/* -----------------------------------------------------------------------------
*
+ * (c) Lennart Augustsson
* (c) The GHC Team, 1998-2000
*
* Miscellaneous support for floating-point primitives
#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
* (lib/fltcode.c).
*/
-#ifdef _SHORT_LIMB
-#define SIZEOF_LIMB_T SIZEOF_UNSIGNED_INT
-#else
-#ifdef _LONG_LONG_LIMB
-#define SIZEOF_LIMB_T SIZEOF_UNSIGNED_LONG_LONG
-#else
-#define SIZEOF_LIMB_T SIZEOF_UNSIGNED_LONG
-#endif
-#endif
-
-#if SIZEOF_LIMB_T == 4
-#define GMP_BASE 4294967296.0
-#elif SIZEOF_LIMB_T == 8
-#define GMP_BASE 18446744073709551616.0
-#else
-#error Cannot cope with SIZEOF_LIMB_T -- please add definition of GMP_BASE
-#endif
-
-#define DNBIGIT ((SIZEOF_DOUBLE+SIZEOF_LIMB_T-1)/SIZEOF_LIMB_T)
-#define FNBIGIT ((SIZEOF_FLOAT +SIZEOF_LIMB_T-1)/SIZEOF_LIMB_T)
-
#if IEEE_FLOATING_POINT
#define MY_DMINEXP ((DBL_MIN_EXP) - (DBL_MANT_DIG) - 1)
/* DMINEXP is defined in values.h on Linux (for example) */
#define __abs(a) (( (a) >= 0 ) ? (a) : (-(a)))
StgDouble
-__encodeDouble (I_ size, StgByteArray ba, I_ e) /* result = s * 2^e */
-{
- StgDouble r;
- const mp_limb_t *const arr = (const mp_limb_t *)ba;
- I_ i;
-
- /* Convert MP_INT to a double; knows a lot about internal rep! */
- for(r = 0.0, i = __abs(size)-1; i >= 0; i--)
- r = (r * GMP_BASE) + arr[i];
-
- /* Now raise to the exponent */
- if ( r != 0.0 ) /* Lennart suggests this avoids a bug in MIPS's ldexp */
- r = ldexp(r, e);
-
- /* sign is encoded in the size */
- if (size < 0)
- r = -r;
-
- return r;
-}
-
-StgDouble
__2Int_encodeDouble (I_ j_high, I_ j_low, I_ e)
{
StgDouble r;
return r;
}
-StgFloat
-__encodeFloat (I_ size, StgByteArray ba, I_ e) /* result = s * 2^e */
-{
- StgFloat r;
- const mp_limb_t *arr = (const mp_limb_t *)ba;
- I_ i;
-
- /* Convert MP_INT to a float; knows a lot about internal rep! */
- for(r = 0.0, i = __abs(size)-1; i >= 0; i--)
- r = (r * GMP_BASE) + arr[i];
-
- /* Now raise to the exponent */
- if ( r != 0.0 ) /* Lennart suggests this avoids a bug in MIPS's ldexp */
- r = ldexp(r, e);
-
- /* sign is encoded in the size */
- if (size < 0)
- r = -r;
-
- return r;
-}
-
/* Special version for small Integers */
StgFloat
__int_encodeFloat (I_ j, I_ e)
/* This only supports IEEE floating point */
void
-__decodeDouble (MP_INT *man, I_ *exp, StgDouble dbl)
-{
- /* Do some bit fiddling on IEEE */
- unsigned int low, high; /* assuming 32 bit ints */
- int sign, iexp;
- union { double d; unsigned int i[2]; } u; /* assuming 32 bit ints, 64 bit double */
-
- ASSERT(sizeof(unsigned int ) == 4 );
- ASSERT(sizeof(dbl ) == SIZEOF_DOUBLE);
- ASSERT(sizeof(man->_mp_d[0]) == SIZEOF_LIMB_T);
- ASSERT(DNBIGIT*SIZEOF_LIMB_T >= SIZEOF_DOUBLE);
-
- u.d = dbl; /* grab chunks of the double */
- low = u.i[L];
- high = u.i[H];
-
- /* we know the MP_INT* passed in has size zero, so we realloc
- no matter what.
- */
- man->_mp_alloc = DNBIGIT;
-
- if (low == 0 && (high & ~DMSBIT) == 0) {
- man->_mp_size = 0;
- *exp = 0L;
- } else {
- man->_mp_size = DNBIGIT;
- iexp = ((high >> 20) & 0x7ff) + MY_DMINEXP;
- sign = high;
-
- high &= DHIGHBIT-1;
- if (iexp != MY_DMINEXP) /* don't add hidden bit to denorms */
- high |= DHIGHBIT;
- else {
- iexp++;
- /* A denorm, normalize the mantissa */
- while (! (high & DHIGHBIT)) {
- high <<= 1;
- if (low & DMSBIT)
- high++;
- low <<= 1;
- iexp--;
- }
- }
- *exp = (I_) iexp;
-#if DNBIGIT == 2
- man->_mp_d[0] = (mp_limb_t)low;
- man->_mp_d[1] = (mp_limb_t)high;
-#else
-#if DNBIGIT == 1
- man->_mp_d[0] = ((mp_limb_t)high) << 32 | (mp_limb_t)low;
-#else
-#error Cannot cope with DNBIGIT
-#endif
-#endif
- if (sign < 0)
- man->_mp_size = -man->_mp_size;
- }
-}
-
-void
__decodeDouble_2Int (I_ *man_sign, W_ *man_high, W_ *man_low, I_ *exp, StgDouble dbl)
{
/* Do some bit fiddling on IEEE */
}
}
-void
-__decodeFloat (MP_INT *man, I_ *exp, StgFloat flt)
-{
- /* Do some bit fiddling on IEEE */
- int high, sign; /* assuming 32 bit ints */
- union { float f; int i; } u; /* assuming 32 bit float and int */
-
- ASSERT(sizeof(int ) == 4 );
- ASSERT(sizeof(flt ) == SIZEOF_FLOAT );
- ASSERT(sizeof(man->_mp_d[0]) == SIZEOF_LIMB_T);
- ASSERT(FNBIGIT*SIZEOF_LIMB_T >= SIZEOF_FLOAT );
-
- u.f = flt; /* grab the float */
- high = u.i;
-
- /* we know the MP_INT* passed in has size zero, so we realloc
- no matter what.
- */
- man->_mp_alloc = FNBIGIT;
-
- if ((high & ~FMSBIT) == 0) {
- man->_mp_size = 0;
- *exp = 0;
- } else {
- man->_mp_size = FNBIGIT;
- *exp = ((high >> 23) & 0xff) + MY_FMINEXP;
- sign = high;
-
- high &= FHIGHBIT-1;
- if (*exp != MY_FMINEXP) /* don't add hidden bit to denorms */
- high |= FHIGHBIT;
- else {
- (*exp)++;
- /* A denorm, normalize the mantissa */
- while (! (high & FHIGHBIT)) {
- high <<= 1;
- (*exp)--;
- }
- }
-#if FNBIGIT == 1
- man->_mp_d[0] = (mp_limb_t)high;
-#else
-#error Cannot cope with FNBIGIT
-#endif
- if (sign < 0)
- man->_mp_size = -man->_mp_size;
- }
-}
-
/* Convenient union types for checking the layout of IEEE 754 types -
based on defs in GNU libc <ieee754.h>
*/
}
}
-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 */
projects / ghc-hetmet.git / blobdiff