# VPDPBUSDS — Multiply and Add Unsigned and Signed Bytes With Saturation

Opcode/Instruction | Op/En | 64/32 bit Mode Support | CPUID Feature Flag | Description
--- | --- | --- | --- | ---
VEX.128.66.0F38.W0 51 /r VPDPBUSDS xmm1, xmm2, xmm3/m128 | A | V/V | AVX-VNNI | Multiply groups of 4 pairs signed bytes in xmm3/m128 with corresponding unsigned bytes of xmm2, summing those products and adding them to doubleword result, with signed saturation in xmm1.
VEX.256.66.0F38.W0 51 /r VPDPBUSDS ymm1, ymm2, ymm3/m256 | A | V/V | AVX-VNNI | Multiply groups of 4 pairs signed bytes in ymm3/m256 with corresponding unsigned bytes of ymm2, summing those products and adding them to doubleword result, with signed saturation in ymm1.
EVEX.128.66.0F38.W0 51 /r VPDPBUSDS xmm1{k1}{z}, xmm2, xmm3/m128/m32bcst | B | V/V | AVX512_VNNI AVX512VL | Multiply groups of 4 pairs signed bytes in xmm3/m128/m32bcst with corresponding unsigned bytes of xmm2, summing those products and adding them to doubleword result, with signed saturation in xmm1, under writemask k1.
EVEX.256.66.0F38.W0 51 /r VPDPBUSDS ymm1{k1}{z}, ymm2, ymm3/m256/m32bcst | B | V/V | AVX512_VNNI AVX512VL | Multiply groups of 4 pairs signed bytes in ymm3/m256/m32bcst with corresponding unsigned bytes of ymm2, summing those products and adding them to doubleword result, with signed saturation in ymm1, under writemask k1.
EVEX.512.66.0F38.W0 51 /r VPDPBUSDS zmm1{k1}{z}, zmm2, zmm3/m512/m32bcst | B | V/V | AVX512_VNNI | Multiply groups of 4 pairs signed bytes in zmm3/m512/m32bcst with corresponding unsigned bytes of zmm2, summing those products and adding them to doubleword result, with signed saturation 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. If the intermediate sum overflows a 32b signed number the result is saturated to either 0x7FFF_FFFF for positive numbers of 0x8000_0000 for negative numbers.

This instruction supports memory fault suppression.

### Operation ¶

#### VPDPBUSDS 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] := SIGNED_DWORD_SATURATE(ORIGDEST.dword[i] + p1word + p2word + p3word + p4word)
    DEST[MAX_VL-1:VL] := 0

#### VPDPBUSDS 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] := SIGNED_DWORD_SATURATE(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 ¶

    VPDPBUSDS __m128i _mm_dpbusds_avx_epi32(__m128i, __m128i, __m128i);

    VPDPBUSDS __m128i _mm_dpbusds_epi32(__m128i, __m128i, __m128i);

    VPDPBUSDS __m128i _mm_mask_dpbusds_epi32(__m128i, __mmask8, __m128i, __m128i);

    VPDPBUSDS __m128i _mm_maskz_dpbusds_epi32(__mmask8, __m128i, __m128i, __m128i);

    VPDPBUSDS __m256i _mm256_dpbusds_avx_epi32(__m256i, __m256i, __m256i);

    VPDPBUSDS __m256i _mm256_dpbusds_epi32(__m256i, __m256i, __m256i);

    VPDPBUSDS __m256i _mm256_mask_dpbusds_epi32(__m256i, __mmask8, __m256i, __m256i);

    VPDPBUSDS __m256i _mm256_maskz_dpbusds_epi32(__mmask8, __m256i, __m256i, __m256i);

    VPDPBUSDS __m512i _mm512_dpbusds_epi32(__m512i, __m512i, __m512i);

    VPDPBUSDS __m512i _mm512_mask_dpbusds_epi32(__m512i, __mmask16, __m512i, __m512i);

    VPDPBUSDS __m512i _mm512_maskz_dpbusds_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.”