Overhead of Last Branch Record

Overhead of Last Branch Record

Hi folks,

a) Can you give a rough idea of how much LBR slows down program execution of common programs - both CPU and IO intensive ? I could not see any substantial overhead (~2-5%) with LBR turned ON for some microbenchmarks.

b) Is branch prediction mechanism turned OFF when LBR tracing is ON ?

Thanks !

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Para obter mais informações sobre otimizações de compiladores, consulte Aviso sobre otimizações.