How to check for CPU capabilities - AVX2?

[francoiste]

in AutoIt we have:

_WinAPI_IsProcessorFeaturePresent($iFeature)

this internally just calls what is provided by microsoft: https://msdn.microsoft.com/en-us/library/windows/desktop/ms724482(v=vs.85).aspx

unfortunately this is completely outdated as we can only check for features like MMX and up to a maximum of SSE2 or SSE3 - which have been introduced back in 2001 / 2004.
but nowadays there is stuff like AVX, AVX2, AVX-512 ...
for example see: https://en.wikipedia.org/wiki/Template:Multimedia_extensions

well, for CPP we have the FeatureDetector (by Mysticial): https://github.com/Mysticial/FeatureDetector
it calls __cpuid / __cpuidex from <intrin.h>.
for additional details see: https://msdn.microsoft.com/en-us/library/hskdteyh.aspx

 

has anyone tried to determine such SIMD features and related CPU capabilites with AutoIt?

Edited February 25, 2018 by francoiste

[Bilgus]

So I was kinda interested in this after reading your question

Looking through the forum I found one user who had a similar question 'Andreik' 

That is pretty cool I didn't even realize we could do assembly in AutoIt!!

I took his asm and altered it a bit to allow us to send a value to eax and get back the result of cpuid

expandcollapse popup

#include <Memory.au3>
#include <String.au3>

MsgBox(0, "", GetVendorID() & " : " & CpuId_Vendor() & @CRLF & CpuId_Processor_Brand())

Func Cpuid_Get_Leaf($iLeaf, $iSubLeaf = 0)

    Local Const $sCode32 =  "0x"     & _ ; use32
                            "55"     & _ ; push ebp
                            "89E5"   & _ ; mov ebp, esp
                            "53"     & _ ; push ebx
                            "8B4508" & _ ; mov eax, [ebp + 08] ;$iLeaf
                            "8B4D0C" & _ ; mov ecx, [epb + 12] ;$iSubLeaf
                            "31DB"   & _ ; xor ebx, ebx ; set ebx = 0
                            "31D2"   & _ ; xor edx, edx ; set edx = 0
                            "0FA2"   & _ ; cpuid
                            "8B6D10" & _ ; mov ebp, [ebp + 16] ;ptr int[4]
                            "894500" & _ ; mov [ebp + 00], eax
                            "895D04" & _ ; mov [edi + 04], ebx
                            "894D08" & _ ; mov [edi + 08], ecx
                            "89550C" & _ ; mov [edi + 12], edx
                            "5B"     & _ ; pop ebx
                            "5D"     & _ ; pop ebp
                            "C3"         ; ret

    Local Const $sCode64 =  "0x"         & _ ; use 64
                            "53"         & _ ; push rbx
                            "89C8"       & _ ; mov  eax, ecx ;$ileaf
                            "89D1"       & _ ; mov  ecx, edx ;$iSubleaf
                            "31DB"       & _ ; xor  ebx, ebx
                            "31D2"       & _ ; xor  edx, edx
                            "0FA2"       & _ ; cpuid
                            "67418900"   & _ ; mov  [r8d], eax ;ptr int[4]
                            "6741895804" & _ ; mov  [r8d + 04], ebx
                            "6741894808" & _ ; mov  [r8d + 08], ecx
                            "674189500C" & _ ; mov  [r8d + 12], edx
                            "5B"         & _ ; pop rbx
                            "C3"             ; ret


    Local Const $sCode = @AutoItX64 ? $sCode64 : $sCode32
    Local Const $iSize = BinaryLen($sCode)
    Local $aE_X[4] = [0, 0, 0, 0]
    Local $iErr

    Do
        $iErr = 1
        Local $pBuffer = _MemVirtualAlloc(0, $iSize, BitOR($MEM_COMMIT, $MEM_RESERVE), $PAGE_EXECUTE_READWRITE)
        If $pBuffer = 0 Then ExitLoop
        $iErr = 2
        DllStructSetData(DllStructCreate("BYTE[" & $iSize & "]", $pBuffer), 1, $sCode)
        If @error Then ExitLoop
        $iErr = 3
        Local $tRet = DllStructCreate("int EAX;int EBX;int ECX;int EDX;")
        If @error Then ExitLoop
        $iErr = 4
        Local $aRet = DllCallAddress("uint:cdecl", $pBuffer, "int", Int($iLeaf), "int", Int($iSubLeaf), "ptr", DllStructGetPtr($tRet))
        If @error Then ExitLoop
        $iErr = 0;Success?
    Until(True)

    _MemVirtualFree($pBuffer, $iSize, $MEM_DECOMMIT)

    ConsoleWrite($iErr <> 0 ? "Error " & $iErr & @CRLF : Hex($aRet[0], 8) & " Leaf: 0x" & Hex($iLeaf, 8) & @CRLF)

    For $i = 0 To $iErr <> 0 ? -1 : UBound($aE_X) - 1
        $aE_X[$i] = "0x" & Hex(DllStructGetData($tRet, $i + 1))
        ConsoleWrite("E" & Chr(65 + $i) & "X: " & $aE_X[$i] & @CRLF)
    Next

    Return SetError($iErr, @error, $aE_X)
EndFunc

Func CpuId_Vendor()
    $aCPUID = Cpuid_Get_Leaf(0x0)
    Return RevBinStr($aCPUID[1]) & RevBinStr($aCPUID[3]) & RevBinStr($aCPUID[2])
EndFunc

Func CpuId_Processor_Brand()
    Local $sPBS = "NOT SUPPORT"
    $aCPUID = Cpuid_Get_Leaf(0x80000000) ;need to get max extended value first
    If $aCPUID[0] < 0x80000004 Then Return $sPBS
    $aCPUID = Cpuid_Get_Leaf(0x80000002)
    $sPBS = RevBinStr($aCPUID[0]) & RevBinStr($aCPUID[1]) & RevBinStr($aCPUID[2]) & RevBinStr($aCPUID[3])
    $aCPUID = Cpuid_Get_Leaf(0x80000003)
    $sPBS &= RevBinStr($aCPUID[0]) & RevBinStr($aCPUID[1]) & RevBinStr($aCPUID[2]) & RevBinStr($aCPUID[3])
    $aCPUID = Cpuid_Get_Leaf(0x80000004)
    $sPBS &= RevBinStr($aCPUID[0]) & RevBinStr($aCPUID[1]) & RevBinStr($aCPUID[2]) & RevBinStr($aCPUID[3])
    Return StringStripWS($sPBS, 7)
EndFunc

Func RevBinStr($val)
    Local $rev
    For $n = BinaryLen($val) To 1 Step -1
        $rev &= Hex(BinaryMid($val, $n, 1))
    Next
    Return BinaryToString("0x" & $rev)
EndFunc

Func Get_BitGroup_Dword($iDword, $iLsb, $iMsb) 
    ;EX - Get_BitGroup_Dword(0xFEDCBA98, 0, 3) => 0x8
    ;EX - Get_BitGroup_Dword(0xFEDCBA98, 3, 3) => 0x1
    ;EX - Get_BitGroup_Dword(0xFEDCBA98, 28, 31) => 0xF
    ;EX - Get_BitGroup_Dword(0xFEDCBA98, 24, 27) => 0xE
    Local $iVal1 = BitShift($iDword, $iLsb) ;>>
    Local Const $iMask = 0xFFFFFFFF
    Local $iVal2 = BitNOT(BitShift($iMask, ($iLsb-$iMsb-1))) ;~<<
    Return BitAND($iVal1, $iVal2)
EndFunc

Func GetVendorID() ;Andreik
    if @AutoItX64 then return "32Bit ONLY"

    $Code = "0x"            & _    ; use32
            "55"            & _    ; push ebp
            "89E5"          & _    ; mov ebp, esp
            "60"            & _    ; pushad
            "B800000000"    & _    ; mov eax,0
            "0FA2"          & _    ; cpuid
            "8B7D08"        & _    ; mov edi, [ebp + 08]
            "891F"          & _    ; mov [edi], ebx
            "895704"        & _    ; mov [edi + 4], edx
            "894F08"        & _    ; mov [edi + 8], ecx
            "B000"          & _    ; mov al, 0
            "88470C"        & _    ; mov [edi + 12], al
            "61"            & _    ; popad
            "5D"            & _    ; pop ebp
            "C20400"               ; ret 4
    $iSize = BinaryLen($Code)
    $pBuffer = _MemVirtualAlloc(0,$iSize,$MEM_COMMIT,$PAGE_EXECUTE_READWRITE)
    $tBuffer = DllStructCreate("byte Code[" & $iSize & "]",$pBuffer)
    DllStructSetData($tBuffer,"Code",$Code)
    $aRet = DllCallAddress("int",$pBuffer,"str","")
    _MemVirtualFree($pBuffer,$iSize,$MEM_DECOMMIT)
    Return $aRet[1]
EndFunc

So you can see how to use it I matched his Version ID call for an example

but you can also call different Leaf IDs and get the appropriate returns to parse what you desire out of eax, ebx, ecx, edx;

Do note when: $iLeaf = 0x0 highest supported ID = EAX and Version ID = EBX, EDX, ECX

See: https://en.wikipedia.org/wiki/CPUID for a list of leaf IDs and the return values you need

 

for instance 0x80000000 would return the highest supported Extended Leaf ID

0x80000002 then 0x80000003 then 0x80000004 would get you the Processor Brand String

Edited February 28, 2018 by Bilgus
Realized a need to zero ECX register, added Functionality, 64 Bit Thanks LARSJ!

[Bilgus]

I expanded the example a bit to add Processor brand and to get the endianess right;

apparently the bytes need reversed for autoit to display them properly..

I originally was passing arrays of bytes to the assembly code function to get Autoit to display the strings correctly.

but I realized as I was looking through the returned values that the endian was reversed to what was shown on the Wiki page.

Once I fixed that the strings were then reversed so I added a RevBinStr function to handle it

In order to get the other values you'll need to pass your EAX value ($iLeaf) and check for set bits

BitAND($aCPUID[?],1) or BitAND($aCPUID[?],2) .... BitAND($aCPUID[?],32)

 

[Bilgus]

francoiste I see you edited your question a bit but what I have above should do what you want 

example for EAX = 7 would be something like this

Func CpuId_EFF()
    ;$aCPUID;; [0] = EAX, [1] = EBX, [2] = ECX, [3] = EDX
    Local $sRet = "NOT SUPPORT"
    $aCPUID = Cpuid_Get_Leaf(0x0) ;need to get max extended value first
    If $aCPUID[0] < 0x7 Then Return $sRet
    $aCPUID = Cpuid_Get_Leaf(0x7) ;This returns extended feature flags in EBX, ECX, and EDX.
    ;EBX------------------------------------------------------
    if BitAND($aCPUID[1], 3) <> 0 then $sRet &= "sgx "
    ;..............................................
    if BitAND($aCPUID[1], 31) <> 0 then $sRet &= "avx512bw "
    if BitAND($aCPUID[1], 32) <> 0 then $sRet &= "avx512vl "
    ;ECX-------------------------------------------------------
    if BitAND($aCPUID[2], 2) <> 0 then $sRet &= "avx512vbmi "
    ;..............................................
    if BitAND($aCPUID[2], 7) <> 0 then $sRet &= "avx512vbmi2 "
    ;..............................................
    if BitAND($aCPUID[2], 11) <> 0 then $sRet &= "avx512vnni "
    ;EDX-------------------------------------------------------
    if BitAND($aCPUID[3], 3) <> 0 then $sRet &= "avx512_4vnniw "
    if BitAND($aCPUID[3], 4) <> 0 then $sRet &= "avx512_4fmaps "
    if BitAND($aCPUID[3], 27) <> 0 then $sRet &= "spec_ctrl "
    Return $sRet
EndFunc

Now this is just an example I think I'd probably make an array of strings or maybe an indexed string of some sort to clean it up a bit but you get the idea

Note: the bit values are all one higher than the wiki page since we are supplying the actual value of the number at that bit rather than the bit position

[LarsJ]

The easiest way to write assembler code in AutoIt is to use flat assembler because there is a fasm.dll that contains all the functions you need.

In this post you can find a short instruction and a small but complete UDF to use the functions in fasm.dll.

[Bilgus]

LarsJ very nice indeed..

[Bilgus]

Reading over a more in-depth reference it appears with EAX = 7 and ECX =0 EAX recieves the max sub level for the command

I have expanded the function yet again with $iSubLeaf to allow this although I'm not sure how Important it is being I don't have any thing new

enough to test it on