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[PATCH] Eliminate redundant sign extensions in pow()
- From: Anton Blanchard <anton at samba dot org>
- To: joseph at codesourcery dot com, tuliom at linux dot vnet dot ibm dot com, cseo at linux dot vnet dot ibm dot com, sjmunroe at us dot ibm dot com
- Cc: libc-alpha at sourceware dot org
- Date: Mon, 16 Nov 2015 21:44:13 +1100
- Subject: [PATCH] Eliminate redundant sign extensions in pow()
- Authentication-results: sourceware.org; auth=none
When looking at the code generated for pow() on ppc64 I noticed quite
a few sign extensions. Making the array indices unsigned reduces the
number of sign extensions from 24 to 7.
--
diff --git a/sysdeps/ieee754/dbl-64/e_pow.c b/sysdeps/ieee754/dbl-64/e_pow.c
index 3b0bbe3..adbd5b8 100644
--- a/sysdeps/ieee754/dbl-64/e_pow.c
+++ b/sysdeps/ieee754/dbl-64/e_pow.c
@@ -245,7 +245,8 @@ static double
SECTION
log1 (double x, double *delta, double *error)
{
- int i, j, m;
+ unsigned int i, j;
+ int m;
double uu, vv, eps, nx, e, e1, e2, t, t1, t2, res, add = 0;
mynumber u, v;
#ifdef BIG_ENDI
@@ -344,7 +345,8 @@ static double
SECTION
my_log2 (double x, double *delta, double *error)
{
- int i, j, m;
+ unsigned int i, j;
+ int m;
double uu, vv, eps, nx, e, e1, e2, t, t1, t2, res, add = 0;
double ou1, ou2, lu1, lu2, ov, lv1, lv2, a, a1, a2;
double y, yy, z, zz, j1, j2, j7, j8;