Bitwise Operations

Question 1

Bitwise Logical Instructions do what?

Answer 1

Manipulate one or more bits in a register

Question 2

A instruction ending in a s means?

Answer 2

Depending on the result of the operation the corresponding flags will be set

Question 3

tst is an alias for which instruction?

Answer 3

ands xzr, Xn, Xm

Question 4

Logical Shifts result in?

Answer 4

The bit pattern is moved left or right a number of bits depending on the argument. Empty spaces created when shifting are filled with a zero and bits shifted out of the register are lost

Question 5

Arithmetic Shifts result in?

Answer 5

The function the same as Logical shifts but the sign bit is preserved

Question 6

Rotations result in?

Answer 6

Depending on the direction the bit is rotated from the right and inserted on the left (right rotation) or vise-versa

Question 7

Sign Extensions result in?

Answer 7

The sign bit is duplicated into the bits outside of the scope of the instruction. So sign extend byte copies the sign bit to bits 7-31 (w registers) (to bit 63 with x registers)

Question 8

Unsigned Extensions result in?

Answer 8

0 is placed into all the bits outside of the scope of the instruction. So unsigned extend byte places 0 in bits 7-31 (w registers) (to bit 63 with x registers)