VPERMPS — Permute Single-Precision Floating-Point Elements

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

VEX.NDS.256.66.0F38.W0 16 /r

VPERMPS ymm1, ymm2, ymm3/m256

 RVM V/V AVX2 Permute single-precision floating-point elements in ymm3/m256 using indexes in ymm2 and store the result in ymm1.

Instruction Operand Encoding

Op/En Operand 1 Operand 2 Operand 3 Operand 4
RVM ModRM:reg (w) VEX.vvvv ModRM:r/m (r) NA

Description

Use the index values in each dword element of the first source operand (the second operand) to select a single-precision floating-point element in the second source operand (the third operand), the resultant data from the second source operand is copied to the destination operand (the first operand) in the corresponding position of the index element. Note that this instruction permits a doubleword in the source operand to be copied to more than one doubleword location in the destination operand.

An attempt to execute VPERMPS encoded with VEX.L= 0 will cause an #UD exception.

Operation

VPERMPS (VEX.256 encoded version)

DEST[31:0] ← (SRC2[255:0] >> (SRC1[2:0] * 32))[31:0];
DEST[63:32] ← (SRC2[255:0] >> (SRC1[34:32] * 32))[31:0];
DEST[95:64] ← (SRC2[255:0] >> (SRC1[66:64] * 32))[31:0];
DEST[127:96] ← (SRC2[255:0] >> (SRC1[98:96] * 32))[31:0];
DEST[159:128] ← (SRC2[255:0] >> (SRC1[130:128] * 32))[31:0];
DEST[191:160] ← (SRC2[255:0] >> (SRC1[162:160] * 32))[31:0];
DEST[223:192] ← (SRC2[255:0] >> (SRC1[194:192] * 32))[31:0];
DEST[255:224] ← (SRC2[255:0] >> (SRC1[226:224] * 32))[31:0];

Intel C/C++ Compiler Intrinsic Equivalent

VPERMPS: __m256i _mm256_permutevar8x32_ps(__m256 a, __m256i offsets)

SIMD Floating-Point Exceptions

None

Other Exceptions

See Exceptions Type 4; additionally

#UD

If VEX.L = 0,

If VEX.W = 1.