12116Sjkh/* s_logbf.c -- float version of s_logb.c. 22116Sjkh * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 32116Sjkh */ 42116Sjkh 52116Sjkh/* 62116Sjkh * ==================================================== 72116Sjkh * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 82116Sjkh * 92116Sjkh * Developed at SunPro, a Sun Microsystems, Inc. business. 102116Sjkh * Permission to use, copy, modify, and distribute this 118870Srgrimes * software is freely granted, provided that this notice 122116Sjkh * is preserved. 132116Sjkh * ==================================================== 142116Sjkh */ 152116Sjkh 16176451Sdas#include <sys/cdefs.h> 17176451Sdas__FBSDID("$FreeBSD: releng/10.3/lib/msun/src/s_logbf.c 176451 2008-02-22 02:30:36Z das $"); 182116Sjkh 192116Sjkh#include "math.h" 202116Sjkh#include "math_private.h" 212116Sjkh 22153049Sbdestatic const float 23153049Sbdetwo25 = 3.355443200e+07; /* 0x4c000000 */ 24153049Sbde 2597413Salfredfloat 2697413Salfredlogbf(float x) 272116Sjkh{ 282116Sjkh int32_t ix; 292116Sjkh GET_FLOAT_WORD(ix,x); 302116Sjkh ix &= 0x7fffffff; /* high |x| */ 312116Sjkh if(ix==0) return (float)-1.0/fabsf(x); 322116Sjkh if(ix>=0x7f800000) return x*x; 33153049Sbde if(ix<0x00800000) { 34153049Sbde x *= two25; /* convert subnormal x to normal */ 35153049Sbde GET_FLOAT_WORD(ix,x); 36153049Sbde ix &= 0x7fffffff; 37153049Sbde return (float) ((ix>>23)-127-25); 38153049Sbde } else 39153049Sbde return (float) ((ix>>23)-127); 402116Sjkh} 41