293 lines
7.0 KiB
C
293 lines
7.0 KiB
C
#ifndef lint
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static char sccsid[] = "@(#)div.c 1.1 94/10/31 SMI";
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#endif
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/*
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* Copyright (c) 1988 by Sun Microsystems, Inc.
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*/
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#include <machine/fpu/fpu_simulator.h>
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#include <machine/fpu/globals.h>
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#ifdef sun4m
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extern int ross625_flag; /* to identify hyperSPARC */
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#endif sun4m
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void
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_fp_div(pfpsd, px, py, pz)
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fp_simd_type *pfpsd;
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unpacked *px, *py, *pz;
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{
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unsigned r[4], *y, q, c;
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int n;
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*pz = *px;
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if (((int)py->fpclass >= (int)fp_quiet) ||
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((int)px->fpclass >= (int)fp_quiet)) {
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#ifdef sun4m
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if (((int)py->fpclass > (int)px->fpclass) ||
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(ross625_flag && ((int)py->fpclass >= (int)px->fpclass)))
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*pz = *py;
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#else sun4m
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if ((int)py->fpclass > (int)px->fpclass) *pz = *py;
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#endif sun4m
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return;
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}
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pz->sign = px->sign ^ py->sign;
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switch (px->fpclass) {
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case fp_quiet:
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case fp_signaling:
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return;
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case fp_zero:
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case fp_infinity:
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if (px->fpclass == py->fpclass) { /* 0/0 or inf/inf */
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fpu_error_nan(pfpsd, pz);
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pz->fpclass = fp_quiet;
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}
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return;
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case fp_normal:
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switch (py->fpclass) {
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case fp_zero: /* number/0 */
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fpu_set_exception(pfpsd, fp_division);
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pz->fpclass = fp_infinity;
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return;
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case fp_infinity: /* number/inf */
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pz->fpclass = fp_zero;
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return;
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}
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}
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/* Now x and y are both normal or subnormal. */
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r[0] = px->significand[0];
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r[1] = px->significand[1];
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r[2] = px->significand[2];
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r[3] = px->significand[3];
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y = py->significand;
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if (fpu_cmpli(r, y, 4) >= 0)
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pz->exponent = px->exponent - py->exponent;
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else
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pz->exponent = px->exponent - py->exponent - 1;
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q=0;
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while (q<0x10000) { /* generate quo[0] */
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q <<= 1;
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if (fpu_cmpli(r, y, 4) >= 0) {
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q += 1; /* if r>y do r-=y and q+=1 */
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c = 0;
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c = fpu_sub3wc(&r[3], r[3], y[3], c);
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c = fpu_sub3wc(&r[2], r[2], y[2], c);
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c = fpu_sub3wc(&r[1], r[1], y[1], c);
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c = fpu_sub3wc(&r[0], r[0], y[0], c);
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}
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r[0] = (r[0]<<1)|((r[1]&0x80000000)>>31); /* r << 1 */
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r[1] = (r[1]<<1)|((r[2]&0x80000000)>>31);
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r[2] = (r[2]<<1)|((r[3]&0x80000000)>>31);
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r[3] = (r[3]<<1);
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}
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pz->significand[0]=q;
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q=0; /* generate quo[1] */
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n = 32;
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while (n--) {
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q <<= 1;
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if (fpu_cmpli(r, y, 4) >= 0) {
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q += 1; /* if r>y do r-=y and q+=1 */
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c = 0;
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c = fpu_sub3wc(&r[3], r[3], y[3], c);
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c = fpu_sub3wc(&r[2], r[2], y[2], c);
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c = fpu_sub3wc(&r[1], r[1], y[1], c);
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c = fpu_sub3wc(&r[0], r[0], y[0], c);
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}
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r[0] = (r[0]<<1)|((r[1]&0x80000000)>>31); /* r << 1 */
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r[1] = (r[1]<<1)|((r[2]&0x80000000)>>31);
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r[2] = (r[2]<<1)|((r[3]&0x80000000)>>31);
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r[3] = (r[3]<<1);
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}
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pz->significand[1] = q;
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q=0; /* generate quo[2] */
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n = 32;
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while (n--) {
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q <<= 1;
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if (fpu_cmpli(r, y, 4) >= 0) {
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q += 1; /* if r>y do r-=y and q+=1 */
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c = 0;
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c = fpu_sub3wc(&r[3], r[3], y[3], c);
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c = fpu_sub3wc(&r[2], r[2], y[2], c);
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c = fpu_sub3wc(&r[1], r[1], y[1], c);
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c = fpu_sub3wc(&r[0], r[0], y[0], c);
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}
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r[0] = (r[0]<<1)|((r[1]&0x80000000)>>31); /* r << 1 */
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r[1] = (r[1]<<1)|((r[2]&0x80000000)>>31);
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r[2] = (r[2]<<1)|((r[3]&0x80000000)>>31);
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r[3] = (r[3]<<1);
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}
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pz->significand[2] = q;
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q=0; /* generate quo[3] */
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n = 32;
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while (n--) {
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q <<= 1;
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if (fpu_cmpli(r, y, 4) >= 0) {
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q += 1; /* if r>y do r-=y and q+=1 */
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c = 0;
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c = fpu_sub3wc(&r[3], r[3], y[3], c);
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c = fpu_sub3wc(&r[2], r[2], y[2], c);
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c = fpu_sub3wc(&r[1], r[1], y[1], c);
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c = fpu_sub3wc(&r[0], r[0], y[0], c);
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}
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r[0] = (r[0]<<1)|((r[1]&0x80000000)>>31); /* r << 1 */
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r[1] = (r[1]<<1)|((r[2]&0x80000000)>>31);
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r[2] = (r[2]<<1)|((r[3]&0x80000000)>>31);
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r[3] = (r[3]<<1);
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}
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pz->significand[3] = q;
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if ((r[0]|r[1]|r[2]|r[3])==0) pz->sticky = pz->rounded = 0;
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else {
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pz->sticky = 1; /* half way case won't occur */
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if (fpu_cmpli(r, y, 4) >= 0) pz->rounded = 1;
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}
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}
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void
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_fp_sqrt(pfpsd, px, pz)
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fp_simd_type *pfpsd;
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unpacked *px, *pz;
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{ /* *pz gets sqrt(*px) */
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unsigned *x, r, c, q, t[4], s[4];
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*pz = *px;
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switch (px->fpclass) {
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case fp_quiet:
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case fp_signaling:
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case fp_zero:
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return;
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case fp_infinity:
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if (px->sign == 1) { /* sqrt(-inf) */
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fpu_error_nan(pfpsd, pz);
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pz->fpclass = fp_quiet;
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}
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return;
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case fp_normal:
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if (px->sign == 1) { /* sqrt(-norm) */
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fpu_error_nan(pfpsd, pz);
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pz->fpclass = fp_quiet;
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return;
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}
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}
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/* Now x is normal. */
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x = px->significand;
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if (px->exponent & 1) { /*
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* sqrt(1.f * 2**odd) = sqrt (2.+2f)
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* 2**(odd-1)/2
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*/
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pz->exponent = (px->exponent - 1) / 2;
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x[0] = (x[0]<<1)|((x[1]&0x80000000)>>31); /* x<<1 */
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x[1] = (x[1]<<1)|((x[2]&0x80000000)>>31);
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x[2] = (x[2]<<1)|((x[3]&0x80000000)>>31);
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x[3] = (x[3]<<1);
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} else { /*
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* sqrt(1.f * 2**even) = sqrt (1.f)
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* 2**(even)/2
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*/
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pz->exponent = px->exponent / 2;
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}
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s[0]=s[1]=s[2]=s[3]=t[0]=t[1]=t[2]=t[3]=0;
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q = 0;
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r = 0x00010000;
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while (r!=0) { /* compute sqrt[0] */
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t[0] = s[0]+r;
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if (t[0] <= x[0]) {
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s[0] = t[0]+r;
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x[0] -= t[0];
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q += r;
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}
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x[0] = (x[0]<<1)|((x[1]&0x80000000)>>31); /* x<<1 */
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x[1] = (x[1]<<1)|((x[2]&0x80000000)>>31);
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x[2] = (x[2]<<1)|((x[3]&0x80000000)>>31);
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x[3] = (x[3]<<1);
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r >>= 1;
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}
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pz->significand[0] = q;
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q = 0;
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r = 0x80000000;
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while (r!=0) { /* compute sqrt[1] */
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t[1] = s[1]+r; /* no carry */
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t[0] = s[0];
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if (fpu_cmpli(t, x, 2) <= 0) {
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c = 0;
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c = fpu_add3wc(&s[1], t[1], r, c);
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c = fpu_add3wc(&s[0], t[0], 0, c);
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c = 0;
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c = fpu_sub3wc(&x[1], x[1], t[1], c);
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c = fpu_sub3wc(&x[0], x[0], t[0], c);
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q += r;
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}
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x[0] = (x[0]<<1)|((x[1]&0x80000000)>>31); /* x<<1 */
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x[1] = (x[1]<<1)|((x[2]&0x80000000)>>31);
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x[2] = (x[2]<<1)|((x[3]&0x80000000)>>31);
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x[3] = (x[3]<<1);
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r >>= 1;
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}
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pz->significand[1] = q;
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q = 0;
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r = 0x80000000;
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while (r!=0) { /* compute sqrt[2] */
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t[2] = s[2]+r; /* no carry */
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t[1] = s[1];
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t[0] = s[0];
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if (fpu_cmpli(t, x, 3) <= 0) {
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c = 0;
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c = fpu_add3wc(&s[2], t[2], r, c);
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c = fpu_add3wc(&s[1], t[1], 0, c);
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c = fpu_add3wc(&s[0], t[0], 0, c);
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c = 0;
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c = fpu_sub3wc(&x[2], x[2], t[2], c);
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c = fpu_sub3wc(&x[1], x[1], t[1], c);
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c = fpu_sub3wc(&x[0], x[0], t[0], c);
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q += r;
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}
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x[0] = (x[0]<<1)|((x[1]&0x80000000)>>31); /* x<<1 */
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x[1] = (x[1]<<1)|((x[2]&0x80000000)>>31);
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x[2] = (x[2]<<1)|((x[3]&0x80000000)>>31);
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x[3] = (x[3]<<1);
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r >>= 1;
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}
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pz->significand[2] = q;
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q = 0;
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r = 0x80000000;
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while (r!=0) { /* compute sqrt[3] */
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t[3] = s[3]+r; /* no carry */
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t[2] = s[2];
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t[1] = s[1];
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t[0] = s[0];
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if (fpu_cmpli(t, x, 4) <= 0) {
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c = 0;
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c = fpu_add3wc(&s[3], t[3], r, c);
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c = fpu_add3wc(&s[2], t[2], 0, c);
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c = fpu_add3wc(&s[1], t[1], 0, c);
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c = fpu_add3wc(&s[0], t[0], 0, c);
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c = 0;
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c = fpu_sub3wc(&x[3], x[3], t[3], c);
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c = fpu_sub3wc(&x[2], x[2], t[2], c);
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c = fpu_sub3wc(&x[1], x[1], t[1], c);
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c = fpu_sub3wc(&x[0], x[0], t[0], c);
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q += r;
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}
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x[0] = (x[0]<<1)|((x[1]&0x80000000)>>31); /* x<<1 */
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x[1] = (x[1]<<1)|((x[2]&0x80000000)>>31);
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x[2] = (x[2]<<1)|((x[3]&0x80000000)>>31);
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x[3] = (x[3]<<1);
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r >>= 1;
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}
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pz->significand[3] = q;
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if ((x[0]|x[1]|x[2]|x[3])==0) {
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pz->sticky = pz->rounded = 0;
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} else {
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pz->sticky = 1;
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if (fpu_cmpli(s, x, 4)<0) pz->rounded=1; else pz->rounded = 0;
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}
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}
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