* fold-const.c (fold): Transform (c1 - x) cmp c2, where cmp is a

	comparison operation and c1/c2 are floating point constants into
	x swap(cmp) (c1 - c2).

	* gcc.dg/20030414-2.c: New test case.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@65584 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 38 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/20030414-2.c b/gcc/testsuite/gcc.dg/20030414-2.c
new file mode 100644
index 00000000000..f4eb8bf36ec
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/20030414-2.c
@@ -0,0 +1,38 @@
+/* Copyright (C) 2003 Free Software Foundation.
+
+   Check that constant folding (c1 - x) op c2 into x swap(op) c1-c2
+   doesn't break anything.
+
+   Written by Roger Sayle, 27th March 2003.  */
+
+/* { dg-do run } */
+/* { dg-options "-O2 -ffast-math" } */
+
+extern void abort (void);
+
+int foo(double x)
+{
+  return (10.0 - x) > 3.0;
+}
+
+int bar (double x)
+{
+  return (10.0 - x) == 5.0;
+}
+
+int main()
+{
+  if (foo (8.0))
+    abort ();
+
+  if (! foo (6.0))
+    abort ();
+
+  if (bar (1.0))
+    abort ();
+
+  if (! bar (5.0))
+    abort ();
+  return 0;
+}
+