[PATCH] Fix PR50363

[Richard Guenther]

This fixes PR50363.

Bootstrapped and tested on x86_64-unknown-linux-gnu.

Richard.

2011-09-27  Richard Guenther  <rguent...@suse.de>

        PR tree-optimization/50363
        * tree-ssa-pre.c (create_expression_by_pieces): Handle
        pointer conversions in POINTER_PLUS_EXPRs properly.

        * gcc.dg/torture/pr50363.c: New testcase.

Index: gcc/tree-ssa-pre.c
===================================================================
--- gcc/tree-ssa-pre.c  (revision 179200)
+++ gcc/tree-ssa-pre.c  (working copy)
@@ -3085,11 +3085,15 @@ create_expression_by_pieces (basic_block
                                                    stmts, domstmt);
            if (!genop[i])
              return NULL_TREE;
-           /* Ensure genop[1] is a ptrofftype for POINTER_PLUS_EXPR.  It
-              may be a constant with the wrong type.  */
-           if (i == 1
-               && nary->opcode == POINTER_PLUS_EXPR)
-             genop[i] = convert_to_ptrofftype (genop[i]);
+           /* Ensure genop[] is properly typed for POINTER_PLUS_EXPR.  It
+              may have conversions stripped.  */
+           if (nary->opcode == POINTER_PLUS_EXPR)
+             {
+               if (i == 0)
+                 genop[i] = fold_convert (nary->type, genop[i]);
+               else if (i == 1)
+                 genop[i] = convert_to_ptrofftype (genop[i]);
+             }
            else
              genop[i] = fold_convert (TREE_TYPE (nary->op[i]), genop[i]);
          }
Index: gcc/testsuite/gcc.dg/torture/pr50363.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr50363.c      (revision 0)
+++ gcc/testsuite/gcc.dg/torture/pr50363.c      (revision 0)
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-fno-tree-ch -fno-tree-fre" } */
+
+void
+foo (int *__restrict__ * r, int n)
+{
+  int *p;
+  for (p = *r; p < *r + n; p++)
+    ;
+}