re PR tree-optimization/64295 (ICE: SIGSEGV (infinite recursion) with…

re PR tree-optimization/64295 (ICE: SIGSEGV (infinite recursion) with -frounding-math -funsafe-math-optimizations)

2014-12-15  Richard Biener  <rguenther@suse.de>

	PR middle-end/64295
	* match.pd (X / CST -> X * (1 / CST): Use const_binop instead of
	fold_binary to compute the constant to multiply with.

	* gcc.dg/pr64295.c: New testcase.

From-SVN: r218748

gcc/ChangeLog

 2014-12-15  Richard Biener  <rguenther@suse.de>
 
+	PR middle-end/64295
+	* match.pd (X / CST -> X * (1 / CST): Use const_binop instead of
+	fold_binary to compute the constant to multiply with.
+
+2014-12-15  Richard Biener  <rguenther@suse.de>
+
 	PR middle-end/64246
 	* cfgloop.c (mark_loop_for_removal): Make safe against multiple
 	invocations on the same loop.

gcc/match.pd

@@ -186,7 +186,7 @@ along with GCC; see the file COPYING3.  If not see
    (if (flag_reciprocal_math
 	&& !real_zerop (@1))
     (with
-     { tree tem = fold_binary (RDIV_EXPR, type, build_one_cst (type), @1); }
+     { tree tem = const_binop (RDIV_EXPR, type, build_one_cst (type), @1); }
      (if (tem)
       (mult @0 { tem; } ))))
    (if (cst != COMPLEX_CST)

gcc/testsuite/ChangeLog

 2014-12-15  Richard Biener  <rguenther@suse.de>
 
+	PR middle-end/64295
+	* gcc.dg/pr64295.c: New testcase.
+
+2014-12-15  Richard Biener  <rguenther@suse.de>
+
 	PR middle-end/64246
 	* gnat.dg/opt46.adb: New testcase.
 	* gnat.dg/opt46.ads: Likewise.

gcc/testsuite/gcc.dg/pr64295.c

+/* { dg-do compile } */
+/* { dg-options "-O -frounding-math -funsafe-math-optimizations" } */
+
+double
+f (double g)
+{
+  return g / 3;
+}