Final Exam Solutions
CS 213 Fall 2001
Copyright By PowCoder代写 加微信 powcoder
Expression Always True?
1. (x
2. ((x+y)<<4) + y-x == 17*y+15*x Y: Associative, commutative, distributes
3. ~x+~y+1 == ~(x+y) Y: (-x-1)+(-y-1)+1 == -(x+y)-1
4. ux-uy == -(y-x) Y
5. (x >= 0) || (x < ux) N: x = -1. Comparison x < ux is never true.
6. ((x >> 1) << 1) <= x Y: x>>1 rounds toward minus infinity.
7. (double)(float) x == (double) x N: Try x = Tmax.
8. dx + dy == (double) (y+x) N: Try x=y=Tmin.
9. dx + dy + dz == dz + dy + dx Y: Within range of exact representation by double’s.
10. dx * dy * dz == dz * dy * dx N: Try dx=Tmax, dy=Tmax-1, dz=Tmax-2
int looper(int n, int *a) {
int x = 0; // 2 points
for(i = 0; i < n; i++) { // 2points
if (a[i] > x) or if (!(a[i] <= x)) // 2 points
x = a[i]; // 2 points
x++; // 2 points
typedef struct node {
unsigned short;
struct node *next;
struct node *prev;
void func() {
node_t *m;
m = n.next->prev;
m->y /= 16;
A. 0xbffff5b0
B. char *, int, file_spec *, l_node, int *
C. descriptor, len, file, root, &result
B. int, struct file_spec *, int, struct l_node *, int
C. len, file, root.tag, root.next, &result
Cache m C B E S t s b
1. 32 1024 4 4 64 24 6 2
2. 32 1024 4 256 1 30 0 2
3. 32 1024 8 1 128 22 7 3
4. 32 1024 8 128 1 29 0 3
5. 32 1024 32 1 32 22 5 5
6. 32 1024 32 4 8 24 3 5
copy_matrix():
a. ROWS=128, COLS=128: 100%
b. ROWS=128, COLS=192: 25%
c. ROWS=128, COLS=256: 100%
copy_n_flip_matrix():
a. ROWS=128, COLS=128: 25%
b. ROWS=128, COLS=192: 25%
copy_n_flip_matrix2()
a. ROWS=128, COLS=128: 25%
b. ROWS=192, COLS=128: 75%
Version Measured CPE Theoretical CPE
A1 4.00 4/1 = 4.00
A2 2.67 8/3 = 2.67
A3 1.67 4/3 = 1.33
A4 1.67 4/3 = 1.33
A5 2.67 8/3 = 2.67
printed 10 times
counter==1 in first line
counter==2 in last line
Output is:
counter = 1
counter = 3
counter = 3
Because signals are not queued, the program
does NOT print the same value of counter each time.
The possible values are counter == {1,2,3,4,5}
depending on the scheduling of the child processes.
**********
Problem 10
**********
First Fit:
40a, 24a, 24a
40a, 24a, 24a, 48a
40a, 24a, 24f, 48a
40f, 24a, 24f, 48a
24a, 16f, 24a, 24f, 48a
24a, 16f, 24a, 72f
24a, 16f, 24a, 56a, 16f
24a, 40f, 56a, 16f
40a, 24a, 24a
40a, 24a, 24a, 48a
40a, 24a, 24f, 48a
40f, 24a, 24f, 48a
40f, 24a, 24a, 48a
40f, 24a, 24a, 48f
40f, 24a, 24a, 56a
64f, 24a, 56a
make_header:
B. header = (size & ~0x7) | (alloc & 0x1) | ((palloc & 0x1) << 1);
set_palloc_in_header:
A. *(long *)block = (curr & ~0x2) | ((palloc & 0x1) << 1);
程序代写 CS代考 加微信: powcoder QQ: 1823890830 Email: powcoder@163.com