Fix atan2 spurious exceptions (bug 11451).

git-mirror · Mar 19, 2012 · 7726d6a · 7726d6a
1 parent 83d1aec
commit 7726d6a
Show file tree

Hide file tree

Showing 4 changed files with 20 additions and 6 deletions.
diff --git 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
@@ -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
@@ -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
@@ -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;