This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: [tree-ssa] Fun with exceptions -- opinions needed
- From: Felix Lee <felix dot 1 at canids dot net>
- To: gcc at gcc dot gnu dot org
- Date: Mon, 16 Jun 2003 12:16:52 -0700
- Subject: Re: [tree-ssa] Fun with exceptions -- opinions needed
law@redhat.com:
> > The copies are an explicit
> >representation of the necessary data and control flow in this situation
> >(namely the separation of the side-effect of calling the function from the
> >side-effect of overwriting the variable).
> It certainly seems that way. This makes me wonder what LLVM does since
> apparently it doesn't have copies.
I'm not familiar with LLVM or exception handling, but I went and
looked out of curiosity. In "The LLVM Instruction Set and
Compilation Strategy" paper, they say
Although we currently do not have a front-end that uses the
exception handling support built into LLVM, all of our
optimizations and transformations are aware of the
exceptional control flow edges, and our unit tests work as
designed.
"exceptional control flow edges" is an "invoke-with-catch"
instruction instead of a "call" instruction. I don't see any
evidence on the developer's list that anyone has looked at
implementing exception support for real yet. It seems to me
they're going to run into the same problem you did.
--