[PATCH v4] x86: Add more feature definitions to isa-level.h

[H.J. Lu]

On Mon, Jun 27, 2022 at 8:49 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> This commit doesn't change anything in itself.  It is just to add
> definitions that will be needed by future patches.
> ---
>  sysdeps/x86/isa-level.h | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/sysdeps/x86/isa-level.h b/sysdeps/x86/isa-level.h
> index f293aea906..2cbce25840 100644
> --- a/sysdeps/x86/isa-level.h
> +++ b/sysdeps/x86/isa-level.h
> @@ -67,15 +67,29 @@
>  /* Depending on the minimum ISA level, a feature check result can be a
>     compile-time constant.. */
>
> +
> +/* ISA CPU_FEATURE_USABLE_P defaults.  */

What does "defaults" mean? "For X86_ISA_CPU_FEATURE_USABLE_P"?

> +
>  /* ISA level >= 4 guaranteed includes.  */
>  #define AVX512F_X86_ISA_LEVEL 4
>  #define AVX512VL_X86_ISA_LEVEL 4
>  #define AVX512BW_X86_ISA_LEVEL 4
> +#define AVX512DQ_X86_ISA_LEVEL 4
>
>  /* ISA level >= 3 guaranteed includes.  */
>  #define AVX_X86_ISA_LEVEL 3
>  #define AVX2_X86_ISA_LEVEL 3
>  #define BMI2_X86_ISA_LEVEL 3
> +#define MOVBE_X86_ISA_LEVEL 3
> +
> +/* ISA level >= 2 guaranteed includes.  */
> +#define SSE4_2_X86_ISA_LEVEL 2
> +#define SSSE3_X86_ISA_LEVEL 2
> +
> +
> +/* ISA CPU_FEATURES_ARCH_P defaults.  */

"For X86_ISA_CPU_FEATURES_ARCH_P"?

> +
> +/* Isa level >= 3 feature(s) enabled.  */

No need for this.  Some features may be disabled.

>
>  /* NB: This feature is enabled when ISA level >= 3, which was disabled
>     for the following CPUs:
> @@ -89,6 +103,9 @@
>     when ISA level < 3.  */
>  #define Prefer_No_VZEROUPPER_X86_ISA_LEVEL 3
>
> +/* Isa level >= 2 feature(s) enabled.  */

These are not features in ISAs.  "Feature(s) enabled when ISA level >= 2"?

> +#define Fast_Unaligned_Load_X86_ISA_LEVEL 2
> +
>  /* Both X86_ISA_CPU_FEATURE_USABLE_P and X86_ISA_CPU_FEATURES_ARCH_P
>     macros are wrappers for the respective CPU_FEATURE{S}_{USABLE|ARCH}_P
>     runtime checks.  They differ in two ways.
> --
> 2.34.1
>


-- 
H.J.