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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Tue, 26 May 2020 09:08:33 -0700
Message-ID: <CAKwvOd==CjrmNcDSEWa3hs4WWPecJorY5txG4T4FsFODhaa2sA@mail.gmail.com>
Subject: Re: [PATCH] compiler/gcc: Raise minimum GCC version for kernel builds
 to 4.8
To:     Guenter Roeck <linux@roeck-us.net>
Cc:     Will Deacon <will@kernel.org>, Brian Cain <bcain@codeaurora.org>,
        linux-hexagon@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Arnd Bergmann <arnd@arndb.de>
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On Tue, May 26, 2020 at 9:03 AM Guenter Roeck <linux@roeck-us.net> wrote:
>
> Hi Nick,
>
> On 5/26/20 8:40 AM, Nick Desaulniers wrote:
> > On Tue, May 26, 2020 at 8:30 AM Guenter Roeck <linux@roeck-us.net> wrote:
> >>
> >> On Mon, May 11, 2020 at 09:41:37PM +0100, Will Deacon wrote:
> >>> It is very rare to see versions of GCC prior to 4.8 being used to build
> >>> the mainline kernel. These old compilers are also known to have codegen
> >>> issues which can lead to silent miscompilation:
> >>>
> >>> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145
> >>>
> >>> Raise the minimum GCC version to 4.8 for building the kernel and remove
> >>> some tautological Kconfig dependencies as a consequence.
> >>
> >> My hexagon compiler is v4.6.1, and I have been unable to find a more
> >> recent version. Does anyone happen to have a pointer to a hexagon toolchain
> >> with gcc 4.8 or later ?
> >
> > IIUC, hexagon moved to LLVM, though that target still has issues
> > building the kernel.
> > https://github.com/ClangBuiltLinux/linux/issues?q=is%3Aopen+is%3Aissue+label%3A%22%5BARCH%5D+hexagon%22
> >
>
> That won't help me for my build tests. It is bad enough having to maintain
> one compiler. I don't want to add another one to the mix, and I'll happily
> leave llvm build tests for ClangBuiltLinux. Guess I'll have to stop hexagon

:( We could use the additional test coverage.

> test builds starting with 5.8.
>
> Guenter


-- 
Thanks,
~Nick Desaulniers