Chapter 2, Problem 2.97HW

Explanation of Solution

Function definition for “float_i2f()” function:

The implementation for “float_i2f()”function is given below:

//Header file

#include <stdio.h>

#include <assert.h>

#include <limits.h>

//Declare the float_bits in unsigned data type

typedef unsigned float_bits;

//Function declaration for float_i2f function

float_bits float_i2f(int i);

//Function definition for compute the bit length

int findBitsLength(int i)

{

  //Check bit length

  if ((i & INT_MIN) != 0)

  {

    //Returns value "32"

    return 32;

  }

  //Assign the unsigned number

  unsigned unum = (unsigned)i;

  //Initializes the length is "0"

  int len = 0;

  //Check the length

  while (unum >= (1<<len))

  {

    len++;

  }

  //Returns the length

  return len;

}

//Function definition to generate mask

unsigned findBitsMask(int bl)

{

  //Returns the bits mask

  return (unsigned) -1 >> (32-bl);

}

//Fnction definition for compute (float)i

float_bits float_i2f(int i)

{

  //Declare variable

unsigned signBit, exponentBit, fractionBit, remainingBit, exp_signBit,rp;

  //declare variable bits and float bits

  unsigned b, fb;

  //Assign bias value

  unsigned biasValue = 0x7F;

  //If "i" is "0", then

  if (i == 0)

  {

    //Assign all bits to "0"

    signBit = 0;

    exponentBit = 0;

    fractionBit = 0;

    //Returns the value

return signBit << 31 | exponentBit << 23 | fractionBit;

  }

  //If "i" is "INT_MIN", then

  if (i == INT_MIN)

  {

    //Assign given value to each bit

    signBit = 1;

    exponentBit = biasValue + 31;

    fractionBit = 0;

    //Returns the value

return signBit << 31 | exponentBit << 23 | fractionBit;

  }

  //Assign sign bit is "0"

  signBit = 0;

  /* For two's complement */

  /* If "i" is less than "0", then */

  if (i < 0)

  {

    //Assign sign bit to "1"

    signBit = 1;

    //Assign "i" to "i - i"

    i = -i;

  }

/* Compute bits length by calling function "findBitsLength" */

  b = findBitsLength(i);

  //Compute float bits

  fb = b - 1;

  //Compute exponent value

  exponentBit = biasValue + fb;

  //Compute remaining bit value

  remainingBit = i & findBitsMask(fb);

  //If "fb" is less than "23", then

  if (fb <= 23)

  {

    //Assign fraction bit and except bit value

    fractionBit = remainingBit << (23 - fb);

    exp_signBit = exponentBit << 23 | fractionBit;

  }

  //Otherwise

  else

  {

    //Compute offset value

    int offsetValue = fb - 23;

    //To find round middle value

    int rm = 1 << (offsetValue - 1);

    //For round part

    rp = remainingBit & findBitsMask(offsetValue);

    //Assign fraction bit and except bit value

    fractionBit = remainingBit >> offsetValue;

    exp_signBit = exponentBit << 23 | fractionBit;

    /*Check if it is round to even */

    if (rp < rm)

    {

    }

    //If round to odd, then

    else if (rp > rm)

    {

 ...