From 0ac5ae2335292908f39031b1ea9fe8edce433c0f Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Wed, 12 Oct 2011 11:27:51 -0400 Subject: Optimize libm libm is now somewhat integrated with gcc's -ffinite-math-only option and lots of the wrapper functions have been optimized. --- math/w_powf.c | 122 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 60 insertions(+), 62 deletions(-) (limited to 'math/w_powf.c') diff --git a/math/w_powf.c b/math/w_powf.c index 761e4d1..c0406f4 100644 --- a/math/w_powf.c +++ b/math/w_powf.c @@ -1,77 +1,75 @@ -/* w_powf.c -- float version of w_pow.c. - * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. - */ +/* Copyright (C) 2011 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper , 2011. -/* - * ==================================================== - * 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. - * ==================================================== - */ + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. -#if defined(LIBM_SCCS) && !defined(lint) -static char rcsid[] = "$NetBSD: w_powf.c,v 1.3 1995/05/10 20:49:41 jtc Exp $"; -#endif + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. -/* - * wrapper powf(x,y) return x**y - */ + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ #include #include -#ifdef __STDC__ - float __powf(float x, float y) /* wrapper powf */ -#else - float __powf(x,y) /* wrapper powf */ - float x,y; -#endif +/* wrapper powf */ +float +__powf (float x, float y) { -#ifdef _IEEE_LIBM - return __ieee754_powf(x,y); -#else - float z; - z=__ieee754_powf(x,y); - if(_LIB_VERSION == _IEEE_|| __isnanf(y)) return z; - if(__isnanf(x)) { - if(y==(float)0.0) - /* powf(NaN,0.0) */ - return (float)__kernel_standard((double)x,(double)y,142); - else - return z; - } - if(x==(float)0.0) { - if(y==(float)0.0) - /* powf(0.0,0.0) */ - return (float)__kernel_standard((double)x,(double)y,120); - if(__finitef(y)&&y<(float)0.0) { - if (signbit (x) && signbit (z)) - /* powf(0.0,negative) */ - return (float)__kernel_standard((double)x,(double)y,123); + float z = __ieee754_powf (x, y); + if (__builtin_expect (!__finitef (z), 0)) + { + if (_LIB_VERSION != _IEEE_) + { + if (__isnanf (x)) + { + if (y == 0.0f) + /* pow(NaN,0.0) */ + return __kernel_standard_f (x, y, 142); + } + else if (__finitef (x) && __finitef (y)) + { + if (__isnanf (z)) + /* pow neg**non-int */ + return __kernel_standard_f (x, y, 124); + else if (x == 0.0f && y < 0.0f) + { + if (signbit (x) && signbit (z)) + /* pow(-0.0,negative) */ + return __kernel_standard_f (x, y, 123); + else + /* pow(+0.0,negative) */ + return __kernel_standard_f (x, y, 143); + } else - return (float)__kernel_standard((double)x,(double)y,143); + /* pow overflow */ + return __kernel_standard_f (x, y, 121); } - return z; } - if(!__finitef(z)) { - if(__finitef(x)&&__finitef(y)) { - if(__isnanf(z)) - /* powf neg**non-int */ - return (float)__kernel_standard((double)x,(double)y,124); - else - /* powf overflow */ - return (float)__kernel_standard((double)x,(double)y,121); - } + } + else if (__builtin_expect (z == 0.0f, 0) && __finitef (x) && __finitef (y) + && _LIB_VERSION != _IEEE_) + { + if (x == 0.0f) + { + if (y == 0.0f) + /* pow(0.0,0.0) */ + return __kernel_standard_f (x, y, 120); } - if(z==(float)0.0&&__finitef(x)&&__finitef(y)) - /* powf underflow */ - return (float)__kernel_standard((double)x,(double)y,122); - return z; -#endif + else + /* pow underflow */ + return __kernel_standard_f (x, y, 122); + } + + return z; } weak_alias (__powf, powf) -- cgit v1.1