By: Felid (Felid.delete@this.mailinator.com), November 15, 2012 3:03 pm
Room: Moderated Discussions
Felid (Felid.delete@this.mailinator.com) on November 15, 2012 2:50 pm wrote:
> SB's IDQ (instruction decode buffer — official name for it) is slightly enhanced: the penalty
> for jump in loop mode (when LSD logic is active) is 0, not 1 clk (as in Nhm). So it's possible
> to read mops across iterations, like: dec + jnz + mov + mov (in a single clk). However, the bottleneck
> here is BTB: shortest time to «predict» the address (even for jmp and call) is 2 clk.
…OTOH, BTB also has loop predictor, which may work with 1 iteration/clk (if the loop is locked in IDQ).
> SB's IDQ (instruction decode buffer — official name for it) is slightly enhanced: the penalty
> for jump in loop mode (when LSD logic is active) is 0, not 1 clk (as in Nhm). So it's possible
> to read mops across iterations, like: dec + jnz + mov + mov (in a single clk). However, the bottleneck
> here is BTB: shortest time to «predict» the address (even for jmp and call) is 2 clk.
…OTOH, BTB also has loop predictor, which may work with 1 iteration/clk (if the loop is locked in IDQ).
