vpconflictd

Detect Conflicts Within a Vector of Packed Dword Values

VPCONFLICTD zmm1 {k1}, zmm2/m512

Detects duplicate values in a vector (Conflict Detection).

Details

Detects conflicting (duplicate) values within a vector of 16 packed 32-bit unsigned integers and writes a conflict mask to the destination. For each element, the instruction generates a 32-bit mask where bit j is set to 1 if the element at position i equals the element at position j (where j > i). This enables efficient identification of duplicate elements within a single vector. Operates only in 64-bit mode; no arithmetic flags are modified.

Pseudocode Operation

for i = 0 to 15:
  conflict_mask = 0
  for j = i + 1 to 15:
    if zmm2/m512[i*32 + 31 : i*32] == zmm2/m512[j*32 + 31 : j*32]:
      conflict_mask |= (1 << j)
  result[i*32 + 31 : i*32] = conflict_mask
if k1_mask[i] == 1:
  zmm1[i*32 + 31 : i*32] = result[i*32 + 31 : i*32]
else if {z} == 1:
  zmm1[i*32 + 31 : i*32] = 0

Example

VPCONFLICTD zmm1, zmm2/m512

Encoding

Binary Layout

EVEX

Format EVEX

Opcode EVEX.512.66.0F38.W0 C4 /r

Extension AVX-512CD

Operands

dest
512-bit ZMM AVX-512 register
src
512-bit ZMM AVX-512 register or Memory operand

Reference (Intel® SDM)

Instruction Forms

Opcode	Instruction	Op/En	64/32-bit Mode	CPUID	Description
EVEX.128.66.0F38.W0 C4 /r	VPCONFLICTD xmm1 {k1}{z}, xmm2/m128/m32bcst	A	V/V	(AVX512VL AND AVX512CD) OR AVX10.1	Detect duplicate double-word values in xmm2/m128/m32bcst using writemask k1.
EVEX.256.66.0F38.W0 C4 /r	VPCONFLICTD ymm1 {k1}{z}, ymm2/m256/m32bcst	A	V/V	(AVX512VL AND AVX512CD) OR AVX10.1	Detect duplicate double-word values in ymm2/m256/m32bcst using writemask k1.
EVEX.512.66.0F38.W0 C4 /r	VPCONFLICTD zmm1 {k1}{z}, zmm2/m512/m32bcst	A	V/V	AVX512CD OR AVX10.1	Detect duplicate double-word values in zmm2/m512/m32bcst using writemask k1.
EVEX.128.66.0F38.W1 C4 /r	VPCONFLICTQ xmm1 {k1}{z}, xmm2/m128/m64bcst	A	V/V	(AVX512VL AND AVX512CD) OR AVX10.1	Detect duplicate quad-word values in xmm2/m128/m64bcst using writemask k1.
EVEX.256.66.0F38.W1 C4 /r	VPCONFLICTQ ymm1 {k1}{z}, ymm2/m256/m64bcst	A	V/V	(AVX512VL AND AVX512CD) OR AVX10.1	Detect duplicate quad-word values in ymm2/m256/m64bcst using writemask k1.
EVEX.512.66.0F38.W1 C4 /r	VPCONFLICTQ zmm1 {k1}{z}, zmm2/m512/m64bcst	A	V/V	AVX512CD OR AVX10.1	Detect duplicate quad-word values in zmm2/m512/m64bcst using writemask k1.

Instruction Operand Encoding

Op/En	Tuple Type	Operand 1	Operand 2	Operand 3	Operand 4
A	Full	ModRM:reg (w)	ModRM:r/m (r)	N/A	N/A

Description

Test each dword/qword element of the source operand (the second operand) for equality with all other elements in the source operand closer to the least significant element. Each element’s comparison results form a bit vector, which is then zero extended and written to the destination according to the writemask. EVEX.512 encoded version: The source operand is a ZMM register, a 512-bit memory location, or a 512-bit vector broadcasted from a 32/64-bit memory location. The destination operand is a ZMM register, conditionally updated using writemask k1. EVEX.256 encoded version: The source operand is a YMM register, a 256-bit memory location, or a 256-bit vector broadcasted from a 32/64-bit memory location. The destination operand is a YMM register, conditionally updated using writemask k1. EVEX.128 encoded version: The source operand is a XMM register, a 128-bit memory location, or a 128-bit vector broadcasted from a 32/64-bit memory location. The destination operand is a XMM register, conditionally updated using writemask k1. EVEX.vvvv is reserved and must be 1111b otherwise instructions will #UD. VPCONFLICTD/Q—Detect Conflicts Within a Vector of Packed Dword/Qword Values Into Dense Memory/ Register Vol. 2C 5-475

Operation

VPCONFLICTD
(KL, VL) = (4, 128), (8, 256), (16, 512)
FOR j := 0 TO KL-1
i := j*32
IF MaskBit(j) OR *no writemask* THEN
FOR k := 0 TO j-1
m := k*32
IF ((SRC[i+31:i] = SRC[m+31:m])) THEN
DEST[i+k] := 1
ELSE
DEST[i+k] := 0
FI
ENDFOR
DEST[i+31:i+j] := 0
ELSE
IF *merging-masking* THEN
*DEST[i+31:i] remains unchanged*
ELSE
DEST[i+31:i] := 0
FI
FI
ENDFOR
DEST[MAXVL-1:VL] := 0

VPCONFLICTQ
(KL, VL) = (2, 128), (4, 256), (8, 512)
FOR j := 0 TO KL-1
i := j*64
IF MaskBit(j) OR *no writemask* THEN
FOR k := 0 TO j-1
m := k*64
IF ((SRC[i+63:i] = SRC[m+63:m])) THEN
DEST[i+k] := 1
ELSE
DEST[i+k] := 0
FI
ENDFOR
DEST[i+63:i+j] := 0
ELSE
IF *merging-masking* THEN
*DEST[i+63:i] remains unchanged*
ELSE
DEST[i+63:i] := 0
FI
FI
ENDFOR
DEST[MAXVL-1:VL] := 0





VPCONFLICTD/Q—Detect Conflicts Within a Vector of Packed Dword/Qword Values Into Dense Memory/ Register                           Vol. 2C 5-476

Intel C/C++ Compiler Intrinsic Equivalent

VPCONFLICTD __m512i _mm512_conflict_epi32( __m512i a);
VPCONFLICTD __m512i _mm512_mask_conflict_epi32(__m512i s, __mmask16 m, __m512i a);
VPCONFLICTD __m512i _mm512_maskz_conflict_epi32(__mmask16 m, __m512i a);
VPCONFLICTQ __m512i _mm512_conflict_epi64( __m512i a);
VPCONFLICTQ __m512i _mm512_mask_conflict_epi64(__m512i s, __mmask8 m, __m512i a);
VPCONFLICTQ __m512i _mm512_maskz_conflict_epi64(__mmask8 m, __m512i a);
VPCONFLICTD __m256i _mm256_conflict_epi32( __m256i a);
VPCONFLICTD __m256i _mm256_mask_conflict_epi32(__m256i s, __mmask8 m, __m256i a);
VPCONFLICTD __m256i _mm256_maskz_conflict_epi32(__mmask8 m, __m256i a);
VPCONFLICTQ __m256i _mm256_conflict_epi64( __m256i a);
VPCONFLICTQ __m256i _mm256_mask_conflict_epi64(__m256i s, __mmask8 m, __m256i a);
VPCONFLICTQ __m256i _mm256_maskz_conflict_epi64(__mmask8 m, __m256i a);
VPCONFLICTD __m128i _mm_conflict_epi32( __m128i a);
VPCONFLICTD __m128i _mm_mask_conflict_epi32(__m128i s, __mmask8 m, __m128i a);
VPCONFLICTD __m128i _mm_maskz_conflict_epi32(__mmask8 m, __m128i a);
VPCONFLICTQ __m128i _mm_conflict_epi64( __m128i a);
VPCONFLICTQ __m128i _mm_mask_conflict_epi64(__m128i s, __mmask8 m, __m128i a);
VPCONFLICTQ __m128i _mm_maskz_conflict_epi64(__mmask8 m, __m128i a);

Exceptions

SIMD Floating-Point Exceptions

None

Other Exceptions

EVEX-encoded instruction, see Table 2-52, “Type E4NF Class Exception Conditions.” VPCONFLICTD/Q—Detect Conflicts Within a Vector of Packed Dword/Qword Values Into Dense Memory/ Register Vol. 2C 5-477