Lab 1 - Manipulating bits

The assignment has now been graded. A few interesting things happened:

• We discovered our testing code wasn't very good. So we ran every assignment using both the original tests plus a set of augmented tests. Your grade was based on how you did on the original tests, but the hardcopy version we return to you shows how you did on the augmented tests. For your interest, an improved version of btest.c is available.
• DLC didn't check for all the rules we wanted to enforce. In particular, it allowed you to use arrays. Many people therefore used table lookup to solve bitCount. We allowed all solutions that passed DLC.

Some people got very competitive, trying to minimize the number of operations. For those of you who are interested, here are the results of the "best" solutions:

• Click here to see the minimum number of operations for each function and which teams achieved this. This list excludes solutions that used operations we intended to make illegal (e.g., arrays).
• We created a composite solution showing optimal implementations of each function.

The due date for the assignment has been shifted by 24 hours. It is now due 11:59pm, Thursday, Sept. 13, 2001.

A number of minor errors have been found, mostly in the comments or in the writeup. The following is a log of changes that have been made to the homework files. None of them affects the code you need to write:

• 04-Sept.
  • Added handin rule to Makefile.
  • Created handin directory.
• 03-Sept.
  • The writeup incorrectly listed logicalShift as counting 2 points. It counts 3.
  • Comments and code for getByte were inconsistent in the name of the second argument. It should be n
• 31-Aug.
  • Comment added to getByte indicating allowed operations.
  • Comment indicating number of allowed operations in bitNor set to 8.
  • isGreater included in writeup.