image/svg+xml VPCMPB/VPCMPUB—Compare Packed Byte Values Into Mask Instruction Operand Encoding Description Performs a SIMD compare of the packed byte values in the second source operand and the first source operand and returns the results of the comparison to the mask destination operand. The comparison predicate operand (imme- diate byte) specifies the type of comparison performed on each pair of packed values in the two source operands. The result of each comparison is a single mask bit result of 1 (comparison true) or 0 (comparison false). VPCMPB performs a comparison between pairs of signed byte values. VPCMPUB performs a comparison between pairs of unsigned byte values. The first source operand (second operand) is a ZMM/YMM/XMM register. The second source operand can be a ZMM/YMM/XMM register or a 512/256/128-bit memory location. The destination operand (first operand) is a mask register k1. Up to 64/32/16 comparisons are performed with results written to the destination operand under the writemask k2. Opcode/ Instruction Op/ En 64/32 bit Mode Support CPUID Feature Flag Description EVEX.128.66.0F3A.W0 3F /r ib VPCMPB k1 {k2}, xmm2, xmm3/m128, imm8 AV/VAVX512VL AVX512BW Compare packed signed byte values in xmm3/m128 and xmm2 using bits 2:0 of imm8 as a comparison predicate with writemask k2 and leave the result in mask register k1. EVEX.256.66.0F3A.W0 3F /r ib VPCMPB k1 {k2}, ymm2, ymm3/m256, imm8 AV/VAVX512VL AVX512BW Compare packed signed byte values in ymm3/m256 and ymm2 using bits 2:0 of imm8 as a comparison predicate with writemask k2 and leave the result in mask register k1. EVEX.512.66.0F3A.W0 3F /r ib VPCMPB k1 {k2}, zmm2, zmm3/m512, imm8 AV/VAVX512BWCompare packed signed byte values in zmm3/m512 and zmm2 using bits 2:0 of imm8 as a comparison predicate with writemask k2 and leave the result in mask register k1. EVEX.128.66.0F3A.W0 3E /r ib VPCMPUB k1 {k2}, xmm2, xmm3/m128, imm8 AV/VAVX512VL AVX512BW Compare packed unsigned byte values in xmm3/m128 and xmm2 using bits 2:0 of imm8 as a comparison predicate with writemask k2 and leave the result in mask register k1. EVEX.256.66.0F3A.W0 3E /r ib VPCMPUB k1 {k2}, ymm2, ymm3/m256, imm8 AV/VAVX512VL AVX512BW Compare packed unsigned byte values in ymm3/m256 and ymm2 using bits 2:0 of imm8 as a comparison predicate with writemask k2 and leave the result in mask register k1. EVEX.512.66.0F3A.W0 3E /r ib VPCMPUB k1 {k2}, zmm2, zmm3/m512, imm8 AV/VAVX512BWCompare packed unsigned byte values in zmm3/m512 and zmm2 using bits 2:0 of imm8 as a comparison predicate with writemask k2 and leave the result in mask register k1. Op/EnTuple TypeOperand 1Operand 2Operand 3Operand 4 AFull MemModRM:reg (w)vvvv (r)ModRM:r/m (r)NA image/svg+xml The comparison predicate operand is an 8-bit immediate: bits 2:0 define the type of comparison to be performed. Bits 3 through 7 of the immediate are reserved. Compiler can implement the pseudo-op mnemonic listed in Table 5-8. : Operation CASE (COMPARISON PREDICATE) OF 0: OP := EQ; 1: OP := LT; 2: OP := LE; 3: OP := FALSE; 4: OP := NEQ; 5: OP := NLT; 6: OP := NLE; 7: OP := TRUE; ESAC; VPCMPB (EVEX encoded versions) (KL, VL) = (16, 128), (32, 256), (64, 512) FOR j := 0 TO KL-1 i := j * 8 IF k2[j] OR *no writemask* THEN CMP := SRC1[i+7:i] OP SRC2[i+7:i]; IF CMP = TRUE THEN DEST[j] := 1; ELSE DEST[j] := 0; FI; ELSE DEST[j] = 0; zeroing-masking onlyFI; FI; ENDFOR DEST[MAX_KL-1:KL] := 0 Table 5-8. Pseudo-Op and VPCMP* Implementation Pseudo-OpPCMPM Implementation VPCMPEQ* reg1, reg2, reg3 VPCMP* reg1, reg2, reg3, 0 VPCMPLT* reg1, reg2, reg3 VPCMP* reg1, reg2, reg3, 1 VPCMPLE* reg1, reg2, reg3 VPCMP* reg1, reg2, reg3, 2 VPCMPNEQ* reg1, reg2, reg3 VPCMP* reg1, reg2, reg3, 4 VPPCMPNLT* reg1, reg2, reg3 VPCMP* reg1, reg2, reg3, 5 VPCMPNLE* reg1, reg2, reg3 VPCMP* reg1, reg2, reg3, 6 image/svg+xml VPCMPUB (EVEX encoded versions) (KL, VL) = (16, 128), (32, 256), (64, 512) FOR j := 0 TO KL-1 i := j * 8 IF k2[j] OR *no writemask* THEN CMP := SRC1[i+7:i] OP SRC2[i+7:i]; IF CMP = TRUE THEN DEST[j] := 1; ELSE DEST[j] := 0; FI; ELSE DEST[j] = 0; zeroing-masking onlyFI; FI; ENDFOR DEST[MAX_KL-1:KL] := 0 Intel C/C++ Compiler Intrinsic Equivalent VPCMPB __mmask64 _mm512_cmp_epi8_mask( __m512i a, __m512i b, int cmp); VPCMPB __mmask64 _mm512_mask_cmp_epi8_mask( __mmask64 m, __m512i a, __m512i b, int cmp); VPCMPB __mmask32 _mm256_cmp_epi8_mask( __m256i a, __m256i b, int cmp); VPCMPB __mmask32 _mm256_mask_cmp_epi8_mask( __mmask32 m, __m256i a, __m256i b, int cmp); VPCMPB __mmask16 _mm_cmp_epi8_mask( __m128i a, __m128i b, int cmp); VPCMPB __mmask16 _mm_mask_cmp_epi8_mask( __mmask16 m, __m128i a, __m128i b, int cmp); VPCMPB __mmask64 _mm512_cmp[eq|ge|gt|le|lt|neq]_epi8_mask( __m512i a, __m512i b); VPCMPB __mmask64 _mm512_mask_cmp[eq|ge|gt|le|lt|neq]_epi8_mask( __mmask64 m, __m512i a, __m512i b); VPCMPB __mmask32 _mm256_cmp[eq|ge|gt|le|lt|neq]_epi8_mask( __m256i a, __m256i b); VPCMPB __mmask32 _mm256_mask_cmp[eq|ge|gt|le|lt|neq]_epi8_mask( __mmask32 m, __m256i a, __m256i b); VPCMPB __mmask16 _mm_cmp[eq|ge|gt|le|lt|neq]_epi8_mask( __m128i a, __m128i b); VPCMPB __mmask16 _mm_mask_cmp[eq|ge|gt|le|lt|neq]_epi8_mask( __mmask16 m, __m128i a, __m128i b); VPCMPUB __mmask64 _mm512_cmp_epu8_mask( __m512i a, __m512i b, int cmp); VPCMPUB __mmask64 _mm512_mask_cmp_epu8_mask( __mmask64 m, __m512i a, __m512i b, int cmp); VPCMPUB __mmask32 _mm256_cmp_epu8_mask( __m256i a, __m256i b, int cmp); VPCMPUB __mmask32 _mm256_mask_cmp_epu8_mask( __mmask32 m, __m256i a, __m256i b, int cmp); VPCMPUB __mmask16 _mm_cmp_epu8_mask( __m128i a, __m128i b, int cmp); VPCMPUB __mmask16 _mm_mask_cmp_epu8_mask( __mmask16 m, __m128i a, __m128i b, int cmp); VPCMPUB __mmask64 _mm512_cmp[eq|ge|gt|le|lt|neq]_epu8_mask( __m512i a, __m512i b, int cmp); VPCMPUB __mmask64 _mm512_mask_cmp[eq|ge|gt|le|lt|neq]_epu8_mask( __mmask64 m, __m512i a, __m512i b, int cmp); VPCMPUB __mmask32 _mm256_cmp[eq|ge|gt|le|lt|neq]_epu8_mask( __m256i a, __m256i b, int cmp); VPCMPUB __mmask32 _mm256_mask_cmp[eq|ge|gt|le|lt|neq]_epu8_mask( __mmask32 m, __m256i a, __m256i b, int cmp); VPCMPUB __mmask16 _mm_cmp[eq|ge|gt|le|lt|neq]_epu8_mask( __m128i a, __m128i b, int cmp); VPCMPUB __mmask16 _mm_mask_cmp[eq|ge|gt|le|lt|neq]_epu8_mask( __mmask16 m, __m128i a, __m128i b, int cmp); SIMD Floating-Point Exceptions None Other Exceptions EVEX-encoded instruction, see Exceptions Type E4.nb in Table2-49, “Type E4 Class Exception Conditions”. This UNOFFICIAL reference was generated from the official Intel® 64 and IA-32 Architectures Software Developer’s Manual by a dumb script. There is no guarantee that some parts aren't mangled or broken and is distributed WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE .