http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47008
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-12-20
13:03:56 UTC ---
--- reload1.c.jj 2010-11-25 18:50:45.000000000 +0100
+++ reload1.c 2010-12-20 12:54:34.924901692 +0100
@@ -3597,9 +3597,20 @@ eliminate_regs_in_insn (rtx insn, int re
of spill registers to be needed in the final reload pass than in
the pre-passes. */
if (val && REG_NOTES (insn) != 0)
- REG_NOTES (insn)
- = eliminate_regs_1 (REG_NOTES (insn), VOIDmode, REG_NOTES (insn), true,
- false);
+ {
+ rtx note;
+ REG_NOTES (insn)
+ = eliminate_regs_1 (REG_NOTES (insn), VOIDmode, REG_NOTES (insn), true,
+ false);
+ /* Register elimination might change a REG_EQUIV note expression from
+ something that is constant to e.g. stack pointer based expression,
+ which can't be safely moved across stack pointer adjustments.
+ Downgrade such notes to REG_EQUAL. */
+ for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
+ if (REG_NOTE_KIND (note) == REG_EQUIV
+ && rtx_varies_p (XEXP (note, 0), 0))
+ PUT_REG_NOTE_KIND (note, REG_EQUAL);
+ }
return val;
}
unfortunately doesn't fix this.
--- postreload.c.jj 2010-12-02 13:15:24.000000000 +0100
+++ postreload.c 2010-12-20 14:01:23.404758077 +0100
@@ -1415,7 +1415,8 @@ reload_combine_note_store (rtx dst, cons
{
dst = XEXP (dst, 0);
if (GET_CODE (dst) == PRE_INC || GET_CODE (dst) == POST_INC
- || GET_CODE (dst) == PRE_DEC || GET_CODE (dst) == POST_DEC)
+ || GET_CODE (dst) == PRE_DEC || GET_CODE (dst) == POST_DEC
+ || GET_CODE (dst) == PRE_MODIFY || GET_CODE (dst) == POST_MODIFY)
{
regno = REGNO (XEXP (dst, 0));
mode = GET_MODE (XEXP (dst, 0));
does though. Perhaps just the latter patch would be good enough, dunno whether
something after reload ever makes a difference between REG_EQUIV and REG_EQUAL.
