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 ?
Thanks,
Guenter
On Tue, May 26, 2020 at 8:30 AM Guenter Roeck <[email protected]> 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
--
Thanks,
~Nick Desaulniers
Hi Nick,
On 5/26/20 8:40 AM, Nick Desaulniers wrote:
> On Tue, May 26, 2020 at 8:30 AM Guenter Roeck <[email protected]> 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
test builds starting with 5.8.
Guenter
On Tue, May 26, 2020 at 9:03 AM Guenter Roeck <[email protected]> wrote:
>
> Hi Nick,
>
> On 5/26/20 8:40 AM, Nick Desaulniers wrote:
> > On Tue, May 26, 2020 at 8:30 AM Guenter Roeck <[email protected]> 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
> -----Original Message-----
> From: [email protected] <linux-hexagon-
> [email protected]> On Behalf Of Nick Desaulniers
...
> On Tue, May 26, 2020 at 8:30 AM Guenter Roeck <[email protected]> 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+lab
> el%3A%22%5BARCH%5D+hexagon%22
Indeed, we did move to llvm. The build works with the clang_rt-builtins lib. But that issue indicates that it's an unnecessary wart to require that. From what I understand, other arches contribute these builtins content to the kernel build, so we'll do the same.
I'll prioritize this update.
-Brian