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 __logbf = logbf 3125c28e83SPiotr Jasiukajtis 3225c28e83SPiotr Jasiukajtis #include "libm.h" 3325c28e83SPiotr Jasiukajtis #include "xpg6.h" /* __xpg6 */ 3425c28e83SPiotr Jasiukajtis #define _C99SUSv3_logb _C99SUSv3_logb_subnormal_is_like_ilogb 3525c28e83SPiotr Jasiukajtis 361ec68d33SRichard Lowe #if defined(__x86) 3725c28e83SPiotr Jasiukajtis static const float two25 = 33554432.0F; 3825c28e83SPiotr Jasiukajtis #else 3925c28e83SPiotr Jasiukajtis /* 4025c28e83SPiotr Jasiukajtis * v: a non-zero subnormal |x| 4125c28e83SPiotr Jasiukajtis */ 4225c28e83SPiotr Jasiukajtis static int ilogbf_subnormal(unsigned v)4325c28e83SPiotr Jasiukajtisilogbf_subnormal(unsigned v) { 4425c28e83SPiotr Jasiukajtis int r = -126 - 23; 4525c28e83SPiotr Jasiukajtis 4625c28e83SPiotr Jasiukajtis if (v & 0xffff0000) 4725c28e83SPiotr Jasiukajtis r += 16, v >>= 16; 4825c28e83SPiotr Jasiukajtis if (v & 0xff00) 4925c28e83SPiotr Jasiukajtis r += 8, v >>= 8; 5025c28e83SPiotr Jasiukajtis if (v & 0xf0) 5125c28e83SPiotr Jasiukajtis r += 4, v >>= 4; 5225c28e83SPiotr Jasiukajtis v <<= 1; 5325c28e83SPiotr Jasiukajtis return (r + ((0xffffaa50 >> v) & 0x3)); 5425c28e83SPiotr Jasiukajtis } 551ec68d33SRichard Lowe #endif /* defined(__x86) */ 5625c28e83SPiotr Jasiukajtis 5725c28e83SPiotr Jasiukajtis static float raise_division(float t)5825c28e83SPiotr Jasiukajtisraise_division(float t) { 5925c28e83SPiotr Jasiukajtis #pragma STDC FENV_ACCESS ON 6025c28e83SPiotr Jasiukajtis static const float zero = 0.0F; 6125c28e83SPiotr Jasiukajtis return (t / zero); 6225c28e83SPiotr Jasiukajtis } 6325c28e83SPiotr Jasiukajtis 6425c28e83SPiotr Jasiukajtis float logbf(float x)6525c28e83SPiotr Jasiukajtislogbf(float x) { 6625c28e83SPiotr Jasiukajtis int k = *((int *) &x) & ~0x80000000; 6725c28e83SPiotr Jasiukajtis 6825c28e83SPiotr Jasiukajtis if (k < 0x00800000) { 6925c28e83SPiotr Jasiukajtis if (k == 0) 7025c28e83SPiotr Jasiukajtis return (raise_division(-1.0F)); 7125c28e83SPiotr Jasiukajtis else if ((__xpg6 & _C99SUSv3_logb) != 0) { 721ec68d33SRichard Lowe #if defined(__x86) 7325c28e83SPiotr Jasiukajtis x *= two25; 7425c28e83SPiotr Jasiukajtis return ((float) (((*((int *) &x) & 0x7f800000) >> 23) - 7525c28e83SPiotr Jasiukajtis 152)); 7625c28e83SPiotr Jasiukajtis #else 7725c28e83SPiotr Jasiukajtis return ((float) ilogbf_subnormal(k)); 7825c28e83SPiotr Jasiukajtis #endif 7925c28e83SPiotr Jasiukajtis } else 8025c28e83SPiotr Jasiukajtis return (-126.F); 8125c28e83SPiotr Jasiukajtis } else if (k < 0x7f800000) 8225c28e83SPiotr Jasiukajtis return ((float) ((k >> 23) - 127)); 8325c28e83SPiotr Jasiukajtis else 8425c28e83SPiotr Jasiukajtis return (x * x); 8525c28e83SPiotr Jasiukajtis } 86