image/svg+xml PEXTRW—Extract Word Instruction Operand Encoding Description Copies the word in the source operand (second operand) specified by the count operand (third operand) to the destination operand (first operand). The source operand can be an MMX technology register or an XMM register. The destination operand can be the low word of a general-purpose register or a 16-bit memory address. The count operand is an 8-bit immediate. When specifying a word location in an MMX technology register, the 2 least-signifi- cant bits of the count operand specify the location; for an XMM register, the 3 least-significant bits specify the loca- tion. The content of the destination register above bit 16 is cleared (set to all 0s). Opcode/ Instruction Op/ En64/32 bit Mode Support CPUID Feature Flag Description NP 0F C5 / r ib 1 PEXTRW reg , mm , imm8 AV/VSSEExtract the word specified by imm8 from mm and move it to reg , bits 15-0. The upper bits of r32 or r64 is zeroed. 66 0F C5 / r ib PEXTRW reg , xmm , imm8 AV/VSSE2Extract the word specified by imm8 from xmm and move it to reg , bits 15-0. The upper bits of r32 or r64 is zeroed. 66 0F 3A 15 /r ib PEXTRW reg/m16, xmm, imm8 BV/VSSE4_1Extract the word specified by imm8 from xmm and copy it to lowest 16 bits of reg or m16 . Zero-extend the result in the destination, r32 or r64. VEX.128.66.0F.W0 C5 /r ib VPEXTRW reg, xmm1, imm8 AV 2 /VAVXExtract the word specified by imm8 from xmm1 and move it to reg, bits 15:0. Zero- extend the result. The upper bits of r64/r32 is filled with zeros. VEX.128.66.0F3A.W0 15 /r ib VPEXTRW reg/m16, xmm2, imm8 BV/VAVXExtract a word integer value from xmm2 at the source word offset specified by imm8 into reg or m16 . The upper bits of r64/r32 is filled with zeros. EVEX.128.66.0F.WIG C5 /r ib VPEXTRW reg, xmm1, imm8 AV/VAVX512B W Extract the word specified by imm8 from xmm1 and move it to reg, bits 15:0. Zero-extend the result. The upper bits of r64/r32 is filled with zeros. EVEX.128.66.0F3A.WIG 15 /r ib VPEXTRW reg/m16, xmm2, imm8 CV/VAVX512B W Extract a word integer value from xmm2 at the source word offset specified by imm8 into reg or m16. The upper bits of r64/r32 is filled with zeros. NOTES: 1. See note in Section 2.4, “AVX and SSE 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 . 2. In 64-bit mode, VEX.W1 is ignored for VPEXTRW (similar to legacy REX.W=1 prefix in PEXTRW). Op/EnTuple TypeOperand 1Operand 2Operand 3Operand 4 ANAModRM:reg (w)ModRM:r/m (r)imm8NA BNAModRM:r/m (w)ModRM:reg (r)imm8NA CTuple1 ScalarModRM:r/m (w)ModRM:reg (r)imm8NA image/svg+xml In 64-bit mode, using a REX prefix in the form of REX.R permits this instruction to access additional registers (XMM8-XMM15, R8-15). If the destination operand is a general-purpose register, the default operand size is 64-bits in 64-bit mode. Note: In VEX.128 encoded versions, VEX.vvvv is reserved and must be 1111b, VEX.L must be 0, otherwise the instruction will #UD. In EVEX.128 encoded versions, EVEX.vvvv is reserved and must be 1111b, EVEX.L must be 0, otherwise the instruction will #UD. If the destination operand is a register, the default operand size in 64-bit mode for VPEXTRW is 64 bits, the bits above the least significant byte/word/dword data are filled with zeros. Operation IF (DEST = Mem16) THEN SEL := COUNT[2:0]; TEMP := (Src >> SEL*16) AND FFFFH; Mem16 := TEMP[15:0]; ELSE IF (64-Bit Mode and destination is a general-purpose register) THEN FOR (PEXTRW instruction with 64-bit source operand) {SEL := COUNT[1:0]; TEMP := (SRC >> (SEL ∗ 16)) AND FFFFH; r64[15:0] := TEMP[15:0]; r64[63:16] := ZERO_FILL; }; FOR (PEXTRW instruction with 128-bit source operand) {SEL := COUNT[2:0]; TEMP := (SRC >> (SEL ∗ 16)) AND FFFFH; r64[15:0] := TEMP[15:0]; r64[63:16] := ZERO_FILL; } ELSE FOR (PEXTRW instruction with 64-bit source operand) {SEL := COUNT[1:0]; TEMP := (SRC >> (SEL ∗ 16)) AND FFFFH; r32[15:0] := TEMP[15:0]; r32[31:16] := ZERO_FILL; }; FOR (PEXTRW instruction with 128-bit source operand) {SEL := COUNT[2:0]; TEMP := (SRC >> (SEL ∗ 16)) AND FFFFH; r32[15:0] := TEMP[15:0]; r32[31:16] := ZERO_FILL; }; FI; FI; VPEXTRW ( dest=m16) SRC_Offset := Imm8[2:0] Mem16 := (Src >> Src_Offset*16) image/svg+xml VPEXTRW ( dest=reg) IF (64-Bit Mode ) THEN SRC_Offset := Imm8[2:0] DEST[15:0] := ((Src >> Src_Offset*16) AND 0FFFFh) DEST[63:16] := ZERO_FILL; ELSE SRC_Offset := Imm8[2:0] DEST[15:0] := ((Src >> Src_Offset*16) AND 0FFFFh) DEST[31:16] := ZERO_FILL; FI Intel C/C ++ Compiler Intrinsic Equivalent PEXTRW:int _mm_extract_pi16 (__m64 a, int n) PEXTRW:int _mm_extract_epi16 ( __m128i a, int imm) Flags Affected None. Numeric Exceptions None. Other Exceptions Non-EVEX-encoded instruction, see Table2-22, “Type 5 Class Exception Conditions”. EVEX-encoded instruction, see Table2-57, “Type E9NF Class Exception Conditions”. Additionally: #UDIf VEX.L = 1 or EVEX.L’L > 0. If VEX.vvvv != 1111B or EVEX.vvvv != 1111B. This UNOFFICIAL reference was generated from the official Intel® 64 and IA-32 Architectures Software Developer’s Manual by a dumb script. There is no guarantee that some parts aren't mangled or broken and is distributed WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE .