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