/* -----------------------------------------------------------------------------
*
+ * (c) Lennart Augustsson
* (c) The GHC Team, 1998-2000
*
* Miscellaneous support for floating-point primitives
return r;
}
+StgDouble
+__2Int_encodeDouble (I_ j_high, I_ j_low, I_ e)
+{
+ StgDouble r;
+
+ /* assuming 32 bit ints */
+ ASSERT(sizeof(int ) == 4 );
+
+ 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;
+}
+
+/* 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 */
StgDouble
__int_encodeDouble (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
+__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;
+ }
+}
+
+void
__decodeFloat (MP_INT *man, I_ *exp, StgFloat flt)
{
/* Do some bit fiddling on IEEE */
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 );
+
+ u.f = flt; /* grab the float */
+ high = u.i;
+
+ if ((high & ~FMSBIT) == 0) {
+ *man = 0;
+ *exp = 0;
+ } else {
+ *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)--;
+ }
+ }
+ *man = high;
+ if (sign < 0)
+ *man = - *man;
+ }
+}
+
union stg_ieee754_flt
{
float f;