Re: Flags -g and -O give very different results

[Segher Boessenkool <segher at kernel dot crashing dot org>]

> Any pointers for how to track this sort of thing down?  What kind  
> of things should I look for?

Mostly casts from one pointer type to another (you probably can
ignore void* and char* though).

Things like

long f(int *x) {
	return *(long *)x;
}

are the most common problems.  So,

	*(<some type> *)<some data address>

[there are more subtle things as well -- but almost all of the
time, the problem is gross implicit violation of the C99 data
aliasing rules).


Segher