Bit-Level Integer Coding Rules:

In several of the following problems, we will artificially restrict what

programming constructs you can use to help you gain a better

understanding of the bit-level, logic, and arithmetic operations of C. In

answering these problems, your code must follow these rules:

1. Assumptions

Integers are represented in twos-complement form.

Right shifts of signed data are performed arithmetically.

Data type int is w bits long. For some of the problems, you will be given a specific value for w, but otherwise your code should work as long as w is a multiple of 8. You can use the expression sizeof(int)<<3 to compute w.

2. Forbidden

Conditionals (if or ?:), loops, switch statements, function calls, and macro invocations.

Division, modulus, and multiplication.

Relative comparison operators (<, >, <=, and >=).

3. Allowed operations

All bit-level and logic operations.

Left and right shifts, but only with shift amounts between 0 and w 1. Addition and subtraction.

Equality (==) and inequality (!=) tests. (Some of the problems do not allow these.)

Integer constants INT_MIN and INT_MAX.

Casting between data types int and unsigned, either explicitly or implicitly.

Write code for a function mul3div4 that, for integer argument x, computes (3 x/4) but follows the bit-level integer coding rules (see above). Your code should replicate the fact that the computation 3*x can cause overflow.