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 2003 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 #include "quad.h"
30
31 #ifdef __sparcv9
32
33 /*
34 * _Qp_sub(pz, ox, oy) sets *pz = *ox - *oy.
35 */
36 void
_Qp_sub(union longdouble * pz,const union longdouble * ox,const union longdouble * oy)37 _Qp_sub(union longdouble *pz, const union longdouble *ox,
38 const union longdouble *oy)
39
40 #else
41
42 /*
43 * _Q_sub(ox, oy) returns *ox - *oy.
44 */
45 union longdouble
46 _Q_sub(const union longdouble *ox, const union longdouble *oy)
47
48 #endif /* __sparcv9 */
49
50 {
51 union longdouble z;
52 const union longdouble *x, *y;
53 unsigned int xm, ym, tm, fsr;
54 int flip;
55
56 /* sort so |x| >= |y| */
57 xm = ox->l.msw & 0x7fffffff;
58 ym = oy->l.msw & 0x7fffffff;
59 if (ym > xm || ym == xm && (oy->l.frac2 > ox->l.frac2 ||
60 oy->l.frac2 == ox->l.frac2 && (oy->l.frac3 > ox->l.frac3 ||
61 oy->l.frac3 == ox->l.frac3 && oy->l.frac4 > ox->l.frac4))) {
62 y = ox;
63 x = oy;
64 tm = xm;
65 xm = ym;
66 ym = tm;
67 flip = 0x80000000;
68 } else {
69 x = ox;
70 y = oy;
71 flip = 0;
72 }
73
74 /* get the fsr */
75 __quad_getfsrp(&fsr);
76
77 /* handle nan and inf cases */
78 if (xm >= 0x7fff0000) {
79 /* x is nan or inf */
80 if (ym >= 0x7fff0000) {
81 /* y is nan or inf */
82 if ((ym & 0xffff) | y->l.frac2 | y->l.frac3 |
83 y->l.frac4) {
84 /* y is nan; x must be nan too */
85 /* the following logic implements V9 app. B */
86 if (!(ym & 0x8000)) {
87 /* y is snan, signal invalid */
88 if (fsr & FSR_NVM) {
89 __quad_fsubq(ox, oy, &Z);
90 } else {
91 Z = (xm & 0x8000)? *y : *oy;
92 Z.l.msw |= 0x8000;
93 fsr = (fsr & ~FSR_CEXC) |
94 FSR_NVA | FSR_NVC;
95 __quad_setfsrp(&fsr);
96 }
97 QUAD_RETURN(Z);
98 }
99 /* x and y are both qnan */
100 Z = *oy;
101 QUAD_RETURN(Z);
102 }
103 if (!((xm & 0xffff) | x->l.frac2 | x->l.frac3 |
104 x->l.frac4)) {
105 /* x and y are both inf */
106 if (!((x->l.msw ^ y->l.msw) & 0x80000000)) {
107 /* inf - inf, signal invalid */
108 if (fsr & FSR_NVM) {
109 __quad_fsubq(ox, oy, &Z);
110 } else {
111 Z.l.msw = 0x7fffffff;
112 Z.l.frac2 = Z.l.frac3 =
113 Z.l.frac4 = 0xffffffff;
114 fsr = (fsr & ~FSR_CEXC) |
115 FSR_NVA | FSR_NVC;
116 __quad_setfsrp(&fsr);
117 }
118 QUAD_RETURN(Z);
119 }
120 /* inf + inf, return inf */
121 Z = *x;
122 Z.l.msw ^= flip;
123 QUAD_RETURN(Z);
124 }
125 }
126 if ((xm & 0xffff) | x->l.frac2 | x->l.frac3 | x->l.frac4) {
127 /* x is nan */
128 if (!(xm & 0x8000)) {
129 /* snan, signal invalid */
130 if (fsr & FSR_NVM) {
131 __quad_fsubq(ox, oy, &Z);
132 } else {
133 Z = *x;
134 Z.l.msw |= 0x8000;
135 fsr = (fsr & ~FSR_CEXC) | FSR_NVA |
136 FSR_NVC;
137 __quad_setfsrp(&fsr);
138 }
139 QUAD_RETURN(Z);
140 }
141 Z = *x;
142 QUAD_RETURN(Z);
143 }
144 /* x is inf */
145 Z = *x;
146 Z.l.msw ^= flip;
147 QUAD_RETURN(Z);
148 }
149
150 /* now x and y are finite and |x| >= |y| */
151 fsr &= ~FSR_CEXC;
152 z.l.msw = (x->l.msw & 0x80000000) ^ flip;
153 if ((x->l.msw ^ y->l.msw) & 0x80000000)
154 __quad_mag_add(x, y, &z, &fsr);
155 else
156 __quad_mag_sub(x, y, &z, &fsr);
157 if ((fsr & FSR_CEXC) & (fsr >> 23)) {
158 __quad_setfsrp(&fsr);
159 __quad_fsubq(ox, oy, &Z);
160 } else {
161 Z = z;
162 fsr |= (fsr & 0x1f) << 5;
163 __quad_setfsrp(&fsr);
164 }
165 QUAD_RETURN(Z);
166 }
167