CS 375, Compilers: Example Questions for Midterm Exam

Addressing:

Consider the following declarations:

     type complex = record  re, im: real  end;

          person  = record name:     alfa;
                           age:      integer;
                           location: complex;
                           weight:   real;
                           salary:   real     end;

     var  people = array [ 7..14, (austin, dallas, houston)]
                          of person;

Assuming integer and boolean are 4 bytes, and alfa, pointers and real are 8 bytes, how much storage is occupied by the array people?
Calculate the effective address of this expression; show how it was derived and give the aref form.
```
   people[10,dallas].location.im
```

Other Questions:

Show how an operator precedence parser would parse the string:
```
     A - (B / C - D) / E + F
```
Show the contents of the stacks at each step; produce a tree as output.
Give one advantage and one disadvantage of hashing as a method of symbol table organization.
Consider the regular expression (a | b)*b+b* . What is the simplest regular expression that denotes the same language?
Give the allowable form of productions for a Regular grammar.
Consider the following grammar:
```
 S  -->  a S
 S  -->  S b
 S  -->  b
```
- What kind of grammar is this in the Chomsky hierarchy?
- What kind of language does it denote?
- Is there a simpler kind of grammar that denotes the same language? If so, give the grammar; if not, explain why not.
Briefly and clearly define the following terms: ... 8 terms chosen from the vocabulary list on the study guide.