SIMPLE: A language-independent tree IR

[Joe Buck]

Joseph:

> > There may be other C assumptions in the current tree forms to consider and
> > maybe change - for example, are the C rules that overflow of signed
> > integer arithmetic is undefined appropriate for all languages, or is this
> > another matter that should be explicitly represented in the various forms?

Toon:
> Fortran doesn't even define the concept of overflowing of INTEGERs
> (which are always signed in arithmetic context).

... which is the same as C (behavior of int addition overflow is not
defined, so the fortran and C compilers generate integer addition
instructions and the user gets whatever the machine does).