_Qfdiv.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Copyright (c) 1988 by Sun Microsystems, Inc.
*/
#include "_Qquad.h"
#include "_Qglobals.h"
void
_fp_div(px, py, pz)
unpacked *px, *py, *pz;
{
unsigned r[4],*y,q,c;
int n;
*pz = *px;
pz->sign = px->sign ^ py->sign;
if ((py->fpclass == fp_quiet) || (py->fpclass == fp_signaling)) {
*pz = *py;
return;
}
switch (px->fpclass) {
case fp_quiet:
case fp_signaling:
return;
case fp_zero:
case fp_infinity:
if (px->fpclass == py->fpclass) { /* 0/0 or inf/inf */
fpu_error_nan(pz);
pz->fpclass = fp_quiet;
}
return;
case fp_normal:
switch (py->fpclass) {
case fp_zero: /* number/0 */
fpu_set_exception(fp_division);
pz->fpclass = fp_infinity;
return;
case fp_infinity: /* number/inf */
pz->fpclass = fp_zero;
return;
}
}
/* Now x and y are both normal or subnormal. */
r[0] = px->significand[0];
r[1] = px->significand[1];
r[2] = px->significand[2];
r[3] = px->significand[3];
y = py->significand;
if(fpu_cmpli(r,y,4)>=0)
pz->exponent = px->exponent - py->exponent;
else
pz->exponent = px->exponent - py->exponent - 1;
q=0;
while(q<0x10000) { /* generate quo[0] */
q<<=1;
if(fpu_cmpli(r,y,4)>=0) {
q += 1; /* if r>y do r-=y and q+=1 */
c = 0;
c = fpu_sub3wc(&r[3],r[3],y[3],c);
c = fpu_sub3wc(&r[2],r[2],y[2],c);
c = fpu_sub3wc(&r[1],r[1],y[1],c);
c = fpu_sub3wc(&r[0],r[0],y[0],c);
}
r[0] = (r[0]<<1)|((r[1]&0x80000000)>>31); /* r << 1 */
r[1] = (r[1]<<1)|((r[2]&0x80000000)>>31);
r[2] = (r[2]<<1)|((r[3]&0x80000000)>>31);
r[3] = (r[3]<<1);
}
pz->significand[0]=q;
q=0; /* generate quo[1] */
n = 32;
while(n--) {
q<<=1;
if(fpu_cmpli(r,y,4)>=0) {
q += 1; /* if r>y do r-=y and q+=1 */
c = 0;
c = fpu_sub3wc(&r[3],r[3],y[3],c);
c = fpu_sub3wc(&r[2],r[2],y[2],c);
c = fpu_sub3wc(&r[1],r[1],y[1],c);
c = fpu_sub3wc(&r[0],r[0],y[0],c);
}
r[0] = (r[0]<<1)|((r[1]&0x80000000)>>31); /* r << 1 */
r[1] = (r[1]<<1)|((r[2]&0x80000000)>>31);
r[2] = (r[2]<<1)|((r[3]&0x80000000)>>31);
r[3] = (r[3]<<1);
}
pz->significand[1] = q;
q=0; /* generate quo[2] */
n = 32;
while(n--) {
q<<=1;
if(fpu_cmpli(r,y,4)>=0) {
q += 1; /* if r>y do r-=y and q+=1 */
c = 0;
c = fpu_sub3wc(&r[3],r[3],y[3],c);
c = fpu_sub3wc(&r[2],r[2],y[2],c);
c = fpu_sub3wc(&r[1],r[1],y[1],c);
c = fpu_sub3wc(&r[0],r[0],y[0],c);
}
r[0] = (r[0]<<1)|((r[1]&0x80000000)>>31); /* r << 1 */
r[1] = (r[1]<<1)|((r[2]&0x80000000)>>31);
r[2] = (r[2]<<1)|((r[3]&0x80000000)>>31);
r[3] = (r[3]<<1);
}
pz->significand[2] = q;
q=0; /* generate quo[3] */
n = 32;
while(n--) {
q<<=1;
if(fpu_cmpli(r,y,4)>=0) {
q += 1; /* if r>y do r-=y and q+=1 */
c = 0;
c = fpu_sub3wc(&r[3],r[3],y[3],c);
c = fpu_sub3wc(&r[2],r[2],y[2],c);
c = fpu_sub3wc(&r[1],r[1],y[1],c);
c = fpu_sub3wc(&r[0],r[0],y[0],c);
}
r[0] = (r[0]<<1)|((r[1]&0x80000000)>>31); /* r << 1 */
r[1] = (r[1]<<1)|((r[2]&0x80000000)>>31);
r[2] = (r[2]<<1)|((r[3]&0x80000000)>>31);
r[3] = (r[3]<<1);
}
pz->significand[3] = q;
if((r[0]|r[1]|r[2]|r[3])==0) pz->sticky = pz->rounded = 0;
else {
pz->sticky = 1; /* half way case won't occur */
if(fpu_cmpli(r,y,4)>=0) pz->rounded = 1;
}
}
void
_fp_sqrt(px, pz)
unpacked *px, *pz;
{ /* *pz gets sqrt(*px) */
unsigned *x,r,c,q,t[4],s[4];
*pz = *px;
switch (px->fpclass) {
case fp_quiet:
case fp_signaling:
case fp_zero:
return;
case fp_infinity:
if (px->sign == 1) { /* sqrt(-inf) */
fpu_error_nan(pz);
pz->fpclass = fp_quiet;
}
return;
case fp_normal:
if (px->sign == 1) { /* sqrt(-norm) */
fpu_error_nan(pz);
pz->fpclass = fp_quiet;
return;
}
}
/* Now x is normal. */
x = px->significand;
if (px->exponent & 1) { /* sqrt(1.f * 2**odd) = sqrt (2.+2f) *
* 2**(odd-1)/2 */
pz->exponent = (px->exponent - 1) / 2;
x[0] = (x[0]<<1)|((x[1]&0x80000000)>>31); /* x<<1 */
x[1] = (x[1]<<1)|((x[2]&0x80000000)>>31);
x[2] = (x[2]<<1)|((x[3]&0x80000000)>>31);
x[3] = (x[3]<<1);
} else { /* sqrt(1.f * 2**even) = sqrt (1.f) *
* 2**(even)/2 */
pz->exponent = px->exponent / 2;
}
s[0]=s[1]=s[2]=s[3]=t[0]=t[1]=t[2]=t[3]=0;
q = 0;
r = 0x00010000;
while(r!=0) { /* compute sqrt[0] */
t[0] = s[0]+r;
if(t[0]<=x[0]) {
s[0] = t[0]+r;
x[0] -= t[0];
q += r;
}
x[0] = (x[0]<<1)|((x[1]&0x80000000)>>31); /* x<<1 */
x[1] = (x[1]<<1)|((x[2]&0x80000000)>>31);
x[2] = (x[2]<<1)|((x[3]&0x80000000)>>31);
x[3] = (x[3]<<1);
r>>=1;
}
pz->significand[0] = q;
q = 0;
r = 0x80000000;
while(r!=0) { /* compute sqrt[1] */
t[1] = s[1]+r; /* no carry */
t[0] = s[0];
if(fpu_cmpli(t,x,2)<=0) {
c = 0;
c = fpu_add3wc(&s[1],t[1],r,c);
c = fpu_add3wc(&s[0],t[0],0,c);
c = 0;
c = fpu_sub3wc(&x[1],x[1],t[1],c);
c = fpu_sub3wc(&x[0],x[0],t[0],c);
q += r;
}
x[0] = (x[0]<<1)|((x[1]&0x80000000)>>31); /* x<<1 */
x[1] = (x[1]<<1)|((x[2]&0x80000000)>>31);
x[2] = (x[2]<<1)|((x[3]&0x80000000)>>31);
x[3] = (x[3]<<1);
r>>=1;
}
pz->significand[1] = q;
q = 0;
r = 0x80000000;
while(r!=0) { /* compute sqrt[2] */
t[2] = s[2]+r; /* no carry */
t[1] = s[1];
t[0] = s[0];
if(fpu_cmpli(t,x,3)<=0) {
c = 0;
c = fpu_add3wc(&s[2],t[2],r,c);
c = fpu_add3wc(&s[1],t[1],0,c);
c = fpu_add3wc(&s[0],t[0],0,c);
c = 0;
c = fpu_sub3wc(&x[2],x[2],t[2],c);
c = fpu_sub3wc(&x[1],x[1],t[1],c);
c = fpu_sub3wc(&x[0],x[0],t[0],c);
q += r;
}
x[0] = (x[0]<<1)|((x[1]&0x80000000)>>31); /* x<<1 */
x[1] = (x[1]<<1)|((x[2]&0x80000000)>>31);
x[2] = (x[2]<<1)|((x[3]&0x80000000)>>31);
x[3] = (x[3]<<1);
r>>=1;
}
pz->significand[2] = q;
q = 0;
r = 0x80000000;
while(r!=0) { /* compute sqrt[3] */
t[3] = s[3]+r; /* no carry */
t[2] = s[2];
t[1] = s[1];
t[0] = s[0];
if(fpu_cmpli(t,x,4)<=0) {
c = 0;
c = fpu_add3wc(&s[3],t[3],r,c);
c = fpu_add3wc(&s[2],t[2],0,c);
c = fpu_add3wc(&s[1],t[1],0,c);
c = fpu_add3wc(&s[0],t[0],0,c);
c = 0;
c = fpu_sub3wc(&x[3],x[3],t[3],c);
c = fpu_sub3wc(&x[2],x[2],t[2],c);
c = fpu_sub3wc(&x[1],x[1],t[1],c);
c = fpu_sub3wc(&x[0],x[0],t[0],c);
q += r;
}
x[0] = (x[0]<<1)|((x[1]&0x80000000)>>31); /* x<<1 */
x[1] = (x[1]<<1)|((x[2]&0x80000000)>>31);
x[2] = (x[2]<<1)|((x[3]&0x80000000)>>31);
x[3] = (x[3]<<1);
r>>=1;
}
pz->significand[3] = q;
if((x[0]|x[1]|x[2]|x[3])==0) {
pz->sticky = pz->rounded = 0;
} else {
pz->sticky = 1;
if(fpu_cmpli(s,x,4)<0) pz->rounded=1; else pz->rounded = 0;
}
}