This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH, S390] Avoid LA with base and index on z13


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 changing the
>> above line to:
>>
>>   if (addr.indx && s390_tune >= PROCESSOR_2817_Z196)
>>
>> (Note that "addr.base && addr.indx" is the same as just checking
>> for addr.indx, since s390_decompose_address will never fill in
>> *just* an index.)
> 
> Good point, I adapted the patch and changed the comment.
> 
> Regards
>  Robin
> 
> --
> 
> gcc/ChangeLog:
> 
> 2018-07-16  Robin Dapp  <rdapp@linux.ibm.com>
> 
> 	* config/s390/s390.c (preferred_la_operand_p): Do not use
> 	LA with index register on z196 or later.
> 

Ok to apply. Thanks!

Andreas


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]