s_logbf.c revision 97413
1177633Sdfr/* s_logbf.c -- float version of s_logb.c. 2177633Sdfr * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 3177633Sdfr */ 4177633Sdfr 5177633Sdfr/* 6177633Sdfr * ==================================================== 7177633Sdfr * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 8177633Sdfr * 9177633Sdfr * Developed at SunPro, a Sun Microsystems, Inc. business. 10177633Sdfr * Permission to use, copy, modify, and distribute this 11177633Sdfr * software is freely granted, provided that this notice 12177633Sdfr * is preserved. 13177633Sdfr * ==================================================== 14177633Sdfr */ 15177633Sdfr 16177633Sdfr#ifndef lint 17177633Sdfrstatic char rcsid[] = "$FreeBSD: head/lib/msun/src/s_logbf.c 97413 2002-05-28 18:15:04Z alfred $"; 18177633Sdfr#endif 19177633Sdfr 20177633Sdfr#include "math.h" 21177633Sdfr#include "math_private.h" 22177633Sdfr 23177633Sdfrfloat 24177633Sdfrlogbf(float x) 25177633Sdfr{ 26177633Sdfr int32_t ix; 27177633Sdfr GET_FLOAT_WORD(ix,x); 28177633Sdfr ix &= 0x7fffffff; /* high |x| */ 29177633Sdfr if(ix==0) return (float)-1.0/fabsf(x); 30177633Sdfr if(ix>=0x7f800000) return x*x; 31177633Sdfr if((ix>>=23)==0) /* IEEE 754 logb */ 32177633Sdfr return -126.0; 33177633Sdfr else 34177633Sdfr return (float) (ix-127); 35177633Sdfr} 36177633Sdfr