I am having trouble understanding how to implement these problems in C using bit operators. I understand the basic logic gates and when I work them out on paper they work just not code wise. Any insight/help would be great.

/* 
 * bitXor - x^y using only ~ and & 
 *   Example: bitXor(4, 5) = 1
 *   Legal ops: ~ &
 *   Max ops: 14
 *   Rating: 2
 */
int bitXor(int x, int y) {
  return ~((~((~y)&x))&(~((~x)&y)));
}

/* 
 * bitAnd - x&y using only ~ and | 
 *   Example: bitAnd(6, 5) = 4
 *   Legal ops: ~ |
 *   Max ops: 8
 *   Rating: 1
 */
int bitAnd(int x, int y) {
  return ~((~x)|(~y));
}

/* 
 * isEqual - return 1 if x == y, and 0 otherwise 
 *   Examples: isEqual(5,5) = 1, isEqual(4,5) = 0
 *   Legal ops: ! ~ & ^ | + << >>
 *   Max ops: 5
 *   Rating: 2
 */
int isEqual(int x, int y) {
  return !(x ^ y);
}

This is the only one I can get working but I don't think I implemented correctly.

/*
 * isZero - returns 1 if x == 0, and 0 otherwise 
 *   Examples: isZero(5) = 0, isZero(0) = 1
 *   Legal ops: ! ~ & ^ | + << >>
 *   Max ops: 2
 *   Rating: 1
 */
int isZero(int x) {

//FINISHED.

  return !(x!=0);

}

And I can't use loops or conditionals.

Thanks Again.

You don't understand the code or the code does not work properly? It seem to work properly for me.

Maybe its the test code that I have to use to test it is not working right?

I mean for what I have is the logic correct? I'd post the test code that was given but it's like 330+lines long.

If I am not wrong, it is logically correct.

Maybe its the test code that I have to use to test it is not working right?

I mean for what I have is the logic correct? I'd post the test code that was given but it's like 330+lines long.

Some quickie test code for my "playing along at home":

#include <stdio.h>

/* 
 * bitXor - x^y using only ~ and & 
 *   Example: bitXor(4, 5) = 1
 *   Legal ops: ~ &
 *   Max ops: 14
 *   Rating: 2
 */
int bitXor(int x, int y)
{
   return ~((~((~y)&x))&(~((~x)&y)));
}

/* 
 * bitAnd - x&y using only ~ and | 
 *   Example: bitAnd(6, 5) = 4
 *   Legal ops: ~ |
 *   Max ops: 8
 *   Rating: 1
 */
int bitAnd(int x, int y)
{
   return ~((~x)|(~y));
}

/* 
 * isEqual - return 1 if x == y, and 0 otherwise 
 *   Examples: isEqual(5,5) = 1, isEqual(4,5) = 0
 *   Legal ops: ! ~ & ^ | + << >>
 *   Max ops: 5
 *   Rating: 2
 */
int isEqual(int x, int y)
{
   return !(x ^ y);
}

/*
 * isZero - returns 1 if x == 0, and 0 otherwise 
 *   Examples: isZero(5) = 0, isZero(0) = 1
 *   Legal ops: ! ~ & ^ | + << >>
 *   Max ops: 2
 *   Rating: 1
 */
int isZero(int x)
{
   return !(x!=0);
}

int test_unary(const char *name, int (*f)(int), int value)
{
   int result = f(value);
   printf("%s(%d) = %d\n", name, value, result);
   return result;
}

int test_binary(const char *name, int (*f)(int, int), int x, int y)
{
   int result = f(x, y);
   printf("%s(%d,%d) = %d\n", name, x, y, result);
   return result;
}

#define printpair(x) #x,x

int main()
{
   test_binary(printpair(bitXor),  4, 5);
   test_binary(printpair(bitAnd),  6, 5);
   test_binary(printpair(isEqual), 5, 5);
   test_binary(printpair(isEqual), 4, 5);
   test_unary(printpair(isZero), 0);
   test_unary(printpair(isZero), 5);
   return 0;
}

/* my output
bitXor(4,5) = 1
bitAnd(6,5) = 4
isEqual(5,5) = 1
isEqual(4,5) = 0
isZero(0) = 1
isZero(5) = 0
*/

I keep getting errors along these lines when I test bitAnd though these are the same general error type for the rest just a dif number for the should be parts.

Gives 2[0x]. Should be 0[0x0].

Then next line down.

Gives 2[0x2]. Should be -21474836[0x80000000].

For what inputs?

int main()
{
   test_binary(printpair(bitAnd),  0xC0000000, 0x80000000);
   return 0;
}

/* my output
bitAnd(-1073741824,-2147483648) = -2147483648
*/

Here is the code that will test my methods. This is given and should not be modified.

I have tried to attach it.

I've worked out bitAnd and isEqual on paper and they should work but they don't when coded.

isEqual

return (~x & y) >> 3;

bitAnd

(~((~(x | (~y)) | ((~x) | y))) << 1

Added template code for methods looks like you need in order to compile btest.

SOLVED.

Thanks everyone for your help with those concepts! All your input and advice really helped me! THANK YOU! <3! No homo. :)