1*25c28e83SPiotr Jasiukajtis /* 2*25c28e83SPiotr Jasiukajtis * CDDL HEADER START 3*25c28e83SPiotr Jasiukajtis * 4*25c28e83SPiotr Jasiukajtis * The contents of this file are subject to the terms of the 5*25c28e83SPiotr Jasiukajtis * Common Development and Distribution License (the "License"). 6*25c28e83SPiotr Jasiukajtis * You may not use this file except in compliance with the License. 7*25c28e83SPiotr Jasiukajtis * 8*25c28e83SPiotr Jasiukajtis * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9*25c28e83SPiotr Jasiukajtis * or http://www.opensolaris.org/os/licensing. 10*25c28e83SPiotr Jasiukajtis * See the License for the specific language governing permissions 11*25c28e83SPiotr Jasiukajtis * and limitations under the License. 12*25c28e83SPiotr Jasiukajtis * 13*25c28e83SPiotr Jasiukajtis * When distributing Covered Code, include this CDDL HEADER in each 14*25c28e83SPiotr Jasiukajtis * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15*25c28e83SPiotr Jasiukajtis * If applicable, add the following below this CDDL HEADER, with the 16*25c28e83SPiotr Jasiukajtis * fields enclosed by brackets "[]" replaced with your own identifying 17*25c28e83SPiotr Jasiukajtis * information: Portions Copyright [yyyy] [name of copyright owner] 18*25c28e83SPiotr Jasiukajtis * 19*25c28e83SPiotr Jasiukajtis * CDDL HEADER END 20*25c28e83SPiotr Jasiukajtis */ 21*25c28e83SPiotr Jasiukajtis 22*25c28e83SPiotr Jasiukajtis /* 23*25c28e83SPiotr Jasiukajtis * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 24*25c28e83SPiotr Jasiukajtis */ 25*25c28e83SPiotr Jasiukajtis /* 26*25c28e83SPiotr Jasiukajtis * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 27*25c28e83SPiotr Jasiukajtis * Use is subject to license terms. 28*25c28e83SPiotr Jasiukajtis */ 29*25c28e83SPiotr Jasiukajtis 30*25c28e83SPiotr Jasiukajtis #if defined(ELFOBJ) 31*25c28e83SPiotr Jasiukajtis #pragma weak scalbnf = __scalbnf 32*25c28e83SPiotr Jasiukajtis #endif 33*25c28e83SPiotr Jasiukajtis 34*25c28e83SPiotr Jasiukajtis #include "libm.h" 35*25c28e83SPiotr Jasiukajtis #include <float.h> /* FLT_MAX, FLT_MIN */ 36*25c28e83SPiotr Jasiukajtis #include <stdlib.h> /* abs */ 37*25c28e83SPiotr Jasiukajtis 38*25c28e83SPiotr Jasiukajtis static const float twom25f = 2.98023223876953125e-8F; 39*25c28e83SPiotr Jasiukajtis #if defined(USE_FPSCALE) || defined(__x86) 40*25c28e83SPiotr Jasiukajtis static const float two23f = 8388608.0F; 41*25c28e83SPiotr Jasiukajtis #else 42*25c28e83SPiotr Jasiukajtis /* 43*25c28e83SPiotr Jasiukajtis * v: a non-zero subnormal |x|; returns [-22, 0] 44*25c28e83SPiotr Jasiukajtis */ 45*25c28e83SPiotr Jasiukajtis static int 46*25c28e83SPiotr Jasiukajtis ilogbf_biased(unsigned v) { 47*25c28e83SPiotr Jasiukajtis int r = -22; 48*25c28e83SPiotr Jasiukajtis 49*25c28e83SPiotr Jasiukajtis if (v & 0xffff0000) 50*25c28e83SPiotr Jasiukajtis r += 16, v >>= 16; 51*25c28e83SPiotr Jasiukajtis if (v & 0xff00) 52*25c28e83SPiotr Jasiukajtis r += 8, v >>= 8; 53*25c28e83SPiotr Jasiukajtis if (v & 0xf0) 54*25c28e83SPiotr Jasiukajtis r += 4, v >>= 4; 55*25c28e83SPiotr Jasiukajtis v <<= 1; 56*25c28e83SPiotr Jasiukajtis return (r + ((0xffffaa50 >> v) & 0x3)); 57*25c28e83SPiotr Jasiukajtis } 58*25c28e83SPiotr Jasiukajtis #endif /* defined(USE_FPSCALE) */ 59*25c28e83SPiotr Jasiukajtis 60*25c28e83SPiotr Jasiukajtis float 61*25c28e83SPiotr Jasiukajtis scalbnf(float x, int n) { 62*25c28e83SPiotr Jasiukajtis int *px = (int *) &x, ix, k; 63*25c28e83SPiotr Jasiukajtis 64*25c28e83SPiotr Jasiukajtis ix = *px & ~0x80000000; 65*25c28e83SPiotr Jasiukajtis k = ix >> 23; 66*25c28e83SPiotr Jasiukajtis if (k == 0xff) 67*25c28e83SPiotr Jasiukajtis #if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN) 68*25c28e83SPiotr Jasiukajtis return (ix > 0x7f800000 ? x * x : x); 69*25c28e83SPiotr Jasiukajtis #else 70*25c28e83SPiotr Jasiukajtis return (x + x); 71*25c28e83SPiotr Jasiukajtis #endif 72*25c28e83SPiotr Jasiukajtis if (ix == 0 || n == 0) 73*25c28e83SPiotr Jasiukajtis return (x); 74*25c28e83SPiotr Jasiukajtis if (k == 0) { 75*25c28e83SPiotr Jasiukajtis #if defined(USE_FPSCALE) || defined(__x86) 76*25c28e83SPiotr Jasiukajtis x *= two23f; 77*25c28e83SPiotr Jasiukajtis k = ((*px & ~0x80000000) >> 23) - 23; 78*25c28e83SPiotr Jasiukajtis #else 79*25c28e83SPiotr Jasiukajtis k = ilogbf_biased(ix); 80*25c28e83SPiotr Jasiukajtis *px = (*px & 0x80000000) | (ix << (-k + 1)); 81*25c28e83SPiotr Jasiukajtis #endif 82*25c28e83SPiotr Jasiukajtis } 83*25c28e83SPiotr Jasiukajtis if ((unsigned) abs(n) >= 131072) /* cast to unsigned for -2^31 */ 84*25c28e83SPiotr Jasiukajtis n >>= 1; /* avoid subsequent integer overflow */ 85*25c28e83SPiotr Jasiukajtis k += n; 86*25c28e83SPiotr Jasiukajtis if (k > 0xfe) 87*25c28e83SPiotr Jasiukajtis return (FLT_MAX * copysignf(FLT_MAX, x)); 88*25c28e83SPiotr Jasiukajtis if (k <= -25) 89*25c28e83SPiotr Jasiukajtis return (FLT_MIN * copysignf(FLT_MIN, x)); 90*25c28e83SPiotr Jasiukajtis if (k > 0) { 91*25c28e83SPiotr Jasiukajtis *px = (*px & ~0x7f800000) | (k << 23); 92*25c28e83SPiotr Jasiukajtis return (x); 93*25c28e83SPiotr Jasiukajtis } 94*25c28e83SPiotr Jasiukajtis k += 25; 95*25c28e83SPiotr Jasiukajtis *px = (*px & ~0x7f800000) | (k << 23); 96*25c28e83SPiotr Jasiukajtis return (x * twom25f); 97*25c28e83SPiotr Jasiukajtis } 98