Whoa: mov is a rename and doesn't take a uop. In the leadup to Sandy Bridge this seemed hinted at (the SB renamer handles 'zeroing' registers if you use the rig

Whoa: mov is a rename and doesn't take a uop. In the leadup to Sandy Bridge this seemed hinted at (the SB renamer handles 'zeroing' registers if you use the right cliche) but SB still didn't do movs as renames. The fact that Ivy Bridge does is pretty cool, and more applicable than a shift to 3-operand forms, as it won't need a recompile to run older code more quickly. This is pretty cool, at least for those of us who care about this sort of nonsense. I think I have a performance-critical 105-operation loop somewhere that might shed about 8-10 pointless execution slots burned on movs...