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VPMOVWB/VPMOVSWB/VPMOVUSWB—Down Convert Word to Byte

Opcode/Instruction Op /En 64/32 bit Mode Support CPUID Feature Flag Description

EVEX.128.F3.0F38.W0 30 /r

VPMOVWB xmm1/m64 {k1}{z}, xmm2

 HVM V/V

AVX512VL

AVX512BW

 Converts 8 packed word integers from xmm2 into 8 packed bytes in xmm1/m64 with truncation under writemask k1.

EVEX.128.F3.0F38.W0 20 /r

VPMOVSWB xmm1/m64 {k1}{z}, xmm2

 HVM V/V

AVX512VL

AVX512BW

 Converts 8 packed signed word integers from xmm2 into 8 packed signed bytes in xmm1/m64 using signed saturation under writemask k1.

EVEX.128.F3.0F38.W0 10 /r

VPMOVUSWB xmm1/m64 {k1}{z}, xmm2

 HVM V/V

AVX512VL

AVX512BW

 Converts 8 packed unsigned word integers from xmm2 into 8 packed unsigned bytes in 8mm1/m64 using unsigned saturation under writemask k1.

EVEX.256.F3.0F38.W0 30 /r

VPMOVWB xmm1/m128 {k1}{z}, ymm2

 HVM V/V

AVX512VL

AVX512BW

 Converts 16 packed word integers from ymm2 into 16 packed bytes in xmm1/m128 with truncation under writemask k1.

EVEX.256.F3.0F38.W0 20 /r

VPMOVSWB xmm1/m128 {k1}{z}, ymm2

 HVM V/V

AVX512VL

AVX512BW

 Converts 16 packed signed word integers from ymm2 into 16 packed signed bytes in xmm1/m128 using signed saturation under writemask k1.

EVEX.256.F3.0F38.W0 10 /r

VPMOVUSWB xmm1/m128 {k1}{z}, ymm2

 HVM V/V

AVX512VL

AVX512BW

 Converts 16 packed unsigned word integers from ymm2 into 16 packed unsigned bytes in xmm1/m128 using unsigned saturation under writemask k1.

EVEX.512.F3.0F38.W0 30 /r

VPMOVWB ymm1/m256 {k1}{z}, zmm2

 HVM V/V AVX512BW Converts 32 packed word integers from zmm2 into 32 packed bytes in ymm1/m256 with truncation under writemask k1.

EVEX.512.F3.0F38.W0 20 /r

VPMOVSWB ymm1/m256 {k1}{z}, zmm2

 HVM V/V AVX512BW Converts 32 packed signed word integers from zmm2 into 32 packed signed bytes in ymm1/m256 using signed saturation under writemask k1.

EVEX.512.F3.0F38.W0 10 /r

VPMOVUSWB ymm1/m256 {k1}{z}, zmm2

 HVM V/V AVX512BW Converts 32 packed unsigned word integers from zmm2 into 32 packed unsigned bytes in ymm1/m256 using unsigned saturation under writemask k1.

Instruction Operand Encoding

Op/En Operand 1 Operand 2 Operand 3 Operand 4
HVM ModRM:r/m (w) ModRM:reg (r) NA NA

Description

VPMOVWB down converts 16-bit integers into packed bytes using truncation. VPMOVSWB converts signed 16-bit integers into packed signed bytes using signed saturation. VPMOVUSWB convert unsigned word values into unsigned byte values using unsigned saturation.

The source operand is a ZMM/YMM/XMM register. The destination operand is a YMM/XMM/XMM register or a 256/128/64-bit memory location.

Down-converted byte elements are written to the destination operand (the first operand) from the least-significant byte. Byte elements of the destination operand are updated according to the writemask. Bits (MAX_VL-1:256/128/64) of the register destination are zeroed.

Note: EVEX.vvvv is reserved and must be 1111b otherwise instructions will #UD.

Operation


VPMOVWB instruction (EVEX encoded versions) when dest is a register

(KL, VL) = (8, 128), (16, 256), (32, 512)
FOR j (cid:197) 0 TO Kl-1
    i (cid:197) j * 8
    m (cid:197) j * 16
    IF k1[j] OR *no writemask*
        THEN DEST[i+7:i] (cid:197) TruncateWordToByte (SRC[m+15:m])
        ELSE
        IF *merging-masking*
            ; merging-masking
            THEN *DEST[i+7:i] remains unchanged*
            ELSE *zeroing-masking*
            ; zeroing-masking
            DEST[i+7:i] = 0
        FI
    FI;
ENDFOR
DEST[MAX_VL-1:VL/2] (cid:197) 0;


VPMOVWB instruction (EVEX encoded versions) when dest is memory

(KL, VL) = (8, 128), (16, 256), (32, 512)
FOR j (cid:197) 0 TO Kl-1
    i (cid:197) j * 8
    m (cid:197) j * 16
    IF k1[j] OR *no writemask*
        THEN DEST[i+7:i] (cid:197) TruncateWordToByte (SRC[m+15:m])
        ELSE
        *DEST[i+7:i] remains unchanged*
        ; merging-masking
    FI;
ENDFOR


VPMOVSWB instruction (EVEX encoded versions) when dest is a register

(KL, VL) = (8, 128), (16, 256), (32, 512)
FOR j (cid:197) 0 TO Kl-1
    i (cid:197) j * 8
    m (cid:197) j * 16
    IF k1[j] OR *no writemask*
        THEN DEST[i+7:i] (cid:197) SaturateSignedWordToByte (SRC[m+15:m])
        ELSE
        IF *merging-masking*
            ; merging-masking
            THEN *DEST[i+7:i] remains unchanged*
            ELSE *zeroing-masking*
            ; zeroing-masking
            DEST[i+7:i] = 0
        FI
    FI;
ENDFOR
DEST[MAX_VL-1:VL/2] (cid:197) 0;


VPMOVSWB instruction (EVEX encoded versions) when dest is memory

(KL, VL) = (8, 128), (16, 256), (32, 512)
FOR j (cid:197) 0 TO Kl-1
    i (cid:197) j * 8
    m (cid:197) j * 16
    IF k1[j] OR *no writemask*
        THEN DEST[i+7:i] (cid:197) SaturateSignedWordToByte (SRC[m+15:m])
        ELSE
        *DEST[i+7:i] remains unchanged*
        ; merging-masking
    FI;
ENDFOR


VPMOVUSWB instruction (EVEX encoded versions) when dest is a register

(KL, VL) = (8, 128), (16, 256), (32, 512)
FOR j (cid:197) 0 TO Kl-1
    i (cid:197) j * 8
    m (cid:197) j * 16
    IF k1[j] OR *no writemask*
        THEN DEST[i+7:i] (cid:197) SaturateUnsignedWordToByte (SRC[m+15:m])
        ELSE
        IF *merging-masking*
            ; merging-masking
            THEN *DEST[i+7:i] remains unchanged*
            ELSE *zeroing-masking*
            ; zeroing-masking
            DEST[i+7:i] = 0
        FI
    FI;
ENDFOR
DEST[MAX_VL-1:VL/2] (cid:197) 0;


VPMOVUSWB instruction (EVEX encoded versions) when dest is memory

(KL, VL) = (8, 128), (16, 256), (32, 512)
FOR j (cid:197) 0 TO Kl-1
    i (cid:197) j * 8
    m (cid:197) j * 16
    IF k1[j] OR *no writemask*
        THEN DEST[i+7:i] (cid:197) SaturateUnsignedWordToByte (SRC[m+15:m])
        ELSE
        *DEST[i+7:i] remains unchanged*
        ; merging-masking
    FI;
ENDFOR



Intel C/C++ Compiler Intrinsic Equivalent


VPMOVUSWB __m256i _mm512_cvtusepi16_epi8(__m512i a);
VPMOVUSWB __m256i _mm512_mask_cvtusepi16_epi8(__m256i a, __mmask32 k, __m512i b);
VPMOVUSWB __m256i _mm512_maskz_cvtusepi16_epi8( __mmask32 k, __m512i b);
VPMOVUSWB void _mm512_mask_cvtusepi16_storeu_epi8(void * , __mmask32 k, __m512i b);
VPMOVSWB __m256i _mm512_cvtsepi16_epi8(__m512i a);
VPMOVSWB __m256i _mm512_mask_cvtsepi16_epi8(__m256i a, __mmask32 k, __m512i b);
VPMOVSWB __m256i _mm512_maskz_cvtsepi16_epi8( __mmask32 k, __m512i b);
VPMOVSWB void _mm512_mask_cvtsepi16_storeu_epi8(void * , __mmask32 k, __m512i b);
VPMOVWB __m256i _mm512_cvtepi16_epi8(__m512i a);
VPMOVWB __m256i _mm512_mask_cvtepi16_epi8(__m256i a, __mmask32 k, __m512i b);
VPMOVWB __m256i _mm512_maskz_cvtepi16_epi8( __mmask32 k, __m512i b);
VPMOVWB void _mm512_mask_cvtepi16_storeu_epi8(void * , __mmask32 k, __m512i b);
VPMOVUSWB __m128i _mm256_cvtusepi16_epi8(__m256i a);
VPMOVUSWB __m128i _mm256_mask_cvtusepi16_epi8(__m128i a, __mmask16 k, __m256i b);
VPMOVUSWB __m128i _mm256_maskz_cvtusepi16_epi8( __mmask16 k, __m256i b);
VPMOVUSWB void _mm256_mask_cvtusepi16_storeu_epi8(void * , __mmask16 k, __m256i b);
VPMOVUSWB __m128i _mm_cvtusepi16_epi8(__m128i a);
VPMOVUSWB __m128i _mm_mask_cvtusepi16_epi8(__m128i a, __mmask8 k, __m128i b);
VPMOVUSWB __m128i _mm_maskz_cvtusepi16_epi8( __mmask8 k, __m128i b);
VPMOVUSWB void _mm_mask_cvtusepi16_storeu_epi8(void * , __mmask8 k, __m128i b);
VPMOVSWB __m128i _mm256_cvtsepi16_epi8(__m256i a);
VPMOVSWB __m128i _mm256_mask_cvtsepi16_epi8(__m128i a, __mmask16 k, __m256i b);
VPMOVSWB __m128i _mm256_maskz_cvtsepi16_epi8( __mmask16 k, __m256i b);
VPMOVSWB void _mm256_mask_cvtsepi16_storeu_epi8(void * , __mmask16 k, __m256i b);
VPMOVSWB __m128i _mm_cvtsepi16_epi8(__m128i a);
VPMOVSWB __m128i _mm_mask_cvtsepi16_epi8(__m128i a, __mmask8 k, __m128i b);
VPMOVSWB __m128i _mm_maskz_cvtsepi16_epi8( __mmask8 k, __m128i b);
VPMOVSWB void _mm_mask_cvtsepi16_storeu_epi8(void * , __mmask8 k, __m128i b);
VPMOVWB __m128i _mm256_cvtepi16_epi8(__m256i a);
VPMOVWB __m128i _mm256_mask_cvtepi16_epi8(__m128i a, __mmask16 k, __m256i b);
VPMOVWB __m128i _mm256_maskz_cvtepi16_epi8( __mmask16 k, __m256i b);
VPMOVWB void _mm256_mask_cvtepi16_storeu_epi8(void * , __mmask16 k, __m256i b);
VPMOVWB __m128i _mm_cvtepi16_epi8(__m128i a);
VPMOVWB __m128i _mm_mask_cvtepi16_epi8(__m128i a, __mmask8 k, __m128i b);
VPMOVWB __m128i _mm_maskz_cvtepi16_epi8( __mmask8 k, __m128i b);
VPMOVWB void _mm_mask_cvtepi16_storeu_epi8(void * , __mmask8 k, __m128i b);



SIMD Floating-Point Exceptions


None


Other Exceptions





EVEX-encoded instruction, see Exceptions Type E6NF



If EVEX.vvvv != 1111B.