re PR tree-optimization/66449 (ICE: in build2_stat, at tree.c:4376 with -O3)

	PR tree-optimization/66449
	* tree-ssa-loop-niter.c (loop_exits_before_overflow): Use
	POINTER_PLUS_EXPR for pointers.

	gcc/testsuite
	PR tree-optimization/66449
	* gcc.dg/vect/pr66449.c: New test.

From-SVN: r224769

gcc/ChangeLog

+2015-06-23  Bin Cheng  <bin.cheng@arm.com>
+
+	PR tree-optimization/66449
+	* tree-ssa-loop-niter.c (loop_exits_before_overflow): Use
+	POINTER_PLUS_EXPR for pointers.
+
 2015-06-23  Alan Modra  <amodra@gmail.com>
 
 	* rtlanal.c (commutative_operand_precedence): Correct comments.

gcc/testsuite/ChangeLog

+2015-06-23  Bin Cheng  <bin.cheng@arm.com>
+
+	PR tree-optimization/66449
+	* gcc.dg/vect/pr66449.c: New test.
+
 2015-06-22  Pierre-Marie de Rodat  <derodat@adacore.com>
 
 	* g++.dg/other/dump-ada-spec-5.C: New test.

gcc/testsuite/gcc.dg/tree-ssa/pr66449.c

+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+
+void *fn1(void *p1, void *p2, long p3)
+{
+  long a = (long)p1, b = (long)p2, c = p3;
+
+  while (c)
+    {
+      int d = ((int *)b)[0];
+
+      c--;
+      ((char *)a)[0] = d;
+      a++;
+    }
+  return 0;
+}
+

gcc/tree-ssa-loop-niter.c

@@ -3888,7 +3888,12 @@ loop_exits_before_overflow (tree base, tree step,
 
 	   by proving the reverse conditions are false using loop's initial
 	   condition.  */
-	stepped = fold_build2 (PLUS_EXPR, TREE_TYPE (base), base, step);
+	if (POINTER_TYPE_P (TREE_TYPE (base)))
+	  code = POINTER_PLUS_EXPR;
+	else
+	  code = PLUS_EXPR;
+
+	stepped = fold_build2 (code, TREE_TYPE (base), base, step);
 	if (operand_equal_p (stepped, civ->base, 0))
 	  {
 	    if (tree_int_cst_sign_bit (step))