12116Sjkh/* s_ilogbf.c -- float version of s_ilogb.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/11.0/lib/msun/src/s_ilogbf.c 176451 2008-02-22 02:30:36Z das $"); 182116Sjkh 19136332Sstefanf#include <limits.h> 20136332Sstefanf 212116Sjkh#include "math.h" 222116Sjkh#include "math_private.h" 232116Sjkh 242116Sjkh int ilogbf(float x) 252116Sjkh{ 262116Sjkh int32_t hx,ix; 272116Sjkh 282116Sjkh GET_FLOAT_WORD(hx,x); 292116Sjkh hx &= 0x7fffffff; 302116Sjkh if(hx<0x00800000) { 318870Srgrimes if(hx==0) 32136332Sstefanf return FP_ILOGB0; 332116Sjkh else /* subnormal x */ 342116Sjkh for (ix = -126,hx<<=8; hx>0; hx<<=1) ix -=1; 352116Sjkh return ix; 362116Sjkh } 372116Sjkh else if (hx<0x7f800000) return (hx>>23)-127; 38136332Sstefanf else if (hx>0x7f800000) return FP_ILOGBNAN; 39136332Sstefanf else return INT_MAX; 402116Sjkh} 41