This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: SIMPLE: A language-independent tree IR


"Joseph S. Myers" wrote:

> On Wed, 2 Jan 2002, Diego Novillo wrote:
> 
> > Any tree expression that does not conform to this must be broken
> > down into a sequence of these 14 expressions.  For reference, I'm
> > attaching SIMPLE's BNF grammar.  For instance,
> 
> One thing I'd like in language-independent trees (at some level) is that
> ordering (sequence point) and aliasing constraints are explicitly
> represented (that is, language-dependent trees, in which these are
> implicit, are converted to language-independent trees, in which these are
> explicit).

Good point.  The concept of sequence point has no equivalent in Fortran,
for example.

> 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?

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

-- 
Toon Moene - mailto:toon@moene.indiv.nluug.nl - phoneto: +31 346 214290
Saturnushof 14, 3738 XG  Maartensdijk, The Netherlands
Maintainer, GNU Fortran 77: http://gcc.gnu.org/onlinedocs/g77_news.html
Join GNU Fortran 95: http://g95.sourceforge.net/ (under construction)


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]