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, 12 insertions, 0 deletions

diff --git a/gcc/cprop.c b/gcc/cprop.c
index 01f40f0..024dd20 100644
--- a/gcc/cprop.c
+++ b/gcc/cprop.c
@@ -48,6 +48,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "df.h"
 #include "dbgcnt.h"
 #include "target.h"
+#include "cfgloop.h"
 
 
 /* An obstack for our working variables.  */
@@ -1610,6 +1611,17 @@ bypass_block (basic_block bb, rtx setcc, rtx jump)
 	      && dest != old_dest
 	      && dest != EXIT_BLOCK_PTR)
             {
+	      if (current_loops != NULL
+		  && e->src->loop_father->latch == e->src)
+		{
+		  /* ???  Now we are creating (or may create) a loop
+		     with multiple entries.  Simply mark it for
+		     removal.  Alternatively we could not do this
+		     threading.  */
+		  e->src->loop_father->header = NULL;
+		  e->src->loop_father->latch = NULL;
+		}
+
 	      redirect_edge_and_branch_force (e, dest);
 
 	      /* Copy the register setter to the redirected edge.