diff options
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 7a0abf2..d322614 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -4036,7 +4036,10 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0, other insns to combine, but the destination of that SET is still live. Also do this if we started with two insns and (at least) one of the - resulting sets is a noop; this noop will be deleted later. */ + resulting sets is a noop; this noop will be deleted later. + + Also do this if we started with two insns neither of which was a simple + move. */ else if (insn_code_number < 0 && asm_noperands (newpat) < 0 && GET_CODE (newpat) == PARALLEL @@ -4066,13 +4069,15 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0, one which uses any regs/memory set in between i2 and i3 can't be first. The PARALLEL might also have been pre-existing in i3, so we need to make sure that we won't wrongly hoist a SET to i2 - that would conflict with a death note present in there. */ + that would conflict with a death note present in there, or would + have its dest modified between i2 and i3. */ if (!modified_between_p (SET_SRC (set1), i2, i3) && !(REG_P (SET_DEST (set1)) && find_reg_note (i2, REG_DEAD, SET_DEST (set1))) && !(GET_CODE (SET_DEST (set1)) == SUBREG && find_reg_note (i2, REG_DEAD, SUBREG_REG (SET_DEST (set1)))) + && !modified_between_p (SET_DEST (set1), i2, i3) && (!HAVE_cc0 || !reg_referenced_p (cc0_rtx, set0)) /* If I3 is a jump, ensure that set0 is a jump so that we do not create invalid RTL. */ @@ -4088,6 +4093,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0, && !(GET_CODE (SET_DEST (set0)) == SUBREG && find_reg_note (i2, REG_DEAD, SUBREG_REG (SET_DEST (set0)))) + && !modified_between_p (SET_DEST (set0), i2, i3) && (!HAVE_cc0 || !reg_referenced_p (cc0_rtx, set1)) /* If I3 is a jump, ensure that set1 is a jump so that we do not create invalid RTL. */ |