Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2015-07-06 Richard Biener <rguent...@suse.de>
PR middle-end/66759
* match.pd: Add missing constraint of y to REAL_CST in
REAL_CST - x CMP y to y - CST CMP x simplification.
* gcc.dg/torture/pr66759.c: New testcase.
Index: gcc/match.pd
===================================================================
--- gcc/match.pd (revision 225443)
+++ gcc/match.pd (working copy)
@@ -1496,7 +1513,7 @@ (define_operator_list CBRT BUILT_IN_CBRT
floating-point types only if -fassociative-math is set. */
(if (flag_associative_math)
(simplify
- (cmp (minus REAL_CST@0 @1) @2)
+ (cmp (minus REAL_CST@0 @1) REAL_CST@2)
(with { tree tem = const_binop (MINUS_EXPR, TREE_TYPE (@1), @0, @2); }
(if (!TREE_OVERFLOW (tem))
(cmp { tem; } @1)))))
Index: gcc/testsuite/gcc.dg/torture/pr66759.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr66759.c (revision 0)
+++ gcc/testsuite/gcc.dg/torture/pr66759.c (working copy)
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-ffast-math" } */
+
+int a, b;
+float c;
+int fn2();
+void fn1()
+{
+ if (fn2() <= 1. - c)
+ b = a;
+}
