125c28e83SPiotr Jasiukajtis /* 225c28e83SPiotr Jasiukajtis * CDDL HEADER START 325c28e83SPiotr Jasiukajtis * 425c28e83SPiotr Jasiukajtis * The contents of this file are subject to the terms of the 525c28e83SPiotr Jasiukajtis * Common Development and Distribution License (the "License"). 625c28e83SPiotr Jasiukajtis * You may not use this file except in compliance with the License. 725c28e83SPiotr Jasiukajtis * 825c28e83SPiotr Jasiukajtis * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 925c28e83SPiotr Jasiukajtis * or http://www.opensolaris.org/os/licensing. 1025c28e83SPiotr Jasiukajtis * See the License for the specific language governing permissions 1125c28e83SPiotr Jasiukajtis * and limitations under the License. 1225c28e83SPiotr Jasiukajtis * 1325c28e83SPiotr Jasiukajtis * When distributing Covered Code, include this CDDL HEADER in each 1425c28e83SPiotr Jasiukajtis * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 1525c28e83SPiotr Jasiukajtis * If applicable, add the following below this CDDL HEADER, with the 1625c28e83SPiotr Jasiukajtis * fields enclosed by brackets "[]" replaced with your own identifying 1725c28e83SPiotr Jasiukajtis * information: Portions Copyright [yyyy] [name of copyright owner] 1825c28e83SPiotr Jasiukajtis * 1925c28e83SPiotr Jasiukajtis * CDDL HEADER END 2025c28e83SPiotr Jasiukajtis */ 2125c28e83SPiotr Jasiukajtis 2225c28e83SPiotr Jasiukajtis /* 2325c28e83SPiotr Jasiukajtis * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 2425c28e83SPiotr Jasiukajtis */ 2525c28e83SPiotr Jasiukajtis /* 2625c28e83SPiotr Jasiukajtis * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 2725c28e83SPiotr Jasiukajtis * Use is subject to license terms. 2825c28e83SPiotr Jasiukajtis */ 2925c28e83SPiotr Jasiukajtis 30*ddc0e0b5SRichard Lowe #pragma weak __ilogb = ilogb 3125c28e83SPiotr Jasiukajtis 3225c28e83SPiotr Jasiukajtis #include "libm.h" 3325c28e83SPiotr Jasiukajtis #include "xpg6.h" /* __xpg6 */ 3425c28e83SPiotr Jasiukajtis 351ec68d33SRichard Lowe #if defined(__x86) 3625c28e83SPiotr Jasiukajtis static const double two52 = 4503599627370496.0; 3725c28e83SPiotr Jasiukajtis #else 3825c28e83SPiotr Jasiukajtis /* 3925c28e83SPiotr Jasiukajtis * v: high part of a non-zero subnormal |x|; w: low part of |x| 4025c28e83SPiotr Jasiukajtis */ 4125c28e83SPiotr Jasiukajtis static int 4225c28e83SPiotr Jasiukajtis ilogb_subnormal(unsigned v, unsigned w) { 4325c28e83SPiotr Jasiukajtis int r = -1022 - 52; 4425c28e83SPiotr Jasiukajtis 4525c28e83SPiotr Jasiukajtis if (v) 4625c28e83SPiotr Jasiukajtis r += 32; 4725c28e83SPiotr Jasiukajtis else 4825c28e83SPiotr Jasiukajtis v = w; 4925c28e83SPiotr Jasiukajtis if (v & 0xffff0000) 5025c28e83SPiotr Jasiukajtis r += 16, v >>= 16; 5125c28e83SPiotr Jasiukajtis if (v & 0xff00) 5225c28e83SPiotr Jasiukajtis r += 8, v >>= 8; 5325c28e83SPiotr Jasiukajtis if (v & 0xf0) 5425c28e83SPiotr Jasiukajtis r += 4, v >>= 4; 5525c28e83SPiotr Jasiukajtis v <<= 1; 5625c28e83SPiotr Jasiukajtis return (r + ((0xffffaa50 >> v) & 0x3)); 5725c28e83SPiotr Jasiukajtis } 581ec68d33SRichard Lowe #endif /* defined(__x86) */ 5925c28e83SPiotr Jasiukajtis 6025c28e83SPiotr Jasiukajtis static int 6125c28e83SPiotr Jasiukajtis raise_invalid(int v) { /* SUSv3 requires ilogb(0,+/-Inf,NaN) raise invalid */ 6225c28e83SPiotr Jasiukajtis #ifndef lint 6325c28e83SPiotr Jasiukajtis if ((__xpg6 & _C99SUSv3_ilogb_0InfNaN_raises_invalid) != 0) { 6425c28e83SPiotr Jasiukajtis static const double zero = 0.0; 6525c28e83SPiotr Jasiukajtis volatile double dummy; 6625c28e83SPiotr Jasiukajtis 6725c28e83SPiotr Jasiukajtis dummy = zero / zero; 6825c28e83SPiotr Jasiukajtis } 6925c28e83SPiotr Jasiukajtis #endif 7025c28e83SPiotr Jasiukajtis return (v); 7125c28e83SPiotr Jasiukajtis } 7225c28e83SPiotr Jasiukajtis 7325c28e83SPiotr Jasiukajtis int 7425c28e83SPiotr Jasiukajtis ilogb(double x) { 7525c28e83SPiotr Jasiukajtis int *px = (int *) &x, k = px[HIWORD] & ~0x80000000; 7625c28e83SPiotr Jasiukajtis 7725c28e83SPiotr Jasiukajtis if (k < 0x00100000) { 7825c28e83SPiotr Jasiukajtis if ((px[LOWORD] | k) == 0) 7925c28e83SPiotr Jasiukajtis return (raise_invalid(0x80000001)); 8025c28e83SPiotr Jasiukajtis else { 811ec68d33SRichard Lowe #if defined(__x86) 8225c28e83SPiotr Jasiukajtis x *= two52; 8325c28e83SPiotr Jasiukajtis return (((px[HIWORD] & 0x7ff00000) >> 20) - 1075); 8425c28e83SPiotr Jasiukajtis #else 8525c28e83SPiotr Jasiukajtis return (ilogb_subnormal(k, px[LOWORD])); 8625c28e83SPiotr Jasiukajtis #endif 8725c28e83SPiotr Jasiukajtis } 8825c28e83SPiotr Jasiukajtis } else if (k < 0x7ff00000) 8925c28e83SPiotr Jasiukajtis return ((k >> 20) - 1023); 9025c28e83SPiotr Jasiukajtis else 9125c28e83SPiotr Jasiukajtis return (raise_invalid(0x7fffffff)); 9225c28e83SPiotr Jasiukajtis } 93