From: Joseph Myers <joseph@codesourcery.com>
Date: Wed, 31 Oct 2012 20:44:59 +0000 (+0000)
Subject: Fix ldbl-128ibm atan2l for x near 1.
X-Git-Tag: glibc-2.17~309
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=16a0e2ec87f104961b88173fe8c96f9348850b0d;p=thirdparty%2Fglibc.git

Fix ldbl-128ibm atan2l for x near 1.
---

diff --git a/ChangeLog b/ChangeLog
index fd72f40445b..e14bac6b3ea 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2012-10-31  Joseph Myers  <joseph@codesourcery.com>
 
+	[BZ #14610]
+	* sysdeps/ieee754/ldbl-128ibm/e_atan2l.c (__ieee754_atan2l): Check
+	for low part of x being zero before using __atanl (y).
+	* math/libm-test.inc (atan2_test): Add another test.
+
 	* manual/install.texi (Configuring and compiling): Document
 	general use of test-wrapper and test-wrapper-env.
 	* INSTALL: Regenerated.
diff --git a/NEWS b/NEWS
index fe569e12407..8b691e5e7cb 100644
--- a/NEWS
+++ b/NEWS
@@ -16,8 +16,8 @@ Version 2.17
   14303, 14307, 14328, 14331, 14336, 14337, 14347, 14349, 14376, 14417,
   14459, 14476, 14477, 14505, 14510, 14516, 14518, 14519, 14530, 14532,
   14538, 14543, 14544, 14545, 14557, 14562, 14568, 14576, 14579, 14583,
-  14587, 14595, 14602, 14621, 14638, 14645, 14648, 14652, 14660, 14661,
-  14683, 14694, 14716, 14743, 14767, 14783.
+  14587, 14595, 14602, 14610, 14621, 14638, 14645, 14648, 14652, 14660,
+  14661, 14683, 14694, 14716, 14743, 14767, 14783.
 
 * Support for STT_GNU_IFUNC symbols added for s390 and s390x.
   Optimized versions of memcpy, memset, and memcmp added for System z10 and
diff --git a/math/libm-test.inc b/math/libm-test.inc
index 91019a12194..9c773927cb2 100644
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -1297,6 +1297,9 @@ atan2_test (void)
   TEST_ff_f (atan2, 1.390625L, 0.9296875L, 0.981498387184244311516296577615519772L);
 
   TEST_ff_f (atan2, -0.00756827042671106339L, -.001792735857538728036L, -1.80338464113663849327153994379639112L);
+#if defined TEST_LDOUBLE && LDBL_MANT_DIG >= 64
+  TEST_ff_f (atan2, 0x1.00000000000001p0L, 0x1.00000000000001p0L, M_PI_4l);
+#endif
 
   END (atan2);
 }
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_atan2l.c b/sysdeps/ieee754/ldbl-128ibm/e_atan2l.c
index fe5c8bd8dc2..3e0535561cb 100644
--- a/sysdeps/ieee754/ldbl-128ibm/e_atan2l.c
+++ b/sysdeps/ieee754/ldbl-128ibm/e_atan2l.c
@@ -65,7 +65,8 @@ __ieee754_atan2l(long double y, long double x)
 	if(((ix)>0x7ff0000000000000LL)||
 	   ((iy)>0x7ff0000000000000LL))	/* x or y is NaN */
 	   return x+y;
-	if(((hx-0x3ff0000000000000LL))==0) return __atanl(y);   /* x=1.0L */
+	if(((hx-0x3ff0000000000000LL))==0
+	   && (lx&0x7fffffffffffffff)==0) return __atanl(y);   /* x=1.0L */
 	m = ((hy>>63)&1)|((hx>>62)&2);	/* 2*sign(x)+sign(y) */
 
     /* when y = 0 */