[Bug rtl-optimization/44374] Hoist same instructions in different branches

[bernds at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44374

--- Comment #6 from Bernd Schmidt <bernds at gcc dot gnu.org> 2010-12-14 00:23:48 UTC ---
Author: bernds
Date: Tue Dec 14 00:23:40 2010
New Revision: 167779

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=167779
Log:
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.


Added:
    trunk/gcc/testsuite/gcc.target/arm/headmerge-1.c
    trunk/gcc/testsuite/gcc.target/arm/headmerge-2.c
    trunk/gcc/testsuite/gcc.target/i386/headmerge-1.c
    trunk/gcc/testsuite/gcc.target/i386/headmerge-2.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/Makefile.in
    trunk/gcc/basic-block.h
    trunk/gcc/cfgcleanup.c
    trunk/gcc/df-core.c
    trunk/gcc/df-problems.c
    trunk/gcc/df.h
    trunk/gcc/ifcvt.c
    trunk/gcc/testsuite/ChangeLog