Does register selection matter to performance on x86 CPUs?
Related there is this old (old enough to be postscript, not PDF!) paper that compared register allocation on the usual 8 registers on Intel vs 32 virtual register that are then allocated to the 8 available registers. Doing the latter created faster code, suggesting that the CPU's register renaming is not as good as it could be. This was on a Pentium 2, so it might be that the results don't hold any more. It's also been at least a decade since I read this paper in detail so I might have remembered it wrong!http://www.smlnj.org/compiler-notes/k32.ps