distorm

Fast x86 and x86-64 disassembler library

diStorm is a binary stream disassembler of x86 instructions. It can operate in 16, 32, and 64 bit modes, and supports FPU, MMX, SSE, SSE2, SSE3, SSE4, 3DNow! (with extensions), x86-64, VMX, AMD SVM, and AVX instruction sets. diStorm was written to decode every instruction quickly and accurately, with robust handling of valid and unused prefixes. The output is a special structure that can describe any x86 instruction, and later be formatted into text for display.