Assembly Part 3

Question 1

We must use the ____ _____ ______ used by x86-64 in a C programming environment

Answer 1

Register save conventions

Question 2

%rax is used for ______ _____

Answer 2

Return values

Question 3

%rsp must be _____ when control is returned to caller function

Answer 3

Restoed

Question 4

If the ____ function wishes to use following register (rax,rbp, r12, r15), the ____ must save/then restore their original values before returning control to caller

Answer 4

Callee

Question 5

Callee saved registers

Answer 5

Rbp, rbp, r12, r15

Question 6

All other registers must be saved by the ____ if the ____ wishes to preserve their values

Answer 6

Caller

Question 7

Caller saved registers

Answer 7

If register contains data needed by Caller after Calle function returns, caller function must reserve them by pushing them on the sack prior to calling the callee function

Question 8

Callee saved registers

Answer 8

If the Callee function wishes to use these registers, the callee function must push them to the stack prior to using them. Callee must assume the data is these registers is important to the caller function. Calle function must pop these registers back prior to returning to caller. Caller then pops them from stack AFTER callee returns

Question 9

The first 6 parameters are passed form Caller to Callee in register _____, ____, ___, ___, ___, ___

Answer 9

Rdi, rsi, rdx, rcx, r8, r9

Question 10

For parameter passing
Caller must assume that Calle function will ____ values in those registers period to return
If caller needs any of the parameters after the call, must push register to stack prior to call and ____ after call

Answer 10

Trash, pop

Question 11

If the ____ function returns a value to ____, it is returned to register _____

Answer 11

Callee, caller, %rax

Question 12

____ functions make no calls to any other function

Answer 12

Leaf

Question 13

If we want to make calls to other functions, we must save and restore and of the parameter registers as well as %r10, %r11 __________ each call if we still want to use the values they contained prior to the call

Answer 13

Before and after

Question 14

If we use %rbx, %rbp, %r12-%r15 for out funrction’s work, we only save them one at a time (_______) and restore them one at a time (______) of our function

Answer 14

At the beginning, at the end

Question 15

When a function taking variable arguments is called, %rax must be set to the total number of _____ _______ passed to the function in vector register

Answer 15

Floating-point parameters