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| author | Geoff Keating <geoffk@cygnus.com> | 2000-08-02 00:53:59 +0000 |
|---|---|---|
| committer | Geoffrey Keating <geoffk@gcc.gnu.org> | 2000-08-02 00:53:59 +0000 |
| commit | 8cd8f856b33bbd6c6627eb0a18e34b046e2163f1 (patch) | |
| tree | 51e7cfa73194f407e18d5c607f8f9f28b8c01196 /gcc/rtl.h | |
| parent | 7d17b34de55c8cd8d83581036f8e87fae492db13 (diff) | |
| download | gcc-8cd8f856b33bbd6c6627eb0a18e34b046e2163f1.zip gcc-8cd8f856b33bbd6c6627eb0a18e34b046e2163f1.tar.gz gcc-8cd8f856b33bbd6c6627eb0a18e34b046e2163f1.tar.bz2 | |
rtl.h (enum reg_note): Add REG_MAYBE_DEAD.
* 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.
From-SVN: r35414
Diffstat (limited to 'gcc/rtl.h')
| -rw-r--r-- | gcc/rtl.h | 8 |
1 files changed, 7 insertions, 1 deletions
@@ -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. */ |