# VPDPBUSD — Multiply and Add Unsigned and Signed Bytes

Opcode/Instruction | Op/En | 64/32 bit Mode Support | CPUID Feature Flag | Description
--- | --- | --- | --- | ---
VEX.128.66.0F38.W0 50 /r VPDPBUSD xmm1, xmm2, xmm3/m128 | A | V/V | AVX-VNNI | Multiply groups of 4 pairs of signed bytes in xmm3/m128 with corresponding unsigned bytes of xmm2, summing those products and adding them to doubleword result in xmm1.
VEX.256.66.0F38.W0 50 /r VPDPBUSD ymm1, ymm2, ymm3/m256 | A | V/V | AVX-VNNI | Multiply groups of 4 pairs of signed bytes in ymm3/m256 with corresponding unsigned bytes of ymm2, summing those products and adding them to doubleword result in ymm1.
EVEX.128.66.0F38.W0 50 /r VPDPBUSD xmm1{k1}{z}, xmm2, xmm3/m128/m32bcst | B | V/V | AVX512_VNNI AVX512VL | Multiply groups of 4 pairs of signed bytes in xmm3/m128/m32bcst with corresponding unsigned bytes of xmm2, summing those products and adding them to doubleword result in xmm1 under writemask k1.
EVEX.256.66.0F38.W0 50 /r VPDPBUSD ymm1{k1}{z}, ymm2, ymm3/m256/m32bcst | B | V/V | AVX512_VNNI AVX512VL | Multiply groups of 4 pairs of signed bytes in ymm3/m256/m32bcst with corresponding unsigned bytes of ymm2, summing those products and adding them to doubleword result in ymm1 under writemask k1.
EVEX.512.66.0F38.W0 50 /r VPDPBUSD zmm1{k1}{z}, zmm2, zmm3/m512/m32bcst | B | V/V | AVX512_VNNI | Multiply groups of 4 pairs of signed bytes in zmm3/m512/m32bcst with corresponding unsigned bytes of zmm2, summing those products and adding them to doubleword result in zmm1 under writemask k1.

## Instruction Operand Encoding ¶

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

### Description ¶

Multiplies the individual unsigned bytes of the first source operand by the corresponding signed bytes of the second source operand, producing intermediate signed word results. The word results are then summed and accumulated in the destination dword element size operand.

This instruction supports memory fault suppression.

### Operation ¶

#### VPDPBUSD dest, src1, src2 (VEX encoded versions) ¶

    VL=(128, 256)
    KL=VL/32
    ORIGDEST := DEST
    FOR i := 0 TO KL-1:
        // Extending to 16b
        // src1extend := ZERO_EXTEND
        // src2extend := SIGN_EXTEND
        p1word := src1extend(SRC1.byte[4*i+0]) * src2extend(SRC2.byte[4*i+0])
        p2word := src1extend(SRC1.byte[4*i+1]) * src2extend(SRC2.byte[4*i+1])
        p3word := src1extend(SRC1.byte[4*i+2]) * src2extend(SRC2.byte[4*i+2])
        p4word := src1extend(SRC1.byte[4*i+3]) * src2extend(SRC2.byte[4*i+3])
        DEST.dword[i] := ORIGDEST.dword[i] + p1word + p2word + p3word + p4word
    DEST[MAX_VL-1:VL] := 0

#### VPDPBUSD dest, src1, src2 (EVEX encoded versions) ¶

    (KL,VL)=(4,128), (8,256), (16,512)
    ORIGDEST := DEST
    FOR i := 0 TO KL-1:
        IF k1[i] or *no writemask*:
            // Byte elements of SRC1 are zero-extended to 16b and
            // byte elements of SRC2 are sign extended to 16b before multiplication.
            IF SRC2 is memory and EVEX.b == 1:
                t := SRC2.dword[0]
            ELSE:
                t := SRC2.dword[i]
            p1word := ZERO_EXTEND(SRC1.byte[4*i]) * SIGN_EXTEND(t.byte[0])
            p2word := ZERO_EXTEND(SRC1.byte[4*i+1]) * SIGN_EXTEND(t.byte[1])
            p3word := ZERO_EXTEND(SRC1.byte[4*i+2]) * SIGN_EXTEND(t.byte[2])
            p4word := ZERO_EXTEND(SRC1.byte[4*i+3]) * SIGN_EXTEND(t.byte[3])
            DEST.dword[i] := ORIGDEST.dword[i] + p1word + p2word + p3word + p4word
        ELSE IF *zeroing*:
            DEST.dword[i] := 0
        ELSE: // Merge masking, dest element unchanged
            DEST.dword[i] := ORIGDEST.dword[i]
    DEST[MAX_VL-1:VL] := 0

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

    VPDPBUSD __m128i _mm_dpbusd_avx_epi32(__m128i, __m128i, __m128i);

    VPDPBUSD __m128i _mm_dpbusd_epi32(__m128i, __m128i, __m128i);

    VPDPBUSD __m128i _mm_mask_dpbusd_epi32(__m128i, __mmask8, __m128i, __m128i);

    VPDPBUSD __m128i _mm_maskz_dpbusd_epi32(__mmask8, __m128i, __m128i, __m128i);

    VPDPBUSD __m256i _mm256_dpbusd_avx_epi32(__m256i, __m256i, __m256i);

    VPDPBUSD __m256i _mm256_dpbusd_epi32(__m256i, __m256i, __m256i);

    VPDPBUSD __m256i _mm256_mask_dpbusd_epi32(__m256i, __mmask8, __m256i, __m256i);

    VPDPBUSD __m256i _mm256_maskz_dpbusd_epi32(__mmask8, __m256i, __m256i, __m256i);

    VPDPBUSD __m512i _mm512_dpbusd_epi32(__m512i, __m512i, __m512i);

    VPDPBUSD __m512i _mm512_mask_dpbusd_epi32(__m512i, __mmask16, __m512i, __m512i);

    VPDPBUSD __m512i _mm512_maskz_dpbusd_epi32(__mmask16, __m512i, __m512i, __m512i);

### 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.”