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 (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 24 */ 25 /* 26 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 27 * Use is subject to license terms. 28 */ 29 30 #if defined(ELFOBJ) 31 #pragma weak modf = __modf 32 #pragma weak _modf = __modf 33 #endif 34 35 /* 36 * modf(x, iptr) decomposes x into an integral part and a fractional 37 * part both having the same sign as x. It stores the integral part 38 * in *iptr and returns the fractional part. 39 * 40 * If x is infinite, modf sets *iptr to x and returns copysign(0.0,x). 41 * If x is NaN, modf sets *iptr to x and returns x. 42 * 43 * If x is a signaling NaN, this code does not attempt to raise the 44 * invalid operation exception. 45 */ 46 47 #include "libm.h" 48 49 double 50 __modf(double x, double *iptr) { 51 union { 52 unsigned i[2]; 53 double d; 54 } xx, yy; 55 unsigned hx, s; 56 57 xx.d = x; 58 hx = xx.i[HIWORD] & ~0x80000000; 59 60 if (hx >= 0x43300000) { /* x is NaN, infinite, or integral */ 61 *iptr = x; 62 if (hx < 0x7ff00000 || (hx == 0x7ff00000 && 63 xx.i[LOWORD] == 0)) { 64 xx.i[HIWORD] &= 0x80000000; 65 xx.i[LOWORD] = 0; 66 } 67 return (xx.d); 68 } 69 70 if (hx < 0x3ff00000) { /* |x| < 1 */ 71 xx.i[HIWORD] &= 0x80000000; 72 xx.i[LOWORD] = 0; 73 *iptr = xx.d; 74 return (x); 75 } 76 77 /* split x at the binary point */ 78 s = xx.i[HIWORD] & 0x80000000; 79 if (hx < 0x41400000) { 80 yy.i[HIWORD] = xx.i[HIWORD] & ~((1 << (0x413 - (hx >> 20))) - 81 1); 82 yy.i[LOWORD] = 0; 83 } else { 84 yy.i[HIWORD] = xx.i[HIWORD]; 85 yy.i[LOWORD] = xx.i[LOWORD] & ~((1 << (0x433 - (hx >> 20))) - 86 1); 87 } 88 *iptr = yy.d; 89 xx.d -= yy.d; 90 xx.i[HIWORD] = (xx.i[HIWORD] & ~0x80000000) | s; 91 /* keep sign of x */ 92 return (xx.d); 93 } 94