Attempting to decode: 66 0f 3a 15 c8 00 iclass PEXTRW_SSE4 category SSE ISA-extension SSE4 ISA-set SSE4 instruction-length 6 operand-width 32 effective-operand-width 32 effective-address-width 32 stack-address-width 32 iform-enum-name PEXTRW_SSE4_GPR32_XMMdq_IMMb iform-enum-name-dispatch (zero based) 0 iclass-max-iform-dispatch 2 Nominal opcode position 3 Nominal opcode 0x15 Operands # TYPE DETAILS VIS RW OC2 BITS BYTES NELEM ELEMSZ ELEMTYPE REGCLASS # ==== ======= === == === ==== ===== ===== ====== ======== ======== 0 REG0 REG0=EAX EXPLICIT W D 32 4 1 32 INT GPR 1 REG1 REG1=XMM1 EXPLICIT R DQ 128 16 4 32 INT XMM 2 IMM0 0x0(8b) EXPLICIT R B 8 1 1 8 UINT INVALID Memory Operands MemopBytes = 0 ATTRIBUTES: MANDATORY 66 PREFIX EXCEPTION TYPE: SSE_TYPE_5 SSE Vector length: 128 Number of legacy prefixes: 1 ISA SET: [SSE4] 0 CPUID GROUP NAME: [SSE4] 0 CPUID RECORD NAME: [SSE4] {Leaf 0x00000001, subleaf 0x00000000, ECX[19:19]} = 1