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 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