This is the mail archive of the gcc-patches@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: [PATCH] Add NON_RECURSIVE attribute for procedures


Hi Janne,

I think, in general, our current system where
-std=gnu means roughly "everything we have implemented so far, except
legacy extensions that break standards conformance" is pretty good.

The problem that I see with implementing this change is stack space,
especially the traditionally limited stack space on some systems with
OpenMP.

We have already seen a few bug reports for this, with the large buffer
that the blocked library version of matmul uses.

If we implement that patch "as is", we will blow up a lot of existing
codes. One problem is that the error messages are bad (segfault)
to mysterious (something that has no apparent relation to the root
cause).

> Now, to play devils advocate with my own patch, one can make the case
> that before making procedures recursive by default we should fix
> -frecursive / -fmax-stack-var-size so that it's robust in the face of
> recursion (and multi-threaded access) and also prevents blowing up the
> stack.

Yes, I think we need to do this.

Regards

	Thomas


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