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 A 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 A 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 A 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 A 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 A 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 A 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 A 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 A 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 A 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 Tuple Type Operand 1 Operand 2 Operand 3 Operand 4
A Half Mem 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 (MAXVL-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 := 0 TO Kl-1

i := j * 8

m := j * 16

IF k1[j] OR *no writemask*

THEN DEST[i+7:i] := 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[MAXVL-1:VL/2] := 0;

VPMOVWB instruction (EVEX encoded versions) when dest is memory

(KL, VL) = (8, 128), (16, 256), (32, 512)

FOR j := 0 TO Kl-1

i := j * 8

m := j * 16

IF k1[j] OR *no writemask*

THEN DEST[i+7:i] := 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 := 0 TO Kl-1

i := j * 8

m := j * 16

IF k1[j] OR *no writemask*

THEN DEST[i+7:i] := 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[MAXVL-1:VL/2] := 0;

VPMOVSWB instruction (EVEX encoded versions) when dest is memory

(KL, VL) = (8, 128), (16, 256), (32, 512)

FOR j := 0 TO Kl-1

i := j * 8

m := j * 16

IF k1[j] OR *no writemask*

THEN DEST[i+7:i] := 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 := 0 TO Kl-1

i := j * 8

m := j * 16

IF k1[j] OR *no writemask*

THEN DEST[i+7:i] := 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[MAXVL-1:VL/2] := 0;

VPMOVUSWB instruction (EVEX encoded versions) when dest is memory

(KL, VL) = (8, 128), (16, 256), (32, 512)

FOR j := 0 TO Kl-1

i := j * 8

m := j * 16

IF k1[j] OR *no writemask*

THEN DEST[i+7:i] := SaturateUnsignedWordToByte (SRC[m+15:m])

ELSE

*DEST[i+7:i] remains unchanged*

; merging-masking

FI;

ENDFOR

Intel C/C++ Compiler Intrinsic Equivalents

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 Table 2-53, “Type E6 Class Exception Conditions”; additionally:
If EVEX.vvvv != 1111B.