From: Segher Boessenkool Date: Wed, 12 Oct 2016 15:23:11 +0000 (+0200) Subject: regrename: Don't rename restores X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=d73c92c9f2297c57153beced2475ed79e0d0736b;p=gcc.git 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 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 77935447474..9b66e887787 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2016-10-12 Segher Boessenkool + + * regrename.c (build_def_use): Invalidate chains that have a + REG_CFA_RESTORE on some instruction. + 2016-10-12 Segher Boessenkool * dce.c (delete_unmarked_insns): Don't delete instructions with diff --git a/gcc/regrename.c b/gcc/regrename.c index 3509e8bab81..e0d2dd1f74c 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)))