Thanks to all who mailed me regarding the problems I was having using -O on the xlc compiler. A new set of binaries are winging their way to me from IBM. Now, I have another problem. Somewhere I have read that it is inadvisable to use -g with -O. Why? I am asking because I wish to use PURIFY, a memory allocation tool and it would be useful if the -g switch could be used. Am I correct in assuming the only reason it shouldn't be used is because the output (post-optimisation) may not be reliable?
