Agner's CPU blog

I recently used the testp tool to measure two instructions in unrolled code 1000 times. rept 1000 mov (r|e)ax, 123 endm I got the following results: mov rax,123 mov eax,123 Clock Core cyc Clock Core cyc 546 442 382 312 558 469 386 312 676 550 388 311 Looking at the results I assumed that it is desir...