From: Joseph Myers <joseph@codesourcery.com>
Date: Mon, 19 Mar 2012 20:11:09 +0000 (+0000)
Subject: Fix atan2 spurious exceptions (bug 11451).
X-Git-Tag: glibc-2.16-tps~760
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7726d6a95d5a2c08c8d43186002f040b9b889c27;p=thirdparty%2Fglibc.git

Fix atan2 spurious exceptions (bug 11451).
---

diff --git a/ChangeLog b/ChangeLog
index 0874b04fd9a..8ac195a4913 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2012-03-19  Joseph Myers  <joseph@codesourcery.com>
 
+	[BZ #11451]
+	* sysdeps/ieee754/dbl-64/e_atan2.c (__ieee754_atan2): Scale large
+	x and y.
+	* math/libm-test.inc (atan2_test): Add another test.
+
 	* Makerules (common-objdir-compile): Remove.
 	* sysdeps/unix/Makefile (config-generated): Do not add
 	$(unix-generated) to variable.
diff --git a/NEWS b/NEWS
index 5af4f68f060..df8e1f03a6b 100644
--- a/NEWS
+++ b/NEWS
@@ -12,11 +12,11 @@ Version 2.16
   174, 350, 411, 2541, 2547, 2548, 2551, 2552, 2553, 2554, 2562, 2563, 2565,
   2566, 2576, 3335, 3976, 3992, 4026, 4108, 4596, 4822, 5077, 5461, 5805,
   5993, 6471, 6884, 6907, 6911, 9739, 9902, 10110, 10135, 10140, 10210,
-  10545, 10716, 11174, 11322, 11365, 11494, 12047, 13058, 13525, 13526,
-  13527, 13528, 13529, 13530, 13531, 13532, 13533, 13547, 13551, 13552,
-  13553, 13555, 13559, 13566, 13583, 13618, 13637, 13656, 13658, 13673,
-  13695, 13704, 13706, 13726, 13738, 13786, 13792, 13806, 13840, 13841,
-  13844, 13846, 13851, 13852, 13854
+  10545, 10716, 11174, 11322, 11365, 11451, 11494, 12047, 13058, 13525,
+  13526, 13527, 13528, 13529, 13530, 13531, 13532, 13533, 13547, 13551,
+  13552, 13553, 13555, 13559, 13566, 13583, 13618, 13637, 13656, 13658,
+  13673, 13695, 13704, 13706, 13726, 13738, 13786, 13792, 13806, 13840,
+  13841, 13844, 13846, 13851, 13852, 13854
 
 * ISO C11 support:
 
diff --git a/math/libm-test.inc b/math/libm-test.inc
index 5638b76869c..817864aeb20 100644
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -949,6 +949,8 @@ atan2_test (void)
   TEST_ff_f (atan2, minus_infty, minus_infty, -M_PI_34l);
   TEST_ff_f (atan2, nan_value, nan_value, nan_value);
 
+  TEST_ff_f (atan2, max_value, max_value, M_PI_4l);
+
   TEST_ff_f (atan2, 0.75L, 1, 0.643501108793284386802809228717322638L);
   TEST_ff_f (atan2, -0.75L, 1.0L, -0.643501108793284386802809228717322638L);
   TEST_ff_f (atan2, 0.75L, -1.0L, 2.49809154479650885165983415456218025L);
diff --git a/sysdeps/ieee754/dbl-64/e_atan2.c b/sysdeps/ieee754/dbl-64/e_atan2.c
index dcef55f0727..497afcab1e3 100644
--- a/sysdeps/ieee754/dbl-64/e_atan2.c
+++ b/sysdeps/ieee754/dbl-64/e_atan2.c
@@ -1,7 +1,7 @@
 /*
  * IBM Accurate Mathematical Library
  * written by International Business Machines Corp.
- * Copyright (C) 2001, 2011 Free Software Foundation
+ * Copyright (C) 2001-2012 Free Software Foundation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
@@ -153,6 +153,13 @@ __ieee754_atan2(double y,double x) {
   /* if either x or y is extremely close to zero, scale abs(x), abs(y). */
   if (ax<twom500.d || ay<twom500.d) { ax*=two500.d;  ay*=two500.d; }
 
+  /* Likewise for large x and y.  */
+  if (ax > two500.d || ay > two500.d)
+    {
+      ax *= twom500.d;
+      ay *= twom500.d;
+    }
+
   /* x,y which are neither special nor extreme */
   if (ay<ax) {
     u=ay/ax;