11dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* s_logbf.c -- float version of s_logb.c. 21dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 31dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 41dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 51dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* 61dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ==================================================== 71dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 81dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 91dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Developed at SunPro, a Sun Microsystems, Inc. business. 101dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Permission to use, copy, modify, and distribute this 111dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * software is freely granted, provided that this notice 121dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * is preserved. 131dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ==================================================== 141dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 151dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 161dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#ifndef lint 171dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectstatic char rcsid[] = "$FreeBSD: src/lib/msun/src/s_logbf.c,v 1.8 2005/12/03 11:57:19 bde Exp $"; 181dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#endif 191dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 201dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include "math.h" 211dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include "math_private.h" 221dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 231dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectstatic const float 241dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projecttwo25 = 3.355443200e+07; /* 0x4c000000 */ 251dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 261dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectfloat 271dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectlogbf(float x) 281dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project{ 291dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project int32_t ix; 301dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project GET_FLOAT_WORD(ix,x); 311dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project ix &= 0x7fffffff; /* high |x| */ 321dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(ix==0) return (float)-1.0/fabsf(x); 331dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(ix>=0x7f800000) return x*x; 341dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(ix<0x00800000) { 351dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project x *= two25; /* convert subnormal x to normal */ 361dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project GET_FLOAT_WORD(ix,x); 371dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project ix &= 0x7fffffff; 381dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (float) ((ix>>23)-127-25); 391dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } else 401dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (float) ((ix>>23)-127); 411dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project} 42