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From: Florian Weimer <fweimer@redhat.com>
To: "H.J. Lu via Libc-alpha" <libc-alpha@sourceware.org>
Cc: "H.J. Lu" <hjl.tools@gmail.com>,  Joseph Myers <joseph@codesourcery.com>
Subject: Re: [PATCH v2] x86: Require full ISA support for x86-64 level marker [BZ #27318]
Date: Mon, 08 Feb 2021 16:06:48 +0100	[thread overview]
Message-ID: <87pn1a1tvb.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <CAMe9rOr+miuOtYVqubTuiTUMgD+TVJcu_6w77=8SYs2twmk85Q@mail.gmail.com> (H. J. Lu via Libc-alpha's message of "Sun, 7 Feb 2021 07:05:09 -0800")

* H. J. Lu via Libc-alpha:

> It is used to check if INCLUDE_X86_ISA_LEVEL should be defined in
> config.h.   INCLUDE_X86_ISA_LEVEL is defined only if GCC enables
> the full ISAs of a level without any ISAs of the higher ISA levels.   Since
> I want to support GCC older than GCC 11,  || is used to detect any
> ISAs in a level and !|| is used to check if any ISAs are missing.

But isn't && the right construct anyway?  As in, if GCC was built to
include *all* feature flags for a specific level, require that level at
run time?

>> Are ISA levels really defined for 32-bit?
>
> 32-bit can just use the same x86-64 ISA level.

At least it requires figuring out the baseline level between i386 and
x86-64-v2, probably based on what GCC's -march=x86-64 option does with
-m32.

Thanks,
Florian
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  reply	other threads:[~2021-02-08 15:06 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-02 21:51 [PATCH] " H.J. Lu
2021-02-02 23:11 ` Joseph Myers
2021-02-02 23:16   ` H.J. Lu
2021-02-03 14:14     ` Joseph Myers
2021-02-03 15:09       ` [PATCH v2] " H.J. Lu
2021-02-04 10:38         ` Florian Weimer
2021-02-04 13:22           ` H.J. Lu
2021-02-04 22:55             ` Andreas K. Hüttel
2021-02-04 23:09               ` H.J. Lu
2021-02-07 10:27                 ` Florian Weimer
2021-02-07 15:05                   ` H.J. Lu
2021-02-08 15:06                     ` Florian Weimer [this message]
2021-02-08 16:09                       ` H.J. Lu
2021-02-09  0:29                         ` [PATCH v3] x86: Disable " H.J. Lu
2021-02-22 10:40                           ` Florian Weimer
2021-02-22 12:51                             ` H.J. Lu
2021-02-22 13:51                               ` Florian Weimer
2021-03-01 16:07                                 ` Florian Weimer
2021-03-01 18:00                                   ` H.J. Lu
2021-03-01 18:06                                     ` Florian Weimer
2021-03-01 19:09                                       ` H.J. Lu
2021-03-03 13:37                                         ` [PATCH v4] x86: Set minimum " H.J. Lu
2021-03-05 19:43                                           ` Florian Weimer
2021-03-06 15:23                                             ` [PATCH v5] " H.J. Lu
2021-03-06 15:42                                               ` Florian Weimer
2021-03-06 15:58                                                 ` [2.33][PATCH] " H.J. Lu
2021-02-08 13:35               ` [PATCH v2] x86: Require full ISA support for " Nix
2021-02-03  9:29 ` [PATCH] " Florian Weimer

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