Question

Finish buildFloat():

It does three things:

1. Given exponent it computes exponentPattern.
   • If exponent is less than or equal to DENORMALIZED_POWER_OF_2 then exponentPattern should be EXPONENT_DENORMALIZED_BIT_PATTERN. (Alternatively, if the hidden bit is off in the mantissa then the number is denormalize and exponentPattern should be EXPONENT_DENORMALIZED_BIT_PATTERN.)
   • If exponent is greater than or equal to INFINITE_POWER_OF_2 then exponentPattern should be EXPONENT_INFINITE_BIT_PATTERN.
   • Otherwise, compute exponentPattern from exponent and EXPONENT_BIAS.
2. Turn off the hidden bit in mantissa. (If you are clever you can turn MANTISSA_HIDDEN_BIT into a mask to remove just that one bit.)
3. Reconstitute the floating point number into number by combining exponentPattern shifted into the proper position with mantissa shifted into the proper position.

It returns number.

// PURPOSE: To return the float with exponent 'exponent' and mantissa-field // 'mantissa'.

float buildFloat (int exponent, unsigned int mantissa )

{

unsigned int exponentPattern;

float number;

// YOUR CODE HERE to compute exponentPattern

// YOUR CODE HERE to turn off the hidden bit in the mantissa

*((unsigned int*)&number) = 0; // CHANGE THAT 0!

// It should be a bitwise integer expression

// combining exponentPattern and mantissa return 0; }

Answer 1

you have not mentioned any signed bit parameter in buildFloat function so I assume that you are using +ve no, you can change it var.raw.sign to -1 if required.

If you want anything else please comment.

#include <math.h>
#include <stdio.h>

float buildFloat (int exponent, unsigned int mantissa );
typedef union {

        float f;
        struct
        {
                unsigned int mantissa : 23;
                unsigned int exponent : 8;
                unsigned int sign : 1;

        } raw;
} myfloat;

unsigned int convertToInt(int* arr, int low, int high)
{
        unsigned f = 0, i;
        for (i = high; i >= low; i--) {
                f = f + arr[i] * pow(2, high - i);
        }
        return f;
}

int main()
{
       buildFloat(128,1048576);  for 2.250000 repesentation is 0 | 10000000 | 00100000000000000000000     0 | 128 |1048576
}
float buildFloat (int exponent, unsigned int mantissa ){
        float number;
        myfloat var;
        var.raw.mantissa = mantissa;
        var.raw.exponent = exponent;
        var.raw.sign = 0; // make it -1 for negative no..
        printf("The float value in"
                        " IEEE-754 representation is : \n");
        printf("%f", var.f);

}