RE: Compile problems w/gcc 9.4.0 in linux-next

[Michael Kelley]

From: Ingo Molnar <mingo@xxxxxxxxxx> Sent: Friday, March 21, 2025 12:38 AM
> 
> * Michael Kelley <mhklinux@xxxxxxxxxxx> wrote:
> 
> > > What are your thoughts as maintainers of lib/zstd?
> >
> > FYI, the same segfault occurs with gcc 10.5. The problem is fixed
> > in gcc 11.4.
> 
> So the patch below would work this around on GCC9 and GCC10?

I've confirmed that the patch gives a clean compile with gcc 9.4.

Note that I confirmed yesterday that the gcc problem is fixed with
11.4. I don't know about earlier gcc 11 minor versions. Lemme see
if I can get the original gcc 11 release and try that to confirm that
your patch has the right version cutoff.

Michael  

> 
> Thanks,
> 
> 	Ingo
> 
> ==============>
>  lib/zstd/common/portability_macros.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/zstd/common/portability_macros.h b/lib/zstd/common/portability_macros.h
> index 0e3b2c0a527d..0dde8bf56595 100644
> --- a/lib/zstd/common/portability_macros.h
> +++ b/lib/zstd/common/portability_macros.h
> @@ -55,7 +55,7 @@
>  #ifndef DYNAMIC_BMI2
>    #if ((defined(__clang__) && __has_attribute(__target__)) \
>        || (defined(__GNUC__) \
> -          && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)))) \
> +          && (__GNUC__ >= 11))) \
>        && (defined(__x86_64__) || defined(_M_X64)) \
>        && !defined(__BMI2__)
>    #  define DYNAMIC_BMI2 1