diff options
Diffstat (limited to 'rts/StgPrimFloat.c')
| -rw-r--r-- | rts/StgPrimFloat.c | 254 |
1 files changed, 5 insertions, 249 deletions
diff --git a/rts/StgPrimFloat.c b/rts/StgPrimFloat.c index 5987aa9589..e523f328c3 100644 --- a/rts/StgPrimFloat.c +++ b/rts/StgPrimFloat.c @@ -10,7 +10,12 @@ #include "PosixSource.h" #include "Rts.h" +#include "StgPrimFloat.h" + #include <math.h> +#include <float.h> + +#define IEEE_FLOATING_POINT 1 /* * Encoding and decoding Doubles. Code based on the HBC code @@ -218,252 +223,3 @@ __decodeFloat_Int (I_ *man, I_ *exp, StgFloat flt) } } -union stg_ieee754_flt -{ - float f; - struct { - -#if WORDS_BIGENDIAN - unsigned int negative:1; - unsigned int exponent:8; - unsigned int mantissa:23; -#else - unsigned int mantissa:23; - unsigned int exponent:8; - unsigned int negative:1; -#endif - } ieee; - struct { - -#if WORDS_BIGENDIAN - unsigned int negative:1; - unsigned int exponent:8; - unsigned int quiet_nan:1; - unsigned int mantissa:22; -#else - unsigned int mantissa:22; - unsigned int quiet_nan:1; - unsigned int exponent:8; - unsigned int negative:1; -#endif - } ieee_nan; -}; - -/* - - To recap, here's the representation of a double precision - IEEE floating point number: - - sign 63 sign bit (0==positive, 1==negative) - exponent 62-52 exponent (biased by 1023) - fraction 51-0 fraction (bits to right of binary point) -*/ - -union stg_ieee754_dbl -{ - double d; - struct { - -#if WORDS_BIGENDIAN - unsigned int negative:1; - unsigned int exponent:11; - unsigned int mantissa0:20; - unsigned int mantissa1:32; -#else -#if FLOAT_WORDS_BIGENDIAN - unsigned int mantissa0:20; - unsigned int exponent:11; - unsigned int negative:1; - unsigned int mantissa1:32; -#else - unsigned int mantissa1:32; - unsigned int mantissa0:20; - unsigned int exponent:11; - unsigned int negative:1; -#endif -#endif - } ieee; - /* This format makes it easier to see if a NaN is a signalling NaN. */ - struct { - -#if WORDS_BIGENDIAN - unsigned int negative:1; - unsigned int exponent:11; - unsigned int quiet_nan:1; - unsigned int mantissa0:19; - unsigned int mantissa1:32; -#else -#if FLOAT_WORDS_BIGENDIAN - unsigned int mantissa0:19; - unsigned int quiet_nan:1; - unsigned int exponent:11; - unsigned int negative:1; - unsigned int mantissa1:32; -#else - unsigned int mantissa1:32; - unsigned int mantissa0:19; - unsigned int quiet_nan:1; - unsigned int exponent:11; - unsigned int negative:1; -#endif -#endif - } ieee_nan; -}; - -/* - * Predicates for testing for extreme IEEE fp values. Used - * by the bytecode evaluator and the Prelude. - * - */ - -/* In case you don't suppport IEEE, you'll just get dummy defs.. */ -#ifdef IEEE_FLOATING_POINT - -StgInt -isDoubleNaN(StgDouble d) -{ - union stg_ieee754_dbl u; - - u.d = d; - - return ( - u.ieee.exponent == 2047 /* 2^11 - 1 */ && /* Is the exponent all ones? */ - (u.ieee.mantissa0 != 0 || u.ieee.mantissa1 != 0) - /* and the mantissa non-zero? */ - ); -} - -StgInt -isDoubleInfinite(StgDouble d) -{ - union stg_ieee754_dbl u; - - u.d = d; - - /* Inf iff exponent is all ones, mantissa all zeros */ - return ( - u.ieee.exponent == 2047 /* 2^11 - 1 */ && - u.ieee.mantissa0 == 0 && - u.ieee.mantissa1 == 0 - ); -} - -StgInt -isDoubleDenormalized(StgDouble d) -{ - union stg_ieee754_dbl u; - - u.d = d; - - /* A (single/double/quad) precision floating point number - is denormalised iff: - - exponent is zero - - mantissa is non-zero. - - (don't care about setting of sign bit.) - - */ - return ( - u.ieee.exponent == 0 && - (u.ieee.mantissa0 != 0 || - u.ieee.mantissa1 != 0) - ); - -} - -StgInt -isDoubleNegativeZero(StgDouble d) -{ - union stg_ieee754_dbl u; - - u.d = d; - /* sign (bit 63) set (only) => negative zero */ - - return ( - u.ieee.negative == 1 && - u.ieee.exponent == 0 && - u.ieee.mantissa0 == 0 && - u.ieee.mantissa1 == 0); -} - -/* Same tests, this time for StgFloats. */ - -/* - To recap, here's the representation of a single precision - IEEE floating point number: - - sign 31 sign bit (0 == positive, 1 == negative) - exponent 30-23 exponent (biased by 127) - fraction 22-0 fraction (bits to right of binary point) -*/ - - -StgInt -isFloatNaN(StgFloat f) -{ - union stg_ieee754_flt u; - u.f = f; - - /* Floating point NaN iff exponent is all ones, mantissa is - non-zero (but see below.) */ - return ( - u.ieee.exponent == 255 /* 2^8 - 1 */ && - u.ieee.mantissa != 0); -} - -StgInt -isFloatInfinite(StgFloat f) -{ - union stg_ieee754_flt u; - u.f = f; - - /* A float is Inf iff exponent is max (all ones), - and mantissa is min(all zeros.) */ - return ( - u.ieee.exponent == 255 /* 2^8 - 1 */ && - u.ieee.mantissa == 0); -} - -StgInt -isFloatDenormalized(StgFloat f) -{ - union stg_ieee754_flt u; - u.f = f; - - /* A (single/double/quad) precision floating point number - is denormalised iff: - - exponent is zero - - mantissa is non-zero. - - (don't care about setting of sign bit.) - - */ - return ( - u.ieee.exponent == 0 && - u.ieee.mantissa != 0); -} - -StgInt -isFloatNegativeZero(StgFloat f) -{ - union stg_ieee754_flt u; - u.f = f; - - /* sign (bit 31) set (only) => negative zero */ - return ( - u.ieee.negative && - u.ieee.exponent == 0 && - u.ieee.mantissa == 0); -} - -#else /* ! IEEE_FLOATING_POINT */ - -/* Dummy definitions of predicates - they all return false */ -StgInt isDoubleNaN(d) StgDouble d; { return 0; } -StgInt isDoubleInfinite(d) StgDouble d; { return 0; } -StgInt isDoubleDenormalized(d) StgDouble d; { return 0; } -StgInt isDoubleNegativeZero(d) StgDouble d; { return 0; } -StgInt isFloatNaN(f) StgFloat f; { return 0; } -StgInt isFloatInfinite(f) StgFloat f; { return 0; } -StgInt isFloatDenormalized(f) StgFloat f; { return 0; } -StgInt isFloatNegativeZero(f) StgFloat f; { return 0; } - -#endif /* ! IEEE_FLOATING_POINT */ |