diff options
Diffstat (limited to 'sysdeps/x86/isa-level.h')
| -rw-r--r-- | sysdeps/x86/isa-level.h | 28 |
1 files changed, 10 insertions, 18 deletions
diff --git a/sysdeps/x86/isa-level.h b/sysdeps/x86/isa-level.h index 7cae11c228..075e7c6ee1 100644 --- a/sysdeps/x86/isa-level.h +++ b/sysdeps/x86/isa-level.h @@ -64,14 +64,8 @@ #define MINIMUM_X86_ISA_LEVEL \ (__X86_ISA_V1 + __X86_ISA_V2 + __X86_ISA_V3 + __X86_ISA_V4) - -/* - * CPU Features that are hard coded as enabled depending on ISA build - * level. - * - Values > 0 features are always ENABLED if: - * Value >= MINIMUM_X86_ISA_LEVEL - */ - +/* Depending on the minimum ISA level, a feature check result can be a + compile-time constant.. */ /* ISA level >= 4 guaranteed includes. */ #define AVX512VL_X86_ISA_LEVEL 4 @@ -81,18 +75,16 @@ #define AVX2_X86_ISA_LEVEL 3 #define BMI2_X86_ISA_LEVEL 3 -/* - * NB: This may not be fully assumable for ISA level >= 3. From - * looking over the architectures supported in cpu-features.h the - * following CPUs may have an issue with this being default set: - * - AMD Excavator - */ +/* NB: This feature is enabled when ISA level >= 3, which was disabled + for the following CPUs: + - AMD Excavator + when ISA level < 3. */ #define AVX_Fast_Unaligned_Load_X86_ISA_LEVEL 3 -/* - * KNL (the only cpu that sets this supported in cpu-features.h) - * builds with ISA V1 so this shouldn't harm any architectures. - */ +/* NB: This feature is disabled when ISA level >= 3, which was enabled + for the following CPUs: + - Intel KNL + when ISA level < 3. */ #define Prefer_No_VZEROUPPER_X86_ISA_LEVEL 3 #define ISA_SHOULD_BUILD(isa_build_level) \ |