From: Jan Beulich <jbeulich@suse.com>
To: "Liu, Hongtao" <hongtao.liu@intel.com>
Cc: Kirill Yukhin <kirill.yukhin@gmail.com>,
"gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH v2] x86: make VPTERNLOG* usable on less than 512-bit operands with just AVX512F
Date: Mon, 19 Jun 2023 09:09:21 +0200 [thread overview]
Message-ID: <5aa77cbb-02cc-195b-c052-22c2d993a966@suse.com> (raw)
In-Reply-To: <SA1PR11MB675778862DE283CFF3F98E8DE55FA@SA1PR11MB6757.namprd11.prod.outlook.com>
On 19.06.2023 04:07, Liu, Hongtao wrote:
>> -----Original Message-----
>> From: Jan Beulich <jbeulich@suse.com>
>> Sent: Friday, June 16, 2023 2:22 PM
>>
>> --- a/gcc/config/i386/sse.md
>> +++ b/gcc/config/i386/sse.md
>> @@ -12597,11 +12597,11 @@
>> (set_attr "mode" "<sseinsnmode>")])
>>
>> (define_insn "*<avx512>_vternlog<mode>_all"
>> - [(set (match_operand:V 0 "register_operand" "=v")
>> + [(set (match_operand:V 0 "register_operand" "=v,v")
>> (unspec:V
>> - [(match_operand:V 1 "register_operand" "0")
>> - (match_operand:V 2 "register_operand" "v")
>> - (match_operand:V 3 "bcst_vector_operand" "vmBr")
>> + [(match_operand:V 1 "register_operand" "0,0")
>> + (match_operand:V 2 "register_operand" "v,v")
>> + (match_operand:V 3 "bcst_vector_operand" "vBr,m")
>> (match_operand:SI 4 "const_0_to_255_operand")]
>> UNSPEC_VTERNLOG))]
>> "TARGET_AVX512F
> Change condition to <MODE_SIZE> == 64 || TARGET_AVX512VL || (TARGET_AVX512F && !TARGET_PREFER_AVX256)
May I ask why you think this is necessary? The condition of the insn
already wasn't in sync with the condition used in all three splitters,
and I didn't see any reason why now they would need to be brought in
sync. First and foremost because of the use of the UNSPEC (equally
before and after this patch).
Furthermore, isn't it the case that I'm already mostly expressing
this with the "enabled" attribute? At the very least I think I
should drop that again then if following your request?
> Also please add a testcase for case TARGET_AVX512F && !TARGET_PREFER_AVX256.
Especially in a case like this one I'm wondering about the usefulness
of a contrived testcase: It won't test more than one minor sub-case of
the whole set of constructs covered here. But well, here as well as
for the other change I'll invent something.
Jan
next prev parent reply other threads:[~2023-06-19 7:09 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-16 6:22 Jan Beulich
2023-06-19 2:07 ` Liu, Hongtao
2023-06-19 7:09 ` Jan Beulich [this message]
2023-06-19 8:46 ` Hongtao Liu
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