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 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