1*7c478bd9Sstevel@tonic-gate /* 2*7c478bd9Sstevel@tonic-gate * CDDL HEADER START 3*7c478bd9Sstevel@tonic-gate * 4*7c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*7c478bd9Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*7c478bd9Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*7c478bd9Sstevel@tonic-gate * with the License. 8*7c478bd9Sstevel@tonic-gate * 9*7c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*7c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*7c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions 12*7c478bd9Sstevel@tonic-gate * and limitations under the License. 13*7c478bd9Sstevel@tonic-gate * 14*7c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*7c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*7c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*7c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*7c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*7c478bd9Sstevel@tonic-gate * 20*7c478bd9Sstevel@tonic-gate * CDDL HEADER END 21*7c478bd9Sstevel@tonic-gate */ 22*7c478bd9Sstevel@tonic-gate /* 23*7c478bd9Sstevel@tonic-gate * Copyright 2003 Sun Microsystems, Inc. All rights reserved. 24*7c478bd9Sstevel@tonic-gate * Use is subject to license terms. 25*7c478bd9Sstevel@tonic-gate */ 26*7c478bd9Sstevel@tonic-gate 27*7c478bd9Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 28*7c478bd9Sstevel@tonic-gate 29*7c478bd9Sstevel@tonic-gate /* 30*7c478bd9Sstevel@tonic-gate * _F_cplx_div_rx(a, w) returns a / w with infinities handled according 31*7c478bd9Sstevel@tonic-gate * to C99. 32*7c478bd9Sstevel@tonic-gate * 33*7c478bd9Sstevel@tonic-gate * If a and w are both finite and w is nonzero, _F_cplx_div_rx(a, w) 34*7c478bd9Sstevel@tonic-gate * delivers the complex quotient q according to the usual formula: 35*7c478bd9Sstevel@tonic-gate * let c = Re(w), and d = Im(w); then q = x + I * y where x = (a * c) 36*7c478bd9Sstevel@tonic-gate * / r and y = (-a * d) / r with r = c * c + d * d. This implementa- 37*7c478bd9Sstevel@tonic-gate * tion computes intermediate results in double precision to avoid 38*7c478bd9Sstevel@tonic-gate * premature underflow or overflow. 39*7c478bd9Sstevel@tonic-gate * 40*7c478bd9Sstevel@tonic-gate * If a is neither NaN nor zero and w is zero, or if a is infinite 41*7c478bd9Sstevel@tonic-gate * and w is finite and nonzero, _F_cplx_div_rx delivers an infinite 42*7c478bd9Sstevel@tonic-gate * result. If a is finite and w is infinite, _F_cplx_div_rx delivers 43*7c478bd9Sstevel@tonic-gate * a zero result. 44*7c478bd9Sstevel@tonic-gate * 45*7c478bd9Sstevel@tonic-gate * If a and w are both zero or both infinite, or if either a or w is 46*7c478bd9Sstevel@tonic-gate * NaN, _F_cplx_div_rx delivers NaN + I * NaN. C99 doesn't specify 47*7c478bd9Sstevel@tonic-gate * these cases. 48*7c478bd9Sstevel@tonic-gate * 49*7c478bd9Sstevel@tonic-gate * This implementation can raise spurious invalid operation, inexact, 50*7c478bd9Sstevel@tonic-gate * and division-by-zero exceptions. C99 allows this. 51*7c478bd9Sstevel@tonic-gate * 52*7c478bd9Sstevel@tonic-gate * Warning: Do not attempt to "optimize" this code by removing multi- 53*7c478bd9Sstevel@tonic-gate * plications by zero. 54*7c478bd9Sstevel@tonic-gate */ 55*7c478bd9Sstevel@tonic-gate 56*7c478bd9Sstevel@tonic-gate #if !defined(sparc) && !defined(__sparc) 57*7c478bd9Sstevel@tonic-gate #error This code is for SPARC only 58*7c478bd9Sstevel@tonic-gate #endif 59*7c478bd9Sstevel@tonic-gate 60*7c478bd9Sstevel@tonic-gate /* 61*7c478bd9Sstevel@tonic-gate * Return +1 if x is +Inf, -1 if x is -Inf, and 0 otherwise 62*7c478bd9Sstevel@tonic-gate */ 63*7c478bd9Sstevel@tonic-gate static int 64*7c478bd9Sstevel@tonic-gate testinff(float x) 65*7c478bd9Sstevel@tonic-gate { 66*7c478bd9Sstevel@tonic-gate union { 67*7c478bd9Sstevel@tonic-gate int i; 68*7c478bd9Sstevel@tonic-gate float f; 69*7c478bd9Sstevel@tonic-gate } xx; 70*7c478bd9Sstevel@tonic-gate 71*7c478bd9Sstevel@tonic-gate xx.f = x; 72*7c478bd9Sstevel@tonic-gate return ((((xx.i << 1) - 0xff000000) == 0)? (1 | (xx.i >> 31)) : 0); 73*7c478bd9Sstevel@tonic-gate } 74*7c478bd9Sstevel@tonic-gate 75*7c478bd9Sstevel@tonic-gate float _Complex 76*7c478bd9Sstevel@tonic-gate _F_cplx_div_rx(float a, float _Complex w) 77*7c478bd9Sstevel@tonic-gate { 78*7c478bd9Sstevel@tonic-gate float _Complex v; 79*7c478bd9Sstevel@tonic-gate union { 80*7c478bd9Sstevel@tonic-gate int i; 81*7c478bd9Sstevel@tonic-gate float f; 82*7c478bd9Sstevel@tonic-gate } cc, dd; 83*7c478bd9Sstevel@tonic-gate float c, d; 84*7c478bd9Sstevel@tonic-gate double r, x, y; 85*7c478bd9Sstevel@tonic-gate int i, j; 86*7c478bd9Sstevel@tonic-gate 87*7c478bd9Sstevel@tonic-gate /* 88*7c478bd9Sstevel@tonic-gate * The following is equivalent to 89*7c478bd9Sstevel@tonic-gate * 90*7c478bd9Sstevel@tonic-gate * c = crealf(w); d = cimagf(w); 91*7c478bd9Sstevel@tonic-gate */ 92*7c478bd9Sstevel@tonic-gate c = ((float *)&w)[0]; 93*7c478bd9Sstevel@tonic-gate d = ((float *)&w)[1]; 94*7c478bd9Sstevel@tonic-gate 95*7c478bd9Sstevel@tonic-gate r = (double)c * c + (double)d * d; 96*7c478bd9Sstevel@tonic-gate 97*7c478bd9Sstevel@tonic-gate if (r == 0.0) { 98*7c478bd9Sstevel@tonic-gate /* w is zero; multiply a by 1/Re(w) - I * Im(w) */ 99*7c478bd9Sstevel@tonic-gate c = 1.0f / c; 100*7c478bd9Sstevel@tonic-gate i = testinff(a); 101*7c478bd9Sstevel@tonic-gate if (i) { /* a is infinite */ 102*7c478bd9Sstevel@tonic-gate a = i; 103*7c478bd9Sstevel@tonic-gate } 104*7c478bd9Sstevel@tonic-gate ((float *)&v)[0] = a * c; 105*7c478bd9Sstevel@tonic-gate ((float *)&v)[1] = (a == 0.0f)? a * c : -a * d; 106*7c478bd9Sstevel@tonic-gate return (v); 107*7c478bd9Sstevel@tonic-gate } 108*7c478bd9Sstevel@tonic-gate 109*7c478bd9Sstevel@tonic-gate r = (double)a / r; 110*7c478bd9Sstevel@tonic-gate x = (double)c * r; 111*7c478bd9Sstevel@tonic-gate y = (double)-d * r; 112*7c478bd9Sstevel@tonic-gate 113*7c478bd9Sstevel@tonic-gate if (x != x || y != y) { 114*7c478bd9Sstevel@tonic-gate /* 115*7c478bd9Sstevel@tonic-gate * x or y is NaN, so a and w can't both be finite and 116*7c478bd9Sstevel@tonic-gate * nonzero. Since we handled the case w = 0 above, the 117*7c478bd9Sstevel@tonic-gate * only case to check here is when w is infinite. 118*7c478bd9Sstevel@tonic-gate */ 119*7c478bd9Sstevel@tonic-gate i = testinff(c); 120*7c478bd9Sstevel@tonic-gate j = testinff(d); 121*7c478bd9Sstevel@tonic-gate if (i | j) { /* w is infinite */ 122*7c478bd9Sstevel@tonic-gate cc.f = c; 123*7c478bd9Sstevel@tonic-gate dd.f = d; 124*7c478bd9Sstevel@tonic-gate c = (cc.i < 0)? -0.0f : 0.0f; 125*7c478bd9Sstevel@tonic-gate d = (dd.i < 0)? -0.0f : 0.0f; 126*7c478bd9Sstevel@tonic-gate x = (double)c * a; 127*7c478bd9Sstevel@tonic-gate y = (double)-d * a; 128*7c478bd9Sstevel@tonic-gate } 129*7c478bd9Sstevel@tonic-gate } 130*7c478bd9Sstevel@tonic-gate 131*7c478bd9Sstevel@tonic-gate /* 132*7c478bd9Sstevel@tonic-gate * The following is equivalent to 133*7c478bd9Sstevel@tonic-gate * 134*7c478bd9Sstevel@tonic-gate * return x + I * y; 135*7c478bd9Sstevel@tonic-gate */ 136*7c478bd9Sstevel@tonic-gate ((float *)&v)[0] = (float)x; 137*7c478bd9Sstevel@tonic-gate ((float *)&v)[1] = (float)y; 138*7c478bd9Sstevel@tonic-gate return (v); 139*7c478bd9Sstevel@tonic-gate } 140