# PMULLD/PMULLQ — Multiply Packed Integers and Store Low Result

Opcode/Instruction | Op/En | 64/32 bit Mode Support | CPUID Feature Flag | Description
--- | --- | --- | --- | ---
66 0F 38 40 /r PMULLD xmm1, xmm2/m128 | A | V/V | SSE4_1 | Multiply the packed dword signed integers in xmm1 and xmm2/m128 and store the low 32 bits of each product in xmm1.
VEX.128.66.0F38.WIG 40 /r VPMULLD xmm1, xmm2, xmm3/m128 | B | V/V | AVX | Multiply the packed dword signed integers in xmm2 and xmm3/m128 and store the low 32 bits of each product in xmm1.
VEX.256.66.0F38.WIG 40 /r VPMULLD ymm1, ymm2, ymm3/m256 | B | V/V | AVX2 | Multiply the packed dword signed integers in ymm2 and ymm3/m256 and store the low 32 bits of each product in ymm1.
EVEX.128.66.0F38.W0 40 /r VPMULLD xmm1 {k1}{z}, xmm2, xmm3/m128/m32bcst | C | V/V | AVX512VL AVX512F | Multiply the packed dword signed integers in xmm2 and xmm3/m128/m32bcst and store the low 32 bits of each product in xmm1 under writemask k1.
EVEX.256.66.0F38.W0 40 /r VPMULLD ymm1 {k1}{z}, ymm2, ymm3/m256/m32bcst | C | V/V | AVX512VL AVX512F | Multiply the packed dword signed integers in ymm2 and ymm3/m256/m32bcst and store the low 32 bits of each product in ymm1 under writemask k1.
EVEX.512.66.0F38.W0 40 /r VPMULLD zmm1 {k1}{z}, zmm2, zmm3/m512/m32bcst | C | V/V | AVX512F | Multiply the packed dword signed integers in zmm2 and zmm3/m512/m32bcst and store the low 32 bits of each product in zmm1 under writemask k1.
EVEX.128.66.0F38.W1 40 /r VPMULLQ xmm1 {k1}{z}, xmm2, xmm3/m128/m64bcst | C | V/V | AVX512VL AVX512DQ | Multiply the packed qword signed integers in xmm2 and xmm3/m128/m64bcst and store the low 64 bits of each product in xmm1 under writemask k1.
EVEX.256.66.0F38.W1 40 /r VPMULLQ ymm1 {k1}{z}, ymm2, ymm3/m256/m64bcst | C | V/V | AVX512VLA VX512DQ | Multiply the packed qword signed integers in ymm2 and ymm3/m256/m64bcst and store the low 64 bits of each product in ymm1 under writemask k1.
EVEX.512.66.0F38.W1 40 /r VPMULLQ zmm1 {k1}{z}, zmm2, zmm3/m512/m64bcst | C | V/V | AVX512DQ | Multiply the packed qword signed integers in zmm2 and zmm3/m512/m64bcst and store the low 64 bits of each product in zmm1 under writemask k1.

## Instruction Operand Encoding ¶

Op/En | Tuple Type | Operand 1 | Operand 2 | Operand 3 | Operand 4
--- | --- | --- | --- | --- | ---
A | N/A | ModRM:reg (r, w) | ModRM:r/m (r) | N/A | N/A
B | N/A | ModRM:reg (w) | VEX.vvvv (r) | ModRM:r/m (r) | N/A
C | Full | ModRM:reg (w) | EVEX.vvvv (r) | ModRM:r/m (r) | N/A

## Description ¶

Performs a SIMD signed multiply of the packed signed dword/qword integers from each element of the first source operand with the corresponding element in the second source operand. The low 32/64 bits of each 64/128-bit intermediate results are stored to the destination operand.

128-bit Legacy SSE version: The first source and destination operands are XMM registers. The second source operand is an XMM register or a 128-bit memory location. Bits (MAXVL-1:128) of the corresponding ZMM destination register remain unchanged.

VEX.128 encoded version: The first source and destination operands are XMM registers. The second source operand is an XMM register or a 128-bit memory location. Bits (MAXVL-1:128) of the corresponding ZMM register are zeroed.

VEX.256 encoded version: The first source operand is a YMM register; The second source operand is a YMM register or 256-bit memory location. Bits (MAXVL-1:256) of the corresponding destination ZMM register are zeroed.

EVEX encoded versions: The first source operand is a ZMM/YMM/XMM register. The second source operand is a ZMM/YMM/XMM register, a 512/256/128-bit memory location or a 512/256/128-bit vector broadcasted from a 32/64-bit memory location. The destination operand is conditionally updated based on writemask k1.

## Operation ¶

### VPMULLQ (EVEX Encoded Versions) ¶

    (KL, VL) = (2, 128), (4, 256), (8, 512)
    FOR j := 0 TO KL-1
        i := j * 64
        IF k1[j] OR *no writemask* THEN
                IF (EVEX.b == 1) AND (SRC2 *is memory*)
                    THEN Temp[127:0] := SRC1[i+63:i] * SRC2[63:0]
                    ELSE Temp[127:0] := SRC1[i+63:i] * SRC2[i+63:i]
                FI;
                DEST[i+63:i] := Temp[63:0]
            ELSE
                IF *merging-masking* ; merging-masking
                    THEN *DEST[i+63:i] remains unchanged*
                    ELSE ; zeroing-masking
                        DEST[i+63:i] := 0
                FI
        FI;
    ENDFOR
    DEST[MAXVL-1:VL] := 0

### VPMULLD (EVEX Encoded Versions) ¶

    (KL, VL) = (4, 128), (8, 256), (16, 512)
    FOR j := 0 TO KL-1
        i := j * 32
        IF k1[j] OR *no writemask* THEN
                IF (EVEX.b = 1) AND (SRC2 *is memory*)
                    THEN Temp[63:0] := SRC1[i+31:i] * SRC2[31:0]
                    ELSE Temp[63:0] := SRC1[i+31:i] * SRC2[i+31:i]
                FI;
                DEST[i+31:i] := Temp[31:0]
            ELSE
                IF *merging-masking* ; merging-masking
                    *DEST[i+31:i] remains unchanged*
                    ELSE
                            ; zeroing-masking
                        DEST[i+31:i] := 0
                FI
        FI;
    ENDFOR
    DEST[MAXVL-1:VL] := 0

### VPMULLD (VEX.256 Encoded Version) ¶

    Temp0[63:0] := SRC1[31:0] * SRC2[31:0]
    Temp1[63:0] := SRC1[63:32] * SRC2[63:32]
    Temp2[63:0] := SRC1[95:64] * SRC2[95:64]
    Temp3[63:0] := SRC1[127:96] * SRC2[127:96]
    Temp4[63:0] := SRC1[159:128] * SRC2[159:128]
    Temp5[63:0] := SRC1[191:160] * SRC2[191:160]
    Temp6[63:0] := SRC1[223:192] * SRC2[223:192]
    Temp7[63:0] := SRC1[255:224] * SRC2[255:224]
    DEST[31:0] := Temp0[31:0]
    DEST[63:32] := Temp1[31:0]
    DEST[95:64] := Temp2[31:0]
    DEST[127:96] := Temp3[31:0]
    DEST[159:128] := Temp4[31:0]
    DEST[191:160] := Temp5[31:0]
    DEST[223:192] := Temp6[31:0]
    DEST[255:224] := Temp7[31:0]
    DEST[MAXVL-1:256] := 0

### VPMULLD (VEX.128 Encoded Version) ¶

    Temp0[63:0] := SRC1[31:0] * SRC2[31:0]
    Temp1[63:0] := SRC1[63:32] * SRC2[63:32]
    Temp2[63:0] := SRC1[95:64] * SRC2[95:64]
    Temp3[63:0] := SRC1[127:96] * SRC2[127:96]
    DEST[31:0] := Temp0[31:0]
    DEST[63:32] := Temp1[31:0]
    DEST[95:64] := Temp2[31:0]
    DEST[127:96] := Temp3[31:0]
    DEST[MAXVL-1:128] := 0

### PMULLD (128-bit Legacy SSE Version) ¶

    Temp0[63:0] := DEST[31:0] * SRC[31:0]
    Temp1[63:0] := DEST[63:32] * SRC[63:32]
    Temp2[63:0] := DEST[95:64] * SRC[95:64]
    Temp3[63:0] := DEST[127:96] * SRC[127:96]
    DEST[31:0] := Temp0[31:0]
    DEST[63:32] := Temp1[31:0]
    DEST[95:64] := Temp2[31:0]
    DEST[127:96] := Temp3[31:0]
    DEST[MAXVL-1:128] (Unmodified)

## Intel C/C++ Compiler Intrinsic Equivalent ¶

    VPMULLD __m512i _mm512_mullo_epi32(__m512i a, __m512i b);

    VPMULLD __m512i _mm512_mask_mullo_epi32(__m512i s, __mmask16 k, __m512i a, __m512i b);

    VPMULLD __m512i _mm512_maskz_mullo_epi32( __mmask16 k, __m512i a, __m512i b);

    VPMULLD __m256i _mm256_mask_mullo_epi32(__m256i s, __mmask8 k, __m256i a, __m256i b);

    VPMULLD __m256i _mm256_maskz_mullo_epi32( __mmask8 k, __m256i a, __m256i b);

    VPMULLD __m128i _mm_mask_mullo_epi32(__m128i s, __mmask8 k, __m128i a, __m128i b);

    VPMULLD __m128i _mm_maskz_mullo_epi32( __mmask8 k, __m128i a, __m128i b);

    VPMULLD __m256i _mm256_mullo_epi32(__m256i a, __m256i b);

    PMULLD __m128i _mm_mullo_epi32(__m128i a, __m128i b);

    VPMULLQ __m512i _mm512_mullo_epi64(__m512i a, __m512i b);

    VPMULLQ __m512i _mm512_mask_mullo_epi64(__m512i s, __mmask8 k, __m512i a, __m512i b);

    VPMULLQ __m512i _mm512_maskz_mullo_epi64( __mmask8 k, __m512i a, __m512i b);

    VPMULLQ __m256i _mm256_mullo_epi64(__m256i a, __m256i b);

    VPMULLQ __m256i _mm256_mask_mullo_epi64(__m256i s, __mmask8 k, __m256i a, __m256i b);

    VPMULLQ __m256i _mm256_maskz_mullo_epi64( __mmask8 k, __m256i a, __m256i b);

    VPMULLQ __m128i _mm_mullo_epi64(__m128i a, __m128i b);

    VPMULLQ __m128i _mm_mask_mullo_epi64(__m128i s, __mmask8 k, __m128i a, __m128i b);

    VPMULLQ __m128i _mm_maskz_mullo_epi64( __mmask8 k, __m128i a, __m128i b);

## SIMD Floating-Point Exceptions ¶

None.

## Other Exceptions ¶

Non-EVEX-encoded instruction, see Table 2-21, “Type 4 Class Exception Conditions.”

EVEX-encoded instruction, see Table 2-49, “Type E4 Class Exception Conditions.”