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From: Richard Henderson <richard.henderson@linaro.org>
To: Robert Hoo <robert.hu@linux.intel.com>,
	pbonzini@redhat.com, ehabkost@redhat.com
Cc: qemu-devel@nongnu.org
Subject: Re: [PATCH v3] i386/cpu_dump: support AVX512 ZMM regs dump
Date: Fri, 26 Mar 2021 07:11:24 -0600	[thread overview]
Message-ID: <54b5fe3c-5bfe-209a-9600-4a86fefb7b2c@linaro.org> (raw)
In-Reply-To: <4226b2c42eb896dc917f096d14c7d38850d9ec80.camel@linux.intel.com>

On 3/25/21 7:47 PM, Robert Hoo wrote:
> On Thu, 2021-03-25 at 06:39 -0600, Richard Henderson wrote:
>> On 3/24/21 9:15 PM, Robert Hoo wrote:
>>>>> +        } else if (env->xcr0 & XFEATURE_AVX) {
>>>>
>>>> This is normally a 2-bit test.
>>>
>>> I beg your pardon. What 2 bits?
>>
>> I forget the names, but isn't the usual test xcr0 & 6 == 6?
> 
> 6 stands for SSE state-component and AVX state-component.
> I'm not sure about this.
> Can you remember where did you this "xcr0 & 6 == 6"? I can look into
> that.

IA-64 and IA32 Software developers manual, Vol 1 Basic Architecture, Section 
14.3 Detection of AVX instructions.


r~


  reply	other threads:[~2021-03-26 13:12 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-24  8:00 [PATCH v3] i386/cpu_dump: support AVX512 ZMM regs dump Robert Hoo
2021-03-24 13:44 ` Richard Henderson
2021-03-25  3:15   ` Robert Hoo
2021-03-25 12:39     ` Richard Henderson
2021-03-26  1:47       ` Robert Hoo
2021-03-26 13:11         ` Richard Henderson [this message]
2021-03-26 14:16           ` Robert Hoo

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