re PR tree-optimization/22325 (missed optimization in loop)

	PR tree-optimization/22325
	* tree-flow.h (compute_phi_arg_on_exit, force_expr_to_var_cost):
	Declare.
	* tree-scalar-evolution.c (scev_const_prop): Add generic final
	value replacement.
	* tree-ssa-loop-ivopts.c (force_expr_to_var_cost): Split from ...
	(force_var_cost): ... this function.
	(compute_phi_arg_on_exit): Export.

From-SVN: r102426

1 files changed, 24 insertions, 15 deletions

diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index fda17f9..e5a8d85 100644
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -3415,12 +3415,11 @@ get_address_cost (bool symbol_present, bool var_present,
 
   return cost + acost;
 }
-/* Estimates cost of forcing EXPR into a variable.  DEPENDS_ON is a set of the
-   invariants the computation depends on.  */
 
-static unsigned
-force_var_cost (struct ivopts_data *data,
-		tree expr, bitmap *depends_on)
+/* Estimates cost of forcing expression EXPR into a variable.  */
+
+unsigned
+force_expr_to_var_cost (tree expr)
 {
   static bool costs_initialized = false;
   static unsigned integer_cost;
@@ -3452,7 +3451,7 @@ force_var_cost (struct ivopts_data *data,
 				    build_int_cst_type (type, 2000))) + 1;
       if (dump_file && (dump_flags & TDF_DETAILS))
 	{
-	  fprintf (dump_file, "force_var_cost:\n");
+	  fprintf (dump_file, "force_expr_to_var_cost:\n");
 	  fprintf (dump_file, "  integer %d\n", (int) integer_cost);
 	  fprintf (dump_file, "  symbol %d\n", (int) symbol_cost);
 	  fprintf (dump_file, "  address %d\n", (int) address_cost);
@@ -3465,12 +3464,6 @@ force_var_cost (struct ivopts_data *data,
 
   STRIP_NOPS (expr);
 
-  if (depends_on)
-    {
-      fd_ivopts_data = data;
-      walk_tree (&expr, find_depends, depends_on, NULL);
-    }
-
   if (SSA_VAR_P (expr))
     return 0;
 
@@ -3505,12 +3498,12 @@ force_var_cost (struct ivopts_data *data,
       if (is_gimple_val (op0))
 	cost0 = 0;
       else
-	cost0 = force_var_cost (data, op0, NULL);
+	cost0 = force_expr_to_var_cost (op0);
 
       if (is_gimple_val (op1))
 	cost1 = 0;
       else
-	cost1 = force_var_cost (data, op1, NULL);
+	cost1 = force_expr_to_var_cost (op1);
 
       break;
 
@@ -3550,6 +3543,22 @@ force_var_cost (struct ivopts_data *data,
   return cost < target_spill_cost ? cost : target_spill_cost;
 }
 
+/* Estimates cost of forcing EXPR into a variable.  DEPENDS_ON is a set of the
+   invariants the computation depends on.  */
+
+static unsigned
+force_var_cost (struct ivopts_data *data,
+		tree expr, bitmap *depends_on)
+{
+  if (depends_on)
+    {
+      fd_ivopts_data = data;
+      walk_tree (&expr, find_depends, depends_on, NULL);
+    }
+
+  return force_expr_to_var_cost (expr);
+}
+
 /* Estimates cost of expressing address ADDR  as var + symbol + offset.  The
    value of offset is added to OFFSET, SYMBOL_PRESENT and VAR_PRESENT are set
    to false if the corresponding part is missing.  DEPENDS_ON is a set of the
@@ -5600,7 +5609,7 @@ protect_loop_closed_ssa_form (edge exit, tree stmt)
    so that they are emitted on the correct place, and so that the loop closed
    ssa form is preserved.  */
 
-static void
+void
 compute_phi_arg_on_exit (edge exit, tree stmts, tree op)
 {
   tree_stmt_iterator tsi;