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

[James Greenhalgh <james.greenhalgh@arm.com>]

On Thu, Jul 26, 2018 at 11:52:15AM -0500, Sam Tebbs wrote:

<snip>

> > 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" } } */
> >
> > Thanks
> > Sudi
> 
> 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!)

Thanks,
James

> 
> Below is the updated changelog
> 
> gcc/
> 2018-07-26  Sam Tebbs  <sam.tebbs@arm.com>
> 
>          * config/aarch64/aarch64-simd.md
>          (*aarch64_get_lane_zero_extendsi<mode>):
>          Rename to...
> (*aarch64_get_lane_zero_extend<GPI:mode><VDQQH:mode>): ... This.
>          Use GPI iterator instead of SI mode.
> 
> gcc/testsuite
> 2018-07-26  Sam Tebbs  <sam.tebbs@arm.com>
> 
>          * gcc.target/aarch64/extract_zero_extend.c: New file
>