Common c control flow instructions, C/C++ Programming

Assignment Help:

In this Lab you will code 8086 assembler equivalents (Virgo) for common C control flow instructions. This will give you an appreciation for how control flow is implemented in assembly (and machine) language. You will find that it is not quite as simple as it is with a high-level language. See special instructions for submission at the end of this file.This lab contains a BONUS section worth an additional 4 points on your final mark! Here is a list of the C instructions for which you will code assembly language equivalents:

If statement
C code
if (condition) {
statements
}
If-Else statement
C code
if (condition) {
then_statements
} else {
else_statements
}
While loop
C code
while (condition) {
statements
}
Do-While loop
C code
do {
statements
} while (condition);
For loop
C code
for (initialization; condition; increment) {
statements
}
Switch statement
C code
switch (expression) {
case val_1:
case_1_statements
case val_2:
case_2_statements

case val_n:
case_n_statements
default:
default_statements
}
Normally, C Switch statements have a Break statement at the end of each case. You will also need to implement Break and Continue statements which can be used inside some of these control flow instructions.
Break statements
A Break statement can occur inside a C loop or Switch statement. It is implemented as an unconditional branch to a label immediately following the loop or Switch statement.
Continue statements
A Continue statement can occur inside a C loop. For While and Do-While loops, it is implemented as an unconditional branch to a label for the condition test of the While or Do-While statement.
A Continue statement in a For loop is implemented as an unconditional branch to a label immediately preceding the code to implement the increment statement.

Note that the assembly code you develop for these C-structure equivalents need only be shown as pseudocode; that is, since the actual conditions are not given, neither the test for the condition nor the jump statement for this test can actually be shown. Typically, the test will be some sort of compare (cmp) instruction and the jump will be one of the many jmp variants. It is only necessary to state that a test must be done at a certain point and that a jump relating to that test should then be done at some other point. In the second and third parts of the assignment, you will code and test two of these instructions using actual assembly language.

Coding for the IF statement is given below as an example of the syntax required. Use a similar syntax for the remaining control flow instructions.

If statement
C code
if (condition) {
statements
}
Assembler pseudo-code
IF:
test condition
jump to Next if false
assembly code for statements
Next:
Part A) Write pseudo-code for the remaining five control flow statements given above and for the Break and Continue statements.
Part B) Code a Do-While loop for the following C-code example in Virgo assembly language (assume
int's are words of 2 bytes). Place each C-code statement at the appropriate place in your assembly code as a comment:
int x = 0;
do
{
x++;
if (x == 5) continue;
sum += x;
} while (x < 10);
Bonus) Code a Switch statement for the following C-code example in assembly language (assume int's are words of 2 bytes). Place each C-code statement at the appropriate place in your assembly code as a comment:

int a;
int b = 0x12;
int c = 0x34;
int p = some constant value;
switch (p)
{
case 0: a = b + c; break;
case 1: a = b - c; break;
case 3: a = b; break;
case 7: a = c; break;
default: a = 0;
}


Related Discussions:- Common c control flow instructions

Luminous Jewels - The Polishing Game, Byteland county is very famous for lu...

Byteland county is very famous for luminous jewels. Luminous jewels are used in making beautiful necklaces. A necklace consists of various luminous jewels of particular colour. Nec

Example of structure, Example of structure: struct item {       ...

Example of structure: struct item {                 int element;                 node_ptr next; }; typedef node_ptr stack; stack create(void) {

Msp, A Padovan string P(n) for a natural number n is defined as: P(0) = ‘X...

A Padovan string P(n) for a natural number n is defined as: P(0) = ‘X’ P(1) = ‘Y’ P(2) = ‘Z’ P(n) = P(n-2) + P(n-3), n>2 where + denotes string concatenation. For a string of t

Write a c program to input three real numbers, Write a C program to input t...

Write a C program to input three real numbers and  print them out as follows : The first variable is ....... and the second one is ...... The last variable is .......... T

Return by reference, Return by reference: The return value of the funct...

Return by reference: The return value of the function must be an address variable.  In following program the function returns the value of x or y and their types are declare

Define register simply with bit fields, Define register with bit fields? ...

Define register with bit fields? We could define register simply with bit fields: struct DISK_REGISTER { unsigned ready:1; unsigned error_occured:1; unsigned disk_spinni

Problem : Compiler Design - Limit the methods, Rahul is a newbie to the pro...

Rahul is a newbie to the programming and while learning the programming language he came to know the following rules: · Each program must start with ''{'' and end with '

Creating shopping carts, how to create a shopping cart and sibmit the code ...

how to create a shopping cart and sibmit the code segment on screan

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd