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