From: Joseph Myers <joseph@codesourcery.com>
Date: Thu, 9 Jun 2016 17:25:54 +0000 (+0000)
Subject: Fix ldbl-128ibm log1pl (sNaN) (bug 20234).
X-Git-Tag: glibc-2.24~128
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b7519f61fe2c57981c69c0c65996968b9a4d9b62;p=thirdparty%2Fglibc.git

Fix ldbl-128ibm log1pl (sNaN) (bug 20234).

The ldbl-128ibm version of log1pl returns sNaN for sNaN input.  This
patch fixes it to add such inputs to themselves so that qNaN is
returned in this case.

Tested for powerpc.

	[BZ #20234]
	* sysdeps/ieee754/ldbl-128ibm/s_log1pl.c (__log1pl): Add positive
	infinity or NaN input to itself.
---

diff --git a/ChangeLog b/ChangeLog
index 6944ac57ec6..81192ce5b84 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2016-06-09  Joseph Myers  <joseph@codesourcery.com>
 
+	[BZ #20234]
+	* sysdeps/ieee754/ldbl-128ibm/s_log1pl.c (__log1pl): Add positive
+	infinity or NaN input to itself.
+
 	[BZ #20233]
 	* sysdeps/ieee754/ldbl-128ibm/s_expm1l.c (__expm1l): Add NaN input
 	to itself.
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_log1pl.c b/sysdeps/ieee754/ldbl-128ibm/s_log1pl.c
index 743693bfd64..5457892a984 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_log1pl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_log1pl.c
@@ -132,7 +132,7 @@ __log1pl (long double xm1)
   xhi = ldbl_high (xm1);
   EXTRACT_WORDS (hx, lx, xhi);
   if (hx >= 0x7ff00000)
-    return xm1;
+    return xm1 + xm1;
 
   /* log1p(+- 0) = +- 0.  */
   if (((hx & 0x7fffffff) | lx) == 0)