Section 9.1 Diving into Assembly: Basics
Exercise 9.1.2. Relationship Between C Code and Assembly Code.
- One line of C code always translates into exactly one assembly instruction.
- Incorrect.
- One line of C code often translates into one or more assembly instructions.
- Correct!
- One line of C code always translates into two or more assembly instructions.
- close, but incorrect!
- There is no relationship between C code and assembly code.
- Incorrect.
Which of the following statements is true about the relationship between a single line of C code and assembly code?
Exercise 9.1.3. General-Purpose Registers.
x0- Correct!
x30- Correct!
pc- Incorrect.
pcis the program counter. It cannot be directly written to. x2- Correct!
Which of the following x86-64 registers are general purpose?
Exercise 9.1.4. Special Use Cases for Registers.
Answer.
Did you know? Register x0 is also used to hold the return value and the first argument to a function!
Exercise 9.1.5. Registers - Capacity.
Order the following registers from smallest to largest capacity.
Exercise 9.1.6. Identifying Operand Types.
For each of the following operands, label it as a (C)onstant, (R)egister, or (M)emory operand.
x3[x3][x3, #8][x3, x4]#0x5#8
Hint.
Just enter the letter as your answer (one of C, R, or M)
Exercise 9.1.7. Identifying Operand Types.
The following tables provide the contents of several registers and memory locations.
| Address | Value |
|---|---|
| 0xFA00 | 0x5F |
| 0xFA08 | 0x16 |
| 0xFA10 | 0x42 |
| 0xFA18 | 0x9C |
| Register | Value |
|---|---|
| x0 | 0xFA08 |
| x1 | 0x10 |
For each of the following operands, determine the associated value in hex.
x0x1[x0][x0, #8][x0, x1]#0xFA18
Hint.
Remember to include the 0x prefix in your answers.
