From: Marc Glisse <marc.glisse@inria.fr>
To: Richard Biener <richard.guenther@gmail.com>
Cc: Richard Sandiford <richard.sandiford@arm.com>,
GCC Patches <gcc-patches@gcc.gnu.org>
Subject: Re: VEC_COND_EXPR optimizations
Date: Fri, 31 Jul 2020 13:57:02 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.23.453.2007311354210.5703@stedding.saclay.inria.fr> (raw)
In-Reply-To: <CAFiYyc1EC7jKDH8v4dKjpC4+byAfaZWj-mCnrMf-oh0Sm0u4aw@mail.gmail.com>
On Fri, 31 Jul 2020, Richard Biener wrote:
>>>> +/* (v ? w : 0) ? a : b is just (v & w) ? a : b */
>>>> +(simplify
>>>> + (vec_cond (vec_cond:s @0 @3 integer_zerop) @1 @2)
>>>> + (vec_cond (bit_and @0 @3) @1 @2))
>>>
>>> Does something check automatically that @0 and @3 have compatible types?
>
> @0 should always have a vector boolean type and thus will not be generally
> compatible with @3. But OTOH then when you see (vec_cond (vec_cond ...
> then @3 must be vector boolean as well...
>
> But in theory with AVX512 the inner vec_cond could have a SImode
> condition @0 producing a regular V4SImode vector mask for an outer
> AVX512 SSE-style vec-cond and you then would get a mismatch.
Ah, I thought the SSE-style vec_cond was impossible in AVX512 mode, at
least I couldn't generate one in a few tests, but I didn't try very hard.
> So indeed better add a type compatibility check.
Ok, it can't hurt.
--
Marc Glisse
next prev parent reply other threads:[~2020-07-31 11:57 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-30 7:49 Marc Glisse
2020-07-31 11:18 ` Richard Sandiford
2020-07-31 11:38 ` Marc Glisse
2020-07-31 11:43 ` Richard Biener
2020-07-31 11:57 ` Marc Glisse [this message]
2020-07-31 12:50 ` Richard Sandiford
2020-07-31 12:59 ` Richard Biener
2020-07-31 13:01 ` Marc Glisse
2020-07-31 13:13 ` Marc Glisse
2020-07-31 11:35 ` Richard Biener
2020-07-31 11:39 ` Richard Biener
2020-07-31 11:47 ` Richard Biener
2020-07-31 12:08 ` Richard Biener
2020-07-31 12:12 ` Marc Glisse
2020-08-05 13:32 ` VEC_COND_EXPR optimizations v2 Marc Glisse
2020-08-05 14:24 ` Richard Biener
2020-08-06 8:17 ` Christophe Lyon
2020-08-06 9:05 ` Marc Glisse
2020-08-06 11:25 ` Christophe Lyon
2020-08-06 11:42 ` Marc Glisse
2020-08-06 12:00 ` Christophe Lyon
2020-08-06 18:07 ` Marc Glisse
2020-08-07 6:38 ` Richard Biener
2020-08-07 8:33 ` Marc Glisse
2020-08-07 8:47 ` Richard Biener
2020-08-07 12:15 ` Marc Glisse
2020-08-07 13:04 ` Richard Biener
2020-08-06 10:29 ` Richard Biener
2020-08-06 11:11 ` Marc Glisse
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