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authorJoseph Myers <joseph@codesourcery.com>2015-10-06 15:14:26 +0000
committerJoseph Myers <joseph@codesourcery.com>2015-10-06 15:14:26 +0000
commitd79b56892651fcfc1ae0f44d3d29d0fa03538ec1 (patch)
treea104e632dd2f035727115b98861f3cb0191d8557 /sysdeps/ieee754
parent3670da6bfb1ffd17d9bdce2d31d79656be0991b5 (diff)
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Fix ldbl-128ibm log1pl (-1) sign of infinity (bug 19076).
The ldbl-128ibm implementation of log1pl produces an infinity with the
wrong sign for log1pl (-1) in FE_DOWNWARD mode.  This patch fixes this
by changing a division (-1.0L / (x - x)) (incorrect in FE_DOWNWARD
mode) to (-1.0L / 0.0L) (correct in all rounding modes).

Tested for powerpc.

	[BZ #19076]
	* sysdeps/ieee754/ldbl-128ibm/s_log1pl.c (__log1pl): Divide by
	constant 0.0L when computing infinite result.
Diffstat (limited to 'sysdeps/ieee754')
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_log1pl.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_log1pl.c b/sysdeps/ieee754/ldbl-128ibm/s_log1pl.c
index a0e24d7f22..ad9a1fe20f 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_log1pl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_log1pl.c
@@ -149,7 +149,7 @@ __log1pl (long double xm1)
   if (x <= 0.0L)
     {
       if (x == 0.0L)
-	return (-1.0L / (x - x));
+	return (-1.0L / 0.0L);
       else
 	return (zero / (x - x));
     }