re PR middle-end/42505 (loop canonicalization causes a lot of unnecessary temporary variables)

2010-07-10  Sandra Loosemore  <sandra@codesourcery.com>

	PR middle-end/42505

	gcc/
	* tree-inline.c (estimate_num_insns): Refactor builtin complexity
	lookup code into....
	* builtins.c (is_simple_builtin, is_inexpensive_builtin): ...these
	new functions.
	* tree.h (is_simple_builtin, is_inexpensive_builtin): Declare.
	* cfgloopanal.c (target_clobbered_regs): Define.
	(init_set_costs): Initialize target_clobbered_regs.
	(estimate_reg_pressure_cost): Add call_p argument.  When true,
	adjust the number of available registers to exclude the
	call-clobbered registers.
	* cfgloop.h (target_clobbered_regs): Declare.
	(estimate_reg_pressure_cost): Adjust declaration.
	* tree-ssa-loop-ivopts.c (struct ivopts_data): Add body_includes_call.
	(ivopts_global_cost_for_size): Pass it to estimate_reg_pressure_cost.
	(determine_set_costs): Dump target_clobbered_regs.
	(loop_body_includes_call): New function.
	(tree_ssa_iv_optimize_loop): Use it to initialize new field.
	* loop-invariant.c (gain_for_invariant): Adjust arguments to pass
	call_p flag through.
	(best_gain_for_invariant): Likewise.
	(find_invariants_to_move): Likewise.
	(move_single_loop_invariants): Likewise, using already-computed
	has_call field.

From-SVN: r162043

1 files changed, 26 insertions, 1 deletions

diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index c0a2194..83ec13e 100644
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -260,6 +260,9 @@ struct ivopts_data
 
   /* Are we optimizing for speed?  */
   bool speed;
+
+  /* Whether the loop body includes any function calls.  */
+  bool body_includes_call;
 };
 
 /* An assignment of iv candidates to uses.  */
@@ -4431,7 +4434,8 @@ ivopts_global_cost_for_size (struct ivopts_data *data, unsigned size)
 {
   /* We add size to the cost, so that we prefer eliminating ivs
      if possible.  */
-  return size + estimate_reg_pressure_cost (size, data->regs_used, data->speed);
+  return size + estimate_reg_pressure_cost (size, data->regs_used, data->speed,
+					    data->body_includes_call);
 }
 
 /* For each size of the induction variable set determine the penalty.  */
@@ -4450,6 +4454,7 @@ determine_set_costs (struct ivopts_data *data)
     {
       fprintf (dump_file, "Global costs:\n");
       fprintf (dump_file, "  target_avail_regs %d\n", target_avail_regs);
+      fprintf (dump_file, "  target_clobbered_regs %d\n", target_clobbered_regs);
       fprintf (dump_file, "  target_reg_cost %d\n", target_reg_cost[data->speed]);
       fprintf (dump_file, "  target_spill_cost %d\n", target_spill_cost[data->speed]);
     }
@@ -5859,6 +5864,25 @@ tree_ssa_iv_optimize_finalize (struct ivopts_data *data)
   VEC_free (iv_cand_p, heap, data->iv_candidates);
 }
 
+/* Returns true if the loop body BODY includes any function calls.  */
+
+static bool
+loop_body_includes_call (basic_block *body, unsigned num_nodes)
+{
+  gimple_stmt_iterator gsi;
+  unsigned i;
+
+  for (i = 0; i < num_nodes; i++)
+    for (gsi = gsi_start_bb (body[i]); !gsi_end_p (gsi); gsi_next (&gsi))
+      {
+	gimple stmt = gsi_stmt (gsi);
+	if (is_gimple_call (stmt)
+	    && !is_inexpensive_builtin (gimple_call_fndecl (stmt)))
+	  return true;
+      }
+  return false;
+}
+
 /* Optimizes the LOOP.  Returns true if anything changed.  */
 
 static bool
@@ -5890,6 +5914,7 @@ tree_ssa_iv_optimize_loop (struct ivopts_data *data, struct loop *loop)
     }
 
   body = get_loop_body (loop);
+  data->body_includes_call = loop_body_includes_call (body, loop->num_nodes);
   renumber_gimple_stmt_uids_in_blocks (body, loop->num_nodes);
   free (body);