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[PATCH] Use builtins in fabs implementations
- From: "Wilco Dijkstra" <wdijkstr at arm dot com>
- To: <libc-alpha at sourceware dot org>
- Date: Fri, 22 May 2015 11:50:36 +0100
- Subject: [PATCH] Use builtins in fabs implementations
- Authentication-results: sourceware.org; auth=none
Since GLIBC is built with a modern GCC which always inlines __builtin_fabs, it is safe to use the
builtin for the definitions of fabs and fabsf (fabsl is typically emulated and unsafe in some cases,
see https://sourceware.org/ml/libc-alpha/2015-05/msg00336.html). This means targets no longer need
to define their own implementations.
OK for commit?
ChangeLog:
2015-05-22 Wilco Dijkstra <wdijkstr@arm.com>
* sysdeps/ieee754/dbl-64/s_fabs.c: (__fabs): Call __builtin_fabs.
* sysdeps/ieee754/flt-32/s_fabsf.c: (__fabsf): Likewise.
---
sysdeps/ieee754/dbl-64/s_fabs.c | 6 +-----
sysdeps/ieee754/flt-32/s_fabsf.c | 6 +-----
2 files changed, 2 insertions(+), 10 deletions(-)
diff --git a/sysdeps/ieee754/dbl-64/s_fabs.c b/sysdeps/ieee754/dbl-64/s_fabs.c
index c82c421..73c09a2 100644
--- a/sysdeps/ieee754/dbl-64/s_fabs.c
+++ b/sysdeps/ieee754/dbl-64/s_fabs.c
@@ -19,15 +19,11 @@ static char rcsid[] = "$NetBSD: s_fabs.c,v 1.7 1995/05/10 20:47:13 jtc Exp $";
*/
#include <math.h>
-#include <math_private.h>
double
__fabs (double x)
{
- u_int32_t high;
- GET_HIGH_WORD (high, x);
- SET_HIGH_WORD (x, high & 0x7fffffff);
- return x;
+ return __builtin_fabs (x);
}
weak_alias (__fabs, fabs)
#ifdef NO_LONG_DOUBLE
diff --git a/sysdeps/ieee754/flt-32/s_fabsf.c b/sysdeps/ieee754/flt-32/s_fabsf.c
index c58aede..297abe6 100644
--- a/sysdeps/ieee754/flt-32/s_fabsf.c
+++ b/sysdeps/ieee754/flt-32/s_fabsf.c
@@ -22,13 +22,9 @@ static char rcsid[] = "$NetBSD: s_fabsf.c,v 1.4 1995/05/10 20:47:15 jtc Exp $";
*/
#include <math.h>
-#include <math_private.h>
float __fabsf(float x)
{
- u_int32_t ix;
- GET_FLOAT_WORD(ix,x);
- SET_FLOAT_WORD(x,ix&0x7fffffff);
- return x;
+ return __builtin_fabsf (x);
}
weak_alias (__fabsf, fabsf)
--
1.9.1