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fixed rounding on ties to round to even, and fixed extend bug (test for 0

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was wrong)
This commit is contained in:
ceriel 1989-11-27 16:26:02 +00:00
parent 1758da9285
commit b91af798bc
2 changed files with 22 additions and 12 deletions
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10
mach/proto/fp/compact.c
View file

@ -63,12 +63,15 @@ dbl_over: trap(EFOVFL);
DBL->_s.p2 |= (f->m1 << DBL_LUNPACK); /* plus 10 == 32 */ DBL->_s.p2 |= (f->m1 << DBL_LUNPACK); /* plus 10 == 32 */
/* if not exact then round to nearest */ /* if not exact then round to nearest */
/* on a tie, round to even */
#ifdef EXCEPTION_INEXACT #ifdef EXCEPTION_INEXACT
if ((f->m2 & DBL_EXACT) != 0) { if ((f->m2 & DBL_EXACT) != 0) {
INEXACT(); INEXACT();
#endif #endif
if (f->m2 & DBL_ROUNDUP) { if (((f->m2 & DBL_EXACT) > DBL_ROUNDUP)
|| ((f->m2 & DBL_EXACT) == DBL_ROUNDUP
&& (f->m2 & (DBL_ROUNDUP << 1)))) {
DBL->_s.p2++; /* rounding up */ DBL->_s.p2++; /* rounding up */
if (DBL->_s.p2 == 0L) { /* carry out */ if (DBL->_s.p2 == 0L) { /* carry out */
DBL->_s.p1.fract++; DBL->_s.p1.fract++;
@ -153,12 +156,15 @@ sgl_over: trap(EFOVFL);
SGL->fract = (f->m1 >> SGL_RUNPACK); SGL->fract = (f->m1 >> SGL_RUNPACK);
/* check for rounding to nearest */ /* check for rounding to nearest */
/* on a tie, round to even */
#ifdef EXCEPTION_INEXACT #ifdef EXCEPTION_INEXACT
if (f->m2 != 0 || if (f->m2 != 0 ||
(f->m1 & SGL_EXACT) != 0L) { (f->m1 & SGL_EXACT) != 0L) {
INEXACT(); INEXACT();
#endif #endif
if (f->m1 & SGL_ROUNDUP) { if (((f->m1 & SGL_EXACT) > SGL_ROUNDUP)
|| ((f->m1 & SGL_EXACT) == SGL_ROUNDUP
&& (f->m1 & (SGL_ROUNDUP << 1)))) {
SGL->fract++; SGL->fract++;
if (f->exp == 0 && (f->m1 & ~SGL_MASK)) { if (f->exp == 0 && (f->m1 & ~SGL_MASK)) {
f->exp++; f->exp++;

24
mach/proto/fp/extend.c
View file

@ -42,16 +42,6 @@ int size;
int leadbit = 0; int leadbit = 0;
cpt1 = (char *) from; cpt1 = (char *) from;
if (((DOUBLE *) cpt1)->_s.p1.fract == 0L ||
((DOUBLE *) cpt1)->_s.p1.fract == 0x80000000) {
if (size == sizeof(SINGLE)) {
zero: zrf_ext(to);
return;
}
else if (((DOUBLE *) cpt1)->_s.p2 == 0L)
goto zero;
}
/* there is a number to convert so lets get started */
#if FL_MSL_AT_LOW_ADDRESS #if FL_MSL_AT_LOW_ADDRESS
#if FL_MSW_AT_LOW_ADDRESS #if FL_MSW_AT_LOW_ADDRESS
@ -86,6 +76,13 @@ zero: zrf_ext(to);
cpt1 += 4; cpt1 += 4;
to->m1 = get4(cpt1); to->m1 = get4(cpt1);
#endif #endif
if (to->exp == 1 && to->m1 == 0 && tmp == 0) {
to->exp = 0;
to->sign = 0;
to->m1 = 0;
to->m2 = 0;
return;
}
to->m1 <<= DBL_M1LEFT; /* shift */ to->m1 <<= DBL_M1LEFT; /* shift */
to->exp -= DBL_BIAS; /* remove bias */ to->exp -= DBL_BIAS; /* remove bias */
to->m1 |= (tmp>>DBL_RPACK); /* plus 10 == 32 */ to->m1 |= (tmp>>DBL_RPACK); /* plus 10 == 32 */
@ -94,6 +91,13 @@ zero: zrf_ext(to);
else { /* size == sizeof(SINGLE) */ else { /* size == sizeof(SINGLE) */
to->m1 = get4(cpt1); to->m1 = get4(cpt1);
to->m1 <<= SGL_M1LEFT; /* shift */ to->m1 <<= SGL_M1LEFT; /* shift */
if (to->exp == 1 && to->m1 == 0) {
to->exp = 0;
to->sign = 0;
to->m1 = 0;
to->m2 = 0;
return;
}
to->exp -= SGL_BIAS; /* remove bias */ to->exp -= SGL_BIAS; /* remove bias */
to->m2 = 0L; to->m2 = 0L;
} }