Rearranging FP expressions

[Doug Gwyn]

In article <4700017 at m.cs.uiuc.edu> wsmith at m.cs.uiuc.edu writes:
>The problem:  How can C know when it is safe to rearrange expressions,
>		especially floating point expressions.

You seem to be assuming that it is obvious what constitutes a
"rearranged" expression.  That is not at all obvious.  The
current proposed C standard spells out what arithmetic order
constraints must be obeyed by a conforming implementation, and
it does appear to have adequately addressed this aspect of
numerical programming needs.