Past exam of the year 1 of the computer science course of the University of Oxford / 2016 / Digital systems, linear algebra, introduction to formal proof / 3 / e / Solution

Keep both the limit and current argument in callee-saved registers, so a call to foo preserves them. Under the same no-delay-slot convention, useAt every break 1, $s1 is the tested value and $v0 is its result. Resuming after the breakpoint continues to the next value; after $n$ the program reaches its separate final stop. The initial guard handles $n<1$ with no calls. Testing equality before incrementing also avoids overflowing the loop variable after the final call when $n$ is the largest positive machine integer. As with the supplied procedures, evaluating all calls assumes enough stack space and representable arithmetic results.