> Before dynamic branch prediction... static branch prediction had been used for decades. I'm not sure that's true. At least not the "predict backwards branche

> Before dynamic branch prediction... static branch prediction had been used for decades. I'm not sure that's true. At least not the "predict backwards branches are taken" part. Many RISC cpus did kind of have "predict forwards as not taken", but really thats just speculative execution with the complete absence of any branch prediction at all. IMO "All branches are not taken" is not a prediction. Actual Static Branch prediction is something that seems to have shown up at the exact same time as dynamic branch prediction (ie Pentium and PowerPC 601). Seems to be more of a "well do speculative execution now, what do we do when there is no dynamic prediction?" thing. Maybe there is a multi-chip CPU out there that has proper static prediction but not dynamic? But I checked the likely candidate (The RS/6000 aka POWER1) and it doesn't have any prediction at all (just a hole where the static prediction bits will go later). Probably because static prediction requires support for speculative execution, which it doesn't do.