CIS 314代做、代写C/C++程序、代做IA32 register、代写C/C++设计

日期：2018-10-30 10:02

Winter ’18 CIS 314 Midterm A Name: SID:

1. [5] What is the decimal value of the byte 0x38, interpreted as an 8-bit unsigned

int Show your work:

2. [5] What is the decimal value the of byte 0x38, interpreted as an 8-bit (signed) int

Show your work:

3. [5] What is the decimal value of the byte 0x83, interpreted as an 8-bit (signed) int?

Show your work:

4. [10] What is the hex value of x >> 4, assuming x is a 32-bit (signed) int with hex

value 0x83838383? Show your work:

5. [15] What is the decimal value of 0xC1540000, interpreted as an IEEE-754 signleprecision

float Show your work:

6. [15] Consider the follow C function:

int is NegativeZero(float f);

Implement the above function such that it will return 1 if f == -0.0f, 0 otherwise. Do

this using only bitwise operators (ands, ors, shifts) and integer equality (==); no

floating-point operations, if statements, or loops. Hint: access the bit representation

of f by casting its address to an unsigned-int pointer (similar to assignment 2), then

test the value at this pointer against the expected IEEE-754 bit representation for

-0.0 as hex. Comment your code:

7. [20] Consider the following IA32 code, resulting from compiling a function int f(int

x, int y):

pushl %ebp

movl %esp, %ebp

movl 8(%ebp), %eax

movl 12(%ebp), %ecx

leal 10(%ecx,%eax,8), %eax

popl %ebp

retl

a. (15) Convert the above code to C. Comment your code:

b. (5) What is returned by f(1, 2)? Show your work:

8. [25] Consider the following C code:

int popCount(unsigned int x) {

int result = 0;

do {

result += x & 0x1;

x >>= 1;

} while (x);

return result;

}

a. (10) The above code counts the number of 1s in the bit representation of x.

Rewrite the code (in C) to use a label and goto statement rather than a loop.

Comment your code:

b. (15) Convert your C code from part A above into IA32, ensuring that register use

is correct with respect to the IA32 register conventions. Comment your code: