e4bf54b4807034ea97fef0059a6p-12927L ], // near underflow
- [-0x1.625p+13L, 0x1.a6bd68a39d11fec3a250cd97f524p-16358L ], // ditto
- [-0x1.62dafp+13L, 0x0.cb629e9813b80ed4d639e875be6cp-16382L ], // near underflow - subnormal
- [-0x1.6549p+13L, 0x0.0000000000000000000000000001p-16382L ], // ditto
- [-0x1.655p+13L, 0 ], // close underflow
- [-0x1p+30L, 0 ], // far underflow
- ];
- }
- else static if (realFormat == RealFormat.ieeeExtended ||
- realFormat == RealFormat.ieeeExtended53)
- {
- static immutable real[2][] exptestpoints =
- [ // x exp(x)
- [ 1.0L, E ],
- [ 0.5L, 0x1.a61298e1e069bc97p+0L ],
- [ 3.0L, E*E*E ],
- [ 0x1.1p+13L, 0x1.29aeffefc8ec645p+12557L ], // near overflow
- [ 0x1.7p+13L, real.infinity ], // close overflow
- [ 0x1p+80L, real.infinity ], // far overflow
- [ real.infinity, real.infinity ],
- [-0x1.18p+13L, 0x1.5e4bf54b4806db9p-12927L ], // near underflow
- [-0x1.625p+13L, 0x1.a6bd68a39d11f35cp-16358L ], // ditto
- [-0x1.62dafp+13L, 0x1.96c53d30277021dp-16383L ], // near underflow - subnormal
- [-0x1.643p+13L, 0x1p-16444L ], // ditto
- [-0x1.645p+13L, 0 ], // close underflow
- [-0x1p+30L, 0 ], // far underflow
- ];
- }
- else static if (realFormat == RealFormat.ieeeDouble)
- {
- static immutable real[2][] exptestpoints =
- [ // x, exp(x)
- [ 1.0L, E ],
- [ 0.5L, 0x1.a61298e1e069cp+0L ],
- [ 3.0L, E*E*E ],
- [ 0x1.6p+9L, 0x1.93bf4ec282efbp+1015L ], // near overflow
- [ 0x1.7p+9L, real.infinity ], // close overflow
- [ 0x1p+80L, real.infinity ], // far overflow
- [ real.infinity, real.infinity ],
- [-0x1.6p+9L, 0x1.44a3824e5285fp-1016L ], // near underflow
- [-0x1.64p+9L, 0x0.06f84920bb2d3p-1022L ], // near underflow - subnormal
- [-0x1.743p+9L, 0x0.0000000000001p-1022L ], // ditto
- [-0x1.8p+9L, 0 ], // close underflow
- [-0x1p30L, 0 ], // far underflow
- ];
- }
- else
- static assert(0, "No exp() tests for real type!");
-
- const minEqualMantissaBits = real.mant_dig - 13;
- real x;
- version (IeeeFlagsSupport) IeeeFlags f;
- foreach (ref pair; exptestpoints)
- {
- version (IeeeFlagsSupport) resetIeeeFlags();
- x = exp(pair[0]);
- assert(feqrel(x, pair[1]) >= minEqualMantissaBits);
- }
-
- // Ideally, exp(0) would not set the inexact flag.
- // Unfortunately, fldl2e sets it!
- // So it's not realistic to avoid setting it.
- assert(exp(0.0L) == 1.0);
-
- // NaN propagation. Doesn't set flags, bcos was already NaN.
- version (IeeeFlagsSupport)
- {
- resetIeeeFlags();
- x = exp(real.nan);
- f = ieeeFlags;
- assert(isIdentical(abs(x), real.nan));
- assert(f.flags == 0);
-
- resetIeeeFlags();
- x = exp(-real.nan);
- f = ieeeFlags;
- assert(isIdentical(abs(x), real.nan));
- assert(f.flags == 0);
- }
- else
- {
- x = exp(real.nan);
- assert(isIdentical(abs(x), real.nan));
-
- x = exp(-real.nan);
- assert(isIdentical(abs(x), real.nan));
- }
-
- x = exp(NaN(0x123));
- assert(isIdentical(x, NaN(0x123)));
-
- // High resolution test (verified against GNU MPFR/Mathematica).
- assert(exp(0.5L) == 0x1.A612_98E1_E069_BC97_2DFE_FAB6_DF34p+0L);
-}
-
-
-/**
- * Calculate cos(y) + i sin(y).
- *
- * On many CPUs (such as x86), this is a very efficient operation;
- * almost twice as fast as calculating sin(y) and cos(y) separately,
- * and is the preferred method when both are required.
- */
-creal expi(real y) @trusted pure nothrow @nogc
-{
- version (InlineAsm_X86_Any)
- {
- version (Win64)
- {
- asm pure nothrow @nogc
- {
- naked;
- fld real ptr [ECX];
- fsincos;
- fxch ST(1), ST(0);
- ret;
- }
- }
- else
- {
- asm pure nothrow @nogc
- {
- fld y;
- fsincos;
- fxch ST(1), ST(0);
- }
- }
- }
- else
- {
- return cos(y) + sin(y)*1i;
- }
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert(expi(1.3e5L) == cos(1.3e5L) + sin(1.3e5L) * 1i);
- assert(expi(0.0L) == 1L + 0.0Li);
-}
-
-/*********************************************************************
- * Separate floating point value into significand and exponent.
- *
- * Returns:
- * Calculate and return $(I x) and $(I exp) such that
- * value =$(I x)*2$(SUPERSCRIPT exp) and
- * .5 $(LT)= |$(I x)| $(LT) 1.0
- *
- * $(I x) has same sign as value.
- *
- * $(TABLE_SV
- * $(TR $(TH value) $(TH returns) $(TH exp))
- * $(TR $(TD $(PLUSMN)0.0) $(TD $(PLUSMN)0.0) $(TD 0))
- * $(TR $(TD +$(INFIN)) $(TD +$(INFIN)) $(TD int.max))
- * $(TR $(TD -$(INFIN)) $(TD -$(INFIN)) $(TD int.min))
- * $(TR $(TD $(PLUSMN)$(NAN)) $(TD $(PLUSMN)$(NAN)) $(TD int.min))
- * )
- */
-T frexp(T)(const T value, out int exp) @trusted pure nothrow @nogc
-if (isFloatingPoint!T)
-{
- Unqual!T vf = value;
- ushort* vu = cast(ushort*)&vf;
- static if (is(Unqual!T == float))
- int* vi = cast(int*)&vf;
- else
- long* vl = cast(long*)&vf;
- int ex;
- alias F = floatTraits!T;
-
- ex = vu[F.EXPPOS_SHORT] & F.EXPMASK;
- static if (F.realFormat == RealFormat.ieeeExtended ||
- F.realFormat == RealFormat.ieeeExtended53)
- {
- if (ex)
- { // If exponent is non-zero
- if (ex == F.EXPMASK) // infinity or NaN
- {
- if (*vl & 0x7FFF_FFFF_FFFF_FFFF) // NaN
- {
- *vl |= 0xC000_0000_0000_0000; // convert NaNS to NaNQ
- exp = int.min;
- }
- else if (vu[F.EXPPOS_SHORT] & 0x8000) // negative infinity
- exp = int.min;
- else // positive infinity
- exp = int.max;
-
- }
- else
- {
- exp = ex - F.EXPBIAS;
- vu[F.EXPPOS_SHORT] = (0x8000 & vu[F.EXPPOS_SHORT]) | 0x3FFE;
- }
- }
- else if (!*vl)
- {
- // vf is +-0.0
- exp = 0;
- }
- else
- {
- // subnormal
-
- vf *= F.RECIP_EPSILON;
- ex = vu[F.EXPPOS_SHORT] & F.EXPMASK;
- exp = ex - F.EXPBIAS - T.mant_dig + 1;
- vu[F.EXPPOS_SHORT] = ((-1 - F.EXPMASK) & vu[F.EXPPOS_SHORT]) | 0x3FFE;
- }
- return vf;
- }
- else static if (F.realFormat == RealFormat.ieeeQuadruple)
- {
- if (ex) // If exponent is non-zero
- {
- if (ex == F.EXPMASK)
- {
- // infinity or NaN
- if (vl[MANTISSA_LSB] |
- (vl[MANTISSA_MSB] & 0x0000_FFFF_FFFF_FFFF)) // NaN
- {
- // convert NaNS to NaNQ
- vl[MANTISSA_MSB] |= 0x0000_8000_0000_0000;
- exp = int.min;
- }
- else if (vu[F.EXPPOS_SHORT] & 0x8000) // negative infinity
- exp = int.min;
- else // positive infinity
- exp = int.max;
- }
- else
- {
- exp = ex - F.EXPBIAS;
- vu[F.EXPPOS_SHORT] = F.EXPBIAS | (0x8000 & vu[F.EXPPOS_SHORT]);
- }
- }
- else if ((vl[MANTISSA_LSB] |
- (vl[MANTISSA_MSB] & 0x0000_FFFF_FFFF_FFFF)) == 0)
- {
- // vf is +-0.0
- exp = 0;
- }
- else
- {
- // subnormal
- vf *= F.RECIP_EPSILON;
- ex = vu[F.EXPPOS_SHORT] & F.EXPMASK;
- exp = ex - F.EXPBIAS - T.mant_dig + 1;
- vu[F.EXPPOS_SHORT] = F.EXPBIAS | (0x8000 & vu[F.EXPPOS_SHORT]);
- }
- return vf;
- }
- else static if (F.realFormat == RealFormat.ieeeDouble)
- {
- if (ex) // If exponent is non-zero
- {
- if (ex == F.EXPMASK) // infinity or NaN
- {
- if (*vl == 0x7FF0_0000_0000_0000) // positive infinity
- {
- exp = int.max;
- }
- else if (*vl == 0xFFF0_0000_0000_0000) // negative infinity
- exp = int.min;
- else
- { // NaN
- *vl |= 0x0008_0000_0000_0000; // convert NaNS to NaNQ
- exp = int.min;
- }
- }
- else
- {
- exp = (ex - F.EXPBIAS) >> 4;
- vu[F.EXPPOS_SHORT] = cast(ushort)((0x800F & vu[F.EXPPOS_SHORT]) | 0x3FE0);
- }
- }
- else if (!(*vl & 0x7FFF_FFFF_FFFF_FFFF))
- {
- // vf is +-0.0
- exp = 0;
- }
- else
- {
- // subnormal
- vf *= F.RECIP_EPSILON;
- ex = vu[F.EXPPOS_SHORT] & F.EXPMASK;
- exp = ((ex - F.EXPBIAS) >> 4) - T.mant_dig + 1;
- vu[F.EXPPOS_SHORT] =
- cast(ushort)(((-1 - F.EXPMASK) & vu[F.EXPPOS_SHORT]) | 0x3FE0);
- }
- return vf;
- }
- else static if (F.realFormat == RealFormat.ieeeSingle)
- {
- if (ex) // If exponent is non-zero
- {
- if (ex == F.EXPMASK) // infinity or NaN
- {
- if (*vi == 0x7F80_0000) // positive infinity
- {
- exp = int.max;
- }
- else if (*vi == 0xFF80_0000) // negative infinity
- exp = int.min;
- else
- { // NaN
- *vi |= 0x0040_0000; // convert NaNS to NaNQ
- exp = int.min;
- }
- }
- else
- {
- exp = (ex - F.EXPBIAS) >> 7;
- vu[F.EXPPOS_SHORT] = cast(ushort)((0x807F & vu[F.EXPPOS_SHORT]) | 0x3F00);
- }
- }
- else if (!(*vi & 0x7FFF_FFFF))
- {
- // vf is +-0.0
- exp = 0;
- }
- else
- {
- // subnormal
- vf *= F.RECIP_EPSILON;
- ex = vu[F.EXPPOS_SHORT] & F.EXPMASK;
- exp = ((ex - F.EXPBIAS) >> 7) - T.mant_dig + 1;
- vu[F.EXPPOS_SHORT] =
- cast(ushort)(((-1 - F.EXPMASK) & vu[F.EXPPOS_SHORT]) | 0x3F00);
- }
- return vf;
- }
- else // static if (F.realFormat == RealFormat.ibmExtended)
- {
- assert(0, "frexp not implemented");
- }
-}
-
-///
-@system unittest
-{
- int exp;
- real mantissa = frexp(123.456L, exp);
-
- // check if values are equal to 19 decimal digits of precision
- assert(equalsDigit(mantissa * pow(2.0L, cast(real) exp), 123.456L, 19));
-
- assert(frexp(-real.nan, exp) && exp == int.min);
- assert(frexp(real.nan, exp) && exp == int.min);
- assert(frexp(-real.infinity, exp) == -real.infinity && exp == int.min);
- assert(frexp(real.infinity, exp) == real.infinity && exp == int.max);
- assert(frexp(-0.0, exp) == -0.0 && exp == 0);
- assert(frexp(0.0, exp) == 0.0 && exp == 0);
-}
-
-@safe unittest
-{
- import std.meta : AliasSeq;
- import std.typecons : tuple, Tuple;
-
- foreach (T; AliasSeq!(real, double, float))
- {
- Tuple!(T, T, int)[] vals = // x,frexp,exp
- [
- tuple(T(0.0), T( 0.0 ), 0),
- tuple(T(-0.0), T( -0.0), 0),
- tuple(T(1.0), T( .5 ), 1),
- tuple(T(-1.0), T( -.5 ), 1),
- tuple(T(2.0), T( .5 ), 2),
- tuple(T(float.min_normal/2.0f), T(.5), -126),
- tuple(T.infinity, T.infinity, int.max),
- tuple(-T.infinity, -T.infinity, int.min),
- tuple(T.nan, T.nan, int.min),
- tuple(-T.nan, -T.nan, int.min),
-
- // Phobos issue #16026:
- tuple(3 * (T.min_normal * T.epsilon), T( .75), (T.min_exp - T.mant_dig) + 2)
- ];
-
- foreach (elem; vals)
- {
- T x = elem[0];
- T e = elem[1];
- int exp = elem[2];
- int eptr;
- T v = frexp(x, eptr);
- assert(isIdentical(e, v));
- assert(exp == eptr);
-
- }
-
- static if (floatTraits!(T).realFormat == RealFormat.ieeeExtended)
- {
- static T[3][] extendedvals = [ // x,frexp,exp
- [0x1.a5f1c2eb3fe4efp+73L, 0x1.A5F1C2EB3FE4EFp-1L, 74], // normal
- [0x1.fa01712e8f0471ap-1064L, 0x1.fa01712e8f0471ap-1L, -1063],
- [T.min_normal, .5, -16381],
- [T.min_normal/2.0L, .5, -16382] // subnormal
- ];
- foreach (elem; extendedvals)
- {
- T x = elem[0];
- T e = elem[1];
- int exp = cast(int) elem[2];
- int eptr;
- T v = frexp(x, eptr);
- assert(isIdentical(e, v));
- assert(exp == eptr);
-
- }
- }
- }
-}
-
-@safe unittest
-{
- import std.meta : AliasSeq;
- void foo() {
- foreach (T; AliasSeq!(real, double, float))
- {
- int exp;
- const T a = 1;
- immutable T b = 2;
- auto c = frexp(a, exp);
- auto d = frexp(b, exp);
- }
- }
-}
-
-/******************************************
- * Extracts the exponent of x as a signed integral value.
- *
- * If x is not a special value, the result is the same as
- * $(D cast(int) logb(x)).
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH ilogb(x)) $(TH Range error?))
- * $(TR $(TD 0) $(TD FP_ILOGB0) $(TD yes))
- * $(TR $(TD $(PLUSMN)$(INFIN)) $(TD int.max) $(TD no))
- * $(TR $(TD $(NAN)) $(TD FP_ILOGBNAN) $(TD no))
- * )
- */
-int ilogb(T)(const T x) @trusted pure nothrow @nogc
-if (isFloatingPoint!T)
-{
- import core.bitop : bsr;
- alias F = floatTraits!T;
-
- union floatBits
- {
- T rv;
- ushort[T.sizeof/2] vu;
- uint[T.sizeof/4] vui;
- static if (T.sizeof >= 8)
- ulong[T.sizeof/8] vul;
- }
- floatBits y = void;
- y.rv = x;
-
- int ex = y.vu[F.EXPPOS_SHORT] & F.EXPMASK;
- static if (F.realFormat == RealFormat.ieeeExtended ||
- F.realFormat == RealFormat.ieeeExtended53)
- {
- if (ex)
- {
- // If exponent is non-zero
- if (ex == F.EXPMASK) // infinity or NaN
- {
- if (y.vul[0] & 0x7FFF_FFFF_FFFF_FFFF) // NaN
- return FP_ILOGBNAN;
- else // +-infinity
- return int.max;
- }
- else
- {
- return ex - F.EXPBIAS - 1;
- }
- }
- else if (!y.vul[0])
- {
- // vf is +-0.0
- return FP_ILOGB0;
- }
- else
- {
- // subnormal
- return ex - F.EXPBIAS - T.mant_dig + 1 + bsr(y.vul[0]);
- }
- }
- else static if (F.realFormat == RealFormat.ieeeQuadruple)
- {
- if (ex) // If exponent is non-zero
- {
- if (ex == F.EXPMASK)
- {
- // infinity or NaN
- if (y.vul[MANTISSA_LSB] | ( y.vul[MANTISSA_MSB] & 0x0000_FFFF_FFFF_FFFF)) // NaN
- return FP_ILOGBNAN;
- else // +- infinity
- return int.max;
- }
- else
- {
- return ex - F.EXPBIAS - 1;
- }
- }
- else if ((y.vul[MANTISSA_LSB] | (y.vul[MANTISSA_MSB] & 0x0000_FFFF_FFFF_FFFF)) == 0)
- {
- // vf is +-0.0
- return FP_ILOGB0;
- }
- else
- {
- // subnormal
- const ulong msb = y.vul[MANTISSA_MSB] & 0x0000_FFFF_FFFF_FFFF;
- const ulong lsb = y.vul[MANTISSA_LSB];
- if (msb)
- return ex - F.EXPBIAS - T.mant_dig + 1 + bsr(msb) + 64;
- else
- return ex - F.EXPBIAS - T.mant_dig + 1 + bsr(lsb);
- }
- }
- else static if (F.realFormat == RealFormat.ieeeDouble)
- {
- if (ex) // If exponent is non-zero
- {
- if (ex == F.EXPMASK) // infinity or NaN
- {
- if ((y.vul[0] & 0x7FFF_FFFF_FFFF_FFFF) == 0x7FF0_0000_0000_0000) // +- infinity
- return int.max;
- else // NaN
- return FP_ILOGBNAN;
- }
- else
- {
- return ((ex - F.EXPBIAS) >> 4) - 1;
- }
- }
- else if (!(y.vul[0] & 0x7FFF_FFFF_FFFF_FFFF))
- {
- // vf is +-0.0
- return FP_ILOGB0;
- }
- else
- {
- // subnormal
- enum MANTISSAMASK_64 = ((cast(ulong) F.MANTISSAMASK_INT) << 32) | 0xFFFF_FFFF;
- return ((ex - F.EXPBIAS) >> 4) - T.mant_dig + 1 + bsr(y.vul[0] & MANTISSAMASK_64);
- }
- }
- else static if (F.realFormat == RealFormat.ieeeSingle)
- {
- if (ex) // If exponent is non-zero
- {
- if (ex == F.EXPMASK) // infinity or NaN
- {
- if ((y.vui[0] & 0x7FFF_FFFF) == 0x7F80_0000) // +- infinity
- return int.max;
- else // NaN
- return FP_ILOGBNAN;
- }
- else
- {
- return ((ex - F.EXPBIAS) >> 7) - 1;
- }
- }
- else if (!(y.vui[0] & 0x7FFF_FFFF))
- {
- // vf is +-0.0
- return FP_ILOGB0;
- }
- else
- {
- // subnormal
- const uint mantissa = y.vui[0] & F.MANTISSAMASK_INT;
- return ((ex - F.EXPBIAS) >> 7) - T.mant_dig + 1 + bsr(mantissa);
- }
- }
- else // static if (F.realFormat == RealFormat.ibmExtended)
- {
- core.stdc.math.ilogbl(x);
- }
-}
-/// ditto
-int ilogb(T)(const T x) @safe pure nothrow @nogc
-if (isIntegral!T && isUnsigned!T)
-{
- import core.bitop : bsr;
- if (x == 0)
- return FP_ILOGB0;
- else
- {
- static assert(T.sizeof <= ulong.sizeof, "integer size too large for the current ilogb implementation");
- return bsr(x);
- }
-}
-/// ditto
-int ilogb(T)(const T x) @safe pure nothrow @nogc
-if (isIntegral!T && isSigned!T)
-{
- import std.traits : Unsigned;
- // Note: abs(x) can not be used because the return type is not Unsigned and
- // the return value would be wrong for x == int.min
- Unsigned!T absx = x >= 0 ? x : -x;
- return ilogb(absx);
-}
-
-alias FP_ILOGB0 = core.stdc.math.FP_ILOGB0;
-alias FP_ILOGBNAN = core.stdc.math.FP_ILOGBNAN;
-
-@system nothrow @nogc unittest
-{
- import std.meta : AliasSeq;
- import std.typecons : Tuple;
- foreach (F; AliasSeq!(float, double, real))
- {
- alias T = Tuple!(F, int);
- T[13] vals = // x, ilogb(x)
- [
- T( F.nan , FP_ILOGBNAN ),
- T( -F.nan , FP_ILOGBNAN ),
- T( F.infinity, int.max ),
- T( -F.infinity, int.max ),
- T( 0.0 , FP_ILOGB0 ),
- T( -0.0 , FP_ILOGB0 ),
- T( 2.0 , 1 ),
- T( 2.0001 , 1 ),
- T( 1.9999 , 0 ),
- T( 0.5 , -1 ),
- T( 123.123 , 6 ),
- T( -123.123 , 6 ),
- T( 0.123 , -4 ),
- ];
-
- foreach (elem; vals)
- {
- assert(ilogb(elem[0]) == elem[1]);
- }
- }
-
- // min_normal and subnormals
- assert(ilogb(-float.min_normal) == -126);
- assert(ilogb(nextUp(-float.min_normal)) == -127);
- assert(ilogb(nextUp(-float(0.0))) == -149);
- assert(ilogb(-double.min_normal) == -1022);
- assert(ilogb(nextUp(-double.min_normal)) == -1023);
- assert(ilogb(nextUp(-double(0.0))) == -1074);
- static if (floatTraits!(real).realFormat == RealFormat.ieeeExtended)
- {
- assert(ilogb(-real.min_normal) == -16382);
- assert(ilogb(nextUp(-real.min_normal)) == -16383);
- assert(ilogb(nextUp(-real(0.0))) == -16445);
- }
- else static if (floatTraits!(real).realFormat == RealFormat.ieeeDouble)
- {
- assert(ilogb(-real.min_normal) == -1022);
- assert(ilogb(nextUp(-real.min_normal)) == -1023);
- assert(ilogb(nextUp(-real(0.0))) == -1074);
- }
-
- // test integer types
- assert(ilogb(0) == FP_ILOGB0);
- assert(ilogb(int.max) == 30);
- assert(ilogb(int.min) == 31);
- assert(ilogb(uint.max) == 31);
- assert(ilogb(long.max) == 62);
- assert(ilogb(long.min) == 63);
- assert(ilogb(ulong.max) == 63);
-}
-
-/*******************************************
- * Compute n * 2$(SUPERSCRIPT exp)
- * References: frexp
- */
-
-real ldexp(real n, int exp) @nogc @safe pure nothrow { pragma(inline, true); return core.math.ldexp(n, exp); }
-//FIXME
-///ditto
-double ldexp(double n, int exp) @safe pure nothrow @nogc { return ldexp(cast(real) n, exp); }
-//FIXME
-///ditto
-float ldexp(float n, int exp) @safe pure nothrow @nogc { return ldexp(cast(real) n, exp); }
-
-///
-@nogc @safe pure nothrow unittest
-{
- import std.meta : AliasSeq;
- foreach (T; AliasSeq!(float, double, real))
- {
- T r;
-
- r = ldexp(3.0L, 3);
- assert(r == 24);
-
- r = ldexp(cast(T) 3.0, cast(int) 3);
- assert(r == 24);
-
- T n = 3.0;
- int exp = 3;
- r = ldexp(n, exp);
- assert(r == 24);
- }
-}
-
-@safe pure nothrow @nogc unittest
-{
- static if (floatTraits!(real).realFormat == RealFormat.ieeeExtended ||
- floatTraits!(real).realFormat == RealFormat.ieeeExtended53 ||
- floatTraits!(real).realFormat == RealFormat.ieeeQuadruple)
- {
- assert(ldexp(1.0L, -16384) == 0x1p-16384L);
- assert(ldexp(1.0L, -16382) == 0x1p-16382L);
- int x;
- real n = frexp(0x1p-16384L, x);
- assert(n == 0.5L);
- assert(x==-16383);
- assert(ldexp(n, x)==0x1p-16384L);
- }
- else static if (floatTraits!(real).realFormat == RealFormat.ieeeDouble)
- {
- assert(ldexp(1.0L, -1024) == 0x1p-1024L);
- assert(ldexp(1.0L, -1022) == 0x1p-1022L);
- int x;
- real n = frexp(0x1p-1024L, x);
- assert(n == 0.5L);
- assert(x==-1023);
- assert(ldexp(n, x)==0x1p-1024L);
- }
- else static assert(false, "Floating point type real not supported");
-}
-
-/* workaround Issue 14718, float parsing depends on platform strtold
-@safe pure nothrow @nogc unittest
-{
- assert(ldexp(1.0, -1024) == 0x1p-1024);
- assert(ldexp(1.0, -1022) == 0x1p-1022);
- int x;
- double n = frexp(0x1p-1024, x);
- assert(n == 0.5);
- assert(x==-1023);
- assert(ldexp(n, x)==0x1p-1024);
-}
-
-@safe pure nothrow @nogc unittest
-{
- assert(ldexp(1.0f, -128) == 0x1p-128f);
- assert(ldexp(1.0f, -126) == 0x1p-126f);
- int x;
- float n = frexp(0x1p-128f, x);
- assert(n == 0.5f);
- assert(x==-127);
- assert(ldexp(n, x)==0x1p-128f);
-}
-*/
-
-@system unittest
-{
- static real[3][] vals = // value,exp,ldexp
- [
- [ 0, 0, 0],
- [ 1, 0, 1],
- [ -1, 0, -1],
- [ 1, 1, 2],
- [ 123, 10, 125952],
- [ real.max, int.max, real.infinity],
- [ real.max, -int.max, 0],
- [ real.min_normal, -int.max, 0],
- ];
- int i;
-
- for (i = 0; i < vals.length; i++)
- {
- real x = vals[i][0];
- int exp = cast(int) vals[i][1];
- real z = vals[i][2];
- real l = ldexp(x, exp);
-
- assert(equalsDigit(z, l, 7));
- }
-
- real function(real, int) pldexp = &ldexp;
- assert(pldexp != null);
-}
-
-private
-{
- version (INLINE_YL2X) {} else
- {
- static if (floatTraits!real.realFormat == RealFormat.ieeeQuadruple)
- {
- // Coefficients for log(1 + x) = x - x**2/2 + x**3 P(x)/Q(x)
- static immutable real[13] logCoeffsP = [
- 1.313572404063446165910279910527789794488E4L,
- 7.771154681358524243729929227226708890930E4L,
- 2.014652742082537582487669938141683759923E5L,
- 3.007007295140399532324943111654767187848E5L,
- 2.854829159639697837788887080758954924001E5L,
- 1.797628303815655343403735250238293741397E5L,
- 7.594356839258970405033155585486712125861E4L,
- 2.128857716871515081352991964243375186031E4L,
- 3.824952356185897735160588078446136783779E3L,
- 4.114517881637811823002128927449878962058E2L,
- 2.321125933898420063925789532045674660756E1L,
- 4.998469661968096229986658302195402690910E-1L,
- 1.538612243596254322971797716843006400388E-6L
- ];
- static immutable real[13] logCoeffsQ = [
- 3.940717212190338497730839731583397586124E4L,
- 2.626900195321832660448791748036714883242E5L,
- 7.777690340007566932935753241556479363645E5L,
- 1.347518538384329112529391120390701166528E6L,
- 1.514882452993549494932585972882995548426E6L,
- 1.158019977462989115839826904108208787040E6L,
- 6.132189329546557743179177159925690841200E5L,
- 2.248234257620569139969141618556349415120E5L,
- 5.605842085972455027590989944010492125825E4L,
- 9.147150349299596453976674231612674085381E3L,
- 9.104928120962988414618126155557301584078E2L,
- 4.839208193348159620282142911143429644326E1L,
- 1.0
- ];
-
- // Coefficients for log(x) = z + z^3 P(z^2)/Q(z^2)
- // where z = 2(x-1)/(x+1)
- static immutable real[6] logCoeffsR = [
- -8.828896441624934385266096344596648080902E-1L,
- 8.057002716646055371965756206836056074715E1L,
- -2.024301798136027039250415126250455056397E3L,
- 2.048819892795278657810231591630928516206E4L,
- -8.977257995689735303686582344659576526998E4L,
- 1.418134209872192732479751274970992665513E5L
- ];
- static immutable real[6] logCoeffsS = [
- 1.701761051846631278975701529965589676574E6L
- -1.332535117259762928288745111081235577029E6L,
- 4.001557694070773974936904547424676279307E5L,
- -5.748542087379434595104154610899551484314E4L,
- 3.998526750980007367835804959888064681098E3L,
- -1.186359407982897997337150403816839480438E2L,
- 1.0
- ];
- }
- else
- {
- // Coefficients for log(1 + x) = x - x**2/2 + x**3 P(x)/Q(x)
- static immutable real[7] logCoeffsP = [
- 2.0039553499201281259648E1L,
- 5.7112963590585538103336E1L,
- 6.0949667980987787057556E1L,
- 2.9911919328553073277375E1L,
- 6.5787325942061044846969E0L,
- 4.9854102823193375972212E-1L,
- 4.5270000862445199635215E-5L,
- ];
- static immutable real[7] logCoeffsQ = [
- 6.0118660497603843919306E1L,
- 2.1642788614495947685003E2L,
- 3.0909872225312059774938E2L,
- 2.2176239823732856465394E2L,
- 8.3047565967967209469434E1L,
- 1.5062909083469192043167E1L,
- 1.0000000000000000000000E0L,
- ];
-
- // Coefficients for log(x) = z + z^3 P(z^2)/Q(z^2)
- // where z = 2(x-1)/(x+1)
- static immutable real[4] logCoeffsR = [
- -3.5717684488096787370998E1L,
- 1.0777257190312272158094E1L,
- -7.1990767473014147232598E-1L,
- 1.9757429581415468984296E-3L,
- ];
- static immutable real[4] logCoeffsS = [
- -4.2861221385716144629696E2L,
- 1.9361891836232102174846E2L,
- -2.6201045551331104417768E1L,
- 1.0000000000000000000000E0L,
- ];
- }
- }
-}
-
-/**************************************
- * Calculate the natural logarithm of x.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH log(x)) $(TH divide by 0?) $(TH invalid?))
- * $(TR $(TD $(PLUSMN)0.0) $(TD -$(INFIN)) $(TD yes) $(TD no))
- * $(TR $(TD $(LT)0.0) $(TD $(NAN)) $(TD no) $(TD yes))
- * $(TR $(TD +$(INFIN)) $(TD +$(INFIN)) $(TD no) $(TD no))
- * )
- */
-real log(real x) @safe pure nothrow @nogc
-{
- version (INLINE_YL2X)
- return core.math.yl2x(x, LN2);
- else
- {
- // C1 + C2 = LN2.
- enum real C1 = 6.93145751953125E-1L;
- enum real C2 = 1.428606820309417232121458176568075500134E-6L;
-
- // Special cases.
- if (isNaN(x))
- return x;
- if (isInfinity(x) && !signbit(x))
- return x;
- if (x == 0.0)
- return -real.infinity;
- if (x < 0.0)
- return real.nan;
-
- // Separate mantissa from exponent.
- // Note, frexp is used so that denormal numbers will be handled properly.
- real y, z;
- int exp;
-
- x = frexp(x, exp);
-
- // Logarithm using log(x) = z + z^^3 R(z) / S(z),
- // where z = 2(x - 1)/(x + 1)
- if ((exp > 2) || (exp < -2))
- {
- if (x < SQRT1_2)
- { // 2(2x - 1)/(2x + 1)
- exp -= 1;
- z = x - 0.5;
- y = 0.5 * z + 0.5;
- }
- else
- { // 2(x - 1)/(x + 1)
- z = x - 0.5;
- z -= 0.5;
- y = 0.5 * x + 0.5;
- }
- x = z / y;
- z = x * x;
- z = x * (z * poly(z, logCoeffsR) / poly(z, logCoeffsS));
- z += exp * C2;
- z += x;
- z += exp * C1;
-
- return z;
- }
-
- // Logarithm using log(1 + x) = x - .5x^^2 + x^^3 P(x) / Q(x)
- if (x < SQRT1_2)
- { // 2x - 1
- exp -= 1;
- x = ldexp(x, 1) - 1.0;
- }
- else
- {
- x = x - 1.0;
- }
- z = x * x;
- y = x * (z * poly(x, logCoeffsP) / poly(x, logCoeffsQ));
- y += exp * C2;
- z = y - ldexp(z, -1);
-
- // Note, the sum of above terms does not exceed x/4,
- // so it contributes at most about 1/4 lsb to the error.
- z += x;
- z += exp * C1;
-
- return z;
- }
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert(log(E) == 1);
-}
-
-/**************************************
- * Calculate the base-10 logarithm of x.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH log10(x)) $(TH divide by 0?) $(TH invalid?))
- * $(TR $(TD $(PLUSMN)0.0) $(TD -$(INFIN)) $(TD yes) $(TD no))
- * $(TR $(TD $(LT)0.0) $(TD $(NAN)) $(TD no) $(TD yes))
- * $(TR $(TD +$(INFIN)) $(TD +$(INFIN)) $(TD no) $(TD no))
- * )
- */
-real log10(real x) @safe pure nothrow @nogc
-{
- version (INLINE_YL2X)
- return core.math.yl2x(x, LOG2);
- else
- {
- // log10(2) split into two parts.
- enum real L102A = 0.3125L;
- enum real L102B = -1.14700043360188047862611052755069732318101185E-2L;
-
- // log10(e) split into two parts.
- enum real L10EA = 0.5L;
- enum real L10EB = -6.570551809674817234887108108339491770560299E-2L;
-
- // Special cases are the same as for log.
- if (isNaN(x))
- return x;
- if (isInfinity(x) && !signbit(x))
- return x;
- if (x == 0.0)
- return -real.infinity;
- if (x < 0.0)
- return real.nan;
-
- // Separate mantissa from exponent.
- // Note, frexp is used so that denormal numbers will be handled properly.
- real y, z;
- int exp;
-
- x = frexp(x, exp);
-
- // Logarithm using log(x) = z + z^^3 R(z) / S(z),
- // where z = 2(x - 1)/(x + 1)
- if ((exp > 2) || (exp < -2))
- {
- if (x < SQRT1_2)
- { // 2(2x - 1)/(2x + 1)
- exp -= 1;
- z = x - 0.5;
- y = 0.5 * z + 0.5;
- }
- else
- { // 2(x - 1)/(x + 1)
- z = x - 0.5;
- z -= 0.5;
- y = 0.5 * x + 0.5;
- }
- x = z / y;
- z = x * x;
- y = x * (z * poly(z, logCoeffsR) / poly(z, logCoeffsS));
- goto Ldone;
- }
-
- // Logarithm using log(1 + x) = x - .5x^^2 + x^^3 P(x) / Q(x)
- if (x < SQRT1_2)
- { // 2x - 1
- exp -= 1;
- x = ldexp(x, 1) - 1.0;
- }
- else
- x = x - 1.0;
-
- z = x * x;
- y = x * (z * poly(x, logCoeffsP) / poly(x, logCoeffsQ));
- y = y - ldexp(z, -1);
-
- // Multiply log of fraction by log10(e) and base 2 exponent by log10(2).
- // This sequence of operations is critical and it may be horribly
- // defeated by some compiler optimizers.
- Ldone:
- z = y * L10EB;
- z += x * L10EB;
- z += exp * L102B;
- z += y * L10EA;
- z += x * L10EA;
- z += exp * L102A;
-
- return z;
- }
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert(fabs(log10(1000) - 3) < .000001);
-}
-
-/******************************************
- * Calculates the natural logarithm of 1 + x.
- *
- * For very small x, log1p(x) will be more accurate than
- * log(1 + x).
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH log1p(x)) $(TH divide by 0?) $(TH invalid?))
- * $(TR $(TD $(PLUSMN)0.0) $(TD $(PLUSMN)0.0) $(TD no) $(TD no))
- * $(TR $(TD -1.0) $(TD -$(INFIN)) $(TD yes) $(TD no))
- * $(TR $(TD $(LT)-1.0) $(TD $(NAN)) $(TD no) $(TD yes))
- * $(TR $(TD +$(INFIN)) $(TD -$(INFIN)) $(TD no) $(TD no))
- * )
- */
-real log1p(real x) @safe pure nothrow @nogc
-{
- version (INLINE_YL2X)
- {
- // On x87, yl2xp1 is valid if and only if -0.5 <= lg(x) <= 0.5,
- // ie if -0.29 <= x <= 0.414
- return (fabs(x) <= 0.25) ? core.math.yl2xp1(x, LN2) : core.math.yl2x(x+1, LN2);
- }
- else
- {
- // Special cases.
- if (isNaN(x) || x == 0.0)
- return x;
- if (isInfinity(x) && !signbit(x))
- return x;
- if (x == -1.0)
- return -real.infinity;
- if (x < -1.0)
- return real.nan;
-
- return log(x + 1.0);
- }
-}
-
-/***************************************
- * Calculates the base-2 logarithm of x:
- * $(SUB log, 2)x
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH log2(x)) $(TH divide by 0?) $(TH invalid?))
- * $(TR $(TD $(PLUSMN)0.0) $(TD -$(INFIN)) $(TD yes) $(TD no) )
- * $(TR $(TD $(LT)0.0) $(TD $(NAN)) $(TD no) $(TD yes) )
- * $(TR $(TD +$(INFIN)) $(TD +$(INFIN)) $(TD no) $(TD no) )
- * )
- */
-real log2(real x) @safe pure nothrow @nogc
-{
- version (INLINE_YL2X)
- return core.math.yl2x(x, 1.0L);
- else
- {
- // Special cases are the same as for log.
- if (isNaN(x))
- return x;
- if (isInfinity(x) && !signbit(x))
- return x;
- if (x == 0.0)
- return -real.infinity;
- if (x < 0.0)
- return real.nan;
-
- // Separate mantissa from exponent.
- // Note, frexp is used so that denormal numbers will be handled properly.
- real y, z;
- int exp;
-
- x = frexp(x, exp);
-
- // Logarithm using log(x) = z + z^^3 R(z) / S(z),
- // where z = 2(x - 1)/(x + 1)
- if ((exp > 2) || (exp < -2))
- {
- if (x < SQRT1_2)
- { // 2(2x - 1)/(2x + 1)
- exp -= 1;
- z = x - 0.5;
- y = 0.5 * z + 0.5;
- }
- else
- { // 2(x - 1)/(x + 1)
- z = x - 0.5;
- z -= 0.5;
- y = 0.5 * x + 0.5;
- }
- x = z / y;
- z = x * x;
- y = x * (z * poly(z, logCoeffsR) / poly(z, logCoeffsS));
- goto Ldone;
- }
-
- // Logarithm using log(1 + x) = x - .5x^^2 + x^^3 P(x) / Q(x)
- if (x < SQRT1_2)
- { // 2x - 1
- exp -= 1;
- x = ldexp(x, 1) - 1.0;
- }
- else
- x = x - 1.0;
-
- z = x * x;
- y = x * (z * poly(x, logCoeffsP) / poly(x, logCoeffsQ));
- y = y - ldexp(z, -1);
-
- // Multiply log of fraction by log10(e) and base 2 exponent by log10(2).
- // This sequence of operations is critical and it may be horribly
- // defeated by some compiler optimizers.
- Ldone:
- z = y * (LOG2E - 1.0);
- z += x * (LOG2E - 1.0);
- z += y;
- z += x;
- z += exp;
-
- return z;
- }
-}
-
-///
-@system unittest
-{
- // check if values are equal to 19 decimal digits of precision
- assert(equalsDigit(log2(1024.0L), 10, 19));
-}
-
-/*****************************************
- * Extracts the exponent of x as a signed integral value.
- *
- * If x is subnormal, it is treated as if it were normalized.
- * For a positive, finite x:
- *
- * 1 $(LT)= $(I x) * FLT_RADIX$(SUPERSCRIPT -logb(x)) $(LT) FLT_RADIX
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH logb(x)) $(TH divide by 0?) )
- * $(TR $(TD $(PLUSMN)$(INFIN)) $(TD +$(INFIN)) $(TD no))
- * $(TR $(TD $(PLUSMN)0.0) $(TD -$(INFIN)) $(TD yes) )
- * )
- */
-real logb(real x) @trusted nothrow @nogc
-{
- version (Win64_DMD_InlineAsm)
- {
- asm pure nothrow @nogc
- {
- naked ;
- fld real ptr [RCX] ;
- fxtract ;
- fstp ST(0) ;
- ret ;
- }
- }
- else version (MSVC_InlineAsm)
- {
- asm pure nothrow @nogc
- {
- fld x ;
- fxtract ;
- fstp ST(0) ;
- }
- }
- else
- return core.stdc.math.logbl(x);
-}
-
-/************************************
- * Calculates the remainder from the calculation x/y.
- * Returns:
- * The value of x - i * y, where i is the number of times that y can
- * be completely subtracted from x. The result has the same sign as x.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH y) $(TH fmod(x, y)) $(TH invalid?))
- * $(TR $(TD $(PLUSMN)0.0) $(TD not 0.0) $(TD $(PLUSMN)0.0) $(TD no))
- * $(TR $(TD $(PLUSMNINF)) $(TD anything) $(TD $(NAN)) $(TD yes))
- * $(TR $(TD anything) $(TD $(PLUSMN)0.0) $(TD $(NAN)) $(TD yes))
- * $(TR $(TD !=$(PLUSMNINF)) $(TD $(PLUSMNINF)) $(TD x) $(TD no))
- * )
- */
-real fmod(real x, real y) @trusted nothrow @nogc
-{
- version (CRuntime_Microsoft)
- {
- return x % y;
- }
- else
- return core.stdc.math.fmodl(x, y);
-}
-
-/************************************
- * Breaks x into an integral part and a fractional part, each of which has
- * the same sign as x. The integral part is stored in i.
- * Returns:
- * The fractional part of x.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH i (on input)) $(TH modf(x, i)) $(TH i (on return)))
- * $(TR $(TD $(PLUSMNINF)) $(TD anything) $(TD $(PLUSMN)0.0) $(TD $(PLUSMNINF)))
- * )
- */
-real modf(real x, ref real i) @trusted nothrow @nogc
-{
- version (CRuntime_Microsoft)
- {
- i = trunc(x);
- return copysign(isInfinity(x) ? 0.0 : x - i, x);
- }
- else
- return core.stdc.math.modfl(x,&i);
-}
-
-/*************************************
- * Efficiently calculates x * 2$(SUPERSCRIPT n).
- *
- * scalbn handles underflow and overflow in
- * the same fashion as the basic arithmetic operators.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH scalb(x)))
- * $(TR $(TD $(PLUSMNINF)) $(TD $(PLUSMNINF)) )
- * $(TR $(TD $(PLUSMN)0.0) $(TD $(PLUSMN)0.0) )
- * )
- */
-real scalbn(real x, int n) @trusted nothrow @nogc
-{
- version (InlineAsm_X86_Any)
- {
- // scalbnl is not supported on DMD-Windows, so use asm pure nothrow @nogc.
- version (Win64)
- {
- asm pure nothrow @nogc {
- naked ;
- mov 16[RSP],RCX ;
- fild word ptr 16[RSP] ;
- fld real ptr [RDX] ;
- fscale ;
- fstp ST(1) ;
- ret ;
- }
- }
- else
- {
- asm pure nothrow @nogc {
- fild n;
- fld x;
- fscale;
- fstp ST(1);
- }
- }
- }
- else
- {
- return core.stdc.math.scalbnl(x, n);
- }
-}
-
-///
-@safe nothrow @nogc unittest
-{
- assert(scalbn(-real.infinity, 5) == -real.infinity);
-}
-
-/***************
- * Calculates the cube root of x.
- *
- * $(TABLE_SV
- * $(TR $(TH $(I x)) $(TH cbrt(x)) $(TH invalid?))
- * $(TR $(TD $(PLUSMN)0.0) $(TD $(PLUSMN)0.0) $(TD no) )
- * $(TR $(TD $(NAN)) $(TD $(NAN)) $(TD yes) )
- * $(TR $(TD $(PLUSMN)$(INFIN)) $(TD $(PLUSMN)$(INFIN)) $(TD no) )
- * )
- */
-real cbrt(real x) @trusted nothrow @nogc
-{
- version (CRuntime_Microsoft)
- {
- version (INLINE_YL2X)
- return copysign(exp2(core.math.yl2x(fabs(x), 1.0L/3.0L)), x);
- else
- return core.stdc.math.cbrtl(x);
- }
- else
- return core.stdc.math.cbrtl(x);
-}
-
-
-/*******************************
- * Returns |x|
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH fabs(x)))
- * $(TR $(TD $(PLUSMN)0.0) $(TD +0.0) )
- * $(TR $(TD $(PLUSMN)$(INFIN)) $(TD +$(INFIN)) )
- * )
- */
-real fabs(real x) @safe pure nothrow @nogc { pragma(inline, true); return core.math.fabs(x); }
-//FIXME
-///ditto
-double fabs(double x) @safe pure nothrow @nogc { return fabs(cast(real) x); }
-//FIXME
-///ditto
-float fabs(float x) @safe pure nothrow @nogc { return fabs(cast(real) x); }
-
-@safe unittest
-{
- real function(real) pfabs = &fabs;
- assert(pfabs != null);
-}
-
-/***********************************************************************
- * Calculates the length of the
- * hypotenuse of a right-angled triangle with sides of length x and y.
- * The hypotenuse is the value of the square root of
- * the sums of the squares of x and y:
- *
- * sqrt($(POWER x, 2) + $(POWER y, 2))
- *
- * Note that hypot(x, y), hypot(y, x) and
- * hypot(x, -y) are equivalent.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH y) $(TH hypot(x, y)) $(TH invalid?))
- * $(TR $(TD x) $(TD $(PLUSMN)0.0) $(TD |x|) $(TD no))
- * $(TR $(TD $(PLUSMNINF)) $(TD y) $(TD +$(INFIN)) $(TD no))
- * $(TR $(TD $(PLUSMNINF)) $(TD $(NAN)) $(TD +$(INFIN)) $(TD no))
- * )
- */
-
-real hypot(real x, real y) @safe pure nothrow @nogc
-{
- // Scale x and y to avoid underflow and overflow.
- // If one is huge and the other tiny, return the larger.
- // If both are huge, avoid overflow by scaling by 1/sqrt(real.max/2).
- // If both are tiny, avoid underflow by scaling by sqrt(real.min_normal*real.epsilon).
-
- enum real SQRTMIN = 0.5 * sqrt(real.min_normal); // This is a power of 2.
- enum real SQRTMAX = 1.0L / SQRTMIN; // 2^^((max_exp)/2) = nextUp(sqrt(real.max))
-
- static assert(2*(SQRTMAX/2)*(SQRTMAX/2) <= real.max);
-
- // Proves that sqrt(real.max) ~~ 0.5/sqrt(real.min_normal)
- static assert(real.min_normal*real.max > 2 && real.min_normal*real.max <= 4);
-
- real u = fabs(x);
- real v = fabs(y);
- if (!(u >= v)) // check for NaN as well.
- {
- v = u;
- u = fabs(y);
- if (u == real.infinity) return u; // hypot(inf, nan) == inf
- if (v == real.infinity) return v; // hypot(nan, inf) == inf
- }
-
- // Now u >= v, or else one is NaN.
- if (v >= SQRTMAX*0.5)
- {
- // hypot(huge, huge) -- avoid overflow
- u *= SQRTMIN*0.5;
- v *= SQRTMIN*0.5;
- return sqrt(u*u + v*v) * SQRTMAX * 2.0;
- }
-
- if (u <= SQRTMIN)
- {
- // hypot (tiny, tiny) -- avoid underflow
- // This is only necessary to avoid setting the underflow
- // flag.
- u *= SQRTMAX / real.epsilon;
- v *= SQRTMAX / real.epsilon;
- return sqrt(u*u + v*v) * SQRTMIN * real.epsilon;
- }
-
- if (u * real.epsilon > v)
- {
- // hypot (huge, tiny) = huge
- return u;
- }
-
- // both are in the normal range
- return sqrt(u*u + v*v);
-}
-
-@safe unittest
-{
- static real[3][] vals = // x,y,hypot
- [
- [ 0.0, 0.0, 0.0],
- [ 0.0, -0.0, 0.0],
- [ -0.0, -0.0, 0.0],
- [ 3.0, 4.0, 5.0],
- [ -300, -400, 500],
- [0.0, 7.0, 7.0],
- [9.0, 9*real.epsilon, 9.0],
- [88/(64*sqrt(real.min_normal)), 105/(64*sqrt(real.min_normal)), 137/(64*sqrt(real.min_normal))],
- [88/(128*sqrt(real.min_normal)), 105/(128*sqrt(real.min_normal)), 137/(128*sqrt(real.min_normal))],
- [3*real.min_normal*real.epsilon, 4*real.min_normal*real.epsilon, 5*real.min_normal*real.epsilon],
- [ real.min_normal, real.min_normal, sqrt(2.0L)*real.min_normal],
- [ real.max/sqrt(2.0L), real.max/sqrt(2.0L), real.max],
- [ real.infinity, real.nan, real.infinity],
- [ real.nan, real.infinity, real.infinity],
- [ real.nan, real.nan, real.nan],
- [ real.nan, real.max, real.nan],
- [ real.max, real.nan, real.nan],
- ];
- for (int i = 0; i < vals.length; i++)
- {
- real x = vals[i][0];
- real y = vals[i][1];
- real z = vals[i][2];
- real h = hypot(x, y);
- assert(isIdentical(z,h) || feqrel(z, h) >= real.mant_dig - 1);
- }
-}
-
-/**************************************
- * Returns the value of x rounded upward to the next integer
- * (toward positive infinity).
- */
-real ceil(real x) @trusted pure nothrow @nogc
-{
- version (Win64_DMD_InlineAsm)
- {
- asm pure nothrow @nogc
- {
- naked ;
- fld real ptr [RCX] ;
- fstcw 8[RSP] ;
- mov AL,9[RSP] ;
- mov DL,AL ;
- and AL,0xC3 ;
- or AL,0x08 ; // round to +infinity
- mov 9[RSP],AL ;
- fldcw 8[RSP] ;
- frndint ;
- mov 9[RSP],DL ;
- fldcw 8[RSP] ;
- ret ;
- }
- }
- else version (MSVC_InlineAsm)
- {
- short cw;
- asm pure nothrow @nogc
- {
- fld x ;
- fstcw cw ;
- mov AL,byte ptr cw+1 ;
- mov DL,AL ;
- and AL,0xC3 ;
- or AL,0x08 ; // round to +infinity
- mov byte ptr cw+1,AL ;
- fldcw cw ;
- frndint ;
- mov byte ptr cw+1,DL ;
- fldcw cw ;
- }
- }
- else
- {
- // Special cases.
- if (isNaN(x) || isInfinity(x))
- return x;
-
- real y = floorImpl(x);
- if (y < x)
- y += 1.0;
-
- return y;
- }
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert(ceil(+123.456L) == +124);
- assert(ceil(-123.456L) == -123);
- assert(ceil(-1.234L) == -1);
- assert(ceil(-0.123L) == 0);
- assert(ceil(0.0L) == 0);
- assert(ceil(+0.123L) == 1);
- assert(ceil(+1.234L) == 2);
- assert(ceil(real.infinity) == real.infinity);
- assert(isNaN(ceil(real.nan)));
- assert(isNaN(ceil(real.init)));
-}
-
-// ditto
-double ceil(double x) @trusted pure nothrow @nogc
-{
- // Special cases.
- if (isNaN(x) || isInfinity(x))
- return x;
-
- double y = floorImpl(x);
- if (y < x)
- y += 1.0;
-
- return y;
-}
-
-@safe pure nothrow @nogc unittest
-{
- assert(ceil(+123.456) == +124);
- assert(ceil(-123.456) == -123);
- assert(ceil(-1.234) == -1);
- assert(ceil(-0.123) == 0);
- assert(ceil(0.0) == 0);
- assert(ceil(+0.123) == 1);
- assert(ceil(+1.234) == 2);
- assert(ceil(double.infinity) == double.infinity);
- assert(isNaN(ceil(double.nan)));
- assert(isNaN(ceil(double.init)));
-}
-
-// ditto
-float ceil(float x) @trusted pure nothrow @nogc
-{
- // Special cases.
- if (isNaN(x) || isInfinity(x))
- return x;
-
- float y = floorImpl(x);
- if (y < x)
- y += 1.0;
-
- return y;
-}
-
-@safe pure nothrow @nogc unittest
-{
- assert(ceil(+123.456f) == +124);
- assert(ceil(-123.456f) == -123);
- assert(ceil(-1.234f) == -1);
- assert(ceil(-0.123f) == 0);
- assert(ceil(0.0f) == 0);
- assert(ceil(+0.123f) == 1);
- assert(ceil(+1.234f) == 2);
- assert(ceil(float.infinity) == float.infinity);
- assert(isNaN(ceil(float.nan)));
- assert(isNaN(ceil(float.init)));
-}
-
-/**************************************
- * Returns the value of x rounded downward to the next integer
- * (toward negative infinity).
- */
-real floor(real x) @trusted pure nothrow @nogc
-{
- version (Win64_DMD_InlineAsm)
- {
- asm pure nothrow @nogc
- {
- naked ;
- fld real ptr [RCX] ;
- fstcw 8[RSP] ;
- mov AL,9[RSP] ;
- mov DL,AL ;
- and AL,0xC3 ;
- or AL,0x04 ; // round to -infinity
- mov 9[RSP],AL ;
- fldcw 8[RSP] ;
- frndint ;
- mov 9[RSP],DL ;
- fldcw 8[RSP] ;
- ret ;
- }
- }
- else version (MSVC_InlineAsm)
- {
- short cw;
- asm pure nothrow @nogc
- {
- fld x ;
- fstcw cw ;
- mov AL,byte ptr cw+1 ;
- mov DL,AL ;
- and AL,0xC3 ;
- or AL,0x04 ; // round to -infinity
- mov byte ptr cw+1,AL ;
- fldcw cw ;
- frndint ;
- mov byte ptr cw+1,DL ;
- fldcw cw ;
- }
- }
- else
- {
- // Special cases.
- if (isNaN(x) || isInfinity(x) || x == 0.0)
- return x;
-
- return floorImpl(x);
- }
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert(floor(+123.456L) == +123);
- assert(floor(-123.456L) == -124);
- assert(floor(-1.234L) == -2);
- assert(floor(-0.123L) == -1);
- assert(floor(0.0L) == 0);
- assert(floor(+0.123L) == 0);
- assert(floor(+1.234L) == 1);
- assert(floor(real.infinity) == real.infinity);
- assert(isNaN(floor(real.nan)));
- assert(isNaN(floor(real.init)));
-}
-
-// ditto
-double floor(double x) @trusted pure nothrow @nogc
-{
- // Special cases.
- if (isNaN(x) || isInfinity(x) || x == 0.0)
- return x;
-
- return floorImpl(x);
-}
-
-@safe pure nothrow @nogc unittest
-{
- assert(floor(+123.456) == +123);
- assert(floor(-123.456) == -124);
- assert(floor(-1.234) == -2);
- assert(floor(-0.123) == -1);
- assert(floor(0.0) == 0);
- assert(floor(+0.123) == 0);
- assert(floor(+1.234) == 1);
- assert(floor(double.infinity) == double.infinity);
- assert(isNaN(floor(double.nan)));
- assert(isNaN(floor(double.init)));
-}
-
-// ditto
-float floor(float x) @trusted pure nothrow @nogc
-{
- // Special cases.
- if (isNaN(x) || isInfinity(x) || x == 0.0)
- return x;
-
- return floorImpl(x);
-}
-
-@safe pure nothrow @nogc unittest
-{
- assert(floor(+123.456f) == +123);
- assert(floor(-123.456f) == -124);
- assert(floor(-1.234f) == -2);
- assert(floor(-0.123f) == -1);
- assert(floor(0.0f) == 0);
- assert(floor(+0.123f) == 0);
- assert(floor(+1.234f) == 1);
- assert(floor(float.infinity) == float.infinity);
- assert(isNaN(floor(float.nan)));
- assert(isNaN(floor(float.init)));
-}
-
-/**
- * Round `val` to a multiple of `unit`. `rfunc` specifies the rounding
- * function to use; by default this is `rint`, which uses the current
- * rounding mode.
- */
-Unqual!F quantize(alias rfunc = rint, F)(const F val, const F unit)
-if (is(typeof(rfunc(F.init)) : F) && isFloatingPoint!F)
-{
- typeof(return) ret = val;
- if (unit != 0)
- {
- const scaled = val / unit;
- if (!scaled.isInfinity)
- ret = rfunc(scaled) * unit;
- }
- return ret;
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert(12345.6789L.quantize(0.01L) == 12345.68L);
- assert(12345.6789L.quantize!floor(0.01L) == 12345.67L);
- assert(12345.6789L.quantize(22.0L) == 12342.0L);
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert(12345.6789L.quantize(0) == 12345.6789L);
- assert(12345.6789L.quantize(real.infinity).isNaN);
- assert(12345.6789L.quantize(real.nan).isNaN);
- assert(real.infinity.quantize(0.01L) == real.infinity);
- assert(real.infinity.quantize(real.nan).isNaN);
- assert(real.nan.quantize(0.01L).isNaN);
- assert(real.nan.quantize(real.infinity).isNaN);
- assert(real.nan.quantize(real.nan).isNaN);
-}
-
-/**
- * Round `val` to a multiple of `pow(base, exp)`. `rfunc` specifies the
- * rounding function to use; by default this is `rint`, which uses the
- * current rounding mode.
- */
-Unqual!F quantize(real base, alias rfunc = rint, F, E)(const F val, const E exp)
-if (is(typeof(rfunc(F.init)) : F) && isFloatingPoint!F && isIntegral!E)
-{
- // TODO: Compile-time optimization for power-of-two bases?
- return quantize!rfunc(val, pow(cast(F) base, exp));
-}
-
-/// ditto
-Unqual!F quantize(real base, long exp = 1, alias rfunc = rint, F)(const F val)
-if (is(typeof(rfunc(F.init)) : F) && isFloatingPoint!F)
-{
- enum unit = cast(F) pow(base, exp);
- return quantize!rfunc(val, unit);
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert(12345.6789L.quantize!10(-2) == 12345.68L);
- assert(12345.6789L.quantize!(10, -2) == 12345.68L);
- assert(12345.6789L.quantize!(10, floor)(-2) == 12345.67L);
- assert(12345.6789L.quantize!(10, -2, floor) == 12345.67L);
-
- assert(12345.6789L.quantize!22(1) == 12342.0L);
- assert(12345.6789L.quantize!22 == 12342.0L);
-}
-
-@safe pure nothrow @nogc unittest
-{
- import std.meta : AliasSeq;
-
- foreach (F; AliasSeq!(real, double, float))
- {
- const maxL10 = cast(int) F.max.log10.floor;
- const maxR10 = pow(cast(F) 10, maxL10);
- assert((cast(F) 0.9L * maxR10).quantize!10(maxL10) == maxR10);
- assert((cast(F)-0.9L * maxR10).quantize!10(maxL10) == -maxR10);
-
- assert(F.max.quantize(F.min_normal) == F.max);
- assert((-F.max).quantize(F.min_normal) == -F.max);
- assert(F.min_normal.quantize(F.max) == 0);
- assert((-F.min_normal).quantize(F.max) == 0);
- assert(F.min_normal.quantize(F.min_normal) == F.min_normal);
- assert((-F.min_normal).quantize(F.min_normal) == -F.min_normal);
- }
-}
-
-/******************************************
- * Rounds x to the nearest integer value, using the current rounding
- * mode.
- *
- * Unlike the rint functions, nearbyint does not raise the
- * FE_INEXACT exception.
- */
-real nearbyint(real x) @trusted nothrow @nogc
-{
- version (CRuntime_Microsoft)
- {
- assert(0); // not implemented in C library
- }
- else
- return core.stdc.math.nearbyintl(x);
-}
-
-/**********************************
- * Rounds x to the nearest integer value, using the current rounding
- * mode.
- * If the return value is not equal to x, the FE_INEXACT
- * exception is raised.
- * $(B nearbyint) performs
- * the same operation, but does not set the FE_INEXACT exception.
- */
-real rint(real x) @safe pure nothrow @nogc { pragma(inline, true); return core.math.rint(x); }
-//FIXME
-///ditto
-double rint(double x) @safe pure nothrow @nogc { return rint(cast(real) x); }
-//FIXME
-///ditto
-float rint(float x) @safe pure nothrow @nogc { return rint(cast(real) x); }
-
-@safe unittest
-{
- real function(real) print = &rint;
- assert(print != null);
-}
-
-/***************************************
- * Rounds x to the nearest integer value, using the current rounding
- * mode.
- *
- * This is generally the fastest method to convert a floating-point number
- * to an integer. Note that the results from this function
- * depend on the rounding mode, if the fractional part of x is exactly 0.5.
- * If using the default rounding mode (ties round to even integers)
- * lrint(4.5) == 4, lrint(5.5)==6.
- */
-long lrint(real x) @trusted pure nothrow @nogc
-{
- version (InlineAsm_X86_Any)
- {
- version (Win64)
- {
- asm pure nothrow @nogc
- {
- naked;
- fld real ptr [RCX];
- fistp qword ptr 8[RSP];
- mov RAX,8[RSP];
- ret;
- }
- }
- else
- {
- long n;
- asm pure nothrow @nogc
- {
- fld x;
- fistp n;
- }
- return n;
- }
- }
- else
- {
- alias F = floatTraits!(real);
- static if (F.realFormat == RealFormat.ieeeDouble)
- {
- long result;
-
- // Rounding limit when casting from real(double) to ulong.
- enum real OF = 4.50359962737049600000E15L;
-
- uint* vi = cast(uint*)(&x);
-
- // Find the exponent and sign
- uint msb = vi[MANTISSA_MSB];
- uint lsb = vi[MANTISSA_LSB];
- int exp = ((msb >> 20) & 0x7ff) - 0x3ff;
- const int sign = msb >> 31;
- msb &= 0xfffff;
- msb |= 0x100000;
-
- if (exp < 63)
- {
- if (exp >= 52)
- result = (cast(long) msb << (exp - 20)) | (lsb << (exp - 52));
- else
- {
- // Adjust x and check result.
- const real j = sign ? -OF : OF;
- x = (j + x) - j;
- msb = vi[MANTISSA_MSB];
- lsb = vi[MANTISSA_LSB];
- exp = ((msb >> 20) & 0x7ff) - 0x3ff;
- msb &= 0xfffff;
- msb |= 0x100000;
-
- if (exp < 0)
- result = 0;
- else if (exp < 20)
- result = cast(long) msb >> (20 - exp);
- else if (exp == 20)
- result = cast(long) msb;
- else
- result = (cast(long) msb << (exp - 20)) | (lsb >> (52 - exp));
- }
- }
- else
- {
- // It is left implementation defined when the number is too large.
- return cast(long) x;
- }
-
- return sign ? -result : result;
- }
- else static if (F.realFormat == RealFormat.ieeeExtended ||
- F.realFormat == RealFormat.ieeeExtended53)
- {
- long result;
-
- // Rounding limit when casting from real(80-bit) to ulong.
- static if (F.realFormat == RealFormat.ieeeExtended)
- enum real OF = 9.22337203685477580800E18L;
- else
- enum real OF = 4.50359962737049600000E15L;
-
- ushort* vu = cast(ushort*)(&x);
- uint* vi = cast(uint*)(&x);
-
- // Find the exponent and sign
- int exp = (vu[F.EXPPOS_SHORT] & 0x7fff) - 0x3fff;
- const int sign = (vu[F.EXPPOS_SHORT] >> 15) & 1;
-
- if (exp < 63)
- {
- // Adjust x and check result.
- const real j = sign ? -OF : OF;
- x = (j + x) - j;
- exp = (vu[F.EXPPOS_SHORT] & 0x7fff) - 0x3fff;
-
- version (LittleEndian)
- {
- if (exp < 0)
- result = 0;
- else if (exp <= 31)
- result = vi[1] >> (31 - exp);
- else
- result = (cast(long) vi[1] << (exp - 31)) | (vi[0] >> (63 - exp));
- }
- else
- {
- if (exp < 0)
- result = 0;
- else if (exp <= 31)
- result = vi[1] >> (31 - exp);
- else
- result = (cast(long) vi[1] << (exp - 31)) | (vi[2] >> (63 - exp));
- }
- }
- else
- {
- // It is left implementation defined when the number is too large
- // to fit in a 64bit long.
- return cast(long) x;
- }
-
- return sign ? -result : result;
- }
- else static if (F.realFormat == RealFormat.ieeeQuadruple)
- {
- const vu = cast(ushort*)(&x);
-
- // Find the exponent and sign
- const sign = (vu[F.EXPPOS_SHORT] >> 15) & 1;
- if ((vu[F.EXPPOS_SHORT] & F.EXPMASK) - (F.EXPBIAS + 1) > 63)
- {
- // The result is left implementation defined when the number is
- // too large to fit in a 64 bit long.
- return cast(long) x;
- }
-
- // Force rounding of lower bits according to current rounding
- // mode by adding ±2^-112 and subtracting it again.
- enum OF = 5.19229685853482762853049632922009600E33L;
- const j = sign ? -OF : OF;
- x = (j + x) - j;
-
- const exp = (vu[F.EXPPOS_SHORT] & F.EXPMASK) - (F.EXPBIAS + 1);
- const implicitOne = 1UL << 48;
- auto vl = cast(ulong*)(&x);
- vl[MANTISSA_MSB] &= implicitOne - 1;
- vl[MANTISSA_MSB] |= implicitOne;
-
- long result;
-
- if (exp < 0)
- result = 0;
- else if (exp <= 48)
- result = vl[MANTISSA_MSB] >> (48 - exp);
- else
- result = (vl[MANTISSA_MSB] << (exp - 48)) | (vl[MANTISSA_LSB] >> (112 - exp));
-
- return sign ? -result : result;
- }
- else
- {
- static assert(false, "real type not supported by lrint()");
- }
- }
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert(lrint(4.5) == 4);
- assert(lrint(5.5) == 6);
- assert(lrint(-4.5) == -4);
- assert(lrint(-5.5) == -6);
-
- assert(lrint(int.max - 0.5) == 2147483646L);
- assert(lrint(int.max + 0.5) == 2147483648L);
- assert(lrint(int.min - 0.5) == -2147483648L);
- assert(lrint(int.min + 0.5) == -2147483648L);
-}
-
-static if (real.mant_dig >= long.sizeof * 8)
-{
- @safe pure nothrow @nogc unittest
- {
- assert(lrint(long.max - 1.5L) == long.max - 1);
- assert(lrint(long.max - 0.5L) == long.max - 1);
- assert(lrint(long.min + 0.5L) == long.min);
- assert(lrint(long.min + 1.5L) == long.min + 2);
- }
-}
-
-/*******************************************
- * Return the value of x rounded to the nearest integer.
- * If the fractional part of x is exactly 0.5, the return value is
- * rounded away from zero.
- */
-real round(real x) @trusted nothrow @nogc
-{
- version (CRuntime_Microsoft)
- {
- auto old = FloatingPointControl.getControlState();
- FloatingPointControl.setControlState(
- (old & ~FloatingPointControl.roundingMask) | FloatingPointControl.roundToZero
- );
- x = rint((x >= 0) ? x + 0.5 : x - 0.5);
- FloatingPointControl.setControlState(old);
- return x;
- }
- else
- return core.stdc.math.roundl(x);
-}
-
-/**********************************************
- * Return the value of x rounded to the nearest integer.
- *
- * If the fractional part of x is exactly 0.5, the return value is rounded
- * away from zero.
- *
- * $(BLUE This function is not implemented for Digital Mars C runtime.)
- */
-long lround(real x) @trusted nothrow @nogc
-{
- version (CRuntime_DigitalMars)
- assert(0, "lround not implemented");
- else
- return core.stdc.math.llroundl(x);
-}
-
-///
-@safe nothrow @nogc unittest
-{
- version (CRuntime_DigitalMars) {}
- else
- {
- assert(lround(0.49) == 0);
- assert(lround(0.5) == 1);
- assert(lround(1.5) == 2);
- }
-}
-
-/****************************************************
- * Returns the integer portion of x, dropping the fractional portion.
- *
- * This is also known as "chop" rounding.
- */
-real trunc(real x) @trusted nothrow @nogc
-{
- version (Win64_DMD_InlineAsm)
- {
- asm pure nothrow @nogc
- {
- naked ;
- fld real ptr [RCX] ;
- fstcw 8[RSP] ;
- mov AL,9[RSP] ;
- mov DL,AL ;
- and AL,0xC3 ;
- or AL,0x0C ; // round to 0
- mov 9[RSP],AL ;
- fldcw 8[RSP] ;
- frndint ;
- mov 9[RSP],DL ;
- fldcw 8[RSP] ;
- ret ;
- }
- }
- else version (MSVC_InlineAsm)
- {
- short cw;
- asm pure nothrow @nogc
- {
- fld x ;
- fstcw cw ;
- mov AL,byte ptr cw+1 ;
- mov DL,AL ;
- and AL,0xC3 ;
- or AL,0x0C ; // round to 0
- mov byte ptr cw+1,AL ;
- fldcw cw ;
- frndint ;
- mov byte ptr cw+1,DL ;
- fldcw cw ;
- }
- }
- else
- return core.stdc.math.truncl(x);
-}
-
-/****************************************************
- * Calculate the remainder x REM y, following IEC 60559.
- *
- * REM is the value of x - y * n, where n is the integer nearest the exact
- * value of x / y.
- * If |n - x / y| == 0.5, n is even.
- * If the result is zero, it has the same sign as x.
- * Otherwise, the sign of the result is the sign of x / y.
- * Precision mode has no effect on the remainder functions.
- *
- * remquo returns n in the parameter n.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH y) $(TH remainder(x, y)) $(TH n) $(TH invalid?))
- * $(TR $(TD $(PLUSMN)0.0) $(TD not 0.0) $(TD $(PLUSMN)0.0) $(TD 0.0) $(TD no))
- * $(TR $(TD $(PLUSMNINF)) $(TD anything) $(TD $(NAN)) $(TD ?) $(TD yes))
- * $(TR $(TD anything) $(TD $(PLUSMN)0.0) $(TD $(NAN)) $(TD ?) $(TD yes))
- * $(TR $(TD != $(PLUSMNINF)) $(TD $(PLUSMNINF)) $(TD x) $(TD ?) $(TD no))
- * )
- *
- * $(BLUE `remquo` and `remainder` not supported on Windows.)
- */
-real remainder(real x, real y) @trusted nothrow @nogc
-{
- version (CRuntime_Microsoft)
- {
- int n;
- return remquo(x, y, n);
- }
- else
- return core.stdc.math.remainderl(x, y);
-}
-
-real remquo(real x, real y, out int n) @trusted nothrow @nogc /// ditto
-{
- version (Posix)
- return core.stdc.math.remquol(x, y, &n);
- else
- assert(0, "remquo not implemented");
-}
-
-
-version (IeeeFlagsSupport)
-{
-
-/** IEEE exception status flags ('sticky bits')
-
- These flags indicate that an exceptional floating-point condition has occurred.
- They indicate that a NaN or an infinity has been generated, that a result
- is inexact, or that a signalling NaN has been encountered. If floating-point
- exceptions are enabled (unmasked), a hardware exception will be generated
- instead of setting these flags.
- */
-struct IeeeFlags
-{
-private:
- // The x87 FPU status register is 16 bits.
- // The Pentium SSE2 status register is 32 bits.
- // The ARM and PowerPC FPSCR is a 32-bit register.
- // The SPARC FSR is a 32bit register (64 bits for SPARC 7 & 8, but high bits are uninteresting).
- // The RISC-V (32 & 64 bit) fcsr is 32-bit register.
- uint flags;
-
- version (CRuntime_Microsoft)
- {
- // Microsoft uses hardware-incompatible custom constants in fenv.h (core.stdc.fenv).
- // Applies to both x87 status word (16 bits) and SSE2 status word(32 bits).
- enum : int
- {
- INEXACT_MASK = 0x20,
- UNDERFLOW_MASK = 0x10,
- OVERFLOW_MASK = 0x08,
- DIVBYZERO_MASK = 0x04,
- INVALID_MASK = 0x01,
-
- EXCEPTIONS_MASK = 0b11_1111
- }
- // Don't bother about subnormals, they are not supported on most CPUs.
- // SUBNORMAL_MASK = 0x02;
- }
- else
- {
- enum : int
- {
- INEXACT_MASK = core.stdc.fenv.FE_INEXACT,
- UNDERFLOW_MASK = core.stdc.fenv.FE_UNDERFLOW,
- OVERFLOW_MASK = core.stdc.fenv.FE_OVERFLOW,
- DIVBYZERO_MASK = core.stdc.fenv.FE_DIVBYZERO,
- INVALID_MASK = core.stdc.fenv.FE_INVALID,
- EXCEPTIONS_MASK = core.stdc.fenv.FE_ALL_EXCEPT,
- }
- }
-
-private:
- static uint getIeeeFlags()
- {
- version (GNU)
- {
- version (X86_Any)
- {
- ushort sw;
- asm pure nothrow @nogc
- {
- "fstsw %0" : "=a" (sw);
- }
- // OR the result with the SSE2 status register (MXCSR).
- if (haveSSE)
- {
- uint mxcsr;
- asm pure nothrow @nogc
- {
- "stmxcsr %0" : "=m" (mxcsr);
- }
- return (sw | mxcsr) & EXCEPTIONS_MASK;
- }
- else
- return sw & EXCEPTIONS_MASK;
- }
- else version (ARM)
- {
- version (ARM_SoftFloat)
- return 0;
- else
- {
- uint result = void;
- asm pure nothrow @nogc
- {
- "vmrs %0, FPSCR; and %0, %0, #0x1F;" : "=r" (result);
- }
- return result;
- }
- }
- else version (RISCV_Any)
- {
- version (D_SoftFloat)
- return 0;
- else
- {
- uint result = void;
- asm pure nothrow @nogc
- {
- "frflags %0" : "=r" (result);
- }
- return result;
- }
- }
- else
- assert(0, "Not yet supported");
- }
- else
- version (InlineAsm_X86_Any)
- {
- ushort sw;
- asm pure nothrow @nogc { fstsw sw; }
-
- // OR the result with the SSE2 status register (MXCSR).
- if (haveSSE)
- {
- uint mxcsr;
- asm pure nothrow @nogc { stmxcsr mxcsr; }
- return (sw | mxcsr) & EXCEPTIONS_MASK;
- }
- else return sw & EXCEPTIONS_MASK;
- }
- else version (SPARC)
- {
- /*
- int retval;
- asm pure nothrow @nogc { st %fsr, retval; }
- return retval;
- */
- assert(0, "Not yet supported");
- }
- else version (ARM)
- {
- assert(false, "Not yet supported.");
- }
- else
- assert(0, "Not yet supported");
- }
-
- static void resetIeeeFlags() @nogc
- {
- version (GNU)
- {
- version (X86_Any)
- {
- asm nothrow @nogc
- {
- "fnclex";
- }
-
- // Also clear exception flags in MXCSR, SSE's control register.
- if (haveSSE)
- {
- uint mxcsr;
- asm nothrow @nogc
- {
- "stmxcsr %0" : "=m" (mxcsr);
- }
- mxcsr &= ~EXCEPTIONS_MASK;
- asm nothrow @nogc
- {
- "ldmxcsr %0" : : "m" (mxcsr);
- }
- }
- }
- else version (ARM)
- {
- version (ARM_SoftFloat)
- return;
- else
- {
- uint old = FloatingPointControl.getControlState();
- old &= ~0b11111; // http://infocenter.arm.com/help/topic/com.arm.doc.ddi0408i/Chdfifdc.html
- asm nothrow @nogc
- {
- "vmsr FPSCR, %0" : : "r" (old);
- }
- }
- }
- else version (RISCV_Any)
- {
- version (D_SoftFloat)
- return;
- else
- {
- uint newValues = 0x0;
- asm nothrow @nogc
- {
- "fsflags %0" : : "r" (newValues);
- }
- }
- }
- else
- assert(0, "Not yet supported");
- }
- else
- version (InlineAsm_X86_Any)
- {
- asm nothrow @nogc
- {
- fnclex;
- }
-
- // Also clear exception flags in MXCSR, SSE's control register.
- if (haveSSE)
- {
- uint mxcsr;
- asm nothrow @nogc { stmxcsr mxcsr; }
- mxcsr &= ~EXCEPTIONS_MASK;
- asm nothrow @nogc { ldmxcsr mxcsr; }
- }
- }
- else
- {
- /* SPARC:
- int tmpval;
- asm pure nothrow @nogc { st %fsr, tmpval; }
- tmpval &=0xFFFF_FC00;
- asm pure nothrow @nogc { ld tmpval, %fsr; }
- */
- assert(0, "Not yet supported");
- }
- }
-public:
- version (IeeeFlagsSupport)
- {
-
- /**
- * The result cannot be represented exactly, so rounding occurred.
- * Example: `x = sin(0.1);`
- */
- @property bool inexact() const { return (flags & INEXACT_MASK) != 0; }
-
- /**
- * A zero was generated by underflow
- * Example: `x = real.min*real.epsilon/2;`
- */
- @property bool underflow() const { return (flags & UNDERFLOW_MASK) != 0; }
-
- /**
- * An infinity was generated by overflow
- * Example: `x = real.max*2;`
- */
- @property bool overflow() const { return (flags & OVERFLOW_MASK) != 0; }
-
- /**
- * An infinity was generated by division by zero
- * Example: `x = 3/0.0;`
- */
- @property bool divByZero() const { return (flags & DIVBYZERO_MASK) != 0; }
-
- /**
- * A machine NaN was generated.
- * Example: `x = real.infinity * 0.0;`
- */
- @property bool invalid() const { return (flags & INVALID_MASK) != 0; }
-
- }
-}
-
-///
-version (IeeeFlagsUnittest)
-@system unittest
-{
- static void func() {
- int a = 10 * 10;
- }
- pragma(inline, false) static void blockopt(ref real x) {}
- real a = 3.5;
- // Set all the flags to zero
- resetIeeeFlags();
- assert(!ieeeFlags.divByZero);
- blockopt(a); // avoid constant propagation by the optimizer
- // Perform a division by zero.
- a /= 0.0L;
- assert(a == real.infinity);
- assert(ieeeFlags.divByZero);
- blockopt(a); // avoid constant propagation by the optimizer
- // Create a NaN
- a *= 0.0L;
- assert(ieeeFlags.invalid);
- assert(isNaN(a));
-
- // Check that calling func() has no effect on the
- // status flags.
- IeeeFlags f = ieeeFlags;
- func();
- assert(ieeeFlags == f);
-}
-
-version (IeeeFlagsUnittest)
-@system unittest
-{
- import std.meta : AliasSeq;
-
- static struct Test
- {
- void delegate() action;
- bool function() ieeeCheck;
- }
-
- foreach (T; AliasSeq!(float, double, real))
- {
- T x; /* Needs to be here to trick -O. It would optimize away the
- calculations if x were local to the function literals. */
- auto tests = [
- Test(
- () { x = 1; x += 0.1; },
- () => ieeeFlags.inexact
- ),
- Test(
- () { x = T.min_normal; x /= T.max; },
- () => ieeeFlags.underflow
- ),
- Test(
- () { x = T.max; x += T.max; },
- () => ieeeFlags.overflow
- ),
- Test(
- () { x = 1; x /= 0; },
- () => ieeeFlags.divByZero
- ),
- Test(
- () { x = 0; x /= 0; },
- () => ieeeFlags.invalid
- )
- ];
- foreach (test; tests)
- {
- resetIeeeFlags();
- assert(!test.ieeeCheck());
- test.action();
- assert(test.ieeeCheck());
- }
- }
-}
-
-/// Set all of the floating-point status flags to false.
-void resetIeeeFlags() @nogc { IeeeFlags.resetIeeeFlags(); }
-
-/// Returns: snapshot of the current state of the floating-point status flags
-@property IeeeFlags ieeeFlags()
-{
- return IeeeFlags(IeeeFlags.getIeeeFlags());
-}
-
-} // IeeeFlagsSupport
-
-
-version (FloatingPointControlSupport)
-{
-
-/** Control the Floating point hardware
-
- Change the IEEE754 floating-point rounding mode and the floating-point
- hardware exceptions.
-
- By default, the rounding mode is roundToNearest and all hardware exceptions
- are disabled. For most applications, debugging is easier if the $(I division
- by zero), $(I overflow), and $(I invalid operation) exceptions are enabled.
- These three are combined into a $(I severeExceptions) value for convenience.
- Note in particular that if $(I invalidException) is enabled, a hardware trap
- will be generated whenever an uninitialized floating-point variable is used.
-
- All changes are temporary. The previous state is restored at the
- end of the scope.
-
-
-Example:
-----
-{
- FloatingPointControl fpctrl;
-
- // Enable hardware exceptions for division by zero, overflow to infinity,
- // invalid operations, and uninitialized floating-point variables.
- fpctrl.enableExceptions(FloatingPointControl.severeExceptions);
-
- // This will generate a hardware exception, if x is a
- // default-initialized floating point variable:
- real x; // Add `= 0` or even `= real.nan` to not throw the exception.
- real y = x * 3.0;
-
- // The exception is only thrown for default-uninitialized NaN-s.
- // NaN-s with other payload are valid:
- real z = y * real.nan; // ok
-
- // Changing the rounding mode:
- fpctrl.rounding = FloatingPointControl.roundUp;
- assert(rint(1.1) == 2);
-
- // The set hardware exceptions will be disabled when leaving this scope.
- // The original rounding mode will also be restored.
-}
-
-// Ensure previous values are returned:
-assert(!FloatingPointControl.enabledExceptions);
-assert(FloatingPointControl.rounding == FloatingPointControl.roundToNearest);
-assert(rint(1.1) == 1);
-----
-
- */
-struct FloatingPointControl
-{
- alias RoundingMode = uint; ///
-
- version (StdDdoc)
- {
- enum : RoundingMode
- {
- /** IEEE rounding modes.
- * The default mode is roundToNearest.
- *
- * roundingMask = A mask of all rounding modes.
- */
- roundToNearest,
- roundDown, /// ditto
- roundUp, /// ditto
- roundToZero, /// ditto
- roundingMask, /// ditto
- }
- }
- else version (CRuntime_Microsoft)
- {
- // Microsoft uses hardware-incompatible custom constants in fenv.h (core.stdc.fenv).
- enum : RoundingMode
- {
- roundToNearest = 0x0000,
- roundDown = 0x0400,
- roundUp = 0x0800,
- roundToZero = 0x0C00,
- roundingMask = roundToNearest | roundDown
- | roundUp | roundToZero,
- }
- }
- else
- {
- enum : RoundingMode
- {
- roundToNearest = core.stdc.fenv.FE_TONEAREST,
- roundDown = core.stdc.fenv.FE_DOWNWARD,
- roundUp = core.stdc.fenv.FE_UPWARD,
- roundToZero = core.stdc.fenv.FE_TOWARDZERO,
- roundingMask = roundToNearest | roundDown
- | roundUp | roundToZero,
- }
- }
-
- //// Change the floating-point hardware rounding mode
- @property void rounding(RoundingMode newMode) @nogc
- {
- initialize();
- setControlState(cast(ushort)((getControlState() & (-1 - roundingMask)) | (newMode & roundingMask)));
- }
-
- /// Returns: the currently active rounding mode
- @property static RoundingMode rounding() @nogc
- {
- return cast(RoundingMode)(getControlState() & roundingMask);
- }
-
- alias ExceptionMask = uint; ///
-
- version (StdDdoc)
- {
- enum : ExceptionMask
- {
- /** IEEE hardware exceptions.
- * By default, all exceptions are masked (disabled).
- *
- * severeExceptions = The overflow, division by zero, and invalid
- * exceptions.
- */
- subnormalException,
- inexactException, /// ditto
- underflowException, /// ditto
- overflowException, /// ditto
- divByZeroException, /// ditto
- invalidException, /// ditto
- severeExceptions, /// ditto
- allExceptions, /// ditto
- }
- }
- else version (ARM_Any)
- {
- enum : ExceptionMask
- {
- subnormalException = 0x8000,
- inexactException = 0x1000,
- underflowException = 0x0800,
- overflowException = 0x0400,
- divByZeroException = 0x0200,
- invalidException = 0x0100,
- severeExceptions = overflowException | divByZeroException
- | invalidException,
- allExceptions = severeExceptions | underflowException
- | inexactException | subnormalException,
- }
- }
- else version (PPC_Any)
- {
- enum : ExceptionMask
- {
- inexactException = 0x0008,
- divByZeroException = 0x0010,
- underflowException = 0x0020,
- overflowException = 0x0040,
- invalidException = 0x0080,
- severeExceptions = overflowException | divByZeroException
- | invalidException,
- allExceptions = severeExceptions | underflowException
- | inexactException,
- }
- }
- else version (HPPA)
- {
- enum : ExceptionMask
- {
- inexactException = 0x01,
- underflowException = 0x02,
- overflowException = 0x04,
- divByZeroException = 0x08,
- invalidException = 0x10,
- severeExceptions = overflowException | divByZeroException
- | invalidException,
- allExceptions = severeExceptions | underflowException
- | inexactException,
- }
- }
- else version (MIPS_Any)
- {
- enum : ExceptionMask
- {
- inexactException = 0x0080,
- divByZeroException = 0x0400,
- overflowException = 0x0200,
- underflowException = 0x0100,
- invalidException = 0x0800,
- severeExceptions = overflowException | divByZeroException
- | invalidException,
- allExceptions = severeExceptions | underflowException
- | inexactException,
- }
- }
- else version (SPARC_Any)
- {
- enum : ExceptionMask
- {
- inexactException = 0x0800000,
- divByZeroException = 0x1000000,
- overflowException = 0x4000000,
- underflowException = 0x2000000,
- invalidException = 0x8000000,
- severeExceptions = overflowException | divByZeroException
- | invalidException,
- allExceptions = severeExceptions | underflowException
- | inexactException,
- }
- }
- else version (IBMZ_Any)
- {
- enum : ExceptionMask
- {
- inexactException = 0x08000000,
- divByZeroException = 0x40000000,
- overflowException = 0x20000000,
- underflowException = 0x10000000,
- invalidException = 0x80000000,
- severeExceptions = overflowException | divByZeroException
- | invalidException,
- allExceptions = severeExceptions | underflowException
- | inexactException,
- }
- }
- else version (RISCV_Any)
- {
- enum : ExceptionMask
- {
- inexactException = 0x01,
- divByZeroException = 0x02,
- underflowException = 0x04,
- overflowException = 0x08,
- invalidException = 0x10,
- severeExceptions = overflowException | divByZeroException
- | invalidException,
- allExceptions = severeExceptions | underflowException
- | inexactException,
- }
- }
- else version (X86_Any)
- {
- enum : ExceptionMask
- {
- inexactException = 0x20,
- underflowException = 0x10,
- overflowException = 0x08,
- divByZeroException = 0x04,
- subnormalException = 0x02,
- invalidException = 0x01,
- severeExceptions = overflowException | divByZeroException
- | invalidException,
- allExceptions = severeExceptions | underflowException
- | inexactException | subnormalException,
- }
- }
- else
- static assert(false, "Not implemented for this architecture");
-
-public:
- /// Returns: true if the current FPU supports exception trapping
- @property static bool hasExceptionTraps() @safe nothrow @nogc
- {
- version (X86_Any)
- return true;
- else version (PPC_Any)
- return true;
- else version (MIPS_Any)
- return true;
- else version (ARM_Any)
- {
- auto oldState = getControlState();
- // If exceptions are not supported, we set the bit but read it back as zero
- // https://sourceware.org/ml/libc-ports/2012-06/msg00091.html
- setControlState(oldState | divByZeroException);
- immutable result = (getControlState() & allExceptions) != 0;
- setControlState(oldState);
- return result;
- }
- else
- assert(0, "Not yet supported");
- }
-
- /// Enable (unmask) specific hardware exceptions. Multiple exceptions may be ORed together.
- void enableExceptions(ExceptionMask exceptions) @nogc
- {
- assert(hasExceptionTraps);
- initialize();
- version (X86_Any)
- setControlState(getControlState() & ~(exceptions & allExceptions));
- else
- setControlState(getControlState() | (exceptions & allExceptions));
- }
-
- /// Disable (mask) specific hardware exceptions. Multiple exceptions may be ORed together.
- void disableExceptions(ExceptionMask exceptions) @nogc
- {
- assert(hasExceptionTraps);
- initialize();
- version (X86_Any)
- setControlState(getControlState() | (exceptions & allExceptions));
- else
- setControlState(getControlState() & ~(exceptions & allExceptions));
- }
-
- /// Returns: the exceptions which are currently enabled (unmasked)
- @property static ExceptionMask enabledExceptions() @nogc
- {
- assert(hasExceptionTraps);
- version (X86_Any)
- return (getControlState() & allExceptions) ^ allExceptions;
- else
- return (getControlState() & allExceptions);
- }
-
- /// Clear all pending exceptions, then restore the original exception state and rounding mode.
- ~this() @nogc
- {
- clearExceptions();
- if (initialized)
- setControlState(savedState);
- }
-
-private:
- ControlState savedState;
-
- bool initialized = false;
-
- version (ARM_Any)
- {
- alias ControlState = uint;
- }
- else version (HPPA)
- {
- alias ControlState = uint;
- }
- else version (PPC_Any)
- {
- alias ControlState = uint;
- }
- else version (MIPS_Any)
- {
- alias ControlState = uint;
- }
- else version (SPARC_Any)
- {
- alias ControlState = ulong;
- }
- else version (IBMZ_Any)
- {
- alias ControlState = uint;
- }
- else version (RISCV_Any)
- {
- alias ControlState = uint;
- }
- else version (X86_Any)
- {
- alias ControlState = ushort;
- }
- else
- static assert(false, "Not implemented for this architecture");
-
- void initialize() @nogc
- {
- // BUG: This works around the absence of this() constructors.
- if (initialized) return;
- clearExceptions();
- savedState = getControlState();
- initialized = true;
- }
-
- // Clear all pending exceptions
- static void clearExceptions() @nogc
- {
- version (IeeeFlagsSupport)
- resetIeeeFlags();
- else
- static assert(false, "Not implemented for this architecture");
- }
-
- // Read from the control register
- static ControlState getControlState() @trusted nothrow @nogc
- {
- version (GNU)
- {
- version (X86_Any)
- {
- ControlState cont;
- asm pure nothrow @nogc
- {
- "fstcw %0" : "=m" (cont);
- }
- return cont;
- }
- else version (AArch64)
- {
- ControlState cont;
- asm pure nothrow @nogc
- {
- "mrs %0, FPCR;" : "=r" (cont);
- }
- return cont;
- }
- else version (ARM)
- {
- ControlState cont;
- version (ARM_SoftFloat)
- cont = 0;
- else
- {
- asm pure nothrow @nogc
- {
- "vmrs %0, FPSCR" : "=r" (cont);
- }
- }
- return cont;
- }
- else version (RISCV_Any)
- {
- version (D_SoftFloat)
- return 0;
- else
- {
- ControlState cont;
- asm pure nothrow @nogc
- {
- "frcsr %0" : "=r" (cont);
- }
- return cont;
- }
- }
- else
- assert(0, "Not yet supported");
- }
- else
- version (D_InlineAsm_X86)
- {
- short cont;
- asm pure nothrow @nogc
- {
- xor EAX, EAX;
- fstcw cont;
- }
- return cont;
- }
- else
- version (D_InlineAsm_X86_64)
- {
- short cont;
- asm pure nothrow @nogc
- {
- xor RAX, RAX;
- fstcw cont;
- }
- return cont;
- }
- else
- assert(0, "Not yet supported");
- }
-
- // Set the control register
- static void setControlState(ControlState newState) @trusted nothrow @nogc
- {
- version (GNU)
- {
- version (X86_Any)
- {
- asm nothrow @nogc
- {
- "fclex; fldcw %0" : : "m" (newState);
- }
-
- // Also update MXCSR, SSE's control register.
- if (haveSSE)
- {
- uint mxcsr;
- asm nothrow @nogc
- {
- "stmxcsr %0" : "=m" (mxcsr);
- }
-
- /* In the FPU control register, rounding mode is in bits 10 and
- 11. In MXCSR it's in bits 13 and 14. */
- mxcsr &= ~(roundingMask << 3); // delete old rounding mode
- mxcsr |= (newState & roundingMask) << 3; // write new rounding mode
-
- /* In the FPU control register, masks are bits 0 through 5.
- In MXCSR they're 7 through 12. */
- mxcsr &= ~(allExceptions << 7); // delete old masks
- mxcsr |= (newState & allExceptions) << 7; // write new exception masks
-
- asm nothrow @nogc
- {
- "ldmxcsr %0" : : "m" (mxcsr);
- }
- }
- }
- else version (AArch64)
- {
- asm nothrow @nogc
- {
- "msr FPCR, %0;" : : "r" (newState);
- }
- }
- else version (ARM)
- {
- version (ARM_SoftFloat)
- return;
- else
- {
- asm nothrow @nogc
- {
- "vmsr FPSCR, %0" : : "r" (newState);
- }
- }
- }
- else version (RISCV_Any)
- {
- version (D_SoftFloat)
- return;
- else
- {
- asm nothrow @nogc
- {
- "fscsr %0" : : "r" (newState);
- }
- }
- }
- else
- assert(0, "Not yet supported");
- }
- else
- version (InlineAsm_X86_Any)
- {
- asm nothrow @nogc
- {
- fclex;
- fldcw newState;
- }
-
- // Also update MXCSR, SSE's control register.
- if (haveSSE)
- {
- uint mxcsr;
- asm nothrow @nogc { stmxcsr mxcsr; }
-
- /* In the FPU control register, rounding mode is in bits 10 and
- 11. In MXCSR it's in bits 13 and 14. */
- mxcsr &= ~(roundingMask << 3); // delete old rounding mode
- mxcsr |= (newState & roundingMask) << 3; // write new rounding mode
-
- /* In the FPU control register, masks are bits 0 through 5.
- In MXCSR they're 7 through 12. */
- mxcsr &= ~(allExceptions << 7); // delete old masks
- mxcsr |= (newState & allExceptions) << 7; // write new exception masks
-
- asm nothrow @nogc { ldmxcsr mxcsr; }
- }
- }
- else
- assert(0, "Not yet supported");
- }
-}
-
-@system unittest
-{
- void ensureDefaults()
- {
- assert(FloatingPointControl.rounding
- == FloatingPointControl.roundToNearest);
- if (FloatingPointControl.hasExceptionTraps)
- assert(FloatingPointControl.enabledExceptions == 0);
- }
-
- {
- FloatingPointControl ctrl;
- }
- ensureDefaults();
-
- {
- FloatingPointControl ctrl;
- ctrl.rounding = FloatingPointControl.roundDown;
- assert(FloatingPointControl.rounding == FloatingPointControl.roundDown);
- }
- ensureDefaults();
-
- if (FloatingPointControl.hasExceptionTraps)
- {
- FloatingPointControl ctrl;
- ctrl.enableExceptions(FloatingPointControl.divByZeroException
- | FloatingPointControl.overflowException);
- assert(ctrl.enabledExceptions ==
- (FloatingPointControl.divByZeroException
- | FloatingPointControl.overflowException));
-
- ctrl.rounding = FloatingPointControl.roundUp;
- assert(FloatingPointControl.rounding == FloatingPointControl.roundUp);
- }
- ensureDefaults();
-}
-
-version (FloatingPointControlUnittest)
-@system unittest // rounding
-{
- import std.meta : AliasSeq;
-
- foreach (T; AliasSeq!(float, double, real))
- {
- /* Be careful with changing the rounding mode, it interferes
- * with common subexpressions. Changing rounding modes should
- * be done with separate functions that are not inlined.
- */
-
- {
- static T addRound(T)(uint rm)
- {
- pragma(inline, false) static void blockopt(ref T x) {}
- pragma(inline, false);
- FloatingPointControl fpctrl;
- fpctrl.rounding = rm;
- T x = 1;
- blockopt(x); // avoid constant propagation by the optimizer
- x += 0.1;
- return x;
- }
-
- T u = addRound!(T)(FloatingPointControl.roundUp);
- T d = addRound!(T)(FloatingPointControl.roundDown);
- T z = addRound!(T)(FloatingPointControl.roundToZero);
-
- assert(u > d);
- assert(z == d);
- }
-
- {
- static T subRound(T)(uint rm)
- {
- pragma(inline, false) static void blockopt(ref T x) {}
- pragma(inline, false);
- FloatingPointControl fpctrl;
- fpctrl.rounding = rm;
- T x = -1;
- blockopt(x); // avoid constant propagation by the optimizer
- x -= 0.1;
- return x;
- }
-
- T u = subRound!(T)(FloatingPointControl.roundUp);
- T d = subRound!(T)(FloatingPointControl.roundDown);
- T z = subRound!(T)(FloatingPointControl.roundToZero);
-
- assert(u > d);
- assert(z == u);
- }
- }
-}
-
-} // FloatingPointControlSupport
-
-
-/*********************************
- * Determines if $(D_PARAM x) is NaN.
- * Params:
- * x = a floating point number.
- * Returns:
- * $(D true) if $(D_PARAM x) is Nan.
- */
-bool isNaN(X)(X x) @nogc @trusted pure nothrow
-if (isFloatingPoint!(X))
-{
- alias F = floatTraits!(X);
- static if (F.realFormat == RealFormat.ieeeSingle)
- {
- const uint p = *cast(uint *)&x;
- return ((p & 0x7F80_0000) == 0x7F80_0000)
- && p & 0x007F_FFFF; // not infinity
- }
- else static if (F.realFormat == RealFormat.ieeeDouble)
- {
- const ulong p = *cast(ulong *)&x;
- return ((p & 0x7FF0_0000_0000_0000) == 0x7FF0_0000_0000_0000)
- && p & 0x000F_FFFF_FFFF_FFFF; // not infinity
- }
- else static if (F.realFormat == RealFormat.ieeeExtended)
- {
- const ushort e = F.EXPMASK & (cast(ushort *)&x)[F.EXPPOS_SHORT];
- const ulong ps = *cast(ulong *)&x;
- return e == F.EXPMASK &&
- ps & 0x7FFF_FFFF_FFFF_FFFF; // not infinity
- }
- else static if (F.realFormat == RealFormat.ieeeQuadruple)
- {
- const ushort e = F.EXPMASK & (cast(ushort *)&x)[F.EXPPOS_SHORT];
- const ulong psLsb = (cast(ulong *)&x)[MANTISSA_LSB];
- const ulong psMsb = (cast(ulong *)&x)[MANTISSA_MSB];
- return e == F.EXPMASK &&
- (psLsb | (psMsb& 0x0000_FFFF_FFFF_FFFF)) != 0;
- }
- else
- {
- return x != x;
- }
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert( isNaN(float.init));
- assert( isNaN(-double.init));
- assert( isNaN(real.nan));
- assert( isNaN(-real.nan));
- assert(!isNaN(cast(float) 53.6));
- assert(!isNaN(cast(real)-53.6));
-}
-
-@safe pure nothrow @nogc unittest
-{
- import std.meta : AliasSeq;
-
- foreach (T; AliasSeq!(float, double, real))
- {
- // CTFE-able tests
- assert(isNaN(T.init));
- assert(isNaN(-T.init));
- assert(isNaN(T.nan));
- assert(isNaN(-T.nan));
- assert(!isNaN(T.infinity));
- assert(!isNaN(-T.infinity));
- assert(!isNaN(cast(T) 53.6));
- assert(!isNaN(cast(T)-53.6));
-
- // Runtime tests
- shared T f;
- f = T.init;
- assert(isNaN(f));
- assert(isNaN(-f));
- f = T.nan;
- assert(isNaN(f));
- assert(isNaN(-f));
- f = T.infinity;
- assert(!isNaN(f));
- assert(!isNaN(-f));
- f = cast(T) 53.6;
- assert(!isNaN(f));
- assert(!isNaN(-f));
- }
-}
-
-/*********************************
- * Determines if $(D_PARAM x) is finite.
- * Params:
- * x = a floating point number.
- * Returns:
- * $(D true) if $(D_PARAM x) is finite.
- */
-bool isFinite(X)(X x) @trusted pure nothrow @nogc
-{
- alias F = floatTraits!(X);
- ushort* pe = cast(ushort *)&x;
- return (pe[F.EXPPOS_SHORT] & F.EXPMASK) != F.EXPMASK;
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert( isFinite(1.23f));
- assert( isFinite(float.max));
- assert( isFinite(float.min_normal));
- assert(!isFinite(float.nan));
- assert(!isFinite(float.infinity));
-}
-
-@safe pure nothrow @nogc unittest
-{
- assert(isFinite(1.23));
- assert(isFinite(double.max));
- assert(isFinite(double.min_normal));
- assert(!isFinite(double.nan));
- assert(!isFinite(double.infinity));
-
- assert(isFinite(1.23L));
- assert(isFinite(real.max));
- assert(isFinite(real.min_normal));
- assert(!isFinite(real.nan));
- assert(!isFinite(real.infinity));
-}
-
-
-/*********************************
- * Determines if $(D_PARAM x) is normalized.
- *
- * A normalized number must not be zero, subnormal, infinite nor $(NAN).
- *
- * Params:
- * x = a floating point number.
- * Returns:
- * $(D true) if $(D_PARAM x) is normalized.
- */
-
-/* Need one for each format because subnormal floats might
- * be converted to normal reals.
- */
-bool isNormal(X)(X x) @trusted pure nothrow @nogc
-{
- alias F = floatTraits!(X);
- static if (F.realFormat == RealFormat.ibmExtended)
- {
- // doubledouble is normal if the least significant part is normal.
- return isNormal((cast(double*)&x)[MANTISSA_LSB]);
- }
- else
- {
- ushort e = F.EXPMASK & (cast(ushort *)&x)[F.EXPPOS_SHORT];
- return (e != F.EXPMASK && e != 0);
- }
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- float f = 3;
- double d = 500;
- real e = 10e+48;
-
- assert(isNormal(f));
- assert(isNormal(d));
- assert(isNormal(e));
- f = d = e = 0;
- assert(!isNormal(f));
- assert(!isNormal(d));
- assert(!isNormal(e));
- assert(!isNormal(real.infinity));
- assert(isNormal(-real.max));
- assert(!isNormal(real.min_normal/4));
-
-}
-
-/*********************************
- * Determines if $(D_PARAM x) is subnormal.
- *
- * Subnormals (also known as "denormal number"), have a 0 exponent
- * and a 0 most significant mantissa bit.
- *
- * Params:
- * x = a floating point number.
- * Returns:
- * $(D true) if $(D_PARAM x) is a denormal number.
- */
-bool isSubnormal(X)(X x) @trusted pure nothrow @nogc
-{
- /*
- Need one for each format because subnormal floats might
- be converted to normal reals.
- */
- alias F = floatTraits!(X);
- static if (F.realFormat == RealFormat.ieeeSingle)
- {
- uint *p = cast(uint *)&x;
- return (*p & F.EXPMASK_INT) == 0 && *p & F.MANTISSAMASK_INT;
- }
- else static if (F.realFormat == RealFormat.ieeeDouble)
- {
- uint *p = cast(uint *)&x;
- return (p[MANTISSA_MSB] & F.EXPMASK_INT) == 0
- && (p[MANTISSA_LSB] || p[MANTISSA_MSB] & F.MANTISSAMASK_INT);
- }
- else static if (F.realFormat == RealFormat.ieeeQuadruple)
- {
- ushort e = F.EXPMASK & (cast(ushort *)&x)[F.EXPPOS_SHORT];
- long* ps = cast(long *)&x;
- return (e == 0 &&
- ((ps[MANTISSA_LSB]|(ps[MANTISSA_MSB]& 0x0000_FFFF_FFFF_FFFF)) != 0));
- }
- else static if (F.realFormat == RealFormat.ieeeExtended ||
- F.realFormat == RealFormat.ieeeExtended53)
- {
- ushort* pe = cast(ushort *)&x;
- long* ps = cast(long *)&x;
-
- return (pe[F.EXPPOS_SHORT] & F.EXPMASK) == 0 && *ps > 0;
- }
- else static if (F.realFormat == RealFormat.ibmExtended)
- {
- return isSubnormal((cast(double*)&x)[MANTISSA_MSB]);
- }
- else
- {
- static assert(false, "Not implemented for this architecture");
- }
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- import std.meta : AliasSeq;
-
- foreach (T; AliasSeq!(float, double, real))
- {
- T f;
- for (f = 1.0; !isSubnormal(f); f /= 2)
- assert(f != 0);
- }
-}
-
-/*********************************
- * Determines if $(D_PARAM x) is $(PLUSMN)$(INFIN).
- * Params:
- * x = a floating point number.
- * Returns:
- * $(D true) if $(D_PARAM x) is $(PLUSMN)$(INFIN).
- */
-bool isInfinity(X)(X x) @nogc @trusted pure nothrow
-if (isFloatingPoint!(X))
-{
- alias F = floatTraits!(X);
- static if (F.realFormat == RealFormat.ieeeSingle)
- {
- return ((*cast(uint *)&x) & 0x7FFF_FFFF) == 0x7F80_0000;
- }
- else static if (F.realFormat == RealFormat.ieeeDouble)
- {
- return ((*cast(ulong *)&x) & 0x7FFF_FFFF_FFFF_FFFF)
- == 0x7FF0_0000_0000_0000;
- }
- else static if (F.realFormat == RealFormat.ieeeExtended ||
- F.realFormat == RealFormat.ieeeExtended53)
- {
- const ushort e = cast(ushort)(F.EXPMASK & (cast(ushort *)&x)[F.EXPPOS_SHORT]);
- const ulong ps = *cast(ulong *)&x;
-
- // On Motorola 68K, infinity can have hidden bit = 1 or 0. On x86, it is always 1.
- return e == F.EXPMASK && (ps & 0x7FFF_FFFF_FFFF_FFFF) == 0;
- }
- else static if (F.realFormat == RealFormat.ibmExtended)
- {
- return (((cast(ulong *)&x)[MANTISSA_MSB]) & 0x7FFF_FFFF_FFFF_FFFF)
- == 0x7FF8_0000_0000_0000;
- }
- else static if (F.realFormat == RealFormat.ieeeQuadruple)
- {
- const long psLsb = (cast(long *)&x)[MANTISSA_LSB];
- const long psMsb = (cast(long *)&x)[MANTISSA_MSB];
- return (psLsb == 0)
- && (psMsb & 0x7FFF_FFFF_FFFF_FFFF) == 0x7FFF_0000_0000_0000;
- }
- else
- {
- return (x < -X.max) || (X.max < x);
- }
-}
-
-///
-@nogc @safe pure nothrow unittest
-{
- assert(!isInfinity(float.init));
- assert(!isInfinity(-float.init));
- assert(!isInfinity(float.nan));
- assert(!isInfinity(-float.nan));
- assert(isInfinity(float.infinity));
- assert(isInfinity(-float.infinity));
- assert(isInfinity(-1.0f / 0.0f));
-}
-
-@safe pure nothrow @nogc unittest
-{
- // CTFE-able tests
- assert(!isInfinity(double.init));
- assert(!isInfinity(-double.init));
- assert(!isInfinity(double.nan));
- assert(!isInfinity(-double.nan));
- assert(isInfinity(double.infinity));
- assert(isInfinity(-double.infinity));
- assert(isInfinity(-1.0 / 0.0));
-
- assert(!isInfinity(real.init));
- assert(!isInfinity(-real.init));
- assert(!isInfinity(real.nan));
- assert(!isInfinity(-real.nan));
- assert(isInfinity(real.infinity));
- assert(isInfinity(-real.infinity));
- assert(isInfinity(-1.0L / 0.0L));
-
- // Runtime tests
- shared float f;
- f = float.init;
- assert(!isInfinity(f));
- assert(!isInfinity(-f));
- f = float.nan;
- assert(!isInfinity(f));
- assert(!isInfinity(-f));
- f = float.infinity;
- assert(isInfinity(f));
- assert(isInfinity(-f));
- f = (-1.0f / 0.0f);
- assert(isInfinity(f));
-
- shared double d;
- d = double.init;
- assert(!isInfinity(d));
- assert(!isInfinity(-d));
- d = double.nan;
- assert(!isInfinity(d));
- assert(!isInfinity(-d));
- d = double.infinity;
- assert(isInfinity(d));
- assert(isInfinity(-d));
- d = (-1.0 / 0.0);
- assert(isInfinity(d));
-
- shared real e;
- e = real.init;
- assert(!isInfinity(e));
- assert(!isInfinity(-e));
- e = real.nan;
- assert(!isInfinity(e));
- assert(!isInfinity(-e));
- e = real.infinity;
- assert(isInfinity(e));
- assert(isInfinity(-e));
- e = (-1.0L / 0.0L);
- assert(isInfinity(e));
-}
-
-/*********************************
- * Is the binary representation of x identical to y?
- *
- * Same as ==, except that positive and negative zero are not identical,
- * and two $(NAN)s are identical if they have the same 'payload'.
- */
-bool isIdentical(real x, real y) @trusted pure nothrow @nogc
-{
- // We're doing a bitwise comparison so the endianness is irrelevant.
- long* pxs = cast(long *)&x;
- long* pys = cast(long *)&y;
- alias F = floatTraits!(real);
- static if (F.realFormat == RealFormat.ieeeDouble)
- {
- return pxs[0] == pys[0];
- }
- else static if (F.realFormat == RealFormat.ieeeQuadruple
- || F.realFormat == RealFormat.ibmExtended)
- {
- return pxs[0] == pys[0] && pxs[1] == pys[1];
- }
- else
- {
- ushort* pxe = cast(ushort *)&x;
- ushort* pye = cast(ushort *)&y;
- return pxe[4] == pye[4] && pxs[0] == pys[0];
- }
-}
-
-/*********************************
- * Return 1 if sign bit of e is set, 0 if not.
- */
-int signbit(X)(X x) @nogc @trusted pure nothrow
-{
- alias F = floatTraits!(X);
- return ((cast(ubyte *)&x)[F.SIGNPOS_BYTE] & 0x80) != 0;
-}
-
-///
-@nogc @safe pure nothrow unittest
-{
- assert(!signbit(float.nan));
- assert(signbit(-float.nan));
- assert(!signbit(168.1234f));
- assert(signbit(-168.1234f));
- assert(!signbit(0.0f));
- assert(signbit(-0.0f));
- assert(signbit(-float.max));
- assert(!signbit(float.max));
-
- assert(!signbit(double.nan));
- assert(signbit(-double.nan));
- assert(!signbit(168.1234));
- assert(signbit(-168.1234));
- assert(!signbit(0.0));
- assert(signbit(-0.0));
- assert(signbit(-double.max));
- assert(!signbit(double.max));
-
- assert(!signbit(real.nan));
- assert(signbit(-real.nan));
- assert(!signbit(168.1234L));
- assert(signbit(-168.1234L));
- assert(!signbit(0.0L));
- assert(signbit(-0.0L));
- assert(signbit(-real.max));
- assert(!signbit(real.max));
-}
-
-
-/*********************************
- * Return a value composed of to with from's sign bit.
- */
-R copysign(R, X)(R to, X from) @trusted pure nothrow @nogc
-if (isFloatingPoint!(R) && isFloatingPoint!(X))
-{
- ubyte* pto = cast(ubyte *)&to;
- const ubyte* pfrom = cast(ubyte *)&from;
-
- alias T = floatTraits!(R);
- alias F = floatTraits!(X);
- pto[T.SIGNPOS_BYTE] &= 0x7F;
- pto[T.SIGNPOS_BYTE] |= pfrom[F.SIGNPOS_BYTE] & 0x80;
- return to;
-}
-
-// ditto
-R copysign(R, X)(X to, R from) @trusted pure nothrow @nogc
-if (isIntegral!(X) && isFloatingPoint!(R))
-{
- return copysign(cast(R) to, from);
-}
-
-@safe pure nothrow @nogc unittest
-{
- import std.meta : AliasSeq;
-
- foreach (X; AliasSeq!(float, double, real, int, long))
- {
- foreach (Y; AliasSeq!(float, double, real))
- (){ // avoid slow optimizations for large functions @@@BUG@@@ 2396
- X x = 21;
- Y y = 23.8;
- Y e = void;
-
- e = copysign(x, y);
- assert(e == 21.0);
-
- e = copysign(-x, y);
- assert(e == 21.0);
-
- e = copysign(x, -y);
- assert(e == -21.0);
-
- e = copysign(-x, -y);
- assert(e == -21.0);
-
- static if (isFloatingPoint!X)
- {
- e = copysign(X.nan, y);
- assert(isNaN(e) && !signbit(e));
-
- e = copysign(X.nan, -y);
- assert(isNaN(e) && signbit(e));
- }
- }();
- }
-}
-
-/*********************************
-Returns $(D -1) if $(D x < 0), $(D x) if $(D x == 0), $(D 1) if
-$(D x > 0), and $(NAN) if x==$(NAN).
- */
-F sgn(F)(F x) @safe pure nothrow @nogc
-{
- // @@@TODO@@@: make this faster
- return x > 0 ? 1 : x < 0 ? -1 : x;
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert(sgn(168.1234) == 1);
- assert(sgn(-168.1234) == -1);
- assert(sgn(0.0) == 0);
- assert(sgn(-0.0) == 0);
-}
-
-// Functions for NaN payloads
-/*
- * A 'payload' can be stored in the significand of a $(NAN). One bit is required
- * to distinguish between a quiet and a signalling $(NAN). This leaves 22 bits
- * of payload for a float; 51 bits for a double; 62 bits for an 80-bit real;
- * and 111 bits for a 128-bit quad.
-*/
-/**
- * Create a quiet $(NAN), storing an integer inside the payload.
- *
- * For floats, the largest possible payload is 0x3F_FFFF.
- * For doubles, it is 0x3_FFFF_FFFF_FFFF.
- * For 80-bit or 128-bit reals, it is 0x3FFF_FFFF_FFFF_FFFF.
- */
-real NaN(ulong payload) @trusted pure nothrow @nogc
-{
- alias F = floatTraits!(real);
- static if (F.realFormat == RealFormat.ieeeExtended ||
- F.realFormat == RealFormat.ieeeExtended53)
- {
- // real80 (in x86 real format, the implied bit is actually
- // not implied but a real bit which is stored in the real)
- ulong v = 3; // implied bit = 1, quiet bit = 1
- }
- else
- {
- ulong v = 1; // no implied bit. quiet bit = 1
- }
-
- ulong a = payload;
-
- // 22 Float bits
- ulong w = a & 0x3F_FFFF;
- a -= w;
-
- v <<=22;
- v |= w;
- a >>=22;
-
- // 29 Double bits
- v <<=29;
- w = a & 0xFFF_FFFF;
- v |= w;
- a -= w;
- a >>=29;
-
- static if (F.realFormat == RealFormat.ieeeDouble)
- {
- v |= 0x7FF0_0000_0000_0000;
- real x;
- * cast(ulong *)(&x) = v;
- return x;
- }
- else
- {
- v <<=11;
- a &= 0x7FF;
- v |= a;
- real x = real.nan;
-
- // Extended real bits
- static if (F.realFormat == RealFormat.ieeeQuadruple)
- {
- v <<= 1; // there's no implicit bit
-
- version (LittleEndian)
- {
- *cast(ulong*)(6+cast(ubyte*)(&x)) = v;
- }
- else
- {
- *cast(ulong*)(2+cast(ubyte*)(&x)) = v;
- }
- }
- else
- {
- *cast(ulong *)(&x) = v;
- }
- return x;
- }
-}
-
-@system pure nothrow @nogc unittest // not @safe because taking address of local.
-{
- static if (floatTraits!(real).realFormat == RealFormat.ieeeDouble)
- {
- auto x = NaN(1);
- auto xl = *cast(ulong*)&x;
- assert(xl & 0x8_0000_0000_0000UL); //non-signaling bit, bit 52
- assert((xl & 0x7FF0_0000_0000_0000UL) == 0x7FF0_0000_0000_0000UL); //all exp bits set
- }
-}
-
-/**
- * Extract an integral payload from a $(NAN).
- *
- * Returns:
- * the integer payload as a ulong.
- *
- * For floats, the largest possible payload is 0x3F_FFFF.
- * For doubles, it is 0x3_FFFF_FFFF_FFFF.
- * For 80-bit or 128-bit reals, it is 0x3FFF_FFFF_FFFF_FFFF.
- */
-ulong getNaNPayload(real x) @trusted pure nothrow @nogc
-{
- // assert(isNaN(x));
- alias F = floatTraits!(real);
- static if (F.realFormat == RealFormat.ieeeDouble)
- {
- ulong m = *cast(ulong *)(&x);
- // Make it look like an 80-bit significand.
- // Skip exponent, and quiet bit
- m &= 0x0007_FFFF_FFFF_FFFF;
- m <<= 11;
- }
- else static if (F.realFormat == RealFormat.ieeeQuadruple)
- {
- version (LittleEndian)
- {
- ulong m = *cast(ulong*)(6+cast(ubyte*)(&x));
- }
- else
- {
- ulong m = *cast(ulong*)(2+cast(ubyte*)(&x));
- }
-
- m >>= 1; // there's no implicit bit
- }
- else
- {
- ulong m = *cast(ulong *)(&x);
- }
-
- // ignore implicit bit and quiet bit
-
- const ulong f = m & 0x3FFF_FF00_0000_0000L;
-
- ulong w = f >>> 40;
- w |= (m & 0x00FF_FFFF_F800L) << (22 - 11);
- w |= (m & 0x7FF) << 51;
- return w;
-}
-
-debug(UnitTest)
-{
- @safe pure nothrow @nogc unittest
- {
- real nan4 = NaN(0x789_ABCD_EF12_3456);
- static if (floatTraits!(real).realFormat == RealFormat.ieeeExtended
- || floatTraits!(real).realFormat == RealFormat.ieeeQuadruple)
- {
- assert(getNaNPayload(nan4) == 0x789_ABCD_EF12_3456);
- }
- else
- {
- assert(getNaNPayload(nan4) == 0x1_ABCD_EF12_3456);
- }
- double nan5 = nan4;
- assert(getNaNPayload(nan5) == 0x1_ABCD_EF12_3456);
- float nan6 = nan4;
- assert(getNaNPayload(nan6) == 0x12_3456);
- nan4 = NaN(0xFABCD);
- assert(getNaNPayload(nan4) == 0xFABCD);
- nan6 = nan4;
- assert(getNaNPayload(nan6) == 0xFABCD);
- nan5 = NaN(0x100_0000_0000_3456);
- assert(getNaNPayload(nan5) == 0x0000_0000_3456);
- }
-}
-
-/**
- * Calculate the next largest floating point value after x.
- *
- * Return the least number greater than x that is representable as a real;
- * thus, it gives the next point on the IEEE number line.
- *
- * $(TABLE_SV
- * $(SVH x, nextUp(x) )
- * $(SV -$(INFIN), -real.max )
- * $(SV $(PLUSMN)0.0, real.min_normal*real.epsilon )
- * $(SV real.max, $(INFIN) )
- * $(SV $(INFIN), $(INFIN) )
- * $(SV $(NAN), $(NAN) )
- * )
- */
-real nextUp(real x) @trusted pure nothrow @nogc
-{
- alias F = floatTraits!(real);
- static if (F.realFormat == RealFormat.ieeeDouble)
- {
- return nextUp(cast(double) x);
- }
- else static if (F.realFormat == RealFormat.ieeeQuadruple)
- {
- ushort e = F.EXPMASK & (cast(ushort *)&x)[F.EXPPOS_SHORT];
- if (e == F.EXPMASK)
- {
- // NaN or Infinity
- if (x == -real.infinity) return -real.max;
- return x; // +Inf and NaN are unchanged.
- }
-
- auto ps = cast(ulong *)&x;
- if (ps[MANTISSA_MSB] & 0x8000_0000_0000_0000)
- {
- // Negative number
- if (ps[MANTISSA_LSB] == 0 && ps[MANTISSA_MSB] == 0x8000_0000_0000_0000)
- {
- // it was negative zero, change to smallest subnormal
- ps[MANTISSA_LSB] = 1;
- ps[MANTISSA_MSB] = 0;
- return x;
- }
- if (ps[MANTISSA_LSB] == 0) --ps[MANTISSA_MSB];
- --ps[MANTISSA_LSB];
- }
- else
- {
- // Positive number
- ++ps[MANTISSA_LSB];
- if (ps[MANTISSA_LSB] == 0) ++ps[MANTISSA_MSB];
- }
- return x;
- }
- else static if (F.realFormat == RealFormat.ieeeExtended ||
- F.realFormat == RealFormat.ieeeExtended53)
- {
- // For 80-bit reals, the "implied bit" is a nuisance...
- ushort *pe = cast(ushort *)&x;
- ulong *ps = cast(ulong *)&x;
- // EPSILON is 1 for 64-bit, and 2048 for 53-bit precision reals.
- enum ulong EPSILON = 2UL ^^ (64 - real.mant_dig);
-
- if ((pe[F.EXPPOS_SHORT] & F.EXPMASK) == F.EXPMASK)
- {
- // First, deal with NANs and infinity
- if (x == -real.infinity) return -real.max;
- return x; // +Inf and NaN are unchanged.
- }
- if (pe[F.EXPPOS_SHORT] & 0x8000)
- {
- // Negative number -- need to decrease the significand
- *ps -= EPSILON;
- // Need to mask with 0x7FFF... so subnormals are treated correctly.
- if ((*ps & 0x7FFF_FFFF_FFFF_FFFF) == 0x7FFF_FFFF_FFFF_FFFF)
- {
- if (pe[F.EXPPOS_SHORT] == 0x8000) // it was negative zero
- {
- *ps = 1;
- pe[F.EXPPOS_SHORT] = 0; // smallest subnormal.
- return x;
- }
-
- --pe[F.EXPPOS_SHORT];
-
- if (pe[F.EXPPOS_SHORT] == 0x8000)
- return x; // it's become a subnormal, implied bit stays low.
-
- *ps = 0xFFFF_FFFF_FFFF_FFFF; // set the implied bit
- return x;
- }
- return x;
- }
- else
- {
- // Positive number -- need to increase the significand.
- // Works automatically for positive zero.
- *ps += EPSILON;
- if ((*ps & 0x7FFF_FFFF_FFFF_FFFF) == 0)
- {
- // change in exponent
- ++pe[F.EXPPOS_SHORT];
- *ps = 0x8000_0000_0000_0000; // set the high bit
- }
- }
- return x;
- }
- else // static if (F.realFormat == RealFormat.ibmExtended)
- {
- assert(0, "nextUp not implemented");
- }
-}
-
-/** ditto */
-double nextUp(double x) @trusted pure nothrow @nogc
-{
- ulong *ps = cast(ulong *)&x;
-
- if ((*ps & 0x7FF0_0000_0000_0000) == 0x7FF0_0000_0000_0000)
- {
- // First, deal with NANs and infinity
- if (x == -x.infinity) return -x.max;
- return x; // +INF and NAN are unchanged.
- }
- if (*ps & 0x8000_0000_0000_0000) // Negative number
- {
- if (*ps == 0x8000_0000_0000_0000) // it was negative zero
- {
- *ps = 0x0000_0000_0000_0001; // change to smallest subnormal
- return x;
- }
- --*ps;
- }
- else
- { // Positive number
- ++*ps;
- }
- return x;
-}
-
-/** ditto */
-float nextUp(float x) @trusted pure nothrow @nogc
-{
- uint *ps = cast(uint *)&x;
-
- if ((*ps & 0x7F80_0000) == 0x7F80_0000)
- {
- // First, deal with NANs and infinity
- if (x == -x.infinity) return -x.max;
-
- return x; // +INF and NAN are unchanged.
- }
- if (*ps & 0x8000_0000) // Negative number
- {
- if (*ps == 0x8000_0000) // it was negative zero
- {
- *ps = 0x0000_0001; // change to smallest subnormal
- return x;
- }
-
- --*ps;
- }
- else
- {
- // Positive number
- ++*ps;
- }
- return x;
-}
-
-/**
- * Calculate the next smallest floating point value before x.
- *
- * Return the greatest number less than x that is representable as a real;
- * thus, it gives the previous point on the IEEE number line.
- *
- * $(TABLE_SV
- * $(SVH x, nextDown(x) )
- * $(SV $(INFIN), real.max )
- * $(SV $(PLUSMN)0.0, -real.min_normal*real.epsilon )
- * $(SV -real.max, -$(INFIN) )
- * $(SV -$(INFIN), -$(INFIN) )
- * $(SV $(NAN), $(NAN) )
- * )
- */
-real nextDown(real x) @safe pure nothrow @nogc
-{
- return -nextUp(-x);
-}
-
-/** ditto */
-double nextDown(double x) @safe pure nothrow @nogc
-{
- return -nextUp(-x);
-}
-
-/** ditto */
-float nextDown(float x) @safe pure nothrow @nogc
-{
- return -nextUp(-x);
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- assert( nextDown(1.0 + real.epsilon) == 1.0);
-}
-
-@safe pure nothrow @nogc unittest
-{
- static if (floatTraits!(real).realFormat == RealFormat.ieeeExtended)
- {
-
- // Tests for 80-bit reals
- assert(isIdentical(nextUp(NaN(0xABC)), NaN(0xABC)));
- // negative numbers
- assert( nextUp(-real.infinity) == -real.max );
- assert( nextUp(-1.0L-real.epsilon) == -1.0 );
- assert( nextUp(-2.0L) == -2.0 + real.epsilon);
- // subnormals and zero
- assert( nextUp(-real.min_normal) == -real.min_normal*(1-real.epsilon) );
- assert( nextUp(-real.min_normal*(1-real.epsilon)) == -real.min_normal*(1-2*real.epsilon) );
- assert( isIdentical(-0.0L, nextUp(-real.min_normal*real.epsilon)) );
- assert( nextUp(-0.0L) == real.min_normal*real.epsilon );
- assert( nextUp(0.0L) == real.min_normal*real.epsilon );
- assert( nextUp(real.min_normal*(1-real.epsilon)) == real.min_normal );
- assert( nextUp(real.min_normal) == real.min_normal*(1+real.epsilon) );
- // positive numbers
- assert( nextUp(1.0L) == 1.0 + real.epsilon );
- assert( nextUp(2.0L-real.epsilon) == 2.0 );
- assert( nextUp(real.max) == real.infinity );
- assert( nextUp(real.infinity)==real.infinity );
- }
-
- double n = NaN(0xABC);
- assert(isIdentical(nextUp(n), n));
- // negative numbers
- assert( nextUp(-double.infinity) == -double.max );
- assert( nextUp(-1-double.epsilon) == -1.0 );
- assert( nextUp(-2.0) == -2.0 + double.epsilon);
- // subnormals and zero
-
- assert( nextUp(-double.min_normal) == -double.min_normal*(1-double.epsilon) );
- assert( nextUp(-double.min_normal*(1-double.epsilon)) == -double.min_normal*(1-2*double.epsilon) );
- assert( isIdentical(-0.0, nextUp(-double.min_normal*double.epsilon)) );
- assert( nextUp(0.0) == double.min_normal*double.epsilon );
- assert( nextUp(-0.0) == double.min_normal*double.epsilon );
- assert( nextUp(double.min_normal*(1-double.epsilon)) == double.min_normal );
- assert( nextUp(double.min_normal) == double.min_normal*(1+double.epsilon) );
- // positive numbers
- assert( nextUp(1.0) == 1.0 + double.epsilon );
- assert( nextUp(2.0-double.epsilon) == 2.0 );
- assert( nextUp(double.max) == double.infinity );
-
- float fn = NaN(0xABC);
- assert(isIdentical(nextUp(fn), fn));
- float f = -float.min_normal*(1-float.epsilon);
- float f1 = -float.min_normal;
- assert( nextUp(f1) == f);
- f = 1.0f+float.epsilon;
- f1 = 1.0f;
- assert( nextUp(f1) == f );
- f1 = -0.0f;
- assert( nextUp(f1) == float.min_normal*float.epsilon);
- assert( nextUp(float.infinity)==float.infinity );
-
- assert(nextDown(1.0L+real.epsilon)==1.0);
- assert(nextDown(1.0+double.epsilon)==1.0);
- f = 1.0f+float.epsilon;
- assert(nextDown(f)==1.0);
- assert(nextafter(1.0+real.epsilon, -real.infinity)==1.0);
-}
-
-
-
-/******************************************
- * Calculates the next representable value after x in the direction of y.
- *
- * If y > x, the result will be the next largest floating-point value;
- * if y < x, the result will be the next smallest value.
- * If x == y, the result is y.
- *
- * Remarks:
- * This function is not generally very useful; it's almost always better to use
- * the faster functions nextUp() or nextDown() instead.
- *
- * The FE_INEXACT and FE_OVERFLOW exceptions will be raised if x is finite and
- * the function result is infinite. The FE_INEXACT and FE_UNDERFLOW
- * exceptions will be raised if the function value is subnormal, and x is
- * not equal to y.
- */
-T nextafter(T)(const T x, const T y) @safe pure nothrow @nogc
-{
- if (x == y) return y;
- return ((y>x) ? nextUp(x) : nextDown(x));
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- float a = 1;
- assert(is(typeof(nextafter(a, a)) == float));
- assert(nextafter(a, a.infinity) > a);
-
- double b = 2;
- assert(is(typeof(nextafter(b, b)) == double));
- assert(nextafter(b, b.infinity) > b);
-
- real c = 3;
- assert(is(typeof(nextafter(c, c)) == real));
- assert(nextafter(c, c.infinity) > c);
-}
-
-//real nexttoward(real x, real y) { return core.stdc.math.nexttowardl(x, y); }
-
-/*******************************************
- * Returns the positive difference between x and y.
- * Returns:
- * $(TABLE_SV
- * $(TR $(TH x, y) $(TH fdim(x, y)))
- * $(TR $(TD x $(GT) y) $(TD x - y))
- * $(TR $(TD x $(LT)= y) $(TD +0.0))
- * )
- */
-real fdim(real x, real y) @safe pure nothrow @nogc { return (x > y) ? x - y : +0.0; }
-
-/****************************************
- * Returns the larger of x and y.
- */
-real fmax(real x, real y) @safe pure nothrow @nogc { return x > y ? x : y; }
-
-/****************************************
- * Returns the smaller of x and y.
- */
-real fmin(real x, real y) @safe pure nothrow @nogc { return x < y ? x : y; }
-
-/**************************************
- * Returns (x * y) + z, rounding only once according to the
- * current rounding mode.
- *
- * BUGS: Not currently implemented - rounds twice.
- */
-real fma(real x, real y, real z) @safe pure nothrow @nogc { return (x * y) + z; }
-
-/*******************************************************************
- * Compute the value of x $(SUPERSCRIPT n), where n is an integer
- */
-Unqual!F pow(F, G)(F x, G n) @nogc @trusted pure nothrow
-if (isFloatingPoint!(F) && isIntegral!(G))
-{
- import std.traits : Unsigned;
- real p = 1.0, v = void;
- Unsigned!(Unqual!G) m = n;
- if (n < 0)
- {
- switch (n)
- {
- case -1:
- return 1 / x;
- case -2:
- return 1 / (x * x);
- default:
- }
-
- m = cast(typeof(m))(0 - n);
- v = p / x;
- }
- else
- {
- switch (n)
- {
- case 0:
- return 1.0;
- case 1:
- return x;
- case 2:
- return x * x;
- default:
- }
-
- v = x;
- }
-
- while (1)
- {
- if (m & 1)
- p *= v;
- m >>= 1;
- if (!m)
- break;
- v *= v;
- }
- return p;
-}
-
-@safe pure nothrow @nogc unittest
-{
- // Make sure it instantiates and works properly on immutable values and
- // with various integer and float types.
- immutable real x = 46;
- immutable float xf = x;
- immutable double xd = x;
- immutable uint one = 1;
- immutable ushort two = 2;
- immutable ubyte three = 3;
- immutable ulong eight = 8;
-
- immutable int neg1 = -1;
- immutable short neg2 = -2;
- immutable byte neg3 = -3;
- immutable long neg8 = -8;
-
-
- assert(pow(x,0) == 1.0);
- assert(pow(xd,one) == x);
- assert(pow(xf,two) == x * x);
- assert(pow(x,three) == x * x * x);
- assert(pow(x,eight) == (x * x) * (x * x) * (x * x) * (x * x));
-
- assert(pow(x, neg1) == 1 / x);
-
- // Test disabled on most targets.
- // See https://issues.dlang.org/show_bug.cgi?id=5628
- version (X86_64) enum BUG5628 = false;
- else version (ARM) enum BUG5628 = false;
- else version (GNU) enum BUG5628 = false;
- else enum BUG5628 = true;
-
- static if (BUG5628)
- {
- assert(pow(xd, neg2) == 1 / (x * x));
- assert(pow(xf, neg8) == 1 / ((x * x) * (x * x) * (x * x) * (x * x)));
- }
-
- assert(feqrel(pow(x, neg3), 1 / (x * x * x)) >= real.mant_dig - 1);
-}
-
-@system unittest
-{
- assert(equalsDigit(pow(2.0L, 10.0L), 1024, 19));
-}
-
-/** Compute the value of an integer x, raised to the power of a positive
- * integer n.
- *
- * If both x and n are 0, the result is 1.
- * If n is negative, an integer divide error will occur at runtime,
- * regardless of the value of x.
- */
-typeof(Unqual!(F).init * Unqual!(G).init) pow(F, G)(F x, G n) @nogc @trusted pure nothrow
-if (isIntegral!(F) && isIntegral!(G))
-{
- if (n<0) return x/0; // Only support positive powers
- typeof(return) p, v = void;
- Unqual!G m = n;
-
- switch (m)
- {
- case 0:
- p = 1;
- break;
-
- case 1:
- p = x;
- break;
-
- case 2:
- p = x * x;
- break;
-
- default:
- v = x;
- p = 1;
- while (1)
- {
- if (m & 1)
- p *= v;
- m >>= 1;
- if (!m)
- break;
- v *= v;
- }
- break;
- }
- return p;
-}
-
-///
-@safe pure nothrow @nogc unittest
-{
- immutable int one = 1;
- immutable byte two = 2;
- immutable ubyte three = 3;
- immutable short four = 4;
- immutable long ten = 10;
-
- assert(pow(two, three) == 8);
- assert(pow(two, ten) == 1024);
- assert(pow(one, ten) == 1);
- assert(pow(ten, four) == 10_000);
- assert(pow(four, 10) == 1_048_576);
- assert(pow(three, four) == 81);
-
-}
-
-/**Computes integer to floating point powers.*/
-real pow(I, F)(I x, F y) @nogc @trusted pure nothrow
-if (isIntegral!I && isFloatingPoint!F)
-{
- return pow(cast(real) x, cast(Unqual!F) y);
-}
-
-/*********************************************
- * Calculates x$(SUPERSCRIPT y).
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH y) $(TH pow(x, y))
- * $(TH div 0) $(TH invalid?))
- * $(TR $(TD anything) $(TD $(PLUSMN)0.0) $(TD 1.0)
- * $(TD no) $(TD no) )
- * $(TR $(TD |x| $(GT) 1) $(TD +$(INFIN)) $(TD +$(INFIN))
- * $(TD no) $(TD no) )
- * $(TR $(TD |x| $(LT) 1) $(TD +$(INFIN)) $(TD +0.0)
- * $(TD no) $(TD no) )
- * $(TR $(TD |x| $(GT) 1) $(TD -$(INFIN)) $(TD +0.0)
- * $(TD no) $(TD no) )
- * $(TR $(TD |x| $(LT) 1) $(TD -$(INFIN)) $(TD +$(INFIN))
- * $(TD no) $(TD no) )
- * $(TR $(TD +$(INFIN)) $(TD $(GT) 0.0) $(TD +$(INFIN))
- * $(TD no) $(TD no) )
- * $(TR $(TD +$(INFIN)) $(TD $(LT) 0.0) $(TD +0.0)
- * $(TD no) $(TD no) )
- * $(TR $(TD -$(INFIN)) $(TD odd integer $(GT) 0.0) $(TD -$(INFIN))
- * $(TD no) $(TD no) )
- * $(TR $(TD -$(INFIN)) $(TD $(GT) 0.0, not odd integer) $(TD +$(INFIN))
- * $(TD no) $(TD no))
- * $(TR $(TD -$(INFIN)) $(TD odd integer $(LT) 0.0) $(TD -0.0)
- * $(TD no) $(TD no) )
- * $(TR $(TD -$(INFIN)) $(TD $(LT) 0.0, not odd integer) $(TD +0.0)
- * $(TD no) $(TD no) )
- * $(TR $(TD $(PLUSMN)1.0) $(TD $(PLUSMN)$(INFIN)) $(TD $(NAN))
- * $(TD no) $(TD yes) )
- * $(TR $(TD $(LT) 0.0) $(TD finite, nonintegral) $(TD $(NAN))
- * $(TD no) $(TD yes))
- * $(TR $(TD $(PLUSMN)0.0) $(TD odd integer $(LT) 0.0) $(TD $(PLUSMNINF))
- * $(TD yes) $(TD no) )
- * $(TR $(TD $(PLUSMN)0.0) $(TD $(LT) 0.0, not odd integer) $(TD +$(INFIN))
- * $(TD yes) $(TD no))
- * $(TR $(TD $(PLUSMN)0.0) $(TD odd integer $(GT) 0.0) $(TD $(PLUSMN)0.0)
- * $(TD no) $(TD no) )
- * $(TR $(TD $(PLUSMN)0.0) $(TD $(GT) 0.0, not odd integer) $(TD +0.0)
- * $(TD no) $(TD no) )
- * )
- */
-Unqual!(Largest!(F, G)) pow(F, G)(F x, G y) @nogc @trusted pure nothrow
-if (isFloatingPoint!(F) && isFloatingPoint!(G))
-{
- alias Float = typeof(return);
-
- static real impl(real x, real y) @nogc pure nothrow
- {
- // Special cases.
- if (isNaN(y))
- return y;
- if (isNaN(x) && y != 0.0)
- return x;
-
- // Even if x is NaN.
- if (y == 0.0)
- return 1.0;
- if (y == 1.0)
- return x;
-
- if (isInfinity(y))
- {
- if (fabs(x) > 1)
- {
- if (signbit(y))
- return +0.0;
- else
- return F.infinity;
- }
- else if (fabs(x) == 1)
- {
- return y * 0; // generate NaN.
- }
- else // < 1
- {
- if (signbit(y))
- return F.infinity;
- else
- return +0.0;
- }
- }
- if (isInfinity(x))
- {
- if (signbit(x))
- {
- long i = cast(long) y;
- if (y > 0.0)
- {
- if (i == y && i & 1)
- return -F.infinity;
- else
- return F.infinity;
- }
- else if (y < 0.0)
- {
- if (i == y && i & 1)
- return -0.0;
- else
- return +0.0;
- }
- }
- else
- {
- if (y > 0.0)
- return F.infinity;
- else if (y < 0.0)
- return +0.0;
- }
- }
-
- if (x == 0.0)
- {
- if (signbit(x))
- {
- long i = cast(long) y;
- if (y > 0.0)
- {
- if (i == y && i & 1)
- return -0.0;
- else
- return +0.0;
- }
- else if (y < 0.0)
- {
- if (i == y && i & 1)
- return -F.infinity;
- else
- return F.infinity;
- }
- }
- else
- {
- if (y > 0.0)
- return +0.0;
- else if (y < 0.0)
- return F.infinity;
- }
- }
- if (x == 1.0)
- return 1.0;
-
- if (y >= F.max)
- {
- if ((x > 0.0 && x < 1.0) || (x > -1.0 && x < 0.0))
- return 0.0;
- if (x > 1.0 || x < -1.0)
- return F.infinity;
- }
- if (y <= -F.max)
- {
- if ((x > 0.0 && x < 1.0) || (x > -1.0 && x < 0.0))
- return F.infinity;
- if (x > 1.0 || x < -1.0)
- return 0.0;
- }
-
- if (x >= F.max)
- {
- if (y > 0.0)
- return F.infinity;
- else
- return 0.0;
- }
- if (x <= -F.max)
- {
- long i = cast(long) y;
- if (y > 0.0)
- {
- if (i == y && i & 1)
- return -F.infinity;
- else
- return F.infinity;
- }
- else if (y < 0.0)
- {
- if (i == y && i & 1)
- return -0.0;
- else
- return +0.0;
- }
- }
-
- // Integer power of x.
- long iy = cast(long) y;
- if (iy == y && fabs(y) < 32_768.0)
- return pow(x, iy);
-
- real sign = 1.0;
- if (x < 0)
- {
- // Result is real only if y is an integer
- // Check for a non-zero fractional part
- enum maxOdd = pow(2.0L, real.mant_dig) - 1.0L;
- static if (maxOdd > ulong.max)
- {
- // Generic method, for any FP type
- if (floor(y) != y)
- return sqrt(x); // Complex result -- create a NaN
-
- const hy = ldexp(y, -1);
- if (floor(hy) != hy)
- sign = -1.0;
- }
- else
- {
- // Much faster, if ulong has enough precision
- const absY = fabs(y);
- if (absY <= maxOdd)
- {
- const uy = cast(ulong) absY;
- if (uy != absY)
- return sqrt(x); // Complex result -- create a NaN
-
- if (uy & 1)
- sign = -1.0;
- }
- }
- x = -x;
- }
- version (INLINE_YL2X)
- {
- // If x > 0, x ^^ y == 2 ^^ ( y * log2(x) )
- // TODO: This is not accurate in practice. A fast and accurate
- // (though complicated) method is described in:
- // "An efficient rounding boundary test for pow(x, y)
- // in double precision", C.Q. Lauter and V. Lefèvre, INRIA (2007).
- return sign * exp2( core.math.yl2x(x, y) );
- }
- else
- {
- // If x > 0, x ^^ y == 2 ^^ ( y * log2(x) )
- // TODO: This is not accurate in practice. A fast and accurate
- // (though complicated) method is described in:
- // "An efficient rounding boundary test for pow(x, y)
- // in double precision", C.Q. Lauter and V. Lefèvre, INRIA (2007).
- Float w = exp2(y * log2(x));
- return sign * w;
- }
- }
- return impl(x, y);
-}
-
-@safe pure nothrow @nogc unittest
-{
- // Test all the special values. These unittests can be run on Windows
- // by temporarily changing the version (linux) to version (all).
- immutable float zero = 0;
- immutable real one = 1;
- immutable double two = 2;
- immutable float three = 3;
- immutable float fnan = float.nan;
- immutable double dnan = double.nan;
- immutable real rnan = real.nan;
- immutable dinf = double.infinity;
- immutable rninf = -real.infinity;
-
- assert(pow(fnan, zero) == 1);
- assert(pow(dnan, zero) == 1);
- assert(pow(rnan, zero) == 1);
-
- assert(pow(two, dinf) == double.infinity);
- assert(isIdentical(pow(0.2f, dinf), +0.0));
- assert(pow(0.99999999L, rninf) == real.infinity);
- assert(isIdentical(pow(1.000000001, rninf), +0.0));
- assert(pow(dinf, 0.001) == dinf);
- assert(isIdentical(pow(dinf, -0.001), +0.0));
- assert(pow(rninf, 3.0L) == rninf);
- assert(pow(rninf, 2.0L) == real.infinity);
- assert(isIdentical(pow(rninf, -3.0), -0.0));
- assert(isIdentical(pow(rninf, -2.0), +0.0));
-
- // @@@BUG@@@ somewhere
- version (OSX) {} else assert(isNaN(pow(one, dinf)));
- version (OSX) {} else assert(isNaN(pow(-one, dinf)));
- assert(isNaN(pow(-0.2, PI)));
- // boundary cases. Note that epsilon == 2^^-n for some n,
- // so 1/epsilon == 2^^n is always even.
- assert(pow(-1.0L, 1/real.epsilon - 1.0L) == -1.0L);
- assert(pow(-1.0L, 1/real.epsilon) == 1.0L);
- assert(isNaN(pow(-1.0L, 1/real.epsilon-0.5L)));
- assert(isNaN(pow(-1.0L, -1/real.epsilon+0.5L)));
-
- assert(pow(0.0, -3.0) == double.infinity);
- assert(pow(-0.0, -3.0) == -double.infinity);
- assert(pow(0.0, -PI) == double.infinity);
- assert(pow(-0.0, -PI) == double.infinity);
- assert(isIdentical(pow(0.0, 5.0), 0.0));
- assert(isIdentical(pow(-0.0, 5.0), -0.0));
- assert(isIdentical(pow(0.0, 6.0), 0.0));
- assert(isIdentical(pow(-0.0, 6.0), 0.0));
-
- // Issue #14786 fixed
- immutable real maxOdd = pow(2.0L, real.mant_dig) - 1.0L;
- assert(pow(-1.0L, maxOdd) == -1.0L);
- assert(pow(-1.0L, -maxOdd) == -1.0L);
- assert(pow(-1.0L, maxOdd + 1.0L) == 1.0L);
- assert(pow(-1.0L, -maxOdd + 1.0L) == 1.0L);
- assert(pow(-1.0L, maxOdd - 1.0L) == 1.0L);
- assert(pow(-1.0L, -maxOdd - 1.0L) == 1.0L);
-
- // Now, actual numbers.
- assert(approxEqual(pow(two, three), 8.0));
- assert(approxEqual(pow(two, -2.5), 0.1767767));
-
- // Test integer to float power.
- immutable uint twoI = 2;
- assert(approxEqual(pow(twoI, three), 8.0));
-}
-
-/**************************************
- * To what precision is x equal to y?
- *
- * Returns: the number of mantissa bits which are equal in x and y.
- * eg, 0x1.F8p+60 and 0x1.F1p+60 are equal to 5 bits of precision.
- *
- * $(TABLE_SV
- * $(TR $(TH x) $(TH y) $(TH feqrel(x, y)))
- * $(TR $(TD x) $(TD x) $(TD real.mant_dig))
- * $(TR $(TD x) $(TD $(GT)= 2*x) $(TD 0))
- * $(TR $(TD x) $(TD $(LT)= x/2) $(TD 0))
- * $(TR $(TD $(NAN)) $(TD any) $(TD 0))
- * $(TR $(TD any) $(TD $(NAN)) $(TD 0))
- * )
- */
-int feqrel(X)(const X x, const X y) @trusted pure nothrow @nogc
-if (isFloatingPoint!(X))
-{
- /* Public Domain. Author: Don Clugston, 18 Aug 2005.
- */
- alias F = floatTraits!(X);
- static if (F.realFormat == RealFormat.ibmExtended)
- {
- if (cast(double*)(&x)[MANTISSA_MSB] == cast(double*)(&y)[MANTISSA_MSB])
- {
- return double.mant_dig
- + feqrel(cast(double*)(&x)[MANTISSA_LSB],
- cast(double*)(&y)[MANTISSA_LSB]);
- }
- else
- {
- return feqrel(cast(double*)(&x)[MANTISSA_MSB],
- cast(double*)(&y)[MANTISSA_MSB]);
- }
- }
- else
- {
- static assert(F.realFormat == RealFormat.ieeeSingle
- || F.realFormat == RealFormat.ieeeDouble
- || F.realFormat == RealFormat.ieeeExtended
- || F.realFormat == RealFormat.ieeeExtended53
- || F.realFormat == RealFormat.ieeeQuadruple);
-
- if (x == y)
- return X.mant_dig; // ensure diff != 0, cope with INF.
-
- Unqual!X diff = fabs(x - y);
-
- ushort *pa = cast(ushort *)(&x);
- ushort *pb = cast(ushort *)(&y);
- ushort *pd = cast(ushort *)(&diff);
-
-
- // The difference in abs(exponent) between x or y and abs(x-y)
- // is equal to the number of significand bits of x which are
- // equal to y. If negative, x and y have different exponents.
- // If positive, x and y are equal to 'bitsdiff' bits.
- // AND with 0x7FFF to form the absolute value.
- // To avoid out-by-1 errors, we subtract 1 so it rounds down
- // if the exponents were different. This means 'bitsdiff' is
- // always 1 lower than we want, except that if bitsdiff == 0,
- // they could have 0 or 1 bits in common.
-
- int bitsdiff = ((( (pa[F.EXPPOS_SHORT] & F.EXPMASK)
- + (pb[F.EXPPOS_SHORT] & F.EXPMASK)
- - (1 << F.EXPSHIFT)) >> 1)
- - (pd[F.EXPPOS_SHORT] & F.EXPMASK)) >> F.EXPSHIFT;
- if ( (pd[F.EXPPOS_SHORT] & F.EXPMASK) == 0)
- { // Difference is subnormal
- // For subnormals, we need to add the number of zeros that
- // lie at the start of diff's significand.
- // We do this by multiplying by 2^^real.mant_dig
- diff *= F.RECIP_EPSILON;
- return bitsdiff + X.mant_dig - ((pd[F.EXPPOS_SHORT] & F.EXPMASK) >> F.EXPSHIFT);
- }
-
- if (bitsdiff > 0)
- return bitsdiff + 1; // add the 1 we subtracted before
-
- // Avoid out-by-1 errors when factor is almost 2.
- if (bitsdiff == 0
- && ((pa[F.EXPPOS_SHORT] ^ pb[F.EXPPOS_SHORT]) & F.EXPMASK) == 0)
- {
- return 1;
- } else return 0;
- }
-}
-
-@safe pure nothrow @nogc unittest
-{
- void testFeqrel(F)()
- {
- // Exact equality
- assert(feqrel(F.max, F.max) == F.mant_dig);
- assert(feqrel!(F)(0.0, 0.0) == F.mant_dig);
- assert(feqrel(F.infinity, F.infinity) == F.mant_dig);
-
- // a few bits away from exact equality
- F w=1;
- for (int i = 1; i < F.mant_dig - 1; ++i)
- {
- assert(feqrel!(F)(1.0 + w * F.epsilon, 1.0) == F.mant_dig-i);
- assert(feqrel!(F)(1.0 - w * F.epsilon, 1.0) == F.mant_dig-i);
- assert(feqrel!(F)(1.0, 1 + (w-1) * F.epsilon) == F.mant_dig - i + 1);
- w*=2;
- }
-
- assert(feqrel!(F)(1.5+F.epsilon, 1.5) == F.mant_dig-1);
- assert(feqrel!(F)(1.5-F.epsilon, 1.5) == F.mant_dig-1);
- assert(feqrel!(F)(1.5-F.epsilon, 1.5+F.epsilon) == F.mant_dig-2);
-
-
- // Numbers that are close
- assert(feqrel!(F)(0x1.Bp+84, 0x1.B8p+84) == 5);
- assert(feqrel!(F)(0x1.8p+10, 0x1.Cp+10) == 2);
- assert(feqrel!(F)(1.5 * (1 - F.epsilon), 1.0L) == 2);
- assert(feqrel!(F)(1.5, 1.0) == 1);
- assert(feqrel!(F)(2 * (1 - F.epsilon), 1.0L) == 1);
-
- // Factors of 2
- assert(feqrel(F.max, F.infinity) == 0);
- assert(feqrel!(F)(2 * (1 - F.epsilon), 1.0L) == 1);
- assert(feqrel!(F)(1.0, 2.0) == 0);
- assert(feqrel!(F)(4.0, 1.0) == 0);
-
- // Extreme inequality
- assert(feqrel(F.nan, F.nan) == 0);
- assert(feqrel!(F)(0.0L, -F.nan) == 0);
- assert(feqrel(F.nan, F.infinity) == 0);
- assert(feqrel(F.infinity, -F.infinity) == 0);
- assert(feqrel(F.max, -F.max) == 0);
-
- assert(feqrel(F.min_normal / 8, F.min_normal / 17) == 3);
-
- const F Const = 2;
- immutable F Immutable = 2;
- auto Compiles = feqrel(Const, Immutable);
- }
-
- assert(feqrel(7.1824L, 7.1824L) == real.mant_dig);
-
- testFeqrel!(real)();
- testFeqrel!(double)();
- testFeqrel!(float)();
-}
-
-package: // Not public yet
-/* Return the value that lies halfway between x and y on the IEEE number line.
- *
- * Formally, the result is the arithmetic mean of the binary significands of x
- * and y, multiplied by the geometric mean of the binary exponents of x and y.
- * x and y must have the same sign, and must not be NaN.
- * Note: this function is useful for ensuring O(log n) behaviour in algorithms
- * involving a 'binary chop'.
- *
- * Special cases:
- * If x and y are within a factor of 2, (ie, feqrel(x, y) > 0), the return value
- * is the arithmetic mean (x + y) / 2.
- * If x and y are even powers of 2, the return value is the geometric mean,
- * ieeeMean(x, y) = sqrt(x * y).
- *
- */
-T ieeeMean(T)(const T x, const T y) @trusted pure nothrow @nogc
-in
-{
- // both x and y must have the same sign, and must not be NaN.
- assert(signbit(x) == signbit(y));
- assert(x == x && y == y);
-}
-body
-{
- // Runtime behaviour for contract violation:
- // If signs are opposite, or one is a NaN, return 0.
- if (!((x >= 0 && y >= 0) || (x <= 0 && y <= 0))) return 0.0;
-
- // The implementation is simple: cast x and y to integers,
- // average them (avoiding overflow), and cast the result back to a floating-point number.
-
- alias F = floatTraits!(T);
- T u;
- static if (F.realFormat == RealFormat.ieeeExtended ||
- F.realFormat == RealFormat.ieeeExtended53)
- {
- // There's slight additional complexity because they are actually
- // 79-bit reals...
- ushort *ue = cast(ushort *)&u;
- ulong *ul = cast(ulong *)&u;
- ushort *xe = cast(ushort *)&x;
- ulong *xl = cast(ulong *)&x;
- ushort *ye = cast(ushort *)&y;
- ulong *yl = cast(ulong *)&y;
-
- // Ignore the useless implicit bit. (Bonus: this prevents overflows)
- ulong m = ((*xl) & 0x7FFF_FFFF_FFFF_FFFFL) + ((*yl) & 0x7FFF_FFFF_FFFF_FFFFL);
-
- // @@@ BUG? @@@
- // Cast shouldn't be here
- ushort e = cast(ushort) ((xe[F.EXPPOS_SHORT] & F.EXPMASK)
- + (ye[F.EXPPOS_SHORT] & F.EXPMASK));
- if (m & 0x8000_0000_0000_0000L)
- {
- ++e;
- m &= 0x7FFF_FFFF_FFFF_FFFFL;
- }
- // Now do a multi-byte right shift
- const uint c = e & 1; // carry
- e >>= 1;
- m >>>= 1;
- if (c)
- m |= 0x4000_0000_0000_0000L; // shift carry into significand
- if (e)
- *ul = m | 0x8000_0000_0000_0000L; // set implicit bit...
- else
- *ul = m; // ... unless exponent is 0 (subnormal or zero).
-
- ue[4]= e | (xe[F.EXPPOS_SHORT]& 0x8000); // restore sign bit
- }
- else static if (F.realFormat == RealFormat.ieeeQuadruple)
- {
- // This would be trivial if 'ucent' were implemented...
- ulong *ul = cast(ulong *)&u;
- ulong *xl = cast(ulong *)&x;
- ulong *yl = cast(ulong *)&y;
-
- // Multi-byte add, then multi-byte right shift.
- import core.checkedint : addu;
- bool carry;
- ulong ml = addu(xl[MANTISSA_LSB], yl[MANTISSA_LSB], carry);
-
- ulong mh = carry + (xl[MANTISSA_MSB] & 0x7FFF_FFFF_FFFF_FFFFL) +
- (yl[MANTISSA_MSB] & 0x7FFF_FFFF_FFFF_FFFFL);
-
- ul[MANTISSA_MSB] = (mh >>> 1) | (xl[MANTISSA_MSB] & 0x8000_0000_0000_0000);
- ul[MANTISSA_LSB] = (ml >>> 1) | (mh & 1) << 63;
- }
- else static if (F.realFormat == RealFormat.ieeeDouble)
- {
- ulong *ul = cast(ulong *)&u;
- ulong *xl = cast(ulong *)&x;
- ulong *yl = cast(ulong *)&y;
- ulong m = (((*xl) & 0x7FFF_FFFF_FFFF_FFFFL)
- + ((*yl) & 0x7FFF_FFFF_FFFF_FFFFL)) >>> 1;
- m |= ((*xl) & 0x8000_0000_0000_0000L);
- *ul = m;
- }
- else static if (F.realFormat == RealFormat.ieeeSingle)
- {
- uint *ul = cast(uint *)&u;
- uint *xl = cast(uint *)&x;
- uint *yl = cast(uint *)&y;
- uint m = (((*xl) & 0x7FFF_FFFF) + ((*yl) & 0x7FFF_FFFF)) >>> 1;
- m |= ((*xl) & 0x8000_0000);
- *ul = m;
- }
- else
- {
- assert(0, "Not implemented");
- }
- return u;
-}
-
-@safe pure nothrow @nogc unittest
-{
- assert(ieeeMean(-0.0,-1e-20)<0);
- assert(ieeeMean(0.0,1e-20)>0);
-
- assert(ieeeMean(1.0L,4.0L)==2L);
- assert(ieeeMean(2.0*1.013,8.0*1.013)==4*1.013);
- assert(ieeeMean(-1.0L,-4.0L)==-2L);
- assert(ieeeMean(-1.0,-4.0)==-2);
- assert(ieeeMean(-1.0f,-4.0f)==-2f);
- assert(ieeeMean(-1.0,-2.0)==-1.5);
- assert(ieeeMean(-1*(1+8*real.epsilon),-2*(1+8*real.epsilon))
- ==-1.5*(1+5*real.epsilon));
- assert(ieeeMean(0x1p60,0x1p-10)==0x1p25);
-
- static if (floatTraits!(real).realFormat == RealFormat.ieeeExtended)
- {
- assert(ieeeMean(1.0L,real.infinity)==0x1p8192L);
- assert(ieeeMean(0.0L,real.infinity)==1.5);
- }
- assert(ieeeMean(0.5*real.min_normal*(1-4*real.epsilon),0.5*real.min_normal)
- == 0.5*real.min_normal*(1-2*real.epsilon));
-}
-
-public:
-
-
-/***********************************
- * Evaluate polynomial A(x) = $(SUB a, 0) + $(SUB a, 1)x + $(SUB a, 2)$(POWER x,2)
- * + $(SUB a,3)$(POWER x,3); ...
- *
- * Uses Horner's rule A(x) = $(SUB a, 0) + x($(SUB a, 1) + x($(SUB a, 2)
- * + x($(SUB a, 3) + ...)))
- * Params:
- * x = the value to evaluate.
- * A = array of coefficients $(SUB a, 0), $(SUB a, 1), etc.
- */
-Unqual!(CommonType!(T1, T2)) poly(T1, T2)(T1 x, in T2[] A) @trusted pure nothrow @nogc
-if (isFloatingPoint!T1 && isFloatingPoint!T2)
-in
-{
- assert(A.length > 0);
-}
-body
-{
- static if (is(Unqual!T2 == real))
- {
- return polyImpl(x, A);
- }
- else
- {
- return polyImplBase(x, A);
- }
-}
-
-///
-@safe nothrow @nogc unittest
-{
- real x = 3.1;
- static real[] pp = [56.1, 32.7, 6];
-
- assert(poly(x, pp) == (56.1L + (32.7L + 6.0L * x) * x));
-}
-
-@safe nothrow @nogc unittest
-{
- double x = 3.1;
- static double[] pp = [56.1, 32.7, 6];
- double y = x;
- y *= 6.0;
- y += 32.7;
- y *= x;
- y += 56.1;
- assert(poly(x, pp) == y);
-}
-
-@safe unittest
-{
- static assert(poly(3.0, [1.0, 2.0, 3.0]) == 34);
-}
-
-private Unqual!(CommonType!(T1, T2)) polyImplBase(T1, T2)(T1 x, in T2[] A) @trusted pure nothrow @nogc
-if (isFloatingPoint!T1 && isFloatingPoint!T2)
-{
- ptrdiff_t i = A.length - 1;
- typeof(return) r = A[i];
- while (--i >= 0)
- {
- r *= x;
- r += A[i];
- }
- return r;
-}
-
-private real polyImpl(real x, in real[] A) @trusted pure nothrow @nogc
-{
- version (D_InlineAsm_X86)
- {
- if (__ctfe)
- {
- return polyImplBase(x, A);
- }
- version (Windows)
- {
- // BUG: This code assumes a frame pointer in EBP.
- asm pure nothrow @nogc // assembler by W. Bright
- {
- // EDX = (A.length - 1) * real.sizeof
- mov ECX,A[EBP] ; // ECX = A.length
- dec ECX ;
- lea EDX,[ECX][ECX*8] ;
- add EDX,ECX ;
- add EDX,A+4[EBP] ;
- fld real ptr [EDX] ; // ST0 = coeff[ECX]
- jecxz return_ST ;
- fld x[EBP] ; // ST0 = x
- fxch ST(1) ; // ST1 = x, ST0 = r
- align 4 ;
- L2: fmul ST,ST(1) ; // r *= x
- fld real ptr -10[EDX] ;
- sub EDX,10 ; // deg--
- faddp ST(1),ST ;
- dec ECX ;
- jne L2 ;
- fxch ST(1) ; // ST1 = r, ST0 = x
- fstp ST(0) ; // dump x
- align 4 ;
- return_ST: ;
- ;
- }
- }
- else version (linux)
- {
- asm pure nothrow @nogc // assembler by W. Bright
- {
- // EDX = (A.length - 1) * real.sizeof
- mov ECX,A[EBP] ; // ECX = A.length
- dec ECX ;
- lea EDX,[ECX*8] ;
- lea EDX,[EDX][ECX*4] ;
- add EDX,A+4[EBP] ;
- fld real ptr [EDX] ; // ST0 = coeff[ECX]
- jecxz return_ST ;
- fld x[EBP] ; // ST0 = x
- fxch ST(1) ; // ST1 = x, ST0 = r
- align 4 ;
- L2: fmul ST,ST(1) ; // r *= x
- fld real ptr -12[EDX] ;
- sub EDX,12 ; // deg--
- faddp ST(1),ST ;
- dec ECX ;
- jne L2 ;
- fxch ST(1) ; // ST1 = r, ST0 = x
- fstp ST(0) ; // dump x
- align 4 ;
- return_ST: ;
- ;
- }
- }
- else version (OSX)
- {
- asm pure nothrow @nogc // assembler by W. Bright
- {
- // EDX = (A.length - 1) * real.sizeof
- mov ECX,A[EBP] ; // ECX = A.length
- dec ECX ;
- lea EDX,[ECX*8] ;
- add EDX,EDX ;
- add EDX,A+4[EBP] ;
- fld real ptr [EDX] ; // ST0 = coeff[ECX]
- jecxz return_ST ;
- fld x[EBP] ; // ST0 = x
- fxch ST(1) ; // ST1 = x, ST0 = r
- align 4 ;
- L2: fmul ST,ST(1) ; // r *= x
- fld real ptr -16[EDX] ;
- sub EDX,16 ; // deg--
- faddp ST(1),ST ;
- dec ECX ;
- jne L2 ;
- fxch ST(1) ; // ST1 = r, ST0 = x
- fstp ST(0) ; // dump x
- align 4 ;
- return_ST: ;
- ;
- }
- }
- else version (FreeBSD)
- {
- asm pure nothrow @nogc // assembler by W. Bright
- {
- // EDX = (A.length - 1) * real.sizeof
- mov ECX,A[EBP] ; // ECX = A.length
- dec ECX ;
- lea EDX,[ECX*8] ;
- lea EDX,[EDX][ECX*4] ;
- add EDX,A+4[EBP] ;
- fld real ptr [EDX] ; // ST0 = coeff[ECX]
- jecxz return_ST ;
- fld x[EBP] ; // ST0 = x
- fxch ST(1) ; // ST1 = x, ST0 = r
- align 4 ;
- L2: fmul ST,ST(1) ; // r *= x
- fld real ptr -12[EDX] ;
- sub EDX,12 ; // deg--
- faddp ST(1),ST ;
- dec ECX ;
- jne L2 ;
- fxch ST(1) ; // ST1 = r, ST0 = x
- fstp ST(0) ; // dump x
- align 4 ;
- return_ST: ;
- ;
- }
- }
- else version (Solaris)
- {
- asm pure nothrow @nogc // assembler by W. Bright
- {
- // EDX = (A.length - 1) * real.sizeof
- mov ECX,A[EBP] ; // ECX = A.length
- dec ECX ;
- lea EDX,[ECX*8] ;
- lea EDX,[EDX][ECX*4] ;
- add EDX,A+4[EBP] ;
- fld real ptr [EDX] ; // ST0 = coeff[ECX]
- jecxz return_ST ;
- fld x[EBP] ; // ST0 = x
- fxch ST(1) ; // ST1 = x, ST0 = r
- align 4 ;
- L2: fmul ST,ST(1) ; // r *= x
- fld real ptr -12[EDX] ;
- sub EDX,12 ; // deg--
- faddp ST(1),ST ;
- dec ECX ;
- jne L2 ;
- fxch ST(1) ; // ST1 = r, ST0 = x
- fstp ST(0) ; // dump x
- align 4 ;
- return_ST: ;
- ;
- }
- }
- else version (DragonFlyBSD)
- {
- asm pure nothrow @nogc // assembler by W. Bright
- {
- // EDX = (A.length - 1) * real.sizeof
- mov ECX,A[EBP] ; // ECX = A.length
- dec ECX ;
- lea EDX,[ECX*8] ;
- lea EDX,[EDX][ECX*4] ;
- add EDX,A+4[EBP] ;
- fld real ptr [EDX] ; // ST0 = coeff[ECX]
- jecxz return_ST ;
- fld x[EBP] ; // ST0 = x
- fxch ST(1) ; // ST1 = x, ST0 = r
- align 4 ;
- L2: fmul ST,ST(1) ; // r *= x
- fld real ptr -12[EDX] ;
- sub EDX,12 ; // deg--
- faddp ST(1),ST ;
- dec ECX ;
- jne L2 ;
- fxch ST(1) ; // ST1 = r, ST0 = x
- fstp ST(0) ; // dump x
- align 4 ;
- return_ST: ;
- ;
- }
- }
- else
- {
- static assert(0);
- }
- }
- else
- {
- return polyImplBase(x, A);
- }
-}
-
-
-/**
- Computes whether two values are approximately equal, admitting a maximum
- relative difference, and a maximum absolute difference.
-
- Params:
- lhs = First item to compare.
- rhs = Second item to compare.
- maxRelDiff = Maximum allowable difference relative to `rhs`.
- maxAbsDiff = Maximum absolute difference.
-
- Returns:
- `true` if the two items are approximately equal under either criterium.
- If one item is a range, and the other is a single value, then the result
- is the logical and-ing of calling `approxEqual` on each element of the
- ranged item against the single item. If both items are ranges, then
- `approxEqual` returns `true` if and only if the ranges have the same
- number of elements and if `approxEqual` evaluates to `true` for each
- pair of elements.
- */
-bool approxEqual(T, U, V)(T lhs, U rhs, V maxRelDiff, V maxAbsDiff = 1e-5)
-{
- import std.range.primitives : empty, front, isInputRange, popFront;
- static if (isInputRange!T)
- {
- static if (isInputRange!U)
- {
- // Two ranges
- for (;; lhs.popFront(), rhs.popFront())
- {
- if (lhs.empty) return rhs.empty;
- if (rhs.empty) return lhs.empty;
- if (!approxEqual(lhs.front, rhs.front, maxRelDiff, maxAbsDiff))
- return false;
- }
- }
- else static if (isIntegral!U)
- {
- // convert rhs to real
- return approxEqual(lhs, real(rhs), maxRelDiff, maxAbsDiff);
- }
- else
- {
- // lhs is range, rhs is number
- for (; !lhs.empty; lhs.popFront())
- {
- if (!approxEqual(lhs.front, rhs, maxRelDiff, maxAbsDiff))
- return false;
- }
- return true;
- }
- }
- else
- {
- static if (isInputRange!U)
- {
- // lhs is number, rhs is range
- for (; !rhs.empty; rhs.popFront())
- {
- if (!approxEqual(lhs, rhs.front, maxRelDiff, maxAbsDiff))
- return false;
- }
- return true;
- }
- else static if (isIntegral!T || isIntegral!U)
- {
- // convert both lhs and rhs to real
- return approxEqual(real(lhs), real(rhs), maxRelDiff, maxAbsDiff);
- }
- else
- {
- // two numbers
- //static assert(is(T : real) && is(U : real));
- if (rhs == 0)
- {
- return fabs(lhs) <= maxAbsDiff;
- }
- static if (is(typeof(lhs.infinity)) && is(typeof(rhs.infinity)))
- {
- if (lhs == lhs.infinity && rhs == rhs.infinity ||
- lhs == -lhs.infinity && rhs == -rhs.infinity) return true;
- }
- return fabs((lhs - rhs) / rhs) <= maxRelDiff
- || maxAbsDiff != 0 && fabs(lhs - rhs) <= maxAbsDiff;
- }
- }
-}
-
-/**
- Returns $(D approxEqual(lhs, rhs, 1e-2, 1e-5)).
- */
-bool approxEqual(T, U)(T lhs, U rhs)
-{
- return approxEqual(lhs, rhs, 1e-2, 1e-5);
-}
-
-///
-@safe pure nothrow unittest
-{
- assert(approxEqual(1.0, 1.0099));
- assert(!approxEqual(1.0, 1.011));
- float[] arr1 = [ 1.0, 2.0, 3.0 ];
- double[] arr2 = [ 1.001, 1.999, 3 ];
- assert(approxEqual(arr1, arr2));
-
- real num = real.infinity;
- assert(num == real.infinity); // Passes.
- assert(approxEqual(num, real.infinity)); // Fails.
- num = -real.infinity;
- assert(num == -real.infinity); // Passes.
- assert(approxEqual(num, -real.infinity)); // Fails.
-
- assert(!approxEqual(3, 0));
- assert(approxEqual(3, 3));
- assert(approxEqual(3.0, 3));
- assert(approxEqual([3, 3, 3], 3.0));
- assert(approxEqual([3.0, 3.0, 3.0], 3));
- int a = 10;
- assert(approxEqual(10, a));
-}
-
-@safe pure nothrow @nogc unittest
-{
- real num = real.infinity;
- assert(num == real.infinity); // Passes.
- assert(approxEqual(num, real.infinity)); // Fails.
-}
-
-
-@safe pure nothrow @nogc unittest
-{
- float f = sqrt(2.0f);
- assert(fabs(f * f - 2.0f) < .00001);
-
- double d = sqrt(2.0);
- assert(fabs(d * d - 2.0) < .00001);
-
- real r = sqrt(2.0L);
- assert(fabs(r * r - 2.0) < .00001);
-}
-
-@safe pure nothrow @nogc unittest
-{
- float f = fabs(-2.0f);
- assert(f == 2);
-
- double d = fabs(-2.0);
- assert(d == 2);
-
- real r = fabs(-2.0L);
- assert(r == 2);
-}
-
-@safe pure nothrow @nogc unittest
-{
- float f = sin(-2.0f);
- assert(fabs(f - -0.909297f) < .00001);
-
- double d = sin(-2.0);
- assert(fabs(d - -0.909297f) < .00001);
-
- real r = sin(-2.0L);
- assert(fabs(r - -0.909297f) < .00001);
-}
-
-@safe pure nothrow @nogc unittest
-{
- float f = cos(-2.0f);
- assert(fabs(f - -0.416147f) < .00001);
-
- double d = cos(-2.0);
- assert(fabs(d - -0.416147f) < .00001);
-
- real r = cos(-2.0L);
- assert(fabs(r - -0.416147f) < .00001);
-}
-
-@safe pure nothrow @nogc unittest
-{
- float f = tan(-2.0f);
- assert(fabs(f - 2.18504f) < .00001);
-
- double d = tan(-2.0);
- assert(fabs(d - 2.18504f) < .00001);
-
- real r = tan(-2.0L);
- assert(fabs(r - 2.18504f) < .00001);
-
- // Verify correct behavior for large inputs
- assert(!isNaN(tan(0x1p63)));
- assert(!isNaN(tan(0x1p300L)));
- assert(!isNaN(tan(-0x1p63)));
- assert(!isNaN(tan(-0x1p300L)));
-}
-
-@safe pure nothrow unittest
-{
- // issue 6381: floor/ceil should be usable in pure function.
- auto x = floor(1.2);
- auto y = ceil(1.2);
-}
-
-@safe pure nothrow unittest
-{
- // relative comparison depends on rhs, make sure proper side is used when
- // comparing range to single value. Based on bugzilla issue 15763
- auto a = [2e-3 - 1e-5];
- auto b = 2e-3 + 1e-5;
- assert(a[0].approxEqual(b));
- assert(!b.approxEqual(a[0]));
- assert(a.approxEqual(b));
- assert(!b.approxEqual(a));
-}
-
-/***********************************
- * Defines a total order on all floating-point numbers.
- *
- * The order is defined as follows:
- * $(UL
- * $(LI All numbers in [-$(INFIN), +$(INFIN)] are ordered
- * the same way as by built-in comparison, with the exception of
- * -0.0, which is less than +0.0;)
- * $(LI If the sign bit is set (that is, it's 'negative'), $(NAN) is less
- * than any number; if the sign bit is not set (it is 'positive'),
- * $(NAN) is greater than any number;)
- * $(LI $(NAN)s of the same sign are ordered by the payload ('negative'
- * ones - in reverse order).)
- * )
- *
- * Returns:
- * negative value if $(D x) precedes $(D y) in the order specified above;
- * 0 if $(D x) and $(D y) are identical, and positive value otherwise.
- *
- * See_Also:
- * $(MYREF isIdentical)
- * Standards: Conforms to IEEE 754-2008
- */
-int cmp(T)(const(T) x, const(T) y) @nogc @trusted pure nothrow
-if (isFloatingPoint!T)
-{
- alias F = floatTraits!T;
-
- static if (F.realFormat == RealFormat.ieeeSingle
- || F.realFormat == RealFormat.ieeeDouble)
- {
- static if (T.sizeof == 4)
- alias UInt = uint;
- else
- alias UInt = ulong;
-
- union Repainter
- {
- T number;
- UInt bits;
- }
-
- enum msb = ~(UInt.max >>> 1);
-
- import std.typecons : Tuple;
- Tuple!(Repainter, Repainter) vars = void;
- vars[0].number = x;
- vars[1].number = y;
-
- foreach (ref var; vars)
- if (var.bits & msb)
- var.bits = ~var.bits;
- else
- var.bits |= msb;
-
- if (vars[0].bits < vars[1].bits)
- return -1;
- else if (vars[0].bits > vars[1].bits)
- return 1;
- else
- return 0;
- }
- else static if (F.realFormat == RealFormat.ieeeExtended53
- || F.realFormat == RealFormat.ieeeExtended
- || F.realFormat == RealFormat.ieeeQuadruple)
- {
- static if (F.realFormat == RealFormat.ieeeQuadruple)
- alias RemT = ulong;
- else
- alias RemT = ushort;
-
- struct Bits
- {
- ulong bulk;
- RemT rem;
- }
-
- union Repainter
- {
- T number;
- Bits bits;
- ubyte[T.sizeof] bytes;
- }
-
- import std.typecons : Tuple;
- Tuple!(Repainter, Repainter) vars = void;
- vars[0].number = x;
- vars[1].number = y;
-
- foreach (ref var; vars)
- if (var.bytes[F.SIGNPOS_BYTE] & 0x80)
- {
- var.bits.bulk = ~var.bits.bulk;
- var.bits.rem = cast(typeof(var.bits.rem))(-1 - var.bits.rem); // ~var.bits.rem
- }
- else
- {
- var.bytes[F.SIGNPOS_BYTE] |= 0x80;
- }
-
- version (LittleEndian)
- {
- if (vars[0].bits.rem < vars[1].bits.rem)
- return -1;
- else if (vars[0].bits.rem > vars[1].bits.rem)
- return 1;
- else if (vars[0].bits.bulk < vars[1].bits.bulk)
- return -1;
- else if (vars[0].bits.bulk > vars[1].bits.bulk)
- return 1;
- else
- return 0;
- }
- else
- {
- if (vars[0].bits.bulk < vars[1].bits.bulk)
- return -1;
- else if (vars[0].bits.bulk > vars[1].bits.bulk)
- return 1;
- else if (vars[0].bits.rem < vars[1].bits.rem)
- return -1;
- else if (vars[0].bits.rem > vars[1].bits.rem)
- return 1;
- else
- return 0;
- }
- }
- else
- {
- // IBM Extended doubledouble does not follow the general
- // sign-exponent-significand layout, so has to be handled generically
-
- const int xSign = signbit(x),
- ySign = signbit(y);
-
- if (xSign == 1 && ySign == 1)
- return cmp(-y, -x);
- else if (xSign == 1)
- return -1;
- else if (ySign == 1)
- return 1;
- else if (x < y)
- return -1;
- else if (x == y)
- return 0;
- else if (x > y)
- return 1;
- else if (isNaN(x) && !isNaN(y))
- return 1;
- else if (isNaN(y) && !isNaN(x))
- return -1;
- else if (getNaNPayload(x) < getNaNPayload(y))
- return -1;
- else if (getNaNPayload(x) > getNaNPayload(y))
- return 1;
- else
- return 0;
- }
-}
-
-/// Most numbers are ordered naturally.
-@safe unittest
-{
- assert(cmp(-double.infinity, -double.max) < 0);
- assert(cmp(-double.max, -100.0) < 0);
- assert(cmp(-100.0, -0.5) < 0);
- assert(cmp(-0.5, 0.0) < 0);
- assert(cmp(0.0, 0.5) < 0);
- assert(cmp(0.5, 100.0) < 0);
- assert(cmp(100.0, double.max) < 0);
- assert(cmp(double.max, double.infinity) < 0);
-
- assert(cmp(1.0, 1.0) == 0);
-}
-
-/// Positive and negative zeroes are distinct.
-@safe unittest
-{
- assert(cmp(-0.0, +0.0) < 0);
- assert(cmp(+0.0, -0.0) > 0);
-}
-
-/// Depending on the sign, $(NAN)s go to either end of the spectrum.
-@safe unittest
-{
- assert(cmp(-double.nan, -double.infinity) < 0);
- assert(cmp(double.infinity, double.nan) < 0);
- assert(cmp(-double.nan, double.nan) < 0);
-}
-
-/// $(NAN)s of the same sign are ordered by the payload.
-@safe unittest
-{
- assert(cmp(NaN(10), NaN(20)) < 0);
- assert(cmp(-NaN(20), -NaN(10)) < 0);
-}
-
-@safe unittest
-{
- import std.meta : AliasSeq;
- foreach (T; AliasSeq!(float, double, real))
- {
- T[] values = [-cast(T) NaN(20), -cast(T) NaN(10), -T.nan, -T.infinity,
- -T.max, -T.max / 2, T(-16.0), T(-1.0).nextDown,
- T(-1.0), T(-1.0).nextUp,
- T(-0.5), -T.min_normal, (-T.min_normal).nextUp,
- -2 * T.min_normal * T.epsilon,
- -T.min_normal * T.epsilon,
- T(-0.0), T(0.0),
- T.min_normal * T.epsilon,
- 2 * T.min_normal * T.epsilon,
- T.min_normal.nextDown, T.min_normal, T(0.5),
- T(1.0).nextDown, T(1.0),
- T(1.0).nextUp, T(16.0), T.max / 2, T.max,
- T.infinity, T.nan, cast(T) NaN(10), cast(T) NaN(20)];
-
- foreach (i, x; values)
- {
- foreach (y; values[i + 1 .. $])
- {
- assert(cmp(x, y) < 0);
- assert(cmp(y, x) > 0);
- }
- assert(cmp(x, x) == 0);
- }
- }
-}
-
-private enum PowType
-{
- floor,
- ceil
-}
-
-pragma(inline, true)
-private T powIntegralImpl(PowType type, T)(T val)
-{
- import core.bitop : bsr;
-
- if (val == 0 || (type == PowType.ceil && (val > T.max / 2 || val == T.min)))
- return 0;
- else
- {
- static if (isSigned!T)
- return cast(Unqual!T) (val < 0 ? -(T(1) << bsr(0 - val) + type) : T(1) << bsr(val) + type);
- else
- return cast(Unqual!T) (T(1) << bsr(val) + type);
- }
-}
-
-private T powFloatingPointImpl(PowType type, T)(T x)
-{
- if (!x.isFinite)
- return x;
-
- if (!x)
- return x;
-
- int exp;
- auto y = frexp(x, exp);
-
- static if (type == PowType.ceil)
- y = ldexp(cast(T) 0.5, exp + 1);
- else
- y = ldexp(cast(T) 0.5, exp);
-
- if (!y.isFinite)
- return cast(T) 0.0;
-
- y = copysign(y, x);
-
- return y;
-}
-
-/**
- * Gives the next power of two after $(D val). `T` can be any built-in
- * numerical type.
- *
- * If the operation would lead to an over/underflow, this function will
- * return `0`.
- *
- * Params:
- * val = any number
- *
- * Returns:
- * the next power of two after $(D val)
- */
-T nextPow2(T)(const T val)
-if (isIntegral!T)
-{
- return powIntegralImpl!(PowType.ceil)(val);
-}
-
-/// ditto
-T nextPow2(T)(const T val)
-if (isFloatingPoint!T)
-{
- return powFloatingPointImpl!(PowType.ceil)(val);
-}
-
-///
-@safe @nogc pure nothrow unittest
-{
- assert(nextPow2(2) == 4);
- assert(nextPow2(10) == 16);
- assert(nextPow2(4000) == 4096);
-
- assert(nextPow2(-2) == -4);
- assert(nextPow2(-10) == -16);
-
- assert(nextPow2(uint.max) == 0);
- assert(nextPow2(uint.min) == 0);
- assert(nextPow2(size_t.max) == 0);
- assert(nextPow2(size_t.min) == 0);
-
- assert(nextPow2(int.max) == 0);
- assert(nextPow2(int.min) == 0);
- assert(nextPow2(long.max) == 0);
- assert(nextPow2(long.min) == 0);
-}
-
-///
-@safe @nogc pure nothrow unittest
-{
- assert(nextPow2(2.1) == 4.0);
- assert(nextPow2(-2.0) == -4.0);
- assert(nextPow2(0.25) == 0.5);
- assert(nextPow2(-4.0) == -8.0);
-
- assert(nextPow2(double.max) == 0.0);
- assert(nextPow2(double.infinity) == double.infinity);
-}
-
-@safe @nogc pure nothrow unittest
-{
- assert(nextPow2(ubyte(2)) == 4);
- assert(nextPow2(ubyte(10)) == 16);
-
- assert(nextPow2(byte(2)) == 4);
- assert(nextPow2(byte(10)) == 16);
-
- assert(nextPow2(short(2)) == 4);
- assert(nextPow2(short(10)) == 16);
- assert(nextPow2(short(4000)) == 4096);
-
- assert(nextPow2(ushort(2)) == 4);
- assert(nextPow2(ushort(10)) == 16);
- assert(nextPow2(ushort(4000)) == 4096);
-}
-
-@safe @nogc pure nothrow unittest
-{
- foreach (ulong i; 1 .. 62)
- {
- assert(nextPow2(1UL << i) == 2UL << i);
- assert(nextPow2((1UL << i) - 1) == 1UL << i);
- assert(nextPow2((1UL << i) + 1) == 2UL << i);
- assert(nextPow2((1UL << i) + (1UL<<(i-1))) == 2UL << i);
- }
-}
-
-@safe @nogc pure nothrow unittest
-{
- import std.meta : AliasSeq;
-
- foreach (T; AliasSeq!(float, double, real))
- {
- enum T subNormal = T.min_normal / 2;
-
- static if (subNormal) assert(nextPow2(subNormal) == T.min_normal);
-
- assert(nextPow2(T(0.0)) == 0.0);
-
- assert(nextPow2(T(2.0)) == 4.0);
- assert(nextPow2(T(2.1)) == 4.0);
- assert(nextPow2(T(3.1)) == 4.0);
- assert(nextPow2(T(4.0)) == 8.0);
- assert(nextPow2(T(0.25)) == 0.5);
-
- assert(nextPow2(T(-2.0)) == -4.0);
- assert(nextPow2(T(-2.1)) == -4.0);
- assert(nextPow2(T(-3.1)) == -4.0);
- assert(nextPow2(T(-4.0)) == -8.0);
- assert(nextPow2(T(-0.25)) == -0.5);
-
- assert(nextPow2(T.max) == 0);
- assert(nextPow2(-T.max) == 0);
-
- assert(nextPow2(T.infinity) == T.infinity);
- assert(nextPow2(T.init).isNaN);
- }
-}
-
-@safe @nogc pure nothrow unittest // Issue 15973
-{
- assert(nextPow2(uint.max / 2) == uint.max / 2 + 1);
- assert(nextPow2(uint.max / 2 + 2) == 0);
- assert(nextPow2(int.max / 2) == int.max / 2 + 1);
- assert(nextPow2(int.max / 2 + 2) == 0);
- assert(nextPow2(int.min + 1) == int.min);
-}
-
-/**
- * Gives the last power of two before $(D val). $(T) can be any built-in
- * numerical type.
- *
- * Params:
- * val = any number
- *
- * Returns:
- * the last power of two before $(D val)
- */
-T truncPow2(T)(const T val)
-if (isIntegral!T)
-{
- return powIntegralImpl!(PowType.floor)(val);
-}
-
-/// ditto
-T truncPow2(T)(const T val)
-if (isFloatingPoint!T)
-{
- return powFloatingPointImpl!(PowType.floor)(val);
-}
-
-///
-@safe @nogc pure nothrow unittest
-{
- assert(truncPow2(3) == 2);
- assert(truncPow2(4) == 4);
- assert(truncPow2(10) == 8);
- assert(truncPow2(4000) == 2048);
-
- assert(truncPow2(-5) == -4);
- assert(truncPow2(-20) == -16);
-
- assert(truncPow2(uint.max) == int.max + 1);
- assert(truncPow2(uint.min) == 0);
- assert(truncPow2(ulong.max) == long.max + 1);
- assert(truncPow2(ulong.min) == 0);
-
- assert(truncPow2(int.max) == (int.max / 2) + 1);
- assert(truncPow2(int.min) == int.min);
- assert(truncPow2(long.max) == (long.max / 2) + 1);
- assert(truncPow2(long.min) == long.min);
-}
-
-///
-@safe @nogc pure nothrow unittest
-{
- assert(truncPow2(2.1) == 2.0);
- assert(truncPow2(7.0) == 4.0);
- assert(truncPow2(-1.9) == -1.0);
- assert(truncPow2(0.24) == 0.125);
- assert(truncPow2(-7.0) == -4.0);
-
- assert(truncPow2(double.infinity) == double.infinity);
-}
-
-@safe @nogc pure nothrow unittest
-{
- assert(truncPow2(ubyte(3)) == 2);
- assert(truncPow2(ubyte(4)) == 4);
- assert(truncPow2(ubyte(10)) == 8);
-
- assert(truncPow2(byte(3)) == 2);
- assert(truncPow2(byte(4)) == 4);
- assert(truncPow2(byte(10)) == 8);
-
- assert(truncPow2(ushort(3)) == 2);
- assert(truncPow2(ushort(4)) == 4);
- assert(truncPow2(ushort(10)) == 8);
- assert(truncPow2(ushort(4000)) == 2048);
-
- assert(truncPow2(short(3)) == 2);
- assert(truncPow2(short(4)) == 4);
- assert(truncPow2(short(10)) == 8);
- assert(truncPow2(short(4000)) == 2048);
-}
-
-@safe @nogc pure nothrow unittest
-{
- foreach (ulong i; 1 .. 62)
- {
- assert(truncPow2(2UL << i) == 2UL << i);
- assert(truncPow2((2UL << i) + 1) == 2UL << i);
- assert(truncPow2((2UL << i) - 1) == 1UL << i);
- assert(truncPow2((2UL << i) - (2UL<<(i-1))) == 1UL << i);
- }
-}
-
-@safe @nogc pure nothrow unittest
-{
- import std.meta : AliasSeq;
-
- foreach (T; AliasSeq!(float, double, real))
- {
- assert(truncPow2(T(0.0)) == 0.0);
-
- assert(truncPow2(T(4.0)) == 4.0);
- assert(truncPow2(T(2.1)) == 2.0);
- assert(truncPow2(T(3.5)) == 2.0);
- assert(truncPow2(T(7.0)) == 4.0);
- assert(truncPow2(T(0.24)) == 0.125);
-
- assert(truncPow2(T(-2.0)) == -2.0);
- assert(truncPow2(T(-2.1)) == -2.0);
- assert(truncPow2(T(-3.1)) == -2.0);
- assert(truncPow2(T(-7.0)) == -4.0);
- assert(truncPow2(T(-0.24)) == -0.125);
-
- assert(truncPow2(T.infinity) == T.infinity);
- assert(truncPow2(T.init).isNaN);
- }
-}
-
-/**
-Check whether a number is an integer power of two.
-
-Note that only positive numbers can be integer powers of two. This
-function always return `false` if `x` is negative or zero.
-
-Params:
- x = the number to test
-
-Returns:
- `true` if `x` is an integer power of two.
-*/
-bool isPowerOf2(X)(const X x) pure @safe nothrow @nogc
-if (isNumeric!X)
-{
- static if (isFloatingPoint!X)
- {
- int exp;
- const X sig = frexp(x, exp);
-
- return (exp != int.min) && (sig is cast(X) 0.5L);
- }
- else
- {
- static if (isSigned!X)
- {
- auto y = cast(typeof(x + 0))x;
- return y > 0 && !(y & (y - 1));
- }
- else
- {
- auto y = cast(typeof(x + 0u))x;
- return (y & -y) > (y - 1);
- }
- }
-}
-///
-@safe unittest
-{
- assert( isPowerOf2(1.0L));
- assert( isPowerOf2(2.0L));
- assert( isPowerOf2(0.5L));
- assert( isPowerOf2(pow(2.0L, 96)));
- assert( isPowerOf2(pow(2.0L, -77)));
-
- assert(!isPowerOf2(-2.0L));
- assert(!isPowerOf2(-0.5L));
- assert(!isPowerOf2(0.0L));
- assert(!isPowerOf2(4.315));
- assert(!isPowerOf2(1.0L / 3.0L));
-
- assert(!isPowerOf2(real.nan));
- assert(!isPowerOf2(real.infinity));
-}
-///
-@safe unittest
-{
- assert( isPowerOf2(1));
- assert( isPowerOf2(2));
- assert( isPowerOf2(1uL << 63));
-
- assert(!isPowerOf2(-4));
- assert(!isPowerOf2(0));
- assert(!isPowerOf2(1337u));
-}
-
-@safe unittest
-{
- import std.meta : AliasSeq;
-
- immutable smallP2 = pow(2.0L, -62);
- immutable bigP2 = pow(2.0L, 50);
- immutable smallP7 = pow(7.0L, -35);
- immutable bigP7 = pow(7.0L, 30);
-
- foreach (X; AliasSeq!(float, double, real))
- {
- immutable min_sub = X.min_normal * X.epsilon;
-
- foreach (x; AliasSeq!(smallP2, min_sub, X.min_normal, .25L, 0.5L, 1.0L,
- 2.0L, 8.0L, pow(2.0L, X.max_exp - 1), bigP2))
- {
- assert( isPowerOf2(cast(X) x));
- assert(!isPowerOf2(cast(X)-x));
- }
-
- foreach (x; AliasSeq!(0.0L, 3 * min_sub, smallP7, 0.1L, 1337.0L, bigP7, X.max, real.nan, real.infinity))
- {
- assert(!isPowerOf2(cast(X) x));
- assert(!isPowerOf2(cast(X)-x));
- }
- }
-
- foreach (X; AliasSeq!(byte, ubyte, short, ushort, int, uint, long, ulong))
- {
- foreach (x; [1, 2, 4, 8, (X.max >>> 1) + 1])
- {
- assert( isPowerOf2(cast(X) x));
- static if (isSigned!X)
- assert(!isPowerOf2(cast(X)-x));
- }
-
- foreach (x; [0, 3, 5, 13, 77, X.min, X.max])
- assert(!isPowerOf2(cast(X) x));
- }
-}