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From: Juan Manuel Guerrero <juan DOT guerrero AT gmx DOT de>
To: djgpp-workers AT delorie DOT com
Subject: Re: atan2 bug
Date: Tue, 15 Sep 2009 00:42:54 +0200
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Reply-To: djgpp-workers AT delorie DOT com

Sorry, I have submited a somewhat broken test program.





diff -aprNU5 djgpp.orig/tests/libc/ansi/math/elefunt/atan2.c djgpp/tests/libc/ansi/math/elefunt/atan2.c
--- djgpp.orig/tests/libc/ansi/math/elefunt/atan2.c	1970-01-01 00:00:00 +0000
+++ djgpp/tests/libc/ansi/math/elefunt/atan2.c	2009-09-15 00:35:38 +0000
@@ -0,0 +1,48 @@
+#include <libc/ieee.h>
+#include <stdio.h>
+#include <errno.h>
+#include <math.h>
+
+
+int main(void)
+{
+  _double_union_t x, y;
+  double result;
+
+  y.d = M_PI;
+  x.dt.sign      = 0;
+  x.dt.exponent  = 0x07FF;
+  x.dt.mantissah = 0x000000000;
+  x.dt.mantissal = 0x000000000;  /*  +Infinity.  */
+
+  /*
+   *  Compute atan of the quotient of a positive finite number with pos. infinite.
+   *  The result must be +0.0
+   */
+  errno = 0;
+  result = atan2(y.d, x.d);
+  if (errno)
+    printf("errno=%d\ny=%f  x=%f:  result=%f  result must be +0.0\n", errno, y.d, x.d, result);
+  else if (result == +0.0)
+    printf("test passed.\n");
+  else
+    printf("test failure not triggered by atan2 bug.\n");
+
+
+  /*
+   *  Compute atan of the quotient of a negative finite number with neg. infinite.
+   *  The result must be -PI
+   */
+  errno = 0;
+  y.dt.sign = 1;  /*  -Finite value.  */
+  x.dt.sign = 1;  /*  -Infinity.  */
+  result = atan2(y.d, x.d);
+  if (errno)
+    printf("errno=%d\ny=%f  x=%f:  result=%f  result must be -PI\n", errno, y.d, x.d, result);
+  else if (result == -M_PI)
+    printf("test passed.\n");
+  else
+    printf("test failure not triggered by atan2 bug.\n");
+
+  return 0;
+}