/* -----------------------------------------------------------------------------
*
+ * (c) Lennart Augustsson
* (c) The GHC Team, 1998-2000
*
* Miscellaneous support for floating-point primitives
#define __abs(a) (( (a) >= 0 ) ? (a) : (-(a)))
StgDouble
-__encodeDouble (I_ size, StgByteArray ba, I_ e) /* result = s * 2^e */
+__2Int_encodeDouble (I_ j_high, I_ j_low, I_ 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);
+ StgDouble r;
+
+ /* assuming 32 bit ints */
+ ASSERT(sizeof(int ) == 4 );
- /* sign is encoded in the size */
- if (size < 0)
- r = -r;
+ r = (StgDouble)((unsigned int)j_high);
+ r *= 4294967296.0; /* exp2f(32); */
+ r += (StgDouble)((unsigned int)j_low);
+
+ /* 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 (j_high < 0)
+ r = -r;
+
+ return r;
+}
- return r;
+/* Special version for words */
+StgDouble
+__word_encodeDouble (W_ j, I_ e)
+{
+ StgDouble r;
+
+ r = (StgDouble)j;
+
+ /* Now raise to the exponent */
+ if ( r != 0.0 ) /* Lennart suggests this avoids a bug in MIPS's ldexp */
+ r = ldexp(r, e);
+
+ return r;
}
/* Special version for small Integers */
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)
return r;
}
+/* Special version for small positive Integers */
+StgFloat
+__word_encodeFloat (W_ j, I_ e)
+{
+ StgFloat r;
+
+ r = (StgFloat)j;
+
+ /* Now raise to the exponent */
+ if ( r != 0.0 ) /* Lennart suggests this avoids a bug in MIPS's ldexp */
+ r = ldexp(r, e);
+
+ return r;
+}
+
/* This only supports IEEE floating point */
void
}
void
-__decodeFloat (MP_INT *man, I_ *exp, StgFloat flt)
+__decodeDouble_2Int (I_ *man_sign, W_ *man_high, W_ *man_low, 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 ) == 8 );
+ ASSERT(sizeof(dbl ) == SIZEOF_DOUBLE);
+
+ u.d = dbl; /* grab chunks of the double */
+ low = u.i[L];
+ high = u.i[H];
+
+ if (low == 0 && (high & ~DMSBIT) == 0) {
+ *man_low = 0;
+ *man_high = 0;
+ *exp = 0L;
+ } else {
+ 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;
+ *man_low = low;
+ *man_high = high;
+ *man_sign = (sign < 0) ? -1 : 1;
+ }
+}
+
+/* Convenient union types for checking the layout of IEEE 754 types -
+ based on defs in GNU libc <ieee754.h>
+*/
+
+void
+__decodeFloat_Int (I_ *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 ) == 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;
+ *man = 0;
*exp = 0;
} else {
- man->_mp_size = FNBIGIT;
*exp = ((high >> 23) & 0xff) + MY_FMINEXP;
sign = high;
(*exp)--;
}
}
-#if FNBIGIT == 1
- man->_mp_d[0] = (mp_limb_t)high;
-#else
-#error Cannot cope with FNBIGIT
-#endif
+ *man = high;
if (sign < 0)
- man->_mp_size = -man->_mp_size;
+ *man = - *man;
}
}
-/* 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;
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