PR tree-optimization/29921

	* fold-const.c (operand_equal_p): Without HONOR_SIGNED_ZEROS, consider
	signed and unsigned zero equal.

	* gcc.dg/pr29921.c: New test.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@119102 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 20 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/pr29921.c b/gcc/testsuite/gcc.dg/pr29921.c
new file mode 100644
index 00000000000..7689f54ce25
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr29921.c
@@ -0,0 +1,20 @@
+/* With -ffast-math, the latice value for t changes from -0.0 to 0.0 in this
+   testcase.  */
+
+/* { dg-do compile } */
+/* { dg-options "-O2 -ffast-math" } */
+
+double test (int param)
+{
+  double a = 0.0, b = -1.0, t;
+  int i;
+
+  for (i = 0; i < 100; i++)
+    {
+      t = a * b;
+      if (param)
+	b = 2.0;
+    }
+
+  return t;
+}