410 lines
8.6 KiB
C
410 lines
8.6 KiB
C
#ifdef sccsid
|
|
static char sccsid[] = "@(#)_Qfpack.c 1.1 94/10/31 SMI";
|
|
#endif
|
|
|
|
/*
|
|
* Copyright (c) 1988 by Sun Microsystems, Inc.
|
|
*/
|
|
|
|
/* Pack procedures for Sparc FPU simulator. */
|
|
|
|
#include "_Qquad.h"
|
|
#include "_Qglobals.h"
|
|
|
|
PRIVATE int
|
|
overflow_to_infinity(sign)
|
|
int sign;
|
|
|
|
/* Returns 1 if overflow should go to infinity, 0 if to max finite. */
|
|
|
|
{
|
|
int inf;
|
|
|
|
switch (fp_direction) {
|
|
case fp_nearest:
|
|
inf = 1;
|
|
break;
|
|
case fp_tozero:
|
|
inf = 0;
|
|
break;
|
|
case fp_positive:
|
|
inf = !sign;
|
|
break;
|
|
case fp_negative:
|
|
inf = sign;
|
|
break;
|
|
}
|
|
return (inf);
|
|
}
|
|
|
|
PRIVATE void
|
|
round(pu)
|
|
unpacked *pu;
|
|
|
|
/* Round according to current rounding mode. */
|
|
|
|
{
|
|
int increment; /* boolean to indicate round up */
|
|
int sr;
|
|
sr = pu->sticky|pu->rounded;
|
|
|
|
if (sr == 0)
|
|
return;
|
|
fpu_set_exception(fp_inexact);
|
|
switch (fp_direction) {
|
|
case fp_nearest:
|
|
increment = pu->rounded;
|
|
break;
|
|
case fp_tozero:
|
|
increment = 0;
|
|
break;
|
|
case fp_positive:
|
|
increment = (pu->sign == 0) & (sr != 0);
|
|
break;
|
|
case fp_negative:
|
|
increment = (pu->sign != 0) & (sr != 0);
|
|
break;
|
|
}
|
|
if (increment) {
|
|
pu->significand[3]++;
|
|
if (pu->significand[3] == 0) {
|
|
pu->significand[2]++;
|
|
if (pu->significand[2] == 0) {
|
|
pu->significand[1]++;
|
|
if (pu->significand[1] == 0) {
|
|
pu->significand[0]++; /* rounding carried out */
|
|
if( pu->significand[0] == 0x20000) {
|
|
pu->exponent++;
|
|
pu->significand[0] = 0x10000;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if ((fp_direction == fp_nearest) &&
|
|
(pu->sticky == 0) && increment!=0) { /* ambiguous case */
|
|
pu->significand[3] &= 0xfffffffe; /* force round to even */
|
|
}
|
|
}
|
|
|
|
PRIVATE void
|
|
packinteger(pu, px)
|
|
unpacked *pu; /* unpacked result */
|
|
int *px; /* packed integer */
|
|
{
|
|
switch (pu->fpclass) {
|
|
case fp_zero:
|
|
*px = 0;
|
|
break;
|
|
case fp_normal:
|
|
if (pu->exponent >= 32)
|
|
goto overflow;
|
|
fpu_rightshift(pu, 112 - pu->exponent);
|
|
round(pu);
|
|
if (pu->significand[3] >= 0x80000000)
|
|
if ((pu->sign == 0)||(pu->significand[3] > 0x80000000))
|
|
goto overflow;
|
|
*px = pu->significand[3];
|
|
if (pu->sign)
|
|
*px = -*px;
|
|
break;
|
|
case fp_infinity:
|
|
case fp_quiet:
|
|
case fp_signaling:
|
|
overflow:
|
|
if (pu->sign)
|
|
*px = 0x80000000;
|
|
else
|
|
*px = 0x7fffffff;
|
|
_fp_current_exceptions &= ~(1 << (int) fp_inexact);
|
|
fpu_set_exception(fp_invalid);
|
|
break;
|
|
}
|
|
}
|
|
|
|
PRIVATE void
|
|
packsingle(pu, px)
|
|
unpacked *pu; /* unpacked result */
|
|
single_type *px; /* packed single */
|
|
{
|
|
px->sign = pu->sign;
|
|
switch (pu->fpclass) {
|
|
case fp_zero:
|
|
px->exponent = 0;
|
|
px->significand = 0;
|
|
break;
|
|
case fp_infinity:
|
|
infinity:
|
|
px->exponent = 0xff;
|
|
px->significand = 0;
|
|
break;
|
|
case fp_quiet:
|
|
case fp_signaling:
|
|
fpu_rightshift(pu, 113-24);
|
|
px->exponent = 0xff;
|
|
px->significand = 0x400000|(0x3fffff&pu->significand[3]);
|
|
break;
|
|
case fp_normal:
|
|
fpu_rightshift(pu, 113-24);
|
|
pu->exponent += SINGLE_BIAS;
|
|
if (pu->exponent <= 0) {
|
|
px->exponent = 0;
|
|
fpu_rightshift(pu, 1 - pu->exponent);
|
|
round(pu);
|
|
if (pu->significand[3] == 0x800000) { /* rounded
|
|
* back up to
|
|
* normal */
|
|
px->exponent = 1;
|
|
px->significand = 0;
|
|
return;
|
|
}
|
|
if (_fp_current_exceptions & (1 << fp_inexact))
|
|
fpu_set_exception(fp_underflow);
|
|
px->significand = 0x7fffff & pu->significand[3];
|
|
return;
|
|
}
|
|
round(pu);
|
|
if (pu->significand[3] == 0x1000000) { /* rounding overflow */
|
|
pu->significand[3] = 0x800000;
|
|
pu->exponent += 1;
|
|
}
|
|
if (pu->exponent >= 0xff) {
|
|
fpu_set_exception(fp_overflow);
|
|
fpu_set_exception(fp_inexact);
|
|
if (overflow_to_infinity(pu->sign))
|
|
goto infinity;
|
|
px->exponent = 0xfe;
|
|
px->significand = 0x7fffff;
|
|
return;
|
|
}
|
|
px->exponent = pu->exponent;
|
|
px->significand = 0x7fffff & pu->significand[3];
|
|
}
|
|
}
|
|
|
|
PRIVATE void
|
|
packdouble(pu, px, py)
|
|
unpacked *pu; /* unpacked result */
|
|
double_type *px; /* packed double */
|
|
unsigned *py;
|
|
{
|
|
px->sign = pu->sign;
|
|
switch (pu->fpclass) {
|
|
case fp_zero:
|
|
px->exponent = 0;
|
|
px->significand = 0;
|
|
*py = 0;
|
|
break;
|
|
case fp_infinity:
|
|
infinity:
|
|
px->exponent = 0x7ff;
|
|
px->significand = 0;
|
|
*py = 0;
|
|
break;
|
|
case fp_quiet:
|
|
case fp_signaling:
|
|
fpu_rightshift(pu, 113-53);
|
|
px->exponent = 0x7ff;
|
|
px->significand = 0x80000 | (0x7ffff & pu->significand[2]);
|
|
*py = pu->significand[3];
|
|
break;
|
|
case fp_normal:
|
|
fpu_rightshift(pu, 113-53);
|
|
pu->exponent += DOUBLE_BIAS;
|
|
if (pu->exponent <= 0) { /* underflow */
|
|
px->exponent = 0;
|
|
fpu_rightshift(pu, 1 - pu->exponent);
|
|
round(pu);
|
|
if (pu->significand[2] == 0x100000) { /* rounded
|
|
* back up to
|
|
* normal */
|
|
px->exponent = 1;
|
|
px->significand = 0;
|
|
*py = 0;
|
|
return;
|
|
}
|
|
if (_fp_current_exceptions & (1 << fp_inexact))
|
|
fpu_set_exception(fp_underflow);
|
|
px->exponent = 0;
|
|
px->significand = 0xfffff & pu->significand[2];
|
|
*py = pu->significand[3];
|
|
return;
|
|
}
|
|
round(pu);
|
|
if (pu->significand[2] == 0x200000) { /* rounding overflow */
|
|
pu->significand[2] = 0x100000;
|
|
pu->exponent += 1;
|
|
}
|
|
if (pu->exponent >= 0x7ff) { /* overflow */
|
|
fpu_set_exception(fp_overflow);
|
|
fpu_set_exception(fp_inexact);
|
|
if (overflow_to_infinity(pu->sign))
|
|
goto infinity;
|
|
px->exponent = 0x7fe;
|
|
px->significand = 0xfffff;
|
|
*py = 0xffffffff;
|
|
return;
|
|
}
|
|
px->exponent = pu->exponent;
|
|
px->significand = 0xfffff & pu->significand[2];
|
|
*py = pu->significand[3];
|
|
break;
|
|
}
|
|
}
|
|
|
|
PRIVATE void
|
|
packextended(pu, px, py, pz, pw)
|
|
unpacked *pu; /* unpacked result */
|
|
extended_type *px; /* packed extended */
|
|
unsigned *py, *pz, *pw;
|
|
{
|
|
px->sign = pu->sign;
|
|
switch (pu->fpclass) {
|
|
case fp_zero:
|
|
px->exponent = 0;
|
|
px->significand = 0;
|
|
*pz = 0;
|
|
*py = 0;
|
|
*pw = 0;
|
|
break;
|
|
case fp_infinity:
|
|
infinity:
|
|
px->exponent = 0x7fff;
|
|
px->significand = 0;
|
|
*pz = 0;
|
|
*py = 0;
|
|
*pw = 0;
|
|
break;
|
|
case fp_quiet:
|
|
case fp_signaling:
|
|
px->exponent = 0x7fff;
|
|
px->significand = 0x8000 | pu->significand[0]; /* Insure quiet
|
|
* nan. */
|
|
*py = pu->significand[1];
|
|
*pz = pu->significand[2];
|
|
*pw = pu->significand[3];
|
|
break;
|
|
case fp_normal:
|
|
pu->exponent += EXTENDED_BIAS;
|
|
if (pu->exponent <= 0) { /* underflow */
|
|
fpu_rightshift(pu, 1-pu->exponent);
|
|
round(pu);
|
|
if (pu->significand[0] < 0x00010000) { /* not rounded
|
|
* back up
|
|
* to normal */
|
|
if (_fp_current_exceptions & (1 << fp_inexact))
|
|
fpu_set_exception(fp_underflow);
|
|
px->exponent = 0;
|
|
} else
|
|
px->exponent = 1;
|
|
px->significand = pu->significand[0];
|
|
*py = pu->significand[1];
|
|
*pz = pu->significand[2];
|
|
*pw = pu->significand[3];
|
|
return;
|
|
}
|
|
round(pu); /* rounding overflow handled in round() */
|
|
if (pu->exponent >= 0x7fff) { /* overflow */
|
|
fpu_set_exception(fp_overflow);
|
|
fpu_set_exception(fp_inexact);
|
|
if (overflow_to_infinity(pu->sign))
|
|
goto infinity;
|
|
px->exponent = 0x7ffe; /* overflow to max norm */
|
|
px->significand = 0xffff;
|
|
*py = 0xffffffff;
|
|
*pz = 0xffffffff;
|
|
*pw = 0xffffffff;
|
|
return;
|
|
}
|
|
px->exponent = pu->exponent;
|
|
px->significand = pu->significand[0];
|
|
*py = pu->significand[1];
|
|
*pz = pu->significand[2];
|
|
*pw = pu->significand[3];
|
|
break;
|
|
}
|
|
}
|
|
|
|
void
|
|
_fp_pack(pu, n, type)
|
|
unpacked *pu; /* unpacked operand */
|
|
int *n; /* output result's address */
|
|
enum fp_op_type type; /* type of datum */
|
|
|
|
{
|
|
switch (type) {
|
|
case fp_op_integer:
|
|
{
|
|
packinteger(pu, n);
|
|
break;
|
|
}
|
|
case fp_op_single:
|
|
{
|
|
single_type x;
|
|
packsingle(pu, &x);
|
|
n[0] = *(int*)&x;
|
|
break;
|
|
}
|
|
case fp_op_double:
|
|
{
|
|
double_type x;
|
|
double t=1.0;
|
|
int i0,i1;
|
|
if((*(int*)&t)!=0) {i0=0;i1=1;} else {i0=1;i1=0;}
|
|
packdouble(pu, &x,&n[i1]);
|
|
n[i0] = *(int*)&x;
|
|
break;
|
|
}
|
|
case fp_op_extended:
|
|
{
|
|
extended_type x;
|
|
unsigned y, z, w;
|
|
unpacked u;
|
|
int k;
|
|
switch (fp_precision) { /* Implement extended
|
|
* rounding precision mode. */
|
|
case fp_single:
|
|
{
|
|
single_type tx;
|
|
packsingle(pu, &tx);
|
|
pu = &u;
|
|
unpacksingle(pu, tx);
|
|
break;
|
|
}
|
|
case fp_double:
|
|
{
|
|
double_type tx;
|
|
unsigned ty;
|
|
packdouble(pu, &tx, &ty);
|
|
pu = &u;
|
|
unpackdouble(pu, tx, ty);
|
|
break;
|
|
}
|
|
case fp_precision_3: /* rounded to 64 bits */
|
|
{
|
|
k = pu->exponent+ EXTENDED_BIAS;
|
|
if(k>=0) k = 113-64;
|
|
else k = 113-64-k;
|
|
fpu_rightshift(pu,113-64);
|
|
round(pu);
|
|
pu->sticky=pu->rounded=0;
|
|
pu->exponent += k;
|
|
fpu_normalize(pu);
|
|
break;
|
|
}
|
|
}
|
|
{
|
|
int i0,i1,i2,i3;
|
|
double t = 1.0;
|
|
if((*(int*)&t)!=0) {i0=0;i1=1;i2=2;i3=3;}
|
|
else {i0=3;i1=2;i2=1;i3=0;}
|
|
packextended(pu, &x, &n[i1], &n[i2], &n[i3]);
|
|
n[i0] = *(int*)&x;
|
|
}
|
|
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|