From 0ac5ae2335292908f39031b1ea9fe8edce433c0f Mon Sep 17 00:00:00 2001
From: Ulrich Drepper <drepper@gmail.com>
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_exp2.c | 26 ++++++++------------------
1 file changed, 8 insertions(+), 18 deletions(-)
(limited to 'math/w_exp2.c')
diff --git a/math/w_exp2.c b/math/w_exp2.c
index c92fb52ad0..bf223265cb 100644
--- a/math/w_exp2.c
+++ b/math/w_exp2.c
@@ -6,28 +6,18 @@
#include <math.h>
#include <math_private.h>
-static const double o_threshold= (double) DBL_MAX_EXP;
-static const double u_threshold= (double) (DBL_MIN_EXP - DBL_MANT_DIG - 1);
+static const double o_threshold = (double) DBL_MAX_EXP;
+static const double u_threshold = (double) (DBL_MIN_EXP - DBL_MANT_DIG - 1);
double
-__exp2 (double x) /* wrapper exp2 */
+__exp2 (double x)
{
-#ifdef _IEEE_LIBM
+ if (__builtin_expect (x <= u_threshold || x > o_threshold, 0)
+ && _LIB_VERSION != _IEEE_ && __finite (x))
+ /* exp2 overflow: 44, exp2 underflow: 45 */
+ return __kernel_standard (x, x, 44 + (x <= o_threshold));
+
return __ieee754_exp2 (x);
-#else
- double z;
- z = __ieee754_exp2 (x);
- if (_LIB_VERSION != _IEEE_ && __finite (x))
- {
- if (x > o_threshold)
- /* exp2 overflow */
- return __kernel_standard (x, x, 44);
- else if (x <= u_threshold)
- /* exp2 underflow */
- return __kernel_standard (x, x, 45);
- }
- return z;
-#endif
}
weak_alias (__exp2, exp2)
#ifdef NO_LONG_DOUBLE
--
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