What you are describing is a Branch Target Buffer (BTB). While local and global predictors describe which direction a direct branch may take, they do little to

What you are describing is a Branch Target Buffer (BTB). While local and global predictors describe which direction a direct branch may take, they do little to help indirect branches. Take the example jmp [rax]. While condition codes for direct branches can be speculated, the value contained within rax isn't easily speculated either. However, we can make note of where jmp [rax] took us the last time we executed. This mapping from branch instruction address to target address is precisely what a BTB is. As for when they were invented, I believe the first paper on them is Lee83; I'm pretty sure the original Pentium had one. Lee83 http://www.eecs.berkeley.edu/Pubs/TechRpts/1983/CSD-83-121.pdf http://www.eecs.berkeley.edu/Pubs/TechRpts/1983/CSD-83-121.p...