cpu

Have been reading Agner Fog's "The microarchitecture of Intel, AMD and VIA CPUs" and on page 34 he describes "return address prediction": http://www.agner.org/optimize/microarchitecture.pdf 3.15 Returns (all processors except P1) A better method is used for returns. A Last-In-First-Out buffer, called the return stack buffer,remembers the return address every time a call instruction is executed, and it uses this for predicting where the corresponding return will go. This mechanism makes sure that return instructions are correctly predicted when the same subroutine is called from several

Are shift operations O(1) or O(n) ? Does it make sense that computers generally require more operations to shift 31 places instead of shifting 1 place? Or does it make sense the number of operations required for shifting is constant regardless of how many places we need to shift? PS: wondering if hardware is an appropriate tag.. old_timer Some instruction sets are limited to one bit shift per instruction. And some instruction sets allow you to specify any number of bits to shift in one instruction, which usually takes one clock cycle on modern processors (modern being an intentionally vague