Attempting to decode: 0f 38 00 ff iclass PSHUFB category MMX ISA-extension SSSE3 ISA-set SSSE3MMX instruction-length 4 operand-width 32 effective-operand-width 32 effective-address-width 32 stack-address-width 32 iform-enum-name PSHUFB_MMXq_MMXq iform-enum-name-dispatch (zero based) 1 iclass-max-iform-dispatch 4 Nominal opcode position 2 Nominal opcode 0x00 Operands # TYPE DETAILS VIS RW OC2 BITS BYTES NELEM ELEMSZ ELEMTYPE REGCLASS # ==== ======= === == === ==== ===== ===== ====== ======== ======== 0 REG0 REG0=MM7 EXPLICIT RW Q 64 8 1 64 INT MMX 1 REG1 REG1=MM7 EXPLICIT R Q 64 8 1 64 INT MMX Memory Operands MemopBytes = 0 ATTRIBUTES: NOTSX EXCEPTION TYPE: MMX_MEM ISA SET: [SSSE3MMX] 0 CPUID GROUP NAME: [SSSE3MMX] 0 CPUID RECORD NAME: [SSSE3] {Leaf 0x00000001, subleaf 0x00000000, ECX[9:9]} = 1 1 CPUID RECORD NAME: [MMX] {Leaf 0x00000001, subleaf 0x00000000, EDX[23:23]} = 1