loop-init.c (loop_optimizer_init): If loops are preserved perform incremental initialization of required loop features.

2012-03-28  Richard Guenther  <rguenther@suse.de>

	* loop-init.c (loop_optimizer_init): If loops are preserved
	perform incremental initialization of required loop features.
	(loop_optimizer_finalize): If loops are to be preserved only
	clean up optional loop features.
	(rtl_loop_done): Forcefully free loops here.
	* cgraph.c (cgraph_release_function_body): Forcefully free
	loops.
	* cfgexpand.c (expand_gimple_cond): Properly add new basic-blocks
	to existing loops.
	(construct_init_block): Likewise.
	(construct_exit_block): Likewise.
	(gimple_expand_cfg): Clear LOOP_CLOSED_SSA loop state.  Cleanup
	the CFG after expanding.
	* cfgloop.c (verify_loop_structure): Calculate or verify
	dominators.  If we needed to calculate them, free them afterwards.
	* tree-pass.h (PROP_loops): New define.
	* tree-ssa-loop.c (pass_tree_loop_init): Provide PROP_loops.
	* basic-block.h (CLEANUP_CFG_CHANGED): New.
	* cfgcleanup.c (merge_blocks_move): Protect loop latches.
	(cleanup_cfg): If we did something and have loops around, fix
	them up.
	* cse.c (rest_of_handle_cse_after_global_opts): Call cleanup_cfg
	with CLEANUP_CFG_CHANGED.
	* cfghooks.c (merge_blocks): If we merge a loop header into
	its predecessor, update the loop structure.
	(duplicate_block): If we copy a loop latch, adjust loop state
	to note we may have multiple latches.
	(delete_basic_block): Mark loops for fixup if we remove a loop.
	* cfganal.c (forwarder_block_p): Protect loop latches, headers
	and preheaders.
	* cfgrtl.c (rtl_can_merge_blocks): Protect loop latches.
	(cfg_layout_can_merge_blocks_p): Likewise.
	* cprop.c (bypass_block): If we create a loop with multiple
	entries, mark it for removal.
	* except.c (emit_to_new_bb_before): Add the new basic-block
	to existing loops.
	* tree-eh.c (lower_resx): Likewise.
	* omp-low.c (finalize_task_copyfn): Do not copy PROP_loops.
	(expand_omp_taskreg): Likewise.
	* tree-inline.c (initialize_cfun): Likewise.
	* tree-mudflap.c (add_bb_to_loop): Prototype.
	(mf_build_check_statement_for): Properly add new basic-blocks
	to existing loops.
	* tree-ssa-threadupdate.c (thread_block): Mark loops for fixup
	if we remove a loop.
	(thread_through_loop_header): Likewise.
	* trans-mem.c (tm_log_emit_save_or_restores): Properly add
	new basic-blocks to existing loops.
	(expand_transaction): Likewise.
	* Makefile.in (except.o): Add $(CFGLOOP_H).
	(expr.o): Likewise.
	(cgraph.o): Likewise.
	(cprop.o): Likewise.
	(cfgexpand.o): Likewise.
	(cfganal.o): Likewise.
	(trans-mem.o): Likewise.
	(tree-eh.o): Likewise.

From-SVN: r185913

1 files changed, 38 insertions, 9 deletions

diff --git a/gcc/loop-init.c b/gcc/loop-init.c
index daf5fa0..b8d7b7e 100644
--- a/gcc/loop-init.c
+++ b/gcc/loop-init.c
@@ -42,15 +42,28 @@ along with GCC; see the file COPYING3.  If not see
 void
 loop_optimizer_init (unsigned flags)
 {
-  struct loops *loops;
+  if (!current_loops)
+    {
+      struct loops *loops = ggc_alloc_cleared_loops ();
+
+      gcc_assert (!(cfun->curr_properties & PROP_loops));
 
-  gcc_assert (!current_loops);
-  loops = ggc_alloc_cleared_loops ();
+      /* Find the loops.  */
 
-  /* Find the loops.  */
+      flow_loops_find (loops);
+      current_loops = loops;
+    }
+  else
+    {
+      gcc_assert (cfun->curr_properties & PROP_loops);
 
-  flow_loops_find (loops);
-  current_loops = loops;
+      /* Ensure that the dominators are computed, like flow_loops_find does.  */
+      calculate_dominance_info (CDI_DOMINATORS);
+
+#ifdef ENABLE_CHECKING
+      verify_loop_structure ();
+#endif
+    }
 
   if (flags & LOOPS_MAY_HAVE_MULTIPLE_LATCHES)
     {
@@ -104,6 +117,22 @@ loop_optimizer_finalize (void)
   struct loop *loop;
   basic_block bb;
 
+  if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
+    release_recorded_exits ();
+
+  /* If we should preserve loop structure, do not free it but clear
+     flags that advanced properties are there as we are not preserving
+     that in full.  */
+  if (cfun->curr_properties & PROP_loops)
+    {
+      loops_state_clear (LOOP_CLOSED_SSA
+			 | LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS
+			 | LOOPS_HAVE_PREHEADERS
+			 | LOOPS_HAVE_SIMPLE_LATCHES
+			 | LOOPS_HAVE_FALLTHRU_PREHEADERS);
+      return;
+    }
+
   gcc_assert (current_loops != NULL);
 
   FOR_EACH_LOOP (li, loop, 0)
@@ -112,8 +141,6 @@ loop_optimizer_finalize (void)
     }
 
   /* Clean up.  */
-  if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
-    release_recorded_exits ();
   flow_loops_free (current_loops);
   ggc_free (current_loops);
   current_loops = NULL;
@@ -200,6 +227,8 @@ struct rtl_opt_pass pass_rtl_loop_init =
 static unsigned int
 rtl_loop_done (void)
 {
+  /* No longer preserve loops, remove them now.  */
+  cfun->curr_properties &= ~PROP_loops;
   loop_optimizer_finalize ();
   free_dominance_info (CDI_DOMINATORS);
 
@@ -223,7 +252,7 @@ struct rtl_opt_pass pass_rtl_loop_done =
   TV_LOOP,                              /* tv_id */
   0,                                    /* properties_required */
   0,                                    /* properties_provided */
-  0,                                    /* properties_destroyed */
+  PROP_loops,                           /* properties_destroyed */
   0,                                    /* todo_flags_start */
   TODO_verify_flow
     | TODO_verify_rtl_sharing           /* todo_flags_finish */