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Re: [GCC][PATCH][Aarch64] Stop redundant zero-extension after UMOV when in DI mode

Hi Sam

On 01/08/18 10:12, Sam Tebbs wrote:

On 07/31/2018 11:16 PM, James Greenhalgh wrote:
On Thu, Jul 26, 2018 at 11:52:15AM -0500, Sam Tebbs wrote:


Thanks for making the changes and adding more test cases. I do however
see that you are only covering 2 out of 4 new
*aarch64_get_lane_zero_extenddi<> patterns. The
*aarch64_get_lane_zero_extendsi<> were already existing. I don't mind
those tests. I would just ask you to add the other two new patterns
as well. Also since the different versions of the instruction generate
same instructions (like foo_16qi and foo_8qi both give out the same
instruction), I would suggest using a -fdump-rtl-final (or any relevant
rtl dump) with the dg-options and using a scan-rtl-dump to scan the
pattern name. Something like:
/* { dg-do compile } */
/* { dg-options "-O3 -fdump-rtl-final" } */
/* { dg-final { scan-rtl-dump "aarch64_get_lane_zero_extenddiv16qi"
"final" } } */

Hi Sudi,

Thanks again. Here's an update that adds 4 more tests, so all 8 patterns
generated are now tested for!
This is OK for trunk, thanks for the patch (and thanks Sudi for the review!)


Thank you James! I'd appreciate it if someone could commit it as I don't have commit rights yet.

I have committed this on your behalf as r263200.



Below is the updated changelog

2018-07-26  Sam Tebbs  <>

          * config/aarch64/
          Rename to...
(*aarch64_get_lane_zero_extend<GPI:mode><VDQQH:mode>): ... This.
          Use GPI iterator instead of SI mode.

2018-07-26  Sam Tebbs  <>

          * New file

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