Bit manipulation

This is an implementation of the following functions for bit manipulation in C:

• bitAnd - computes x&y using only ~ and |
• getByte - extracts byte n from word x
• logicalShift - shift x to the right by n, using a logical shift
• bitCount - returns count of number of 1's in word
• bang - computes !x without using !
• tmin - returns minimum two's complement integer
• fitsBits - returns 1 if x can be represented as an n-bit, two's complement integer
• divpwr2 - computes x/(2^n), for 0 <= n <= 30
• negate - return -x
• isPositive - returns 1 if x > 0, return 0 otherwise
• isLessOrEqual - if x <= y then return 1, else return 0
• ilog2 - returns floor(log base 2 of x), where x > 0

How to run and test

The Makefile in this directory compiles bits.c with additional code to create a program (or test harness) named btest.

To compile and run the btest program, type:

unix> make btest
unix> ./btest [optional cmd line args]