WHOPR Linux distribution

[Richard Guenther]

On Mon, May 30, 2011 at 1:14 PM, Robert Beeporbop <rbeeporbop@yahoo.com> wrote:
> Thank you for the information!
>
> So it sounds like right now, I could use 4.6.0 (4.7.0?), and be architecture-independent between processors of the same type. Like, code could be compiled to GIMPLE with no optimization for generic x86, then optimized and linked differently depending on the target processor, say for a 80386 and a core2, as long as the memory layout is the same. Would this work? This is still really good!

To some extent yes.  When programs check feature availability based
on preprocessor macros like __SSE2__ it of course can't (those are
evaluated early).

> I have read what has been written about GIMPLE, on the website, I have not yet read the code. Is there any other documentation which would be useful to read?

I don't think the information is useful for your case.

> How hard would it be to make GIMPLE fully architecture-independent? Could placement of items in memory be handled by the linker, and everything before linking be symbolically referenced? Sorry this is a pretty general question, and I haven't looked at the code, is this within the realm of possibility? Other than sizes of types and memory layout, what is architecture-dependent in GIMPLE?

It's impossible, already the language frontends expose some ABI details.

> Pretty stable is good enough, if gcc could be upgraded through a minor version or two, or bugfix patched, without the need to recompile everything, that would be great! On a major release of the distribution, everything would be recompiled anyways, so it doesn't matter if the GIMPLE format changes.

I would expect that we try to remain compatible on a release branch.
But given the lack of any automated way to detect if we break something
there the guarantee is pretty low.

Richard.