PUNPCKLBW/PUNPCKLWD/PUNPCKLDQ/PUNPCKLQDQ—Unpack Low Data

Opcode/Instruction Op/En 64/32 bit Mode Support CPUID Feature Flag Description
0F 60 /r1 PUNPCKLBW mm, mm/m32 RM V/V MMX Interleave low-order bytes from mm and mm/m32 into mm.
66 0F 60 /r PUNPCKLBW xmm1, xmm2/m128 RM V/V SSE2 Interleave low-order bytes from xmm1 and xmm2/m128 into xmm1.
0F 61 /r1 PUNPCKLWD mm, mm/m32 RM V/V MMX Interleave low-order words from mm and mm/m32 into mm.
66 0F 61 /r PUNPCKLWD xmm1, xmm2/m128 RM V/V SSE2 Interleave low-order words from xmm1 and xmm2/m128 into xmm1.
0F 62 /r1 PUNPCKLDQ mm, mm/m32 RM V/V MMX Interleave low-order doublewords from mm and mm/m32 into mm.
66 0F 62 /r PUNPCKLDQ xmm1, xmm2/m128 RM V/V SSE2 Interleave low-order doublewords from xmm1 and xmm2/m128 into xmm1.
66 0F 6C /r PUNPCKLQDQ xmm1, xmm2/m128 RM V/V SSE2 Interleave low-order quadword from xmm1 and xmm2/m128 into xmm1 register.
VEX.NDS.128.66.0F.WIG 60/r VPUNPCKLBW xmm1,xmm2, xmm3/m128 RVM V/V AVX Interleave low-order bytes from xmm2 and xmm3/m128 into xmm1.
VEX.NDS.128.66.0F.WIG 61/r VPUNPCKLWD xmm1,xmm2, xmm3/m128 RVM V/V AVX Interleave low-order words from xmm2 and xmm3/m128 into xmm1.
VEX.NDS.128.66.0F.WIG 62/r VPUNPCKLDQ xmm1, xmm2, xmm3/m128 RVM V/V AVX Interleave low-order doublewords from xmm2 and xmm3/m128 into xmm1.
VEX.NDS.128.66.0F.WIG 6C/r VPUNPCKLQDQ xmm1, xmm2, xmm3/m128 RVM V/V AVX Interleave low-order quadword from xmm2 and xmm3/m128 into xmm1 register.
VEX.NDS.256.66.0F.WIG 60 /r VPUNPCKLBW ymm1, ymm2, ymm3/m256 RVM V/V AVX2 Interleave low-order bytes from ymm2 and ymm3/m256 into ymm1 register.
VEX.NDS.256.66.0F.WIG 61 /r VPUNPCKLWD ymm1, ymm2, ymm3/m256 RVM V/V AVX2 Interleave low-order words from ymm2 and ymm3/m256 into ymm1 register.
VEX.NDS.256.66.0F.WIG 62 /r VPUNPCKLDQ ymm1, ymm2, ymm3/m256 RVM V/V AVX2 Interleave low-order doublewords from ymm2 and ymm3/m256 into ymm1 register.
VEX.NDS.256.66.0F.WIG 6C /r VPUNPCKLQDQ ymm1, ymm2, ymm3/m256 RVM V/V AVX2 Interleave low-order quadword from ymm2 and ymm3/m256 into ymm1 register.

Notes: 1. See note in Section 2.4, “Instruction Exception Specification” in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 2A and Section 22.25.3, “Exception Conditions of Legacy SIMD Instructions Operating on MMX Registers” in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 3A.

Instruction Operand Encoding

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

Description

Unpacks and interleaves the low-order data elements (bytes, words, doublewords, and quadwords) of the destination operand (first operand) and source operand (second operand) into the destination operand. (Figure 4-18 shows the unpack operation for bytes in 64-bit operands.). The high-order data elements are ignored.

SRC SRC Y7 Figure 4-18. 255 Y7 Y6 Y6 Figure 4-19. Y5 Y5 Y4 PUNPCKLBW Instruction Operation Using 64-bit Operands Y4 Y3 Y3 Y2 Y2 256-bit VPUNPCKLDQ Instruction Operation Y1 DEST Y1 DEST Y0 Y3 0 Y0 255 Y5 X7 Y2 255 X7 Y4 X6 X2 X6 X4 X5 Y1 X5 Y1 X4 X1 X4 X1 X3 Y0 X3 Y0 X2 X0 X2 X0 X1 X1 0 X0 31 X0 DEST 0

When the source data comes from a 128-bit memory operand, an implementation may fetch only the appropriate 64 bits; however, alignment to a 16-byte boundary and normal segment checking will still be enforced.

The (V)PUNPCKLBW instruction interleaves the low-order bytes of the source and destination operands, the (V)PUNPCKLWD instruction interleaves the low-order words of the source and destination operands, the (V)PUNPCKLDQ instruction interleaves the low-order doubleword (or doublewords) of the source and destination operands, and the (V)PUNPCKLQDQ instruction interleaves the low-order quadwords of the source and destination operands.

These instructions can be used to convert bytes to words, words to doublewords, doublewords to quadwords, and quadwords to double quadwords, respectively, by placing all 0s in the source operand. Here, if the source operand contains all 0s, the result (stored in the destination operand) contains zero extensions of the high-order data elements from the original value in the destination operand. For example, with the (V)PUNPCKLBW instruction the high-order bytes are zero extended (that is, unpacked into unsigned word integers), and with the (V)PUNPCKLWD instruction, the high-order words are zero extended (unpacked into unsigned doubleword integers).

In 64-bit mode, using a REX prefix in the form of REX.R permits this instruction to access additional registers (XMM8-XMM15).

Legacy SSE versions: The source operand can be an MMX technology register or a 32-bit memory location. The destination operand is an MMX technology register. 128-bit Legacy SSE versions: The second source operand is an XMM register or a 128-bit memory location. The first source operand and destination operands are XMM registers. Bits (VLMAX-1:128) of the corresponding YMM destination register remain unchanged. VEX.128 encoded versions: The second source operand is an XMM register or a 128-bit memory location. The first source operand and destination operands are XMM registers. Bits (VLMAX-1:128) of the destination YMM register are zeroed.

VEX.256 encoded version: The second source operand is an YMM register or a 256-bit memory location. The first source operand and destination operands are YMM registers.

Note: VEX.L must be 0, otherwise instructions will #UD.

Operation

PUNPCKLBW instruction with 64-bit operands:
  DEST[63:56] ← SRC[31:24];
  DEST[55:48] ← DEST[31:24];
  DEST[47:40] ← SRC[23:16];
  DEST[39:32] ← DEST[23:16];
  DEST[31:24] ← SRC[15:8];
  DEST[23:16] ← DEST[15:8];
  DEST[15:8] ← SRC[7:0];
  DEST[7:0] ← DEST[7:0];
PUNPCKLWD instruction with 64-bit operands:
  DEST[63:48] ← SRC[31:16];
  DEST[47:32] ← DEST[31:16];
  DEST[31:16] ← SRC[15:0];
  DEST[15:0] ← DEST[15:0];
PUNPCKLDQ instruction with 64-bit operands:
  DEST[63:32] ← SRC[31:0];
  DEST[31:0] ← DEST[31:0];
PUNPCKLBW instruction with 128-bit operands:
  DEST[7:0]← DEST[7:0];
  DEST[15:8]
  DEST[23:16] ← DEST[15:8];
  DEST[31:24] ← SRC[15:8];
  DEST[39:32] ← DEST[23:16];
  DEST[47:40] ← SRC[23:16];
  DEST[55:48] ← DEST[31:24];
  DEST[63:56] ← SRC[31:24];
  DEST[71:64] ← DEST[39:32];
  DEST[79:72] ← SRC[39:32];
  DEST[87:80] ← DEST[47:40];
  DEST[95:88] ← SRC[47:40];
  DEST[103:96]
  DEST[111:104] ← SRC[55:48];
  DEST[119:112] ← DEST[63:56];
  DEST[127:120] ← SRC[63:56];
PUNPCKLWD instruction with 128-bit operands:
  DEST[15:0]
  DEST[31:16] ← SRC[15:0];
  DEST[47:32] ← DEST[31:16];
  DEST[63:48] ← SRC[31:16];
  DEST[79:64] ← DEST[47:32];
  DEST[95:80] ← SRC[47:32];
  DEST[111:96]
  DEST[127:112] ← SRC[63:48];
PUNPCKLDQ instruction with 128-bit operands:
  DEST[31:0] ← DEST[31:0];
  DEST[63:32]
  DEST[95:64]
  DEST[127:96] ← SRC[63:32];
PUNPCKLQDQ
  DEST[63:0] ← DEST[63:0];
  DEST[127:64] ← SRC[63:0];
INTERLEAVE_BYTES_256b (SRC1, SRC2)
DEST[7:0] ← SRC1[7:0]
DEST[15:8] ← SRC2[7:0]
DEST[23:16] ← SRC1[15:8]
DEST[31:24] ← SRC2[15:8]
DEST[39:32] ← SRC1[23:16]
DEST[47:40] ← SRC2[23:16]
DEST[55:48] ← SRC1[31:24]
DEST[63:56] ←SRC2[31:24]
DEST[71:64] ← SRC1[39:32]
DEST[79:72] ← SRC2[39:32]
DEST[87:80] ← SRC1[47:40]
DEST[95:88] ← SRC2[47:40]
DEST[103:96] ← SRC1[55:48]
DEST[111:104] ← SRC2[55:48]
DEST[119:112] ← SRC1[63:56]
DEST[127:120] ← SRC2[63:56]
DEST[135:128] ← SRC1[135:128]
DEST[143:136] ← SRC2[135:128]
DEST[151:144] ← SRC1[143:136]
DEST[159:152] ← SRC2[143:136]
DEST[167:160] ← SRC1[151:144]
DEST[175:168] ← SRC2[151:144]
DEST[183:176] ← SRC1[159:152]
DEST[191:184] ←SRC2[159:152]
DEST[199:192] ← SRC1[167:160]
DEST[207:200] ← SRC2[167:160]
DEST[215:208] ← SRC1[175:168]
DEST[223:216] ← SRC2[175:168]
DEST[231:224] ← SRC1[183:176]
DEST[239:232] ← SRC2[183:176]
DEST[247:240] ← SRC1[191:184]
DEST[255:248] ← SRC2[191:184]
INTERLEAVE_BYTES (SRC1, SRC2)
DEST[7:0] ← SRC1[7:0]
DEST[15:8] ← SRC2[7:0]
DEST[23:16] ← SRC2[15:8]
DEST[31:24] ← SRC2[15:8]
DEST[39:32] ← SRC1[23:16]
DEST[47:40] ← SRC2[23:16]
DEST[55:48] ← SRC1[31:24]
DEST[63:56] ←SRC2[31:24]
DEST[71:64] ← SRC1[39:32]
DEST[79:72] ← SRC2[39:32]
DEST[87:80] ← SRC1[47:40]
DEST[95:88] ← SRC2[47:40]
DEST[103:96] ← SRC1[55:48]
DEST[111:104] ← SRC2[55:48]
DEST[119:112] ← SRC1[63:56]
DEST[127:120] ← SRC2[63:56]
INTERLEAVE_WORDS_256b(SRC1, SRC2)
DEST[15:0] ← SRC1[15:0]
DEST[31:16] ← SRC2[15:0]
DEST[47:32] ← SRC1[31:16]
DEST[63:48] ← SRC2[31:16]
DEST[79:64] ← SRC1[47:32]
DEST[95:80] ← SRC2[47:32]
DEST[111:96] ← SRC1[63:48]
DEST[127:112] ← SRC2[63:48]
DEST[143:128] ← SRC1[143:128]
DEST[159:144] ← SRC2[143:128]
DEST[175:160] ← SRC1[159:144]
DEST[191:176] ← SRC2[159:144]
DEST[207:192] ← SRC1[175:160]
DEST[223:208] ← SRC2[175:160]
DEST[239:224] ← SRC1[191:176]
DEST[255:240] ← SRC2[191:176]
INTERLEAVE_WORDS (SRC1, SRC2)
DEST[15:0] ← SRC1[15:0]
DEST[31:16] ← SRC2[15:0]
DEST[47:32] ← SRC1[31:16]
DEST[63:48] ← SRC2[31:16]
DEST[79:64] ← SRC1[47:32]
DEST[95:80] ← SRC2[47:32]
DEST[111:96] ← SRC1[63:48]
DEST[127:112] ← SRC2[63:48]
INTERLEAVE_DWORDS_256b(SRC1, SRC2)
DEST[31:0] ← SRC1[31:0]
DEST[63:32] ← SRC2[31:0]
DEST[95:64] ← SRC1[63:32]
DEST[127:96] ← SRC2[63:32]
DEST[159:128] ← SRC1[159:128]
DEST[191:160] ← SRC2[159:128]
DEST[223:192] ← SRC1[191:160]
DEST[255:224] ← SRC2[191:160]
INTERLEAVE_DWORDS(SRC1, SRC2)
DEST[31:0] ← SRC1[31:0]
DEST[63:32] ← SRC2[31:0]
DEST[95:64] ← SRC1[63:32]
DEST[127:96] ← SRC2[63:32]
INTERLEAVE_QWORDS_256b(SRC1, SRC2)
DEST[63:0] ← SRC1[63:0]
DEST[127:64] ← SRC2[63:0]
DEST[191:128] ← SRC1[191:128]
DEST[255:192] ← SRC2[191:128]
INTERLEAVE_QWORDS(SRC1, SRC2)
DEST[63:0] ← SRC1[63:0]
DEST[127:64] ← SRC2[63:0]
PUNPCKLBW (128-bit Legacy SSE Version)
DEST[127:0] ← INTERLEAVE_BYTES(DEST, SRC)
DEST[255:127] (Unmodified)
VPUNPCKLBW (VEX.128 encoded instruction)
DEST[127:0] ← INTERLEAVE_BYTES(SRC1, SRC2)
DEST[VLMAX-1:128] ← 0
VPUNPCKLBW (VEX.256 encoded instruction)
DEST[255:0] ← INTERLEAVE_BYTES_128b(SRC1, SRC2)
PUNPCKLWD (128-bit Legacy SSE Version)
DEST[127:0] ← INTERLEAVE_WORDS(DEST, SRC)
DEST[255:127] (Unmodified)
VPUNPCKLWD (VEX.128 encoded instruction)
DEST[127:0] ← INTERLEAVE_WORDS(SRC1, SRC2)
DEST[VLMAX-1:128] ← 0
VPUNPCKLWD (VEX.256 encoded instruction)
DEST[255:0] ← INTERLEAVE_WORDS(SRC1, SRC2)
PUNPCKLDQ (128-bit Legacy SSE Version)
DEST[127:0] ← INTERLEAVE_DWORDS(DEST, SRC)
DEST[255:127] (Unmodified)
VPUNPCKLDQ (VEX.128 encoded instruction)
DEST[127:0] ← INTERLEAVE_DWORDS(SRC1, SRC2)
DEST[VLMAX-1:128] ← 0
VPUNPCKLDQ (VEX.256 encoded instruction)
DEST[255:0] ← INTERLEAVE_DWORDS(SRC1, SRC2)
PUNPCKLQDQ (128-bit Legacy SSE Version)
DEST[127:0] ← INTERLEAVE_QWORDS(DEST, SRC)
DEST[255:127] (Unmodified)
VPUNPCKLQDQ (VEX.128 encoded instruction)
DEST[127:0] ← INTERLEAVE_QWORDS(SRC1, SRC2)
DEST[VLMAX-1:128] ← 0
VPUNPCKLQDQ (VEX.256 encoded instruction)
DEST[255:0] ← INTERLEAVE_QWORDS(SRC1, SRC2)

Intel C/C++ Compiler Intrinsic Equivalents

PUNPCKLBW: __m64 _mm_unpacklo_pi8 (__m64 m1, __m64 m2)
(V)PUNPCKLBW: __m128i _mm_unpacklo_epi8 (__m128i m1, __m128i m2)
VPUNPCKLBW: __m256i _mm256_unpacklo_epi8 (__m256i m1, __m256i m2)
PUNPCKLWD: __m64 _mm_unpacklo_pi16 (__m64 m1, __m64 m2)
(V)PUNPCKLWD: __m128i _mm_unpacklo_epi16 (__m128i m1, __m128i m2)
VPUNPCKLWD: __m256i _mm256_unpacklo_epi16 (__m256i m1, __m256i m2)
PUNPCKLDQ: __m64 _mm_unpacklo_pi32 (__m64 m1, __m64 m2)
(V)PUNPCKLDQ: __m128i _mm_unpacklo_epi32 (__m128i m1, __m128i m2)
VPUNPCKLDQ: __m256i _mm256_unpacklo_epi32 (__m256i m1, __m256i m2)
(V)PUNPCKLQDQ: __m128i _mm_unpacklo_epi64 (__m128i m1, __m128i m2)
VPUNPCKLQDQ: __m256i _mm256_unpacklo_epi64 (__m256i m1, __m256i m2)

Flags Affected

None.

Numeric Exceptions

None.

Other Exceptions

See Exceptions Type 4; additionally

#UD If VEX.L = 1.