[llvm-dev] how to force llvm generate gather intrinsic

zhi chen via llvm-dev llvm-dev at lists.llvm.org
Wed Feb 24 15:20:28 PST 2016


Hi Elena,

Are the masked_load and gather working now?

Best,
Zhi

On Sat, Jan 23, 2016 at 12:06 PM, Demikhovsky, Elena <
elena.demikhovsky at intel.com> wrote:

> Ø  Can we legalize the same set of masked load/store operations for AVX1
> as AVX2?
>
> Yes, of course.
>
>
>
> -          * Elena*
>
>
>
> *From:* Sanjay Patel [mailto:spatel at rotateright.com]
> *Sent:* Saturday, January 23, 2016 18:42
> *To:* Nema, Ashutosh <Ashutosh.Nema at amd.com>
> *Cc:* Demikhovsky, Elena <elena.demikhovsky at intel.com>; zhi chen <
> zchenhn at gmail.com>; llvm-dev <llvm-dev at lists.llvm.org>
> *Subject:* Re: [llvm-dev] how to force llvm generate gather intrinsic
>
>
>
>
>
> On Sat, Jan 23, 2016 at 6:45 AM, Nema, Ashutosh <Ashutosh.Nema at amd.com>
> wrote:
>
> Thanks Sanjay for highlighting this, few days back I also faced similar
> problem
>
> while generating masked store in avx1 mode, found its only supported under
>
> avx2 else we scalarize it.
>
>
>
> >  1)   I did not switch-on masked_load/store to AVX1, I can do this.
>
>
>
> Yes Elena, This should be supported for FP type in avx1 mode (for INT
> type, I doubt X86 has masked_load/store instruction in avx1 mode).
>
>
>
> Thanks everyone for the answers. My immediate motivation is to improve the
> masked load/store ops for an AVX target. If we can fix scatter/gather
> similarly, that would be great.
>
> Can we legalize the same set of masked load/store operations for AVX1 as
> AVX2? If I'm understanding them correctly, the AVX1 FP instructions
> (vmaskmovps/pd) can be used in place of the AVX2 int instructions
> (vpmaskmovd/q), just with domain crossing penalties thrown in. I think we
> do this for other missing integer ops for an AVX1 target either in x86
> lowering or in the tablegen patterns.
>
>  Elena - I'm not too familiar with the vectorizers or scatter/gather, but
> I'll certainly take a look at D15690. Thanks for pointing out the patch!
>
>
>
> ---------------------------------------------------------------------
> Intel Israel (74) Limited
>
> This e-mail and any attachments may contain confidential material for
> the sole use of the intended recipient(s). Any review or distribution
> by others is strictly prohibited. If you are not the intended
> recipient, please contact the sender and delete all copies.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160224/c3e856ec/attachment.html>


More information about the llvm-dev mailing list