Create a diff that adds comments explaining the code.

Creating diff with comments code

```c
float Q_rsqrt( float number ) {
  long i;
  float x2, y;
  const float threehalfs = 1.5F;

  x2 = number * 0.5F;
  y  = number;
  i  = * ( long * ) &y;
  i  = 0x5f3759df - ( i >> 1 );
  y  = * ( float * ) &i;
  y  = y * ( threehalfs - ( x2 * y * y ) );
  // y  = y * ( threehalfs - ( x2 * y * y ) );

  return y;
}
```

Q_rsqrt(float number)

```diff
 float Q_rsqrt( float number ) {
+  // Declare variables
   long i;
   float x2, y;
   const float threehalfs = 1.5F;

+  // Multiply number by 0.5 and store result in x2
   x2 = number * 0.5F;
+  // Store number in y
   y  = number;
+  // Convert the bits of y into a long and store in i
   i  = * ( long * ) &y;
+  // Perform a bitwise shift and subtraction on i, and store result back in i
   i  = 0x5f3759df - ( i >> 1 );
+  // Convert the bits of i back into a float and store in y
   y  = * ( float * ) &i;
+  // Perform the final calculation and store result back in y
   y  = y * ( threehalfs - ( x2 * y * y ) );
   // y  = y * ( threehalfs - ( x2 * y * y ) );

+  // Return the final result
   return y;
 }
```

Q_rsqrt Algorithm

Create a diff that adds comments explaining the code.

```c
float Q_rsqrt( float number ) {
  long i;
  float x2, y;
  const float threehalfs = 1.5F;

  x2 = number * 0.5F;
  y  = number;
  i  = * ( long * ) &y;
  i  = 0x5f3759df - ( i >> 1 );
  y  = * ( float * ) &i;
  y  = y * ( threehalfs - ( x2 * y * y ) );
  // y  = y * ( threehalfs - ( x2 * y * y ) );

  return y;
}
```

```diff
 float Q_rsqrt( float number ) {
+  // Declare variables
   long i;
   float x2, y;
   const float threehalfs = 1.5F;

+  // Multiply number by 0.5 and store result in x2
   x2 = number * 0.5F;
+  // Store number in y
   y  = number;
+  // Convert the bits of y into a long and store in i
   i  = * ( long * ) &y;
+  // Perform a bitwise shift and subtraction on i, and store result back in i
   i  = 0x5f3759df - ( i >> 1 );
+  // Convert the bits of i back into a float and store in y
   y  = * ( float * ) &i;
+  // Perform the final calculation and store result back in y
   y  = y * ( threehalfs - ( x2 * y * y ) );
   // y  = y * ( threehalfs - ( x2 * y * y ) );

+  // Return the final result
   return y;
 }
```