sentences:  Starting with Barcelona-based processors, AMD introduced the "SSE4a" instruction set, which has 4 SSE4 instructions and 4 new SSE instructions.These instructions are not found in Intel's processors supporting SSE4.1 and AMD processors only started supporting Intel's SSE4.1 and SSE4.2 (the full SSE4 instruction set) in the Bulldozer-based FX processors.With SSE4a the misaligned SSE feature was also introduced which meant unaligned load instructions were as fast as aligned versions on aligned addresses.