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| author | law <law@138bc75d-0d04-0410-961f-82ee72b054a4> | 2013-01-18 07:54:47 +0000 |
|---|---|---|
| committer | law <law@138bc75d-0d04-0410-961f-82ee72b054a4> | 2013-01-18 07:54:47 +0000 |
| commit | 1bcf869e98785b311cd21e579677207a5f22abc1 (patch) | |
| tree | eeafc6e254984b4679789b0594673c47e2dc2585 /gcc/regrename.c | |
| parent | eaac79393946885d2ebbab2ac82956508782887e (diff) | |
| download | gcc-1bcf869e98785b311cd21e579677207a5f22abc1.tar.gz | |
PR rtl-optimization/52573
* regrename.c (build_def_use): Ignore REG_DEAD notes if there is
a REG_UNUSED for the same register.
* gcc.dg/pr52573.c: New test.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@195288 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/regrename.c')
| -rw-r--r-- | gcc/regrename.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/gcc/regrename.c b/gcc/regrename.c index df3d341db51..20e2ae9f792 100644 --- a/gcc/regrename.c +++ b/gcc/regrename.c @@ -1710,9 +1710,16 @@ build_def_use (basic_block bb) scan_rtx (insn, &XEXP (note, 0), ALL_REGS, mark_read, OP_INOUT); - /* Step 4: Close chains for registers that die here. */ + /* Step 4: Close chains for registers that die here, unless + the register is mentioned in a REG_UNUSED note. In that + case we keep the chain open until step #7 below to ensure + it conflicts with other output operands of this insn. + See PR 52573. Arguably the insn should not have both + notes; it has proven difficult to fix that without + other undesirable side effects. */ for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) - if (REG_NOTE_KIND (note) == REG_DEAD) + if (REG_NOTE_KIND (note) == REG_DEAD + && !find_regno_note (insn, REG_UNUSED, REGNO (XEXP (note, 0)))) { remove_from_hard_reg_set (&live_hard_regs, GET_MODE (XEXP (note, 0)), |