vperm2i128
Permute 128-bit Integer Blocks
Shuffles two 128-bit lanes between registers.
Pseudocode Operation
ctrl_low = src3[3:0]
ctrl_high = src3[7:4]
if ctrl_low == 0x8:
dest[127:0] ← 0
else:
dest[127:0] ← src1[127:0] if (ctrl_low & 0x4) == 0 else src1[255:128]
if ctrl_high == 0x8:
dest[255:128] ← 0
else:
dest[255:128] ← src2[127:0] if (ctrl_high & 0x4) == 0 else src2[255:128]Example
Encoding
Operands
-
dest
256-bit YMM AVX register -
src1
256-bit YMM AVX register -
src2
256-bit YMM AVX register or Memory operand -
src3
8-bit signed immediate
Related
More in AVX2
Reference
Instruction Forms
| Opcode | Instruction | Op/En | 64/32-bit Mode | CPUID | Description |
|---|---|---|---|---|---|
| VEX.256.66.0F3A.W0 46 /r ib | VPERM2I128 ymm1, ymm2, ymm3/m256, imm8 | RVMI | V/V | AVX2 | Permute 128-bit integer data in ymm2 and ymm3/mem using controls from imm8 and store result in ymm1. |
Description
Permute 128 bit integer data from the first source operand (second operand) and second source operand (third operand) using bits in the 8-bit immediate and store results in the destination operand (first operand). The first source operand is a YMM register, the second source operand is a YMM register or a 256-bit memory location, and the destination operand is a YMM register.
SRC2 Y1 Y0
SRC1 X1 X0
DEST X0, X1, Y0, or Y1 X0, X1, Y0, or Y1
Imm8[1:0] select the source for the first destination 128-bit field, imm8[5:4] select the source for the second destination field. If imm8[3] is set, the low 128-bit field is zeroed. If imm8[7] is set, the high 128-bit field is zeroed. VEX.L must be 1, otherwise the instruction will #UD.
Operation
VPERM2I128 CASE IMM8[1:0] of 0: DEST[127:0] := SRC1[127:0] 1: DEST[127:0] := SRC1[255:128] 2: DEST[127:0] := SRC2[127:0] 3: DEST[127:0] := SRC2[255:128] ESAC CASE IMM8[5:4] of 0: DEST[255:128] := SRC1[127:0] 1: DEST[255:128] := SRC1[255:128] 2: DEST[255:128] := SRC2[127:0] 3: DEST[255:128] := SRC2[255:128] ESAC IF (imm8[3]) DEST[127:0] := 0 FI IF (imm8[7]) DEST[255:128] := 0 FI
Intel C/C++ Compiler Intrinsic Equivalent
VPERM2I128: __m256i _mm256_permute2x128_si256 (__m256i a, __m256i b, int control)