Well, sure, but I was thinking along the lines of "reserving a spot on the stack and reserving a register seem like about the same level of clever", especially

Well, sure, but I was thinking along the lines of "reserving a spot on the stack and reserving a register seem like about the same level of clever", especially thinking about how mixed register/stack argument passing works in even relatively stupid C compilers. Eliding the entire loop seems relatively similarly clever for either architecture, but would've counted as cheating in the frame I was pondering from. Still neat to see even if x86 asm continues to make my eyes cross ;)