Skip to content

Automatically detect hardware type for zen5 and later #927

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
edwsmyth wants to merge 1 commit into
base: master
Choose a base branch
from
+325 −46
Open

Automatically detect hardware type for zen5 and later #927

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
321 changes: 291 additions & 30 deletions frame/base/bli_cpuid.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,7 @@
libraries.

Copyright (C) 2014, The University of Texas at Austin
Copyright (C) 2018-2020, Advanced Micro Devices, Inc.
Copyright (C) 2018 - 2026, Advanced Micro Devices, Inc. All rights reserved.
Copyright (C) 2019, Dave Love, University of Manchester

Redistribution and use in source and binary forms, with or without
Expand Down Expand Up @@ -82,6 +82,18 @@

#include "cpuid.h"

// Variables to return if different AVX instructions are supported. These will
// be updated in bli_cpuid_query_id(), which is called only once from
// bli_arch_set_id(), using the pthread_once mechanism. This assume that the
// cpuid information will not change once the library is loaded.
// Cached values can be returned by the specific functions for each below.

static bool is_avx2fma3_supported = FALSE;
static bool is_avx512_supported = FALSE;
static bool is_avx512vnni_supported = FALSE;
static bool is_avx512bf16_supported = FALSE;
static bool is_avx512fp16_supported = FALSE;

arch_t bli_cpuid_query_id( void )
{
uint32_t vendor, family, model, features;
Expand All @@ -91,12 +103,31 @@ arch_t bli_cpuid_query_id( void )
// vendor.
vendor = bli_cpuid_query( &family, &model, &features );

if ( vendor == VENDOR_INTEL || vendor == VENDOR_AMD )
{
// Check different levels of AVX instruction support.
bli_cpuid_check_avx2fma3_support( family, model, features );
bli_cpuid_check_avx512_support( family, model, features );
bli_cpuid_check_avx512vnni_support( family, model, features );
bli_cpuid_check_avx512bf16_support( family, model, features );
bli_cpuid_check_avx512fp16_support( family, model, features );
}

#if 0
printf( "vendor = %s\n", vendor==1 ? "AMD": "INTEL" );
printf("family = %x\n", family );
printf( "model = %x\n", model );
printf( "\nBLIS CPUID information\n" );

printf( " vendor = %s\n", vendor==1 ? "AMD": "INTEL" );
printf( " family = %x h\n", family );
printf( " model = %x h\n", model );
printf( " features = %x h\n", features );

printf( "features = %x\n", features );
printf( " Key ISA support\n" );

printf( " AVX2/FMA3 = %d\n", is_avx2fma3_supported );
printf( " AVX512 F/DQ/CD/BW/VL = %d\n", is_avx512_supported );
printf( " AVX512 VNNI = %d\n", is_avx512vnni_supported );
printf( " AVX512 BF16 = %d\n", is_avx512bf16_supported );
printf( " AVX512 FP16 = %d\n", is_avx512fp16_supported );
#endif

if ( vendor == VENDOR_INTEL )
Expand Down Expand Up @@ -144,6 +175,12 @@ arch_t bli_cpuid_query_id( void )
if ( bli_cpuid_is_zen( family, model, features ) )
return BLIS_ARCH_ZEN;
#endif
#ifdef BLIS_CONFIG_ZEN3
// Fallback test for future AMD processors
// Use zen3 if AVX512 support is not available but AVX2 is.
if ( is_avx2fma3_supported )

@devinamatthews devinamatthews Jun 28, 2026

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

No AVX512 test for Zen4/5 fallback?

return BLIS_ARCH_ZEN3;
#endif
#ifdef BLIS_CONFIG_EXCAVATOR
if ( bli_cpuid_is_excavator( family, model, features ) )
return BLIS_ARCH_EXCAVATOR;
Expand Down Expand Up @@ -485,6 +522,204 @@ bool bli_cpuid_is_bulldozer
return TRUE;
}

// Determine if the CPU has support for AVX2 and FMA3.
void bli_cpuid_check_avx2fma3_support
(
uint32_t family,
uint32_t model,
uint32_t features
)
{
// Check for expected CPU features.
const uint32_t expected = FEATURE_AVX |

@devinamatthews devinamatthews Jun 28, 2026

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It would be better not to have static global variables. Instead you could do:

enum
{
    FEATURE_SET_AVX2FMA3 = this | that | theother,
    ...
};

and use bli_cpuid_has_features directly thereafter.

FEATURE_FMA3 |
FEATURE_AVX2;

if ( !bli_cpuid_has_features( features, expected ) )
{
is_avx2fma3_supported = FALSE;
}
else
{
is_avx2fma3_supported = TRUE;
}
}


// Determine if the CPU has support for AVX512.
void bli_cpuid_check_avx512_support
(
uint32_t family,
uint32_t model,
uint32_t features
)
{
// Check for expected CPU features.
const uint32_t expected = FEATURE_AVX |
FEATURE_FMA3 |
FEATURE_AVX2 |
FEATURE_AVX512F |
FEATURE_AVX512DQ |
FEATURE_AVX512CD |
FEATURE_AVX512BW |
FEATURE_AVX512VL;

if ( !bli_cpuid_has_features( features, expected ) )
{
is_avx512_supported = FALSE;
}
else
{
is_avx512_supported = TRUE;
}
}

// Determine if the CPU has support for AVX512_VNNI.
void bli_cpuid_check_avx512vnni_support
(
uint32_t family,
uint32_t model,
uint32_t features
)
{
// Check for expected CPU features.
const uint32_t expected = FEATURE_AVX |
FEATURE_FMA3 |
FEATURE_AVX2 |
FEATURE_AVX512F |
FEATURE_AVX512DQ |
FEATURE_AVX512CD |
FEATURE_AVX512BW |
FEATURE_AVX512VL |
FEATURE_AVX512VNNI;

if ( !bli_cpuid_has_features( features, expected ) )
{
is_avx512vnni_supported = FALSE;
}
else
{
is_avx512vnni_supported = TRUE;
}
}

// Determine if the CPU has support for AVX512_BF16.
void bli_cpuid_check_avx512bf16_support
(
uint32_t family,
uint32_t model,
uint32_t features
)
{
// Check for expected CPU features.
const uint32_t expected = FEATURE_AVX |
FEATURE_FMA3 |
FEATURE_AVX2 |
FEATURE_AVX512F |
FEATURE_AVX512DQ |
FEATURE_AVX512CD |
FEATURE_AVX512BW |
FEATURE_AVX512VL |
FEATURE_AVX512VNNI |
FEATURE_AVX512BF16;

if ( !bli_cpuid_has_features( features, expected ) )
{
is_avx512bf16_supported = FALSE;
}
else
{
is_avx512bf16_supported = TRUE;
}
}

// Determine if the CPU has support for AVX512_FP16.
void bli_cpuid_check_avx512fp16_support
(
uint32_t family,
uint32_t model,
uint32_t features
)
{
// Check for expected CPU features.
const uint32_t expected = FEATURE_AVX |
FEATURE_FMA3 |
FEATURE_AVX2 |
FEATURE_AVX512F |
FEATURE_AVX512DQ |
FEATURE_AVX512CD |
FEATURE_AVX512BW |
FEATURE_AVX512VL |
FEATURE_AVX512VNNI |
FEATURE_AVX512BF16 |
FEATURE_MOVDIRI |
FEATURE_MOVDIR64B |
FEATURE_AVX512VP2INTERSECT |
FEATURE_AVXVNNI |
FEATURE_AVX512FP16;

if ( !bli_cpuid_has_features( features, expected ) )
{
is_avx512fp16_supported = FALSE;
}
else
{
is_avx512fp16_supported = TRUE;
}
}

// Ensure that actual support determination happens only once from AVX
// support routines below.

static bli_pthread_once_t once_check_cpuid_query_id = BLIS_PTHREAD_ONCE_INIT;

void bli_cpuid_query_id_wrapper( void )
{
arch_t __attribute__ ((unused)) id_w;
id_w = bli_cpuid_query_id();
}
void bli_cpuid_query_id_once( void )

@devinamatthews devinamatthews Jun 28, 2026

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

If you want to avoid repeated overhead, better to cache return value of bli_cpuid_query_id (perhaps rename to bli_cpuid_query_id_impl) in static global variable of bli_cpuid_query_id_once (rename without _onceto avoid changing lots of dependents). Again not crazy about global vars but just one for caching is OK. This does of course break big.LITTLE or P/E systems but there are larger issues there anyways.

{
#ifndef BLIS_CONFIGURETIME_CPUID
bli_pthread_once( &once_check_cpuid_query_id, bli_cpuid_query_id_wrapper );
#endif
}

// API to check if AVX2 and FMA3 are supported or not on the current platform.
bool bli_cpuid_is_avx2fma3_supported( void )

@devinamatthews devinamatthews Jun 28, 2026

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Are these actually needed? They're not used ATM.

{
bli_cpuid_query_id_once();
return is_avx2fma3_supported;
}

// API to check if AVX512 is supported or not on the current platform.
bool bli_cpuid_is_avx512_supported( void )
{
bli_cpuid_query_id_once();
return is_avx512_supported;
}

// API to check if AVX512_VNNI is supported or not on the current platform.
bool bli_cpuid_is_avx512vnni_supported( void )
{
bli_cpuid_query_id_once();
return is_avx512vnni_supported;
}

// API to check if AVX512_bf16 is supported or not on the current platform.
bool bli_cpuid_is_avx512bf16_supported( void )
{
bli_cpuid_query_id_once();
return is_avx512bf16_supported;
}

// API to check if AVX512_fp16 is supported or not on the current platform.
bool bli_cpuid_is_avx512fp16_supported( void )
{
bli_cpuid_query_id_once();
return is_avx512fp16_supported;
}

#elif defined(__aarch64__) || defined(__arm__) || defined(_M_ARM) || defined(_ARCH_PPC)

// courtesy OpenBSD
Expand Down Expand Up @@ -593,7 +828,7 @@ bool bli_cpuid_is_cortexa9

Copyright (C) 2017, The University of Texas at Austin
Copyright (C) 2017, Devin Matthews
Copyright (C) 2018 - 2019, Advanced Micro Devices, Inc.
Copyright (C) 2018 - 2026, Advanced Micro Devices, Inc. All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
Expand Down Expand Up @@ -625,27 +860,36 @@ bool bli_cpuid_is_cortexa9

enum
{
// input register(s) output register
FEATURE_MASK_SSE3 = (1u<< 0), // cpuid[eax=1] :ecx[0]
FEATURE_MASK_SSSE3 = (1u<< 9), // cpuid[eax=1] :ecx[9]
FEATURE_MASK_SSE41 = (1u<<19), // cpuid[eax=1] :ecx[19]
FEATURE_MASK_SSE42 = (1u<<20), // cpuid[eax=1] :ecx[20]
FEATURE_MASK_AVX = (1u<<28), // cpuid[eax=1] :ecx[28]
FEATURE_MASK_AVX2 = (1u<< 5), // cpuid[eax=7,ecx=0] :ebx[5]
FEATURE_MASK_FMA3 = (1u<<12), // cpuid[eax=1] :ecx[12]
FEATURE_MASK_FMA4 = (1u<<16), // cpuid[eax=0x80000001]:ecx[16]
FEATURE_MASK_AVX512F = (1u<<16), // cpuid[eax=7,ecx=0] :ebx[16]
FEATURE_MASK_AVX512DQ = (1u<<17), // cpuid[eax=7,ecx=0] :ebx[17]
FEATURE_MASK_AVX512PF = (1u<<26), // cpuid[eax=7,ecx=0] :ebx[26]
FEATURE_MASK_AVX512ER = (1u<<27), // cpuid[eax=7,ecx=0] :ebx[27]
FEATURE_MASK_AVX512CD = (1u<<28), // cpuid[eax=7,ecx=0] :ebx[28]
FEATURE_MASK_AVX512BW = (1u<<30), // cpuid[eax=7,ecx=0] :ebx[30]
FEATURE_MASK_AVX512VL = (1u<<31), // cpuid[eax=7,ecx=0] :ebx[31]
FEATURE_MASK_XGETBV = (1u<<26)|
(1u<<27), // cpuid[eax=1] :ecx[27:26]
XGETBV_MASK_XMM = 0x02u, // xcr0[1]
XGETBV_MASK_YMM = 0x04u, // xcr0[2]
XGETBV_MASK_ZMM = 0xe0u // xcr0[7:5]
// input register(s) output register
FEATURE_MASK_SSE3 = (1u<< 0), // cpuid[eax=1] :ecx[0]
FEATURE_MASK_SSSE3 = (1u<< 9), // cpuid[eax=1] :ecx[9]
FEATURE_MASK_SSE41 = (1u<<19), // cpuid[eax=1] :ecx[19]
FEATURE_MASK_SSE42 = (1u<<20), // cpuid[eax=1] :ecx[20]
FEATURE_MASK_AVX = (1u<<28), // cpuid[eax=1] :ecx[28]
FEATURE_MASK_AVX2 = (1u<< 5), // cpuid[eax=7,ecx=0] :ebx[5]
FEATURE_MASK_FMA3 = (1u<<12), // cpuid[eax=1] :ecx[12]
FEATURE_MASK_FMA4 = (1u<<16), // cpuid[eax=0x80000001] :ecx[16]
FEATURE_MASK_AVX512F = (1u<<16), // cpuid[eax=7,ecx=0] :ebx[16]
FEATURE_MASK_AVX512DQ = (1u<<17), // cpuid[eax=7,ecx=0] :ebx[17]
FEATURE_MASK_AVX512PF = (1u<<26), // cpuid[eax=7,ecx=0] :ebx[26]
FEATURE_MASK_AVX512ER = (1u<<27), // cpuid[eax=7,ecx=0] :ebx[27]
FEATURE_MASK_AVX512CD = (1u<<28), // cpuid[eax=7,ecx=0] :ebx[28]
FEATURE_MASK_AVX512BW = (1u<<30), // cpuid[eax=7,ecx=0] :ebx[30]
FEATURE_MASK_AVX512VL = (1u<<31), // cpuid[eax=7,ecx=0] :ebx[31]
FEATURE_MASK_AVX512VNNI = (1u<<11), // cpuid[eax=7,ecx=0] :ecx[11]
FEATURE_MASK_MOVDIRI = (1u<<27), // cpuid[eax=7,ecx=0] :ecx[27]
FEATURE_MASK_MOVDIR64B = (1u<<28), // cpuid[eax=7,ecx=0] :ecx[28]
FEATURE_MASK_AVX512VP2INTERSECT = (1u<< 8), // cpuid[eax=7,ecx=0] :edx[8]
FEATURE_MASK_AVX512FP16 = (1u<<23), // cpuid[eax=7,ecx=0] :edx[23]

FEATURE_MASK_AVXVNNI = (1u<< 4), // cpuid[eax=7,ecx=1] :eax[4]
FEATURE_MASK_AVX512BF16 = (1u<< 5), // cpuid[eax=7,ecx=1] :eax[5]

FEATURE_MASK_XGETBV = (1u<<26)|
(1u<<27), // cpuid[eax=1] :ecx[27:26]
XGETBV_MASK_XMM = 0x02u, // xcr0[1]
XGETBV_MASK_YMM = 0x04u, // xcr0[2]
XGETBV_MASK_ZMM = 0xe0u, // xcr0[7:5]
};


Expand Down Expand Up @@ -707,6 +951,23 @@ uint32_t bli_cpuid_query
if ( bli_cpuid_has_features( ebx, FEATURE_MASK_AVX512CD ) ) *features |= FEATURE_AVX512CD;
if ( bli_cpuid_has_features( ebx, FEATURE_MASK_AVX512BW ) ) *features |= FEATURE_AVX512BW;
if ( bli_cpuid_has_features( ebx, FEATURE_MASK_AVX512VL ) ) *features |= FEATURE_AVX512VL;

if ( bli_cpuid_has_features( ecx, FEATURE_MASK_AVX512VNNI ) ) *features |= FEATURE_AVX512VNNI;
if ( bli_cpuid_has_features( ecx, FEATURE_MASK_MOVDIRI ) ) *features |= FEATURE_MOVDIRI;
if ( bli_cpuid_has_features( ecx, FEATURE_MASK_MOVDIR64B ) ) *features |= FEATURE_MOVDIR64B;

if ( bli_cpuid_has_features( edx, FEATURE_MASK_AVX512VP2INTERSECT ) ) *features |= FEATURE_AVX512VP2INTERSECT;
if ( bli_cpuid_has_features( edx, FEATURE_MASK_AVX512FP16 ) ) *features |= FEATURE_AVX512FP16;

// This is actually a macro that modifies the last four operands,
// hence why they are not passed by address.
// This returns extended feature flags in EAX.
// The availability of AVX512_BF16 can be found using the
// 5th feature bit of the returned value
__cpuid_count( 7, 1, eax, ebx, ecx, edx );

if ( bli_cpuid_has_features( eax, FEATURE_MASK_AVXVNNI ) ) *features |= FEATURE_AVXVNNI;
if ( bli_cpuid_has_features( eax, FEATURE_MASK_AVX512BF16 ) ) *features |= FEATURE_AVX512BF16;
}

// Check extended processor info / features bits for AMD-specific features.
Expand Down Expand Up @@ -825,8 +1086,8 @@ uint32_t bli_cpuid_query
// only if the xcr[7:5] bits are set. If they are not set, then
// clear all feature bits related to AVX-512.
if ( !bli_cpuid_has_features( eax, XGETBV_MASK_XMM |
XGETBV_MASK_YMM |
XGETBV_MASK_ZMM ) )
XGETBV_MASK_YMM |
XGETBV_MASK_ZMM ) )
{
*features &= ~( FEATURE_AVX512F |
FEATURE_AVX512DQ |
Expand All @@ -841,7 +1102,7 @@ uint32_t bli_cpuid_query
// only if the xcr[2] bit is set. If it is not set, then
// clear all feature bits related to AVX.
if ( !bli_cpuid_has_features( eax, XGETBV_MASK_XMM |
XGETBV_MASK_YMM ) )
XGETBV_MASK_YMM ) )
{
*features &= ~( FEATURE_AVX |
FEATURE_AVX2 |
Expand Down
Loading