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| author | Segher Boessenkool <segher@kernel.crashing.org> | 2016-10-12 17:23:11 +0200 |
|---|---|---|
| committer | Segher Boessenkool <segher@gcc.gnu.org> | 2016-10-12 17:23:11 +0200 |
| commit | d73c92c9f2297c57153beced2475ed79e0d0736b (patch) | |
| tree | bf4ef45290eb7a87c261dac5fc92ecd751a50c82 /gcc | |
| parent | aab648a9fcf8c222ab43612915d11b093e11849d (diff) | |
| download | gcc-d73c92c9f2297c57153beced2475ed79e0d0736b.zip gcc-d73c92c9f2297c57153beced2475ed79e0d0736b.tar.gz gcc-d73c92c9f2297c57153beced2475ed79e0d0736b.tar.bz2 | |
regrename: Don't rename restores
A restore is supposed to restore some certain register. Restoring it
into some other register will not work. Don't.
* regrename.c (build_def_use): Invalidate chains that have a
REG_CFA_RESTORE on some instruction.
From-SVN: r241061
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/regrename.c | 7 |
2 files changed, 12 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7793544..9b66e88 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,10 @@ 2016-10-12 Segher Boessenkool <segher@kernel.crashing.org> + * regrename.c (build_def_use): Invalidate chains that have a + REG_CFA_RESTORE on some instruction. + +2016-10-12 Segher Boessenkool <segher@kernel.crashing.org> + * dce.c (delete_unmarked_insns): Don't delete instructions with a REG_CFA_RESTORE note. diff --git a/gcc/regrename.c b/gcc/regrename.c index 3509e8b..e0d2dd1 100644 --- a/gcc/regrename.c +++ b/gcc/regrename.c @@ -1655,6 +1655,7 @@ build_def_use (basic_block bb) (6) For any non-earlyclobber write we find in an operand, make a new chain or mark the hard register as live. (7) For any REG_UNUSED, close any chains we just opened. + (8) For any REG_CFA_RESTORE, kill any chain containing it. We cannot deal with situations where we track a reg in one mode and see a reference in another mode; these will cause the chain @@ -1867,6 +1868,12 @@ build_def_use (basic_block bb) scan_rtx (insn, &XEXP (note, 0), NO_REGS, terminate_dead, OP_IN); } + + /* Step 8: Kill the chains involving register restores. Those + should restore _that_ register. */ + for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) + if (REG_NOTE_KIND (note) == REG_CFA_RESTORE) + scan_rtx (insn, &XEXP (note, 0), NO_REGS, mark_all_read, OP_IN); } else if (DEBUG_INSN_P (insn) && !VAR_LOC_UNKNOWN_P (INSN_VAR_LOCATION_LOC (insn))) |