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authorAlexey Samsonov <samsonov@google.com>2014-02-14 09:20:33 +0000
committerAlexey Samsonov <samsonov@google.com>2014-02-14 09:20:33 +0000
commit53aa4fda49f94920139300227786ac47c393f1ce (patch)
tree6d022d04ee279fe1afd89668f346e28a9e3e1559 /lib/muldf3.c
parent6d999e478fecb10dc43f20b85385d25cc239db0a (diff)
downloadcompiler-rt-53aa4fda49f94920139300227786ac47c393f1ce.tar.gz
Move original compiler-rt functions (libgcc replacement) to lib/builtins directory
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@201393 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/muldf3.c')
-rw-r--r--lib/muldf3.c122
1 files changed, 0 insertions, 122 deletions
diff --git a/lib/muldf3.c b/lib/muldf3.c
deleted file mode 100644
index c38edba90..000000000
--- a/lib/muldf3.c
+++ /dev/null
@@ -1,122 +0,0 @@
-//===-- lib/muldf3.c - Double-precision multiplication ------------*- C -*-===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements double-precision soft-float multiplication
-// with the IEEE-754 default rounding (to nearest, ties to even).
-//
-//===----------------------------------------------------------------------===//
-
-#define DOUBLE_PRECISION
-#include "fp_lib.h"
-
-ARM_EABI_FNALIAS(dmul, muldf3)
-
-COMPILER_RT_ABI fp_t
-__muldf3(fp_t a, fp_t b) {
-
- const unsigned int aExponent = toRep(a) >> significandBits & maxExponent;
- const unsigned int bExponent = toRep(b) >> significandBits & maxExponent;
- const rep_t productSign = (toRep(a) ^ toRep(b)) & signBit;
-
- rep_t aSignificand = toRep(a) & significandMask;
- rep_t bSignificand = toRep(b) & significandMask;
- int scale = 0;
-
- // Detect if a or b is zero, denormal, infinity, or NaN.
- if (aExponent-1U >= maxExponent-1U || bExponent-1U >= maxExponent-1U) {
-
- const rep_t aAbs = toRep(a) & absMask;
- const rep_t bAbs = toRep(b) & absMask;
-
- // NaN * anything = qNaN
- if (aAbs > infRep) return fromRep(toRep(a) | quietBit);
- // anything * NaN = qNaN
- if (bAbs > infRep) return fromRep(toRep(b) | quietBit);
-
- if (aAbs == infRep) {
- // infinity * non-zero = +/- infinity
- if (bAbs) return fromRep(aAbs | productSign);
- // infinity * zero = NaN
- else return fromRep(qnanRep);
- }
-
- if (bAbs == infRep) {
- // non-zero * infinity = +/- infinity
- if (aAbs) return fromRep(bAbs | productSign);
- // zero * infinity = NaN
- else return fromRep(qnanRep);
- }
-
- // zero * anything = +/- zero
- if (!aAbs) return fromRep(productSign);
- // anything * zero = +/- zero
- if (!bAbs) return fromRep(productSign);
-
- // one or both of a or b is denormal, the other (if applicable) is a
- // normal number. Renormalize one or both of a and b, and set scale to
- // include the necessary exponent adjustment.
- if (aAbs < implicitBit) scale += normalize(&aSignificand);
- if (bAbs < implicitBit) scale += normalize(&bSignificand);
- }
-
- // Or in the implicit significand bit. (If we fell through from the
- // denormal path it was already set by normalize( ), but setting it twice
- // won't hurt anything.)
- aSignificand |= implicitBit;
- bSignificand |= implicitBit;
-
- // Get the significand of a*b. Before multiplying the significands, shift
- // one of them left to left-align it in the field. Thus, the product will
- // have (exponentBits + 2) integral digits, all but two of which must be
- // zero. Normalizing this result is just a conditional left-shift by one
- // and bumping the exponent accordingly.
- rep_t productHi, productLo;
- wideMultiply(aSignificand, bSignificand << exponentBits,
- &productHi, &productLo);
-
- int productExponent = aExponent + bExponent - exponentBias + scale;
-
- // Normalize the significand, adjust exponent if needed.
- if (productHi & implicitBit) productExponent++;
- else wideLeftShift(&productHi, &productLo, 1);
-
- // If we have overflowed the type, return +/- infinity.
- if (productExponent >= maxExponent) return fromRep(infRep | productSign);
-
- if (productExponent <= 0) {
- // Result is denormal before rounding
- //
- // If the result is so small that it just underflows to zero, return
- // a zero of the appropriate sign. Mathematically there is no need to
- // handle this case separately, but we make it a special case to
- // simplify the shift logic.
- const unsigned int shift = 1U - (unsigned int)productExponent;
- if (shift >= typeWidth) return fromRep(productSign);
-
- // Otherwise, shift the significand of the result so that the round
- // bit is the high bit of productLo.
- wideRightShiftWithSticky(&productHi, &productLo, shift);
- }
-
- else {
- // Result is normal before rounding; insert the exponent.
- productHi &= significandMask;
- productHi |= (rep_t)productExponent << significandBits;
- }
-
- // Insert the sign of the result:
- productHi |= productSign;
-
- // Final rounding. The final result may overflow to infinity, or underflow
- // to zero, but those are the correct results in those cases. We use the
- // default IEEE-754 round-to-nearest, ties-to-even rounding mode.
- if (productLo > signBit) productHi++;
- if (productLo == signBit) productHi += productHi & 1;
- return fromRep(productHi);
-}