RE: [PATCH PR66449]Fix ICE by using POINTER_PLUS_EXPR for pointers.

[Bin Cheng]

And the patch...

Thanks,
bin

> -----Original Message-----
> From: gcc-patches-ow...@gcc.gnu.org [mailto:gcc-patches-
> ow...@gcc.gnu.org] On Behalf Of Bin Cheng
> Sent: Thursday, June 18, 2015 6:13 PM
> To: gcc-patches@gcc.gnu.org
> Subject: [PATCH PR66449]Fix ICE by using POINTER_PLUS_EXPR for pointers.
> 
> Hi,
> This patch fixes ICE in PR66449 by using POINTER_PLUS_EXPR for pointers.
> Bootstrap and test on x86_64.  Is it OK trunk?
> 
> Thanks,
> bin
> 
> 2015-06-18  Bin Cheng  <bin.ch...@arm.com>
> 
>       PR tree-optimization/66449
>       * tree-ssa-loop-niter.c (loop_exits_before_overflow): Use
>       POINTER_PLUS_EXPR for pointers.
> 
> gcc/testsuite/ChangeLog
> 2015-06-18  Bin Cheng  <bin.ch...@arm.com>
> 
>       PR tree-optimization/66449
>       * gcc.dg/vect/pr66449.c: New.
> 


Index: gcc/testsuite/gcc.dg/tree-ssa/pr66449.c
===================================================================
--- gcc/testsuite/gcc.dg/tree-ssa/pr66449.c     (revision 0)
+++ gcc/testsuite/gcc.dg/tree-ssa/pr66449.c     (revision 0)
@@ -0,0 +1,18 @@
+/* { 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;
+}
+
Index: gcc/tree-ssa-loop-niter.c
===================================================================
--- gcc/tree-ssa-loop-niter.c   (revision 224020)
+++ gcc/tree-ssa-loop-niter.c   (working copy)
@@ -3902,7 +3902,12 @@ 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))