re PR tree-optimization/63898 (r217560 caused segfault building 462.libquantum from cpu2006)

2014-11-17  Richard Biener  <rguenther@suse.de>

	PR middle-end/63898
	* match.pd: Guard X / CST -> X * CST' transform against
	zero CST.

From-SVN: r217650

gcc/ChangeLog

+2014-11-17  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/63898
+	* match.pd: Guard X / CST -> X * CST' transform against
+	zero CST.
+
 2014-11-17  Terry Guo  <terry.guo@arm.com>
 
 	* config/arm/thumb1.md (*addsi3_cbranch_scratch): Updated to UAL

gcc/match.pd

@@ -166,7 +166,8 @@ along with GCC; see the file COPYING3.  If not see
  (simplify
   (rdiv @0 cst@1)
   (if (optimize)
-   (if (flag_reciprocal_math)
+   (if (flag_reciprocal_math
+	&& !real_zerop (@1))
     (with
      { tree tem = fold_binary (RDIV_EXPR, type, build_one_cst (type), @1); }
      (if (tem)