On Thu, Nov 13, 2014 at 7:57 PM, Ulrich Weigand <uweig...@de.ibm.com> wrote:
> Richard Henderson wrote:
>> On 11/12/2014 09:41 PM, Ulrich Weigand wrote:
>> > * optabs.c (prepare_operand): Gracefully fail if the mode of X
>> > does not match the operand mode expected by the insn pattern.
>>
>> This is ok.
>
> I've checked this in now, thanks.
>
>> I wondered whether s390 benefit from following i386 in allowing
>> mov<>cc to accept immediate operands pre-reload. This could then
>> be re-used by cstorecc4 to allow any CC mode to expand to LOCR
>> when available.
>
> Well, we already compile
>
> int test (long x, long y)
> {
> return x < y;
> }
>
> to
>
> cgr %r2,%r3 # 44 *cmpdi_ccs/1 [length = 4]
> lhi %r1,0 # 43 *movsi_zarch/1 [length = 4]
> lhi %r2,1 # 7 *movsi_zarch/1 [length = 4]
> locrnl %r2,%r1 # 45 *movsicc/2 [length = 4]
> lgfr %r2,%r2 # 17 *extendsidi2/1 [length = 4]
> br %r14 # 50 return [length = 2]
>
> with -march=z196 or higher. The LOCR is not introduced via
> cstorecc4, but instead directly by noce_emit_cmove via
> emit_conditional_move. It doesn't seem to matter that the
> patterns don't accept immediate operands; those are loaded
> into registers by maybe_legitimize_operand, which already
> tries a copy_to_mode_reg.
This probably caused bootstrap on s390x-linux to fail as in PR63952
(last checked with rev. 217714).
Richard.
> Bye,
> Ulrich
>
> --
> Dr. Ulrich Weigand
> GNU/Linux compilers and toolchain
> ulrich.weig...@de.ibm.com
>
