[patch] PR tree-optimization/55350: invalid pointer operand to PLUS_EXPR

[Aldy Hernandez]

The problem here is that the SLSR pass is promoting a POINTER_PLUS_EXPR 
to a PLUS_EXPR.  Since pointer arithmetic is invalid in 
{PLUS,MINUS}_EXPR's, the gimple verifier chokes on the invalid statement.

Fixed by maintaining the POINTER_PLUS_EXPR when appropriate.
OK for trunk?
commit ae7b615a11be6a0c5cc00f7ea0bf29c142931490
Author: Aldy Hernandez <al...@redhat.com>
Date:   Tue Nov 20 11:20:58 2012 -0600

        PR tree-optimization/55350
        * gimple-ssa-strength-reduction.c (replace_dependent): Handle
        POINTER_{PLUS,MINUS}_EXPR correctly.

diff --git a/gcc/gimple-ssa-strength-reduction.c 
b/gcc/gimple-ssa-strength-reduction.c
index 8e2a247..65fc6b1 100644
--- a/gcc/gimple-ssa-strength-reduction.c
+++ b/gcc/gimple-ssa-strength-reduction.c
@@ -1643,10 +1643,19 @@ replace_dependent (slsr_cand_t c, enum tree_code 
cand_code)
 
   basis = lookup_cand (c->basis);
   basis_name = gimple_assign_lhs (basis->cand_stmt);
-  incr_type = TREE_TYPE (gimple_assign_rhs1 (c->cand_stmt));
-  code = PLUS_EXPR;
+  if (cand_code == POINTER_PLUS_EXPR)
+    {
+      incr_type = sizetype;
+      code = cand_code;
+    }
+  else
+    {
+      incr_type = TREE_TYPE (gimple_assign_rhs1 (c->cand_stmt));
+      code = PLUS_EXPR;
+    }
 
-  if (bump.is_negative ())
+  if (bump.is_negative ()
+      && cand_code != POINTER_PLUS_EXPR)
     {
       code = MINUS_EXPR;
       bump = -bump;
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr55350.c 
b/gcc/testsuite/gcc.c-torture/compile/pr55350.c
new file mode 100644
index 0000000..f10daea
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr55350.c
@@ -0,0 +1,8 @@
+void
+foo (__INTPTR_TYPE__ x, __INTPTR_TYPE__ y)
+{
+  int i;
+  void **a = (void *)  (8UL * (x / 8UL));
+  for (i = 0; i < x; i++)
+    a[i] = (void *) y;
+}