On 07/16/2018 01:02 PM, Robin Dapp wrote:
>> But on zEC12 LA works pretty much the same as on z13/z14, it is
>> indeed not cracked, but still a 2-cycle instruction when using
>> an index register. So I guess the change really should apply
>> to zEC12 as well, and this could be as simple as changin
> But on zEC12 LA works pretty much the same as on z13/z14, it is
> indeed not cracked, but still a 2-cycle instruction when using
> an index register. So I guess the change really should apply
> to zEC12 as well, and this could be as simple as changing the
> above line to:
>
> if (addr.indx &&
Robin Dapp wrote:
> * config/s390/s390.c (preferred_la_operand_p): Do not use
> LA with base and index on z13 or later.
The code just before your change reads:
/* Avoid LA instructions with index register on z196; it is
preferable to use regular add instructions when possibl
Hi,
this patch avoids emitting LA on z13 and later when the address has both
an index and a base since a regular add is faster in that case.
Regtested on s390x.
Regards
Robin
--
gcc/ChangeLog:
2018-07-05 Robin Dapp
* config/s390/s390.c (preferred_la_operand_p): Do not use
