SDP10 Final - Part II

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

• Adder

• Equality

• MUX

• Set membership

What is the difference between logical and bitwise operators. (for example && and &)

• 

  The logical and operator ‘&&’ expects its operands to be boolean expressions (either 1 or 0) and returns a boolean value.
  The bitwise and operator ‘&’ works on Integral (short, int, unsigned, char, bool, unsigned char, long) values and return Integral value.

  If an integral value is used as an operand for ‘&&’ which is supposed to work on boolean values, following rule is used in C.
  …..A zero is considered as false and non-zero is considered as true.
  For example in the following program x and y are considered as 1.

  The ‘&&’ operator doesn’t evaluate second operand if first operand becomes false. Similarly ‘||’ doesn’t evaluate second operand when first operand becomes true. The bitwise ‘&’ and ‘|’ operators always evaluate their operands.

• && (logical and operator) - The left and right operands are boolean expressions. If both the operands are non-zero, then the condition becomes true.
  >
  & (bitwise and operator) - The left and right operands are integral types. Binary AND Operator copies a bit to the result if it exists in both operands.

• это открытый вопрос, выше два примера как можно ответить (этот вариант отмечен как правильный)

Initially byte i of memory is i + 0x20 (mod 256), %eax contains the number 3, and %ebx contains the number 5. What is in %ebx after running x86 movl (%eax), %ebx?

• None of the above

• 3

• 0x25

• 0x23

Choose the correct compilation of rax = (rbx ? rcx : rdx)?

Object files are:

• не вариантов

• не правильный вариант

Thread (as with OpenMP) Which of the following is true?

• нет вариантов

• не правильный ответ

______construct encloses code, forming a parallel region.

• parallel

• не правильный вариант

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

• static

• не правильный вариант

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 program can be greatly improved with a dynamic schedule. 

• не правильный вариант

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

• barrier

• не правильный вариант

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

• 0x0000

• 0x0001

• 0xFFF

• 0x1200

We say that pipelining generally increases throughput. That statement means (select all that are part of the definition of “increases throughput”):

• A entire programs take more time to complete

• B entire programs take less time to complete

• C each instruction takes less time to complete

• D each instruction takes more time to complete

Given that a and b are each either 0 or 1, which one of the following is not always true?

• (a ∧ b) == ((a - b) & 1)

• (a ∧ b) == (a != b)

• (a ∧ b) == ((a + b) >> 1)

• (a ∧ b) == (a ? !b : b)

What is a “caller-save” register?

• A special register that saves who called the procedure

• A program register that the called procedure may not modify

• A program register that the called procedure may modify

• none of the above

A fully-associative cache is like a

• direct-mapped cache with only one set

• direct-mapped cache with only one line per set

• set-associative cache with only one line per set

• set-associative cache with only one set

In C, assuming that an int takes 4 bytes, if array a is declared as follows and a has the value 0x10000, what is the value of the expression a + 2? int a[12];

• 0x10002

• 0x10008

• 0x10004

• 8 plus the contents of location 0x10000

Given unsigned int variables a and b, if a + b == a ^ b is true, then which of the following must also be true?

• a + b == a * b

• a + b == a | b

• a + b == a - b

• a + b == a & b

The bias of any IEEE-style floating point number is 2e−1 − 1, where e is the number of exponent bits. Suppose 010010 is a six-bit IEEE-style floating point number that represents the decimal value 2.5. How many exponent bits does the number have?

• 1

• 5

• 4

• 3

• 2

Consider a six-bit IEEE-style floating-point number with 1 sign, 2 exponent, and 3 fraction bits. Assume the bias is 1. Answers are written in binary. What is the largest denormalized value?

• 0.0111

• 0.01111

• 0.111

• 1111

Consider a six-bit IEEE-style floating-point number with 1 sign, 2 exponent, and 3 fraction bits. Assume the bias is 1. Answers are written in binary. How many of the 26 bit patters in this format are NaNs?

• 1

• 5, 6, or 7

• 8

• between 9 and 15

• 32

Consider a six-bit IEEE-style floating-point number with 1 sign, 2 exponent, and 3 fraction bits. Assume the bias is 1. Answers are written in binary.EEE
What is the smallest non-negative normalized value?

• 1

• 0.1

• 0.0001

• 0

Consider a 5-bit IEEE-style floating point number with 3 exponent bits (bias 3). Which of the following can be expressed in this format? Options are written in binary

• 1.01

• −0.0001

• 11000

• −111

• None of the above can be represented in this format

• None of the above because you can’t have a 5-bit IEEE-style floating point number with 3 exponent bits

Y86 does not have an instruction for jumping to an address stored in a register location; instead the conceptual action jmp %eax can be implemented by

• rmmovl %eax, $1234 ; jmp $1234

• pushl %eax ; ret

• rrmovl %eax, %PC

• All of the above work

• None of the above work

Given int variables a and b, which of the following implements if (!a) b == 0;?

• b &= !!a;

• b &= !-a;

• b &= !a;

• b &= a;

• b &= -a;

• b &= -!a;

• none of the above