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Re: [Committed] S/390: Fix bootstrap comparison failure with --with-arch=z10
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Andreas Krebbel <krebbel at linux dot vnet dot ibm dot com>
- Cc: gcc-patches at gcc dot gnu dot org, Alexandre Oliva <aoliva at redhat dot com>
- Date: Fri, 16 Oct 2009 12:37:54 +0200
- Subject: Re: [Committed] S/390: Fix bootstrap comparison failure with --with-arch=z10
- References: <20091016100649.GA11719@bart>
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
On Fri, Oct 16, 2009 at 12:06:49PM +0200, Andreas Krebbel wrote:
> 2009-10-16 Andreas Krebbel <Andreas.Krebbel@de.ibm.com>
>
> * config/s390/s390.c (s390_z10_optimize_cmp): Skip notes when
> investigating previous or next insns.
>
>
> Index: gcc/config/s390/s390.c
> ===================================================================
> *** gcc/config/s390/s390.c.orig 2009-10-16 10:17:13.000000000 +0200
> --- gcc/config/s390/s390.c 2009-10-16 10:24:40.000000000 +0200
> *************** s390_z10_optimize_cmp (rtx insn)
> *** 9866,9872 ****
>
> /* Swap the COMPARE arguments and its mask if there is a
> conflicting access in the previous insn. */
> ! prev_insn = PREV_INSN (insn);
> if (prev_insn != NULL_RTX && INSN_P (prev_insn)
> && reg_referenced_p (*op1, PATTERN (prev_insn)))
> s390_swap_cmp (cond, op0, op1, insn);
> --- 9866,9872 ----
>
> /* Swap the COMPARE arguments and its mask if there is a
> conflicting access in the previous insn. */
> ! prev_insn = prev_nonnote_insn (insn);
> if (prev_insn != NULL_RTX && INSN_P (prev_insn)
> && reg_referenced_p (*op1, PATTERN (prev_insn)))
> s390_swap_cmp (cond, op0, op1, insn);
Shouldn't you skip over DEBUG_INSNs as well? prev_nonnote_insn
may give you a DEBUG_INSN, in which case it would be a -fcompare-debug
bug. I don't see a helper function which would skip over both nonnotes
and DEBUG_INSNs though, except for prev_active_insn (but that one
skips over USE and CLOBBER INSN patterns as well, not sure if that is
desirable or not in this case).
> *************** s390_z10_optimize_cmp (rtx insn)
> *** 9877,9883 ****
> the operands, or if swapping them would cause a conflict
> with the previous insn, issue a NOP after the COMPARE in
> order to separate the two instuctions. */
> ! next_insn = NEXT_INSN (insn);
> if (next_insn != NULL_RTX && INSN_P (next_insn)
> && s390_non_addr_reg_read_p (*op1, next_insn))
> {
> --- 9877,9883 ----
> the operands, or if swapping them would cause a conflict
> with the previous insn, issue a NOP after the COMPARE in
> order to separate the two instuctions. */
> ! next_insn = next_nonnote_insn (insn);
> if (next_insn != NULL_RTX && INSN_P (next_insn)
> && s390_non_addr_reg_read_p (*op1, next_insn))
> {
Jakub