SDP10_Final_Exam_Part2

1

Consider the following code. Assume the compiler is performing no optimization. Which of the following strategies would improve the speed of this code the most in the case where it returns true?

1

By default, OpenMp _____ assigns loop iterations to threads. When the parallel for block is entered, it assigns each thread the set of loop iterations it is to execute?

1

OpenMP assigns one iteration to each thread. When the thread finishes, it will be assigned the next iteration that hasn’t been executed yet.

1

This is an example of? (IMAGE)

/set elements of array to 0/
void clear_array (int desc, int n){
int i;
for (i = 0; i<n; i++)
dest[i] = 0;
}

/set elements of array to 0, Unrolled X4*/

...
...

1

This is an example of? (IMAGE)

/convert string to lowercase: slow/

void lower1 (char s)
{ int i;
for (i = 0; i < strlen(s); i++)
if (s{i} >= 'A' && s[i] <= 'Z')
s[i] -= ('A' - 'a');
}

/Convert string to lowercase: faster/
void lower2(char s) {
...
...
}

1

In given two C modules which rule will Unix linker use to resolve multiple symbol definition?

1

In C, on a 34-bit x86 machine, the expression (1<<31) results in a negative integer

1

Which of the following move operations is the following instruction an example of: movl (%edx), %eax ?

1

What is the value of the following C expression? x = 0xBC and y = 0x35 (x & !y)

1

In general, which of the following is slowest?

1

Good software design includes writing procedures for code you might otherwise repeat in-line. Pulling code into procedures can help some branch predictors; how else can it improve your program’s performance and/or your compiler’s ability to optimize your code?

1

This is an example of?

1

This is an example of?

1

The code ( a && b ) || (!a && !b) implements —

1

Consider the following code fragment (IMAGE)

int a; int b;
int main(int argc, char * argv[]){
int x;
int y;
… /* some code*/
}

1

Compare the size of int and int*

1

In C, if x is an integer variable, the expression “x << 3” computes x * 8 but does not change the value of x.

1

Using a base address [Eb]%edx=0x1000, and index register [ei]%ecx=0x02, compute the effective address for (IMAGE) :

movl 8(%edx,%ecx, 4), %eax)

1

Using a base address [Eb]%edx=0x1000, and index register [ei]%ecx=0x03, compute the effective address for (IMAGE):

movl 8(%edx, %ecx, 4), %eax

1

What value ends up in EAX after the following code is executed?

1

Two computers A and B with a cache in the CPU chip differ only in that A has an L2 cache and B does not. Which of the following are possible?

1

Which of the following code snippets is fastest ? Assume n is very large(more than ten thousand)

1

Which of the following code snippets is fastest? Assume n is very large (more than ten thousand).

1

Good software design includes writing procedures for code you might otherwise repeat in-line. Pulling code into procedures involves call/return overhead; how else can it HURT your program's performance and/or your compiler's ability to optimize your code?

1

Good software design includes writing procedures for code you might otherwise repeat in-line. Pulling code into procedures can help some branch predictors; how else can it IMPROVE your program’s performance and/or your compiler’s ability to optimize your code?

1

Consider a direct-mapped cache with 256 sets and 16 byte blocks. In this cache the address 0x12345 maps to the same set as which of the following addresses?

1

Parallel processing mechanisms to achieve parallelism in uniprocessor system are:

1

This is an example of?

1

This is an example of? (IMAGE)

1

This is an example of?

1

Program take as input a collection of relocatable object ﬁles and command-line arguments and generate as output a fully linked executable object ﬁle that can be loaded and run:

1

... involve identifying a computation that is performed multiple times (e.g., within a loop), but such that the result of the computation will not change.

1

... construct encloses code, forming a parallel region.

1

... is the default schedule type. Upon entering the loop, each thread independently decides which chunk of the loop they will process.

1

By default, OpenMP _____ assigns loop iterations to threads. When the parallel for block is entered, it assigns each thread the set of loop iterations it is to execute?

1

The _______ directive causes threads encountering the barrier to wait until all the other threads in the same team have encountered the barrier.

final_part2_sdp10

SDP10_Final_Exam_Part2

Consider the following code. Assume the compiler is performing no optimization. Which of the following strategies would improve the speed of this code the most in the case where it returns true?

By default, OpenMp _____ assigns loop iterations to threads. When the parallel for block is entered, it assigns each thread the set of loop iterations it is to execute?

OpenMP assigns one iteration to each thread. When the thread finishes, it will be assigned the next iteration that hasn’t been executed yet.

This is an example of? (IMAGE) /*set elements of array to 0*/ void clear_array (int *desc, int n){ int i; for (i = 0; i<n; i++) dest[i] = 0; } /*set elements of array to 0, Unrolled X4*/ ... ...

This is an example of? (IMAGE) /*convert string to lowercase: slow*/ void lower1 (char *s) { int i; for (i = 0; i < strlen(s); i++) if (s{i} >= 'A' && s[i] <= 'Z') s[i] -= ('A' - 'a'); } /*Convert string to lowercase: faster*/ void lower2(char *s) { ... ... }

In given two C modules which rule will Unix linker use to resolve multiple symbol definition?

In C, on a 34-bit x86 machine, the expression (1<<31) results in a negative integer

Which of the following move operations is the following instruction an example of: movl (%edx), %eax ?

What is the value of the following C expression? x = 0xBC and y = 0x35 (x & !y)

In general, which of the following is slowest?

Good software design includes writing procedures for code you might otherwise repeat in-line. Pulling code into procedures can help some branch predictors; how else can it improve your program’s performance and/or your compiler’s ability to optimize your code?

This is an example of?

This is an example of?

The code ( a && b ) || (!a && !b) implements —

Consider the following code fragment (IMAGE) int a; int b; int main(int argc, char * argv[]){ int x; int y; … /* some code*/ }

Compare the size of int and int*

In C, if x is an integer variable, the expression “x << 3” computes x * 8 but does not change the value of x.

Using a base address [Eb]%edx=0x1000, and index register [ei]%ecx=0x02, compute the effective address for (IMAGE) : movl 8(%edx,%ecx, 4), %eax)

Using a base address [Eb]%edx=0x1000, and index register [ei]%ecx=0x03, compute the effective address for (IMAGE): movl 8(%edx, %ecx, 4), %eax

What value ends up in EAX after the following code is executed?

This is an example of? (IMAGE)

/set elements of array to 0/
void clear_array (int desc, int n){
int i;
for (i = 0; i<n; i++)
dest[i] = 0;
}

/set elements of array to 0, Unrolled X4*/

...
...

This is an example of? (IMAGE)

/convert string to lowercase: slow/

void lower1 (char s)
{ int i;
for (i = 0; i < strlen(s); i++)
if (s{i} >= 'A' && s[i] <= 'Z')
s[i] -= ('A' - 'a');
}

/Convert string to lowercase: faster/
void lower2(char s) {
...
...
}

Consider the following code fragment (IMAGE)

int a; int b;
int main(int argc, char * argv[]){
int x;
int y;
… /* some code*/
}

Using a base address [Eb]%edx=0x1000, and index register [ei]%ecx=0x02, compute the effective address for (IMAGE) :

movl 8(%edx,%ecx, 4), %eax)

Using a base address [Eb]%edx=0x1000, and index register [ei]%ecx=0x03, compute the effective address for (IMAGE):

movl 8(%edx, %ecx, 4), %eax