Re: [PATCH] [x86_64] Detection of availability of AVX512F and AVX512DQ ISAs

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Wed, May 27, 2015 at 3:46 AM, Andrew Senkevich
<andrew.n.senkevich@gmail.com> wrote:
>> Please add/use bit_ZMM0_15_state and bit_ZMM16_31_state.
>> This file is used by both 32-bit and 64-bit. Does it work for both
>> 32-bit and 64-bit?
>
> Yes, here is refactored patch.
>
> ChangeLog
>
> 2015-05-27  Andrew Senkevich  <andrew.senkevich@intel.com>
>
>         * sysdeps/x86_64/multiarch/init-arch.h (bit_AVX512F_Usable,
>         bit_AVX512DQ_Usable, bit_Opmask_state, bit_ZMM0_15_state,
>         bit_ZMM16_31_state): New macro.
>         * sysdeps/x86_64/multiarch/init-arch.c (__init_cpu_features):
>         Check and set bit_AVX512F_Usable, bit_AVX512DQ_Usable.
>
> diff --git a/sysdeps/x86_64/multiarch/init-arch.c
> b/sysdeps/x86_64/multiarch/init-arch.c
> index 7dec218..aaad5fa 100644
> --- a/sysdeps/x86_64/multiarch/init-arch.c
> +++ b/sysdeps/x86_64/multiarch/init-arch.c
> @@ -179,6 +179,23 @@ __init_cpu_features (void)
>    if (CPUID_AVX2)
>      __cpu_features.feature[index_AVX2_Usable]
>        |= bit_AVX2_Usable | bit_AVX_Fast_Unaligned_Load;
> +  /* Check if OPMASK state, upper 256-bit of ZMM0-ZMM15 and
> +     ZMM16-ZMM31 state are enabled.  */
> +  if ((xcrlow & (bit_Opmask_state | bit_ZMM0_15_state
> + | bit_ZMM16_31_state)) ==
> +      (bit_Opmask_state | bit_ZMM0_15_state | bit_ZMM16_31_state))
> +    {
> +      /* Determine if AVX512F is usable.  */
> +      if (CPUID_AVX512F)
> + {
> +  __cpu_features.feature[index_AVX512F_Usable]
> +    |= bit_AVX512F_Usable;
> +  /* Determine if AVX512DQ is usable.  */
> +  if (CPUID_AVX512DQ)
> +    __cpu_features.feature[index_AVX512DQ_Usable]
> +      |= bit_AVX512DQ_Usable;
> + }
> +    }
>    /* Determine if FMA is usable.  */
>    if (CPUID_FMA)
>      __cpu_features.feature[index_FMA_Usable] |= bit_FMA_Usable;
> diff --git a/sysdeps/x86_64/multiarch/init-arch.h
> b/sysdeps/x86_64/multiarch/init-arch.h
> index e6b5ba5..cfc6e70 100644
> --- a/sysdeps/x86_64/multiarch/init-arch.h
> +++ b/sysdeps/x86_64/multiarch/init-arch.h
> @@ -26,6 +26,8 @@
>  #define bit_Slow_SSE4_2 (1 << 9)
>  #define bit_AVX2_Usable (1 << 10)
>  #define bit_AVX_Fast_Unaligned_Load (1 << 11)
> +#define bit_AVX512F_Usable (1 << 12)
> +#define bit_AVX512DQ_Usable (1 << 13)
>
>  /* CPUID Feature flags.  */
>
> @@ -43,10 +45,15 @@
>  /* COMMON_CPUID_INDEX_7.  */
>  #define bit_RTM (1 << 11)
>  #define bit_AVX2 (1 << 5)
> +#define bit_AVX512F (1 << 16)
> +#define bit_AVX512DQ (1 << 17)
>
>  /* XCR0 Feature flags.  */
>  #define bit_XMM_state  (1 << 1)
>  #define bit_YMM_state  (2 << 1)
> +#define bit_Opmask_state (1 << 5)
> +#define bit_ZMM0_15_state (1 << 6)
> +#define bit_ZMM16_31_state (1 << 7)
>
>  /* The integer bit array index for the first set of internal feature bits.  */
>  # define FEATURE_INDEX_1 0
> @@ -76,6 +83,8 @@
>  # define index_Slow_SSE4_2 FEATURE_INDEX_1*FEATURE_SIZE
>  # define index_AVX2_Usable FEATURE_INDEX_1*FEATURE_SIZE
>  # define index_AVX_Fast_Unaligned_Load FEATURE_INDEX_1*FEATURE_SIZE
> +# define index_AVX512F_Usable FEATURE_INDEX_1*FEATURE_SIZE
> +# define index_AVX512DQ_Usable FEATURE_INDEX_1*FEATURE_SIZE
>
>  #else /* __ASSEMBLER__ */
>
> @@ -152,6 +161,10 @@ extern const struct cpu_features *__get_cpu_features (void)
>    HAS_CPUID_FLAG (COMMON_CPUID_INDEX_7, ebx, bit_RTM)
>  # define CPUID_AVX2 \
>    HAS_CPUID_FLAG (COMMON_CPUID_INDEX_7, ebx, bit_AVX2)
> +# define CPUID_AVX512F \
> +  HAS_CPUID_FLAG (COMMON_CPUID_INDEX_7, ebx, bit_AVX512F)
> +# define CPUID_AVX512DQ \
> +  HAS_CPUID_FLAG (COMMON_CPUID_INDEX_7, ebx, bit_AVX512DQ)
>
>  /* HAS_* evaluates to true if we may use the feature at runtime.  */
>  # define HAS_SSE2 HAS_CPU_FEATURE (COMMON_CPUID_INDEX_1, edx, bit_SSE2)
> @@ -172,6 +185,8 @@ extern const struct cpu_features *__get_cpu_features (void)
>  # define index_Slow_SSE4_2 FEATURE_INDEX_1
>  # define index_AVX2_Usable FEATURE_INDEX_1
>  # define index_AVX_Fast_Unaligned_Load FEATURE_INDEX_1
> +# define index_AVX512F_Usable FEATURE_INDEX_1
> +# define index_AVX512DQ_Usable FEATURE_INDEX_1
>
>  # define HAS_ARCH_FEATURE(name) \
>    ((__get_cpu_features ()->feature[index_##name] & (bit_##name)) != 0)
> @@ -182,6 +197,8 @@ extern const struct cpu_features *__get_cpu_features (void)
>  # define HAS_FAST_UNALIGNED_LOAD HAS_ARCH_FEATURE (Fast_Unaligned_Load)
>  # define HAS_AVX HAS_ARCH_FEATURE (AVX_Usable)
>  # define HAS_AVX2 HAS_ARCH_FEATURE (AVX2_Usable)
> +# define HAS_AVX512F HAS_ARCH_FEATURE (AVX512F_Usable)
> +# define HAS_AVX512DQ HAS_ARCH_FEATURE (AVX512DQ_Usable)
>  # define HAS_FMA HAS_ARCH_FEATURE (FMA_Usable)
>  # define HAS_FMA4 HAS_ARCH_FEATURE (FMA4_Usable)
>  # define HAS_AVX_FAST_UNALIGNED_LOAD HAS_ARCH_FEATURE (AVX_Fast_Unaligned_Load)
>
> Is it ok?
>

OK.

Thanks.


-- 
H.J.