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The call stack may contain local variables

The program needs to have a register (e.g. R14) that points

to the stack frame for the currently executing procedure

If a stack overflow occurs, the program should remove all the

stack frames from the stack and then continue execution

Suppose we are traversing an array of records, and we

don't know how many elements are in the array, but we do

know the address of the end of the array. Which is better?

traverse the array with a for loop

traverse the array with a while loop, using a pointer to

the current element

There is an array of records, and each record contains 4 elements.

Each record element is an integer, and their names are

fieldA, fieldB, fieldC, fieldD.

Suppose R5 contains a pointer to an element of the array.

Which instructions will implement *R5.fieldD := *R5.fieldC?

   load  R1,3[R5]
   store R1,2[R5]

   load  R1,2[R5]
   store R1,3[R5]

   lea   R1,2[R5]
   store R1,3[R5]

   lea   R1,3[R5]
   store R1,2[R5]

Suppose we perform a trap instruction to write an array of

characters. The array contains one element which is defined by

   data -1

What will happen?

The character whose code is 65535 will be printed, and this

is unlikely to produce useful output

The computer will see that you are asking it to print a number

rather than a character, so it will print an error message

The string '-1' will be printed

Suppose you have a loop that must execute the body at least one time,

and from then on a Boolean condition determines whether it should

continue. Which looping construct would be more appropriate?

Suppose you have a loop that should not execute the body at all

if a Boolean condition is False. Which looping construct

would be more appropriate?

Suppose there is a compound Boolean conditional

i<n && x[i]>0

Which of the following is NOT a good reason for implementing

this using "short circuiting"?

Short circuiting is more efficient

Short circuiting could get a different result than evaluating

both parts of the condition and calculating the logical and

Short circuiting prevents accessing x[i] if that array

element doesn't exist

Here are some statements about load, store and lea. Most of them

are correct but one is not. Which is the false statement?

Suppose p is a pointer. To put p into R5, use lea R5,p[R0]

Lea can be used to add a constant to a register.

All three instructions -- load, store, lea -- use the effective address,

and they all calculate the effective address exactly the same way.

Store is used to copy a word from a register to memory. It doesn't

matter whether the word is a number, a character, or something else.

Load is used to copy a word from memory to a register. It doesn't

matter whether the word is a number, a character, or something else.

Lea can be used to put a constant into a register.

Here are some statements about load and lea. One of them is correct,

but the others are all misconceptions. Which is the correct statement?

To put an existing pointer p into R1, use lea R1,p[R0]

The only purpose of lea is to put a constant into a register

To create a pointer to x and put it in R1, use lea R1,x[R0]

To put an existing pointer p into R1, use load R1,p[R0]

Whenever you have an integer variable, use load, but if you have

a pointer variable use lea

There is an array of records, and each record contains 4 elements.

Each record element is an integer.

Suppose R5 contains a pointer to an element of the array.

Which instruction will update R5 to make it point to

the next element of the array?