Other-Application-Targeted-ZMM

Other-Application-Targeted-ZMM#

_mm512_clmulepi64_epi128#

Tech:

Other

Category:

Application-Targeted

Header:

immintrin.h

Searchable:

Other-Application-Targeted-ZMM

Register:

ZMM 512 bit

Return Type:

__m512i

Param Types:

__m512i b, __m512i c, const int Imm8

Param ETypes:

M128 b, M128 c, IMM Imm8

__m512i _mm512_clmulepi64_epi128(__m512i b, __m512i c,
                                 const int Imm8)

Intel Description

Carry-less multiplication of one quadword of

‘b’ by one quadword of ‘c’, stores the 128-bit result in ‘dst’. The immediate ‘Imm8’ is used to determine which quadwords of ‘b’ and ‘c’ should be used.

Intel Implementation Psudeo-Code

DEFINE PCLMUL128(X,Y) {
        FOR i := 0 to 63
                TMP[i] := X[ 0 ] and Y[ i ]
                FOR j := 1 to i
                        TMP[i] := TMP[i] xor (X[ j ] and Y[ i - j ])
                ENDFOR
                DEST[ i ] := TMP[ i ]
        ENDFOR
        FOR i := 64 to 126
                TMP[i] := 0
                FOR j := i - 63 to 63
                        TMP[i] := TMP[i] xor (X[ j ] and Y[ i - j ])
                ENDFOR
                DEST[ i ] := TMP[ i ]
        ENDFOR
        DEST[127] := 0
        RETURN DEST // 128b vector
}
FOR i := 0 to 3
        IF Imm8[0] == 0
                TEMP1 := b.m128[i].qword[0]
        ELSE
                TEMP1 := b.m128[i].qword[1]
        FI
        IF Imm8[4] == 0
                TEMP2 := c.m128[i].qword[0]
        ELSE
                TEMP2 := c.m128[i].qword[1]
        FI
        dst.m128[i] := PCLMUL128(TEMP1, TEMP2)
ENDFOR
dst[MAX:512] := 0
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