gcc/

	PR rtl-optimization/44374
	Reapply patch with fixes.
	* basic-block.h (enum bb_flags): Add BB_MODIFIED.
	* df-core.c (df_set_bb_dirty): Set it.
	* ifcvt.c (find_memory): Remove function.
	(dead_or_predicable): Use can_move_insns_across.
	* df.h (can_move_insns_across): Declare function.
	* cfgcleanup.c (block_was_dirty): New static variable.
	(flow_find_head_matching_sequence): Test for epilogue notes.
	(try_crossjump_bb, try_forward_edges): Test BB_MODIFIED flag rather
	than df_get_bb_dirty.
	(try_head_merge_bb): New static function.
	(try_optimize_cfg): Call it.  Call df_analyze if block_was_dirty
	is set.
	* df-problems.c: Include "target.h"
	(df_simulate_find_uses): New static function.
	(MEMREF_NORMAL, MEMREF_VOLATILE): New macros.
	(find_memory, find_memory_store): New static functions.
	(can_move_insns_across): New function.
	* Makefile.in (df-problems.o): Update dependencies.

gcc/testsuite/
	PR rtl-optimization/44374
	Reapply patch with fixes.
	* gcc.target/arm/headmerge-1.c: New test.
	* gcc.target/arm/headmerge-2.c: New test.
	* gcc.target/i386/headmerge-1.c: New test.
	* gcc.target/i386/headmerge-2.c: New test.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@167779 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 1 insertions, 0 deletions

diff --git a/gcc/df-core.c b/gcc/df-core.c
index 06ff854b57b..36270bf8993 100644
--- a/gcc/df-core.c
+++ b/gcc/df-core.c
@@ -1413,6 +1413,7 @@ df_get_bb_dirty (basic_block bb)
 void
 df_set_bb_dirty (basic_block bb)
 {
+  bb->flags |= BB_MODIFIED;
   if (df)
     {
       int p;