tree-ssa-loop-ivopts.c (alloc_iv): Lower address expressions.

	* tree-ssa-loop-ivopts.c (alloc_iv): Lower address expressions.
	* tree-affine.c (get_inner_reference_aff): Return base.
	* tree-affine.h (get_inner_reference_aff): Change prototype.

	* gcc.dg/tree-ssa/loop-2.c: Refine check condition.
	* gcc.dg/tree-ssa/ivopt_infer_2.c: Ditto.
	* gcc.dg/tree-ssa/ivopt_mult_3.c: Ditto.

From-SVN: r204497

1 files changed, 20 insertions, 1 deletions

diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index 0210dbb..220aae6 100644
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -924,11 +924,30 @@ determine_base_object (tree expr)
 static struct iv *
 alloc_iv (tree base, tree step)
 {
+  tree base_object = base;
   struct iv *iv = XCNEW (struct iv);
   gcc_assert (step != NULL_TREE);
 
+  /* Lower all address expressions except ones with DECL_P as operand.
+     By doing this:
+       1) More accurate cost can be computed for address expressions;
+       2) Duplicate candidates won't be created for bases in different
+          forms, like &a[0] and &a.  */
+  STRIP_NOPS (base_object);
+  if (TREE_CODE (base_object) == ADDR_EXPR
+      && !DECL_P (TREE_OPERAND (base_object, 0)))
+    {
+      aff_tree comb;
+      double_int size;
+      base_object = get_inner_reference_aff (TREE_OPERAND (base_object, 0),
+					     &comb, &size);
+      gcc_assert (base_object != NULL_TREE);
+      base_object = build_fold_addr_expr (base_object);
+      base = fold_convert (TREE_TYPE (base), aff_combination_to_tree (&comb));
+    }
+
   iv->base = base;
-  iv->base_object = determine_base_object (base);
+  iv->base_object = determine_base_object (base_object);
   iv->step = step;
   iv->biv_p = false;
   iv->have_use_for = false;