5.117 · exercise

Fill in the blank: loops

Fill in the branches and the subtract that open a loop, close it, and count it down.

0 of 5 correct

Fill in the blank

A pre-test loop keeps its test below the body. Complete the line above the body that sends execution to the test before the first pass.

loop_test

Fill in the blank

The test at the bottom of a pre-test loop sends execution back into the body while the signed counter i_r is at most n_r. Complete the branch after cmp i_r, n_r.

b. loop_body

Fill in the blank

A guessing game asks again while the guess is wrong: do { ... } while (guess != secret). After cmp guess_r, secret_r at the bottom, complete the branch back to the top.

b. ask

Fill in the blank

A countdown subtracts 1 from count_r at the end of each pass with sub, which leaves the flags alone. Complete the branch that goes back to tick until the count reaches 0, with no cmp in front.

count_r, tick

Fill in the blank

Count down with one instruction that subtracts 1 from count_r and also sets the flags, so the b.ne after it needs no cmp.

count_r, count_r, 1