vpermilps

Permute In-Lane Packed Single

VPERMILPS ymm1, ymm2/m256, imm8

Shuffles floats within 128-bit lanes (AVX).

Details

Permutes 32-bit float elements within 128-bit lanes independently using an 8-bit immediate, allowing shuffles within the lower and upper halves of a 256-bit register. No EFLAGS are affected. The immediate encoding selects 2-bit indices per float element.

Pseudocode Operation

for each 128-bit lane L in 0..1:
  for each 32-bit element i in 0..3:
    idx ← (Src1[L*128 + i*2 + 1 : L*128 + i*2]) & 0x3
    Dest[L*128 + i*32 : L*128 + i*32 + 31] ← Src1[L*128 + idx*32 : L*128 + idx*32 + 31]

Example

VPERMILPS ymm1, ymm2/m256, 3

Encoding

Binary Layout
VEX
+0
opcode
+3
ModRM
+4
 
Format AVX
Opcode VEX.256.66.0F3A.W0 04 /r ib
Extension AVX

Operands

  • dest
    256-bit YMM AVX register
  • src1
    256-bit YMM AVX register or Memory operand
  • src2
    8-bit signed immediate

Reference (Intel® SDM)

Instruction Forms

Opcode Instruction Op/En 64/32-bit Mode CPUID Description
VEX.128.66.0F38.W0 0C /r VPERMILPS xmm1, xmm2, xmm3/m128 A V/V AVX Permute single precision floating-point values in xmm2 using controls from xmm3/m128 and store result in xmm1.
VEX.128.66.0F3A.W0 04 /r ib VPERMILPS xmm1, xmm2/m128, imm8 B V/V AVX Permute single precision floating-point values in xmm2/m128 using controls from imm8 and store result in xmm1.
VEX.256.66.0F38.W0 0C /r VPERMILPS ymm1, ymm2, ymm3/m256 A V/V AVX Permute single precision floating-point values in ymm2 using controls from ymm3/m256 and store result in ymm1.
VEX.256.66.0F3A.W0 04 /r ib VPERMILPS ymm1, ymm2/m256, imm8 B V/V AVX Permute single precision floating-point values in ymm2/m256 using controls from imm8 and store result in ymm1.
EVEX.128.66.0F38.W0 0C /r VPERMILPS xmm1 {k1}{z}, xmm2, xmm3/m128/m32bcst C V/V (AVX512VL AND AVX512F) OR AVX10.1 Permute single-precision floating-point values xmm2 using control from xmm3/m128/m32bcst and store the result in xmm1 using writemask k1.
EVEX.256.66.0F38.W0 0C /r VPERMILPS ymm1 {k1}{z}, ymm2, ymm3/m256/m32bcst C V/V (AVX512VL AND AVX512F) OR AVX10.1 Permute single-precision floating-point values ymm2 using control from ymm3/m256/m32bcst and store the result in ymm1 using writemask k1.
EVEX.512.66.0F38.W0 0C /r VPERMILPS zmm1 {k1}{z}, zmm2, zmm3/m512/m32bcst C V/V AVX512F OR AVX10.1 Permute single-precision floating-point values zmm2 using control from zmm3/m512/m32bcst and store the result in zmm1 using writemask k1.
EVEX.128.66.0F3A.W0 04 /r ib VPERMILPS xmm1 {k1}{z}, xmm2/m128/m32bcst, imm8 D V/V (AVX512VL AND AVX512F) OR AVX10.1 Permute single-precision floating-point values xmm2/m128/m32bcst using controls from imm8 and store the result in xmm1 using writemask k1.
EVEX.256.66.0F3A.W0 04 /r ib VPERMILPS ymm1 {k1}{z}, ymm2/m256/m32bcst, imm8 D V/V (AVX512VL AND AVX512F) OR AVX10.1 Permute single-precision floating-point values ymm2/m256/m32bcst using controls from imm8 and store the result in ymm1 using writemask k1.

Instruction Operand Encoding

Op/En Tuple Type Operand 1 Operand 2 Operand 3 Operand 4
A N/A ModRM:reg (w) VEX.vvvv (r) ModRM:r/m (r) N/A
B N/A ModRM:reg (w) ModRM:r/m (r) N/A N/A
C Full ModRM:reg (w) EVEX.vvvv (r) ModRM:r/m (r) N/A
D Full ModRM:reg (w) ModRM:r/m (r) N/A N/A

Description

Variable control version: Permute quadruples of single precision floating-point values in the first source operand (second operand), each quadruplet using a 2-bit control field in the corresponding dword element of the second source operand. Permuted results are stored in the destination operand (first operand). The 2-bit control fields are located at the low two bits of each dword element (see Figure 5-26). Each control determines which of the source element in an input quadruple is selected for the destination element. Each quadruple of source elements must lie in the same 128-bit region as the destination. EVEX version: The second source operand (third operand) is a ZMM/YMM/XMM register, a 512/256/128-bit memory location or a 512/256/128-bit vector broadcasted from a 32-bit memory location. Permuted results are written to the destination under the writemask. SRC1 X7 X6 X5 X4 X3 X2 X1 X0 DEST X7 .. X4 X7 .. X4 X7 .. X4 X7 .. X4 X3 ..X0 X3 ..X0 X3 .. X0 X3 .. X0 Figure 5-25. VPERMILPS Operation Bit 255 226 225 224 63 34 33 32 31 1 0 ignored sel sel ignored sel . . . ignored Control Field 7 Control Field 2 Control Field 1 Figure 5-26. VPERMILPS Shuffle Control (Immediate control version) Permute quadruples of single precision floating-point values in the first source operand (second operand), each quadruplet using a 2-bit control field in the imm8 byte. Each 128-bit lane in the destination operand (first operand) use the four control fields of the same imm8 byte. VEX version: The source operand is a YMM/XMM register or a 256/128-bit memory location and the destination operand is a YMM/XMM register. EVEX version: The source operand (second operand) is a ZMM/YMM/XMM register, a 512/256/128-bit memory location or a 512/256/128-bit vector broadcasted from a 32-bit memory location. Permuted results are written to the destination under the writemask. Note: For the imm8 version, VEX.vvvv and EVEX.vvvv are reserved and must be 1111b otherwise instruction will #UD. VPERMILPS—Permute In-Lane of Quadruples of Single Precision Floating-Point Values Vol. 2C 5-518

Operation

Select4(SRC, control) {
CASE (control[1:0]) OF
0:  TMP := SRC[31:0];
1:  TMP := SRC[63:32];
2:  TMP := SRC[95:64];
3:  TMP := SRC[127:96];
ESAC;
RETURN TMP
}

VPERMILPS (EVEX immediate versions)
(KL, VL) = (4, 128), (8, 256), (16, 512)
FOR j := 0 TO KL-1
i := j * 32
IF (EVEX.b = 1) AND (SRC1 *is memory*)
THEN TMP_SRC1[i+31:i] := SRC1[31:0];
ELSE TMP_SRC1[i+31:i] := SRC1[i+31:i];
FI;
ENDFOR;

TMP_DEST[31:0] := Select4(TMP_SRC1[127:0], imm8[1:0]);
TMP_DEST[63:32] := Select4(TMP_SRC1[127:0], imm8[3:2]);
TMP_DEST[95:64] := Select4(TMP_SRC1[127:0], imm8[5:4]);
TMP_DEST[127:96] := Select4(TMP_SRC1[127:0], imm8[7:6]); FI;
IF VL >= 256
TMP_DEST[159:128] := Select4(TMP_SRC1[255:128], imm8[1:0]); FI;
TMP_DEST[191:160] := Select4(TMP_SRC1[255:128], imm8[3:2]); FI;
TMP_DEST[223:192] := Select4(TMP_SRC1[255:128], imm8[5:4]); FI;
TMP_DEST[255:224] := Select4(TMP_SRC1[255:128], imm8[7:6]); FI;
FI;
IF VL >= 512
TMP_DEST[287:256] := Select4(TMP_SRC1[383:256], imm8[1:0]); FI;
TMP_DEST[319:288] := Select4(TMP_SRC1[383:256], imm8[3:2]); FI;
TMP_DEST[351:320] := Select4(TMP_SRC1[383:256], imm8[5:4]); FI;
TMP_DEST[383:352] := Select4(TMP_SRC1[383:256], imm8[7:6]); FI;
TMP_DEST[415:384] := Select4(TMP_SRC1[511:384], imm8[1:0]); FI;
TMP_DEST[447:416] := Select4(TMP_SRC1[511:384], imm8[3:2]); FI;
TMP_DEST[479:448] := Select4(TMP_SRC1[511:384], imm8[5:4]); FI;
TMP_DEST[511:480] := Select4(TMP_SRC1[511:384], imm8[7:6]); FI;
FI;
FOR j := 0 TO KL-1
i := j * 32
IF k1[j] OR *no writemask*
THEN DEST[i+31:i] := TMP_DEST[i+31:i]
ELSE
IF *merging-masking*
THEN *DEST[i+31:i] remains unchanged*
ELSE DEST[i+31:i] := 0               ;zeroing-masking
FI;
FI;
ENDFOR
DEST[MAXVL-1:VL] := 0



VPERMILPS—Permute In-Lane of Quadruples of Single Precision Floating-Point Values                                                        Vol. 2C 5-519
VPERMILPS (256-bit immediate version)
DEST[31:0] := Select4(SRC1[127:0], imm8[1:0]);
DEST[63:32] := Select4(SRC1[127:0], imm8[3:2]);
DEST[95:64] := Select4(SRC1[127:0], imm8[5:4]);
DEST[127:96] := Select4(SRC1[127:0], imm8[7:6]);
DEST[159:128] := Select4(SRC1[255:128], imm8[1:0]);
DEST[191:160] := Select4(SRC1[255:128], imm8[3:2]);
DEST[223:192] := Select4(SRC1[255:128], imm8[5:4]);
DEST[255:224] := Select4(SRC1[255:128], imm8[7:6]);

VPERMILPS (128-bit immediate version)
DEST[31:0] := Select4(SRC1[127:0], imm8[1:0]);
DEST[63:32] := Select4(SRC1[127:0], imm8[3:2]);
DEST[95:64] := Select4(SRC1[127:0], imm8[5:4]);
DEST[127:96] := Select4(SRC1[127:0], imm8[7:6]);
DEST[MAXVL-1:128] := 0

VPERMILPS (EVEX variable versions)
(KL, VL) = (16, 512)
FOR j := 0 TO KL-1
i := j * 32
IF (EVEX.b = 1) AND (SRC2 *is memory*)
THEN TMP_SRC2[i+31:i] := SRC2[31:0];
ELSE TMP_SRC2[i+31:i] := SRC2[i+31:i];
FI;
ENDFOR;
TMP_DEST[31:0] := Select4(SRC1[127:0], TMP_SRC2[1:0]);
TMP_DEST[63:32] := Select4(SRC1[127:0], TMP_SRC2[33:32]);
TMP_DEST[95:64] := Select4(SRC1[127:0], TMP_SRC2[65:64]);
TMP_DEST[127:96] := Select4(SRC1[127:0], TMP_SRC2[97:96]);
IF VL >= 256
TMP_DEST[159:128] := Select4(SRC1[255:128], TMP_SRC2[129:128]);
TMP_DEST[191:160] := Select4(SRC1[255:128], TMP_SRC2[161:160]);
TMP_DEST[223:192] := Select4(SRC1[255:128], TMP_SRC2[193:192]);
TMP_DEST[255:224] := Select4(SRC1[255:128], TMP_SRC2[225:224]);
FI;
IF VL >= 512
TMP_DEST[287:256] := Select4(SRC1[383:256], TMP_SRC2[257:256]);
TMP_DEST[319:288] := Select4(SRC1[383:256], TMP_SRC2[289:288]);
TMP_DEST[351:320] := Select4(SRC1[383:256], TMP_SRC2[321:320]);
TMP_DEST[383:352] := Select4(SRC1[383:256], TMP_SRC2[353:352]);
TMP_DEST[415:384] := Select4(SRC1[511:384], TMP_SRC2[385:384]);
TMP_DEST[447:416] := Select4(SRC1[511:384], TMP_SRC2[417:416]);
TMP_DEST[479:448] := Select4(SRC1[511:384], TMP_SRC2[449:448]);
TMP_DEST[511:480] := Select4(SRC1[511:384], TMP_SRC2[481:480]);
FI;
FOR j := 0 TO KL-1
i := j * 32
IF k1[j] OR *no writemask*
THEN DEST[i+31:i] := TMP_DEST[i+31:i]
ELSE
IF *merging-masking*
THEN *DEST[i+31:i] remains unchanged*
ELSE DEST[i+31:i] := 0               ;zeroing-masking


VPERMILPS—Permute In-Lane of Quadruples of Single Precision Floating-Point Values                                                        Vol. 2C 5-520
FI;
FI;
ENDFOR
DEST[MAXVL-1:VL] := 0

VPERMILPS (256-bit variable version)
DEST[31:0] := Select4(SRC1[127:0], SRC2[1:0]);
DEST[63:32] := Select4(SRC1[127:0], SRC2[33:32]);
DEST[95:64] := Select4(SRC1[127:0], SRC2[65:64]);
DEST[127:96] := Select4(SRC1[127:0], SRC2[97:96]);
DEST[159:128] := Select4(SRC1[255:128], SRC2[129:128]);
DEST[191:160] := Select4(SRC1[255:128], SRC2[161:160]);
DEST[223:192] := Select4(SRC1[255:128], SRC2[193:192]);
DEST[255:224] := Select4(SRC1[255:128], SRC2[225:224]);
DEST[MAXVL-1:256] := 0

VPERMILPS (128-bit variable version)
DEST[31:0] := Select4(SRC1[127:0], SRC2[1:0]);
DEST[63:32] := Select4(SRC1[127:0], SRC2[33:32]);
DEST[95:64] :=Select4(SRC1[127:0], SRC2[65:64]);
DEST[127:96] := Select4(SRC1[127:0], SRC2[97:96]);
DEST[MAXVL-1:128] := 0

Intel C/C++ Compiler Intrinsic Equivalent

VPERMILPS __m512 _mm512_permute_ps( __m512 a, int imm);
VPERMILPS __m512 _mm512_mask_permute_ps(__m512 s, __mmask16 k, __m512 a, int imm);
VPERMILPS __m512 _mm512_maskz_permute_ps( __mmask16 k, __m512 a, int imm);
VPERMILPS __m256 _mm256_mask_permute_ps(__m256 s, __mmask8 k, __m256 a, int imm);
VPERMILPS __m256 _mm256_maskz_permute_ps( __mmask8 k, __m256 a, int imm);
VPERMILPS __m128 _mm_mask_permute_ps(__m128 s, __mmask8 k, __m128 a, int imm);
VPERMILPS __m128 _mm_maskz_permute_ps( __mmask8 k, __m128 a, int imm);
VPERMILPS __m512 _mm512_permutevar_ps( __m512i i, __m512 a);
VPERMILPS __m512 _mm512_mask_permutevar_ps(__m512 s, __mmask16 k, __m512i i, __m512 a);
VPERMILPS __m512 _mm512_maskz_permutevar_ps( __mmask16 k, __m512i i, __m512 a);
VPERMILPS __m256 _mm256_mask_permutevar_ps(__m256 s, __mmask8 k, __m256 i, __m256 a);
VPERMILPS __m256 _mm256_maskz_permutevar_ps( __mmask8 k, __m256 i, __m256 a);
VPERMILPS __m128 _mm_mask_permutevar_ps(__m128 s, __mmask8 k, __m128 i, __m128 a);
VPERMILPS __m128 _mm_maskz_permutevar_ps( __mmask8 k, __m128 i, __m128 a);
VPERMILPS __m128 _mm_permute_ps (__m128 a, int control);
VPERMILPS __m256 _mm256_permute_ps (__m256 a, int control);
VPERMILPS __m128 _mm_permutevar_ps (__m128 a, __m128i control);
VPERMILPS __m256 _mm256_permutevar_ps (__m256 a, __m256i control);

Exceptions

SIMD Floating-Point Exceptions

None.

Other Exceptions

Non-EVEX-encoded instruction, see Table 2-21, “Type 4 Class Exception Conditions.” Additionally: #UD If VEX.W = 1. EVEX-encoded instruction, see Table 2-52, “Type E4NF Class Exception Conditions.” Additionally: #UD If either (E)VEX.vvvv != 1111B and with imm8. VPERMILPS—Permute In-Lane of Quadruples of Single Precision Floating-Point Values Vol. 2C 5-521