Re: [PATCH] rs6000: Use rldimi for vec init instead of shift + ior

["Kewen.Lin" <linkw@linux.ibm.com>]

Hi Segher & Will,

Thanks for your review comments!

on 2021/2/19 上午2:33, Segher Boessenkool wrote:
> Hi!
> 
> On Wed, Feb 03, 2021 at 02:37:05PM +0800, Kewen.Lin wrote:
>> This patch merges the previously approved one[1] and its relied patch
>> made by Segher here[2], it's to make unsigned int vector init go with
>> rldimi to merge two integers instead of shift and ior.
> 
>> gcc/ChangeLog:
>>
>> 2020-02-03  Segher Boessenkool  <segher@kernel.crashing.org>
>> 	    Kewen Lin  <linkw@gcc.gnu.org>
>>
>> 	* config/rs6000/rs6000.md (*rotl<mode>3_insert_3): Renamed to...
>> 	(rotl<mode>3_insert_3): ...this.
>> 	(plus_ior_xor): New code_iterator.
>> 	(define_split for GPR rl*imi): New splitter.
>> 	* config/rs6000/vsx.md (vsx_init_v4si): Use gen_rotldi3_insert_3
>> 	for integer merging.
>>
>> gcc/testsuite/ChangeLog:
>>
>> 	* gcc.target/powerpc/vec-init-10.c: New test.
> 
> Is there a PR you should mention here?

I thought this is trivial so didn't file one upstream PR.  I did a
searching in upstream bugzilla, PR93453 looks similar but different.
I confirmed that the current patch can't make it pass (just two insns
instead of three insns).

Do you happen to have one related in mind?  If no, I will commit it
without PR.

> 
>> +/* { dg-final { scan-assembler-not "sldi" } } */
>> +/* { dg-final { scan-assembler-not "or" } } */
>> +/* { dg-final { scan-assembler-times {\mrldimi\M} 4 } } */
> 
> /* { dg-final { scan-assembler-not {\msldi\M} } } */
> /* { dg-final { scan-assembler-not {\mor\M} } } */
> /* { dg-final { scan-assembler-times {\mrldimi\M} 4 } } */
> 
> Okay for trunk with that tweak.  Thanks!
> 

Will fix it, thanks!


BR,
Kewen