tree-ssa-loop-ch.c (should_duplicate_loop_header_p): Check that loop is not cold.

* tree-ssa-loop-ch.c (should_duplicate_loop_header_p): Check that loop
	is not cold.
	* predict.c (optimize_bb_for_size_p, optimize_bb_for_speed_p):
	Constify arguments.
	(optimize_loop_for_size_p, optimize_loop_for_speed_p): New functions.
	* basic-block.h (optimize_bb_for_size_p, optimize_bb_for_speed_p):
	Constify.
	(optimize_loop_for_size_p, optimize_loop_for_speed_p): Declare.

From-SVN: r139756

gcc/ChangeLog

@@ -1,3 +1,14 @@
+2008-08-29  Jan Hubicka  <jh@suse.cz>
+
+	* tree-ssa-loop-ch.c (should_duplicate_loop_header_p): Check that loop
+	is not cold.
+	* predict.c (optimize_bb_for_size_p, optimize_bb_for_speed_p):
+	Constify arguments.
+	(optimize_loop_for_size_p, optimize_loop_for_speed_p): New functions.
+	* basic-block.h (optimize_bb_for_size_p, optimize_bb_for_speed_p):
+	Constify.
+	(optimize_loop_for_size_p, optimize_loop_for_speed_p): Declare.
+
 2008-08-29  Jan Hubicka  <jh@suse.cz>
 
 	* tree-pass.h (pass_strip_predict_hints): Declare.

gcc/basic-block.h

@@ -831,14 +831,16 @@ extern bool maybe_hot_bb_p (const_basic_block);
 extern bool maybe_hot_edge_p (edge);
 extern bool probably_cold_bb_p (const_basic_block);
 extern bool probably_never_executed_bb_p (const_basic_block);
-extern bool optimize_bb_for_size_p (basic_block);
-extern bool optimize_bb_for_speed_p (basic_block);
+extern bool optimize_bb_for_size_p (const_basic_block);
+extern bool optimize_bb_for_speed_p (const_basic_block);
 extern bool optimize_edge_for_size_p (edge);
 extern bool optimize_edge_for_speed_p (edge);
 extern bool optimize_insn_for_size_p (void);
 extern bool optimize_insn_for_speed_p (void);
 extern bool optimize_function_for_size_p (struct function *);
 extern bool optimize_function_for_speed_p (struct function *);
+extern bool optimize_loop_for_size_p (struct loop *);
+extern bool optimize_loop_for_speed_p (struct loop *);
 extern bool gimple_predicted_by_p (const_basic_block, enum br_predictor);
 extern bool rtl_predicted_by_p (const_basic_block, enum br_predictor);
 extern void gimple_predict_edge (edge, enum br_predictor, int);

gcc/predict.c

@@ -200,7 +200,7 @@ optimize_function_for_speed_p (struct function *fun)
 /* Return TRUE when BB should be optimized for size.  */
 
 bool
-optimize_bb_for_size_p (basic_block bb)
+optimize_bb_for_size_p (const_basic_block bb)
 {
   return optimize_function_for_size_p (cfun) || !maybe_hot_bb_p (bb);
 }
@@ -208,7 +208,7 @@ optimize_bb_for_size_p (basic_block bb)
 /* Return TRUE when BB should be optimized for speed.  */
 
 bool
-optimize_bb_for_speed_p (basic_block bb)
+optimize_bb_for_speed_p (const_basic_block bb)
 {
   return !optimize_bb_for_size_p (bb);
 }
@@ -245,6 +245,22 @@ optimize_insn_for_speed_p (void)
   return !optimize_insn_for_size_p ();
 }
 
+/* Return TRUE when LOOP should be optimized for size.  */
+
+bool
+optimize_loop_for_size_p (struct loop *loop)
+{
+  return optimize_bb_for_size_p (loop->header);
+}
+
+/* Return TRUE when LOOP should be optimized for speed.  */
+
+bool
+optimize_loop_for_speed_p (struct loop *loop)
+{
+  return optimize_bb_for_speed_p (loop->header);
+}
+
 /* Set RTL expansion for BB profile.  */
 
 void

gcc/tree-ssa-loop-ch.c

@@ -58,6 +58,13 @@ should_duplicate_loop_header_p (basic_block header, struct loop *loop,
   if (header->aux)
     return false;
 
+  /* Loop header copying usually increases size of the code.  This used not to
+     be true, since quite often it is possible to verify that the condition is
+     satisfied in the first iteration and therefore to eliminate it.  Jump
+     threading handles these cases now.  */
+  if (optimize_loop_for_size_p (loop))
+    return false;
+
   gcc_assert (EDGE_COUNT (header->succs) > 0);
   if (single_succ_p (header))
     return false;