Conditional Control and Loops

Section 7.4 Conditional Control and Loops

Assume that register %rax contains the value 0xFFFFFFFF. Which condition code flags will be set to 1 after the following instruction executes?

add $1, %rax

ZF
Correct!
SF
Incorrect.
CF
Correct!
OF
Incorrect. Consider that 0xFFFF is -1. Adding 1 to -1 should result in a 0 result if there is no overflow, which it does if you perform binary addition.

Assume that %rax contains 12 and %rcx contains 22. Which condition code flags will be set by the following instruction:

cmp %rcx, %rax

Find values for %rax and %rcx for which cmp %rcx, %rax would result in setting all condition code flags to 0.

For which of the following values for %rax and %rcx does the instruction cmp %rcx, %rax not set any flags?

Assume that %rax contains 0. Check all the flags that would be set by the following instruction:

test %rax, %rax

Given the following initial state:

%rcx 0x1

%rdx 0x8

What value is in the %rdx register after the following code is executed? Enter your answer in hex.

cmp $rcx, %rdx
jge label
inc %rdx
label:
sub $2, %rdx

Your Answer:

Under what conditions would the following instructions jump to label Foo?

cmp %rax, %rcx

jle Foo