Overhead of Last Branch Record

Overhead of Last Branch Record

Bild des Benutzers Joy A.

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 !

1 Beitrag / 0 neu
Nähere Informationen zur Compiler-Optimierung finden Sie in unserem Optimierungshinweis.