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authorUlrich Drepper <drepper@gmail.com>2011-10-12 11:27:51 -0400
committerUlrich Drepper <drepper@gmail.com>2011-10-12 11:27:51 -0400
commit0ac5ae2335292908f39031b1ea9fe8edce433c0f (patch)
treef9d26c8abc0de39d18d4c13e70f6022cdc6b461f /math/e_scalb.c
parenta843a204a3e8a0dd53584dad3668771abaec84ac (diff)
downloadglibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.tar.gz
Optimize libm
libm is now somewhat integrated with gcc's -ffinite-math-only option and lots of the wrapper functions have been optimized.
Diffstat (limited to 'math/e_scalb.c')
-rw-r--r--math/e_scalb.c112
1 files changed, 50 insertions, 62 deletions
diff --git a/math/e_scalb.c b/math/e_scalb.c
index f2c207ac8b..3b81dd5653 100644
--- a/math/e_scalb.c
+++ b/math/e_scalb.c
@@ -1,71 +1,59 @@
-/* @(#)e_scalb.c 5.1 93/09/24 */
-/*
- * ====================================================
- * 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.
- * ====================================================
- */
+/* Copyright (C) 2011 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
-#if defined(LIBM_SCCS) && !defined(lint)
-static char rcsid[] = "$NetBSD: e_scalb.c,v 1.6 1995/05/10 20:46:09 jtc Exp $";
-#endif
+ 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.
-/*
- * __ieee754_scalb(x, fn) is provide for
- * passing various standard test suite. One
- * should use scalbn() instead.
- */
+ 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.
+
+ 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 <fenv.h>
#include <math.h>
#include <math_private.h>
-#ifdef _SCALB_INT
-#ifdef __STDC__
- double __ieee754_scalb(double x, int fn)
-#else
- double __ieee754_scalb(x,fn)
- double x; int fn;
-#endif
-#else
-#ifdef __STDC__
- double __ieee754_scalb(double x, double fn)
-#else
- double __ieee754_scalb(x,fn)
- double x, fn;
-#endif
-#endif
+
+static double
+__attribute__ ((noinline))
+invalid_fn (double x, double fn)
{
-#ifdef _SCALB_INT
- return __scalbn(x,fn);
-#else
- if (__isnan(x)||__isnan(fn)) return x*fn;
- if (!__finite(fn)) {
- if(fn>0.0) return x*fn;
- else if (x == 0)
- return x;
- else if (!__finite (x))
- {
-# ifdef FE_INVALID
- feraiseexcept (FE_INVALID);
-# endif
- return __nan ("");
- }
- else return x/(-fn);
- }
- if (__rint(fn)!=fn)
- {
-# ifdef FE_INVALID
- feraiseexcept (FE_INVALID);
-# endif
- return __nan ("");
- }
- if ( fn > 65000.0) return __scalbn(x, 65000);
- if (-fn > 65000.0) return __scalbn(x,-65000);
- return __scalbn(x,(int)fn);
-#endif
+ if (__rint (fn) != fn)
+ {
+ feraiseexcept (FE_INVALID);
+ return __nan ("");
+ }
+ else if (fn > 65000.0)
+ return __scalbn (x, 65000);
+ else
+ return __scalbn (x,-65000);
+}
+
+
+double
+__ieee754_scalb (double x, double fn)
+{
+ if (__builtin_expect (__isnan (x), 0))
+ return x * fn;
+ if (__builtin_expect (!__finite (fn), 0))
+ {
+ if (__isnan (fn) || fn > 0.0)
+ return x * fn;
+ if (x == 0.0)
+ return x;
+ return x / -fn;
+ }
+ if (__builtin_expect ((double) (int) fn != fn, 0))
+ return invalid_fn (x, fn);
+
+ return __scalbn (x, (int) fn);
}
+strong_alias (__ieee754_scalb, __scalb_finite)