1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright (c) 1988 by Sun Microsystems, Inc.
24 */
25
26 #ident "%Z%%M% %I% %E% SMI" /* SunOS-4.1 1.8 88/12/06 */
27
28 #include <sys/fpu/fpu_simulator.h>
29 #include <sys/fpu/globals.h>
30
31 void
_fp_mul(pfpsd,px,py,pz)32 _fp_mul(pfpsd, px, py, pz)
33 fp_simd_type *pfpsd;
34 unpacked *px, *py, *pz;
35
36 {
37 unpacked *pt;
38 unsigned acc[4]; /* Product accumulator. */
39 unsigned j, y, *x, s, r, c;
40
41 if ((int) px->fpclass <= (int) py->fpclass) {
42 pt = px;
43 px = py;
44 py = pt;
45 }
46 /* Now class(x) >= class(y). */
47
48 *pz = *px;
49 if (pz->fpclass < fp_quiet)
50 pz->sign = px->sign ^ py->sign;
51
52 switch (px->fpclass) {
53 case fp_quiet:
54 case fp_signaling:
55 case fp_zero:
56 return;
57 case fp_infinity:
58 if (py->fpclass == fp_zero) {
59 fpu_error_nan(pfpsd, pz);
60 pz->fpclass = fp_quiet;
61 }
62 return;
63 case fp_normal:
64 if (py->fpclass == fp_zero) {
65 pz->fpclass = fp_zero;
66 return;
67 }
68 }
69
70 /* Now x and y are both normal or subnormal. */
71
72 x = px->significand; /* save typing */
73
74 /* intialize acc to zero */
75 s = r = acc[0] = acc[1] = acc[2] = acc[3] = 0;
76
77 y = py->significand[3]; /* py->significand[3] * x */
78 if (y != 0) {
79 j = 1;
80 do {
81 s |= r; /* shift acc right one bit */
82 r = acc[3]&1;
83 acc[3] = ((acc[2]&1)<<31)|(acc[3]>>1);
84 acc[2] = ((acc[1]&1)<<31)|(acc[2]>>1);
85 acc[1] = ((acc[0]&1)<<31)|(acc[1]>>1);
86 acc[0] = (acc[0]>>1);
87 if (j&y) { /* bit i of y != 0, add x to acc */
88 c = 0;
89 c = fpu_add3wc(&acc[3], acc[3], x[3], c);
90 c = fpu_add3wc(&acc[2], acc[2], x[2], c);
91 c = fpu_add3wc(&acc[1], acc[1], x[1], c);
92 c = fpu_add3wc(&acc[0], acc[0], x[0], c);
93 }
94 j += j;
95 } while (j != 0);
96 }
97
98 y = py->significand[2]; /* py->significand[2] * x */
99 if (y != 0) {
100 j = 1;
101 do {
102 s |= r; /* shift acc right one bit */
103 r = acc[3]&1;
104 acc[3] = ((acc[2]&1)<<31)|(acc[3]>>1);
105 acc[2] = ((acc[1]&1)<<31)|(acc[2]>>1);
106 acc[1] = ((acc[0]&1)<<31)|(acc[1]>>1);
107 acc[0] = (acc[0]>>1);
108 if (j&y) { /* bit i of y != 0, add x to acc */
109 c = 0;
110 c = fpu_add3wc(&acc[3], acc[3], x[3], c);
111 c = fpu_add3wc(&acc[2], acc[2], x[2], c);
112 c = fpu_add3wc(&acc[1], acc[1], x[1], c);
113 c = fpu_add3wc(&acc[0], acc[0], x[0], c);
114 }
115 j += j;
116 } while (j != 0);
117 } else {
118 s |= r|(acc[3]&0x7fffffff);
119 r = (acc[3]&0x80000000)>>31;
120 acc[3] = acc[2]; acc[2] = acc[1]; acc[1] = acc[0]; acc[0] = 0;
121 }
122
123 y = py->significand[1]; /* py->significand[1] * x */
124 if (y != 0) {
125 j = 1;
126 do {
127 s |= r; /* shift acc right one bit */
128 r = acc[3]&1;
129 acc[3] = ((acc[2]&1)<<31)|(acc[3]>>1);
130 acc[2] = ((acc[1]&1)<<31)|(acc[2]>>1);
131 acc[1] = ((acc[0]&1)<<31)|(acc[1]>>1);
132 acc[0] = (acc[0]>>1);
133 if (j&y) { /* bit i of y != 0, add x to acc */
134 c = 0;
135 c = fpu_add3wc(&acc[3], acc[3], x[3], c);
136 c = fpu_add3wc(&acc[2], acc[2], x[2], c);
137 c = fpu_add3wc(&acc[1], acc[1], x[1], c);
138 c = fpu_add3wc(&acc[0], acc[0], x[0], c);
139 }
140 j += j;
141 } while (j != 0);
142 } else {
143 s |= r|(acc[3]&0x7fffffff);
144 r = (acc[3]&0x80000000)>>31;
145 acc[3] = acc[2]; acc[2] = acc[1]; acc[1] = acc[0]; acc[0] = 0;
146 }
147
148 /* py->significand[0] * x */
149 y = py->significand[0]; /* y is of form 0x0001???? */
150 j = 1;
151 do {
152 s |= r; /* shift acc right one bit */
153 r = acc[3]&1;
154 acc[3] = ((acc[2]&1)<<31)|(acc[3]>>1);
155 acc[2] = ((acc[1]&1)<<31)|(acc[2]>>1);
156 acc[1] = ((acc[0]&1)<<31)|(acc[1]>>1);
157 acc[0] = (acc[0]>>1);
158 if (j&y) { /* bit i of y != 0, add x to acc */
159 c = 0;
160 c = fpu_add3wc(&acc[3], acc[3], x[3], c);
161 c = fpu_add3wc(&acc[2], acc[2], x[2], c);
162 c = fpu_add3wc(&acc[1], acc[1], x[1], c);
163 c = fpu_add3wc(&acc[0], acc[0], x[0], c);
164 }
165 j += j;
166 } while (j <= y);
167
168 if (acc[0] >= 0x20000) { /* right shift one bit to normalize */
169 pz->exponent = px->exponent + py->exponent + 1;
170 pz->sticky = s|r;
171 pz->rounded = acc[3]&1;
172 pz->significand[3] = ((acc[2]&1)<<31)|(acc[3]>>1);
173 pz->significand[2] = ((acc[1]&1)<<31)|(acc[2]>>1);
174 pz->significand[1] = ((acc[0]&1)<<31)|(acc[1]>>1);
175 pz->significand[0] = (acc[0]>>1);
176 } else {
177 pz->exponent = px->exponent + py->exponent;
178 pz->sticky = s;
179 pz->rounded = r;
180 pz->significand[3] = acc[3];
181 pz->significand[2] = acc[2];
182 pz->significand[1] = acc[1];
183 pz->significand[0] = acc[0];
184 }
185 }
186