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 #pragma weak modf = __modf 31 #pragma weak _modf = __modf 32 33 /* 34 * modf(x, iptr) decomposes x into an integral part and a fractional 35 * part both having the same sign as x. It stores the integral part 36 * in *iptr and returns the fractional part. 37 * 38 * If x is infinite, modf sets *iptr to x and returns copysign(0.0,x). 39 * If x is NaN, modf sets *iptr to x and returns x. 40 * 41 * If x is a signaling NaN, this code does not attempt to raise the 42 * invalid operation exception. 43 */ 44 45 #include "libm.h" 46 47 double 48 __modf(double x, double *iptr) { 49 union { 50 unsigned i[2]; 51 double d; 52 } xx, yy; 53 unsigned hx, s; 54 55 xx.d = x; 56 hx = xx.i[HIWORD] & ~0x80000000; 57 58 if (hx >= 0x43300000) { /* x is NaN, infinite, or integral */ 59 *iptr = x; 60 if (hx < 0x7ff00000 || (hx == 0x7ff00000 && 61 xx.i[LOWORD] == 0)) { 62 xx.i[HIWORD] &= 0x80000000; 63 xx.i[LOWORD] = 0; 64 } 65 return (xx.d); 66 } 67 68 if (hx < 0x3ff00000) { /* |x| < 1 */ 69 xx.i[HIWORD] &= 0x80000000; 70 xx.i[LOWORD] = 0; 71 *iptr = xx.d; 72 return (x); 73 } 74 75 /* split x at the binary point */ 76 s = xx.i[HIWORD] & 0x80000000; 77 if (hx < 0x41400000) { 78 yy.i[HIWORD] = xx.i[HIWORD] & ~((1 << (0x413 - (hx >> 20))) - 79 1); 80 yy.i[LOWORD] = 0; 81 } else { 82 yy.i[HIWORD] = xx.i[HIWORD]; 83 yy.i[LOWORD] = xx.i[LOWORD] & ~((1 << (0x433 - (hx >> 20))) - 84 1); 85 } 86 *iptr = yy.d; 87 xx.d -= yy.d; 88 xx.i[HIWORD] = (xx.i[HIWORD] & ~0x80000000) | s; 89 /* keep sign of x */ 90 return (xx.d); 91 } 92