diff options
| author | geoffk <geoffk@138bc75d-0d04-0410-961f-82ee72b054a4> | 2000-08-02 00:53:59 +0000 |
|---|---|---|
| committer | geoffk <geoffk@138bc75d-0d04-0410-961f-82ee72b054a4> | 2000-08-02 00:53:59 +0000 |
| commit | efc2922d7c58278878cd89408050d4c7a9c0df4c (patch) | |
| tree | 51e7cfa73194f407e18d5c607f8f9f28b8c01196 /gcc/rtl.h | |
| parent | 8c75b6d416f92cf7fe17d6762d4c988de29e6dc3 (diff) | |
| download | gcc-efc2922d7c58278878cd89408050d4c7a9c0df4c.tar.gz | |
* rtl.h (enum reg_note): Add REG_MAYBE_DEAD.
* rtl.c (reg_note_name): Add REG_MAYBE_DEAD.
* flow.c (propagate_one_insn): Allow deletion of prologue/epilogue
insns if they have a REG_MAYBE_DEAD note attached.
* config/rs6000/rs6000.c (rs6000_maybe_dead): New function.
(rs6000_emit_load_toc_table): TOC loads may go dead.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@35414 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/rtl.h')
| -rw-r--r-- | gcc/rtl.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/gcc/rtl.h b/gcc/rtl.h index 24102a9742a..b96c53f3267 100644 --- a/gcc/rtl.h +++ b/gcc/rtl.h @@ -515,7 +515,13 @@ enum reg_note REG_EH_RETHROW, /* Used by haifa-sched to save NOTE_INSN notes across scheduling. */ - REG_SAVE_NOTE + REG_SAVE_NOTE, + + /* Indicates that this insn (which is part of the prologue) computes + a value which might not be used later, and if so it's OK to delete + the insn. Normally, deleting any insn in the prologue is an error. + At present the parameter is unused and set to (const_int 0). */ + REG_MAYBE_DEAD }; /* The base value for branch probability notes. */ |