testFlt32.c File Reference

Driver to test functions of flt32.c (do not modify) More...

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "field.h"
#include "flt32.h"

Functions
void	printBinaryMSB (int value, int msb)
void	printBinary (int value)
static void	usage ()
static void	print_result (int result)
int	main (int argc, char *argv[])

Detailed Description

This is a driver program to test the functions defined in flt32.h and implemented in flt32.c. The program takes one or more command line parameters and calls one of the methods, then prints the results. To see how to use the program, execute testFlt32 in a terminal window. This will print a usage statement defining how to run the program. The first parameter of the program is always a key defining which function to run. The options are:

• abs absolute value of a floating point number
• all extract sign, exponent, value of a floating point number
• add add two floating point numbers
• bin print binary representation of floating point number
• exp extract exponent of a floating point number
• lm1 find the left most 1 bit in number
• neg negate a floating point number
• sign extract sign of floating point number
• sub subract two floating point numbers
• val extract value of floating point number

A sample execution might be: testFlt32 abs -2.5

which prints

2.5

To use the bin option do testFlt32 bin 1.5

which prints

dec: 1069547520  hex: 0x3FC00000  bin: 0011-1111-1100-0000-0000-0000-0000-0000

This is the decimal, hex and binary representation of the floating point number 1.5. You will find the bin option very useful as you can determine what the correct representation of the answer should be. To test you program, choose values where the correct answer is easy to compute in your head. Then use the bin option to determine what the answer looks like. Finally, run your program and if your answer differs from the answer you computed, use the bin option to see the pattern of your answer. Then you need to read your program, perhaps add debugging output, and determine what your program is actually doing.

Author

Fritz Sieker

Function Documentation

int main	(	int	argc,
		char *	argv[]
	)

Entry point of the program

Parameters

argc	count of arguments, will always be at least 1
argv	array of parameters to program argv[0] is the name of the program, so additional parameters will begin at index 1.

Returns

0 the Linux convention for success.

static void print_result ( int  result )

static

print the value in decimal, hex and binary.

Parameters

result

the value to be printed.

void printBinary

(

int

value

)

Print a 32 bit binary representation of a value.

Parameters

value

the value to be printed

void printBinaryMSB	(	int	value,
		int	msb
	)

Print the binary representation of a value starting at the specified bit position. A separator is printed every 4 bits for easy reading.

Parameters

value	the value to be printed
msb	the bit position to begin printing (31 to 0)

static void usage ( )

static

Print a usage statement, then exit the program returning a non zero value, the Linux convention indicating an error