re PR c++/53050 (ssa_forward_propagate_and_combine: segmentation fault)

2012-04-20  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/53050
	* tree-ssa-forwprop.c (ssa_forward_propagate_and_combine):
	Do only one transform on COND_EXPRs at the same time.

From-SVN: r186620

gcc/ChangeLog

+2012-04-20  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/53050
+	* tree-ssa-forwprop.c (ssa_forward_propagate_and_combine):
+	Do only one transform on COND_EXPRs at the same time.
+
 2012-04-19  Jan Hubicka  <jh@suse.cz>
 
 	* symtab.c (dump_symtab_base): Revert accidental checkin.

gcc/tree-ssa-forwprop.c

@@ -2536,9 +2536,12 @@ ssa_forward_propagate_and_combine (void)
 			 || code == VEC_COND_EXPR)
 		  {
 		    /* In this case the entire COND_EXPR is in rhs1. */
-		    changed |= forward_propagate_into_cond (&gsi);
-		    changed |= combine_cond_exprs (&gsi);
-		    stmt = gsi_stmt (gsi);
+		    if (forward_propagate_into_cond (&gsi)
+			|| combine_cond_exprs (&gsi))
+		      {
+			changed = true;
+			stmt = gsi_stmt (gsi);
+		      }
 		  }
 		else if (TREE_CODE_CLASS (code) == tcc_comparison)
 		  {