low level optimization

[Dan Bernstein]

In article <22004 at lanl.gov> jlg at cochiti.lanl.gov (Jim Giles) writes:
> It has been suggested that a program of the following type constitutes
> a counterexample to my previous statements about pointers and aliasing:
> func(i,j)
> char *i;
> float *j;

Well, no, that's not what I said, and you should learn the difference
between char/void pointers and non-char/void pointers.

> However, my original statement about pointers and aliasing was that
> pointer arguments to the _same_ underlying type must be assumed to be
> aliased to each other and to all globals of that type

Jim, I despise the way that you are trying to escape your mistake by
failing to quote what you claim to be responding to. You were arguing
with Doug Gwyn; you said ``I have never seen any of these hypothetical
contexts in which anonymous pointer arguments passed in as parameters
can be safely assumed not to be aliased.'' I showed you how a very
common type of sorting routine provided exactly such a context.

Now are you saying you've never seen such sorting routines? Or do you
admit that you simply haven't thought through the issues here?

---Dan