From 0b44a0315b47dd8eced9f3b7f31580cf14bbfc01 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sat, 12 Feb 2011 00:22:29 -0500 Subject: initial check-in, version 0.5.0 --- src/math/s_logbf.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 src/math/s_logbf.c (limited to 'src/math/s_logbf.c') diff --git a/src/math/s_logbf.c b/src/math/s_logbf.c new file mode 100644 index 00000000..747664d3 --- /dev/null +++ b/src/math/s_logbf.c @@ -0,0 +1,31 @@ +/* s_logbf.c -- float version of s_logb.c. + * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. + */ + +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +#include +#include "math_private.h" + +float +logbf(float x) +{ + int32_t ix; + GET_FLOAT_WORD(ix,x); + ix &= 0x7fffffff; /* high |x| */ + if(ix==0) return (float)-1.0/fabsf(x); + if(ix>=0x7f800000) return x*x; + if((ix>>=23)==0) /* IEEE 754 logb */ + return -126.0; + else + return (float) (ix-127); +} -- cgit v1.2.3-70-g09d2