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From: Florian Weimer via Libc-alpha <libc-alpha@sourceware.org>
To: "H.J. Lu via Libc-alpha" <libc-alpha@sourceware.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Subject: Re: [PATCH] <bits/platform/x86.h>: Correct x86_cpu_TBM
Date: Mon, 22 Feb 2021 10:49:44 +0100	[thread overview]
Message-ID: <871rd88m9z.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <20210202150139.GA545211@gmail.com> (H. J. Lu via Libc-alpha's message of "Tue, 2 Feb 2021 07:01:39 -0800")

* H. J. Lu via Libc-alpha:

>> Checking HAS_CPU_FEATURE (TBM):
>>   HAS_CPU_FEATURE (TBM): 0
>>   cpuinfo (tbm): 1
>>  *** failure ***
>
> Please try th patch enclosed here.
>
>> 2 differences between /proc/cpuinfo and glibc code.
>> 
>
> Thanks.
>
> H.J.
> ---
> x86_cpu_TBM should be x86_cpu_index_80000001_ecx + 21.
> ---
>  sysdeps/x86/bits/platform/x86.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/sysdeps/x86/bits/platform/x86.h b/sysdeps/x86/bits/platform/x86.h
> index 8f423ae721..dd59224b7f 100644
> --- a/sysdeps/x86/bits/platform/x86.h
> +++ b/sysdeps/x86/bits/platform/x86.h
> @@ -244,7 +244,7 @@ enum
>    x86_cpu_XOP			= x86_cpu_index_80000001_ecx + 11,
>    x86_cpu_LWP			= x86_cpu_index_80000001_ecx + 15,
>    x86_cpu_FMA4			= x86_cpu_index_80000001_ecx + 16,
> -  x86_cpu_TBM			= x86_cpu_index_80000001_ecx + 20,
> +  x86_cpu_TBM			= x86_cpu_index_80000001_ecx + 21,
>  
>    x86_cpu_index_80000001_edx
>      = (CPUID_INDEX_80000001 * 8 * 4 * sizeof (unsigned int)

I've verified this works works on a system with tbm in /proc/cpuinfo.
the bit offset also matches what's documented elsewhere.  Looks good to
me.

Thanks,
Florian


  reply	other threads:[~2021-02-22  9:49 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-21 19:47 [PATCH] x86: Properly match CPU feature [BZ #27222] H.J. Lu via Libc-alpha
2021-01-22 15:01 ` H.J. Lu via Libc-alpha
2021-01-22 16:56   ` Adhemerval Zanella via Libc-alpha
2021-01-22 18:11     ` H.J. Lu via Libc-alpha
2021-02-02 11:07       ` Andreas Schwab
2021-02-02 15:01         ` [PATCH] <bits/platform/x86.h>: Correct x86_cpu_TBM H.J. Lu via Libc-alpha
2021-02-22  9:49           ` Florian Weimer via Libc-alpha [this message]
2022-02-17  0:10             ` H.J. Lu via Libc-alpha

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