Re: C++ compile-time regressions (was: GCC 3.0.1 Status Report)

[Daniel Berlin <dan at cgsoftware dot com>]

Gerald Pfeifer <pfeifer@dbai.tuwien.ac.at> writes:


> On Mon, 23 Jul 2001, Joe Buck wrote:
>> Can you try to isolate where the bad code is?
> 
> Not really.  This code base is relatively large and the inner loops
> are quite complicated (actually not really loops as you'd see in usual
> scientific computing code) amounting to several thousand lines of code,
> and my day job is very time demanding these days, so I'm afraid I simply
> won't have the time anytime soon.
> 
> I'm rather sure, though, that g++ is not generating efficient code for
> complicated, nested STL and STL-like structures in the presence of
> libstdc++-v3 (iterators are now classes instead of pointers).

This is probably alias analysis's fault.
Can you *try* the patch i posted to do alias analysis for classes,
just to see if it gets better code (Unless mark is wrong, and its not
more complicated than i thought it was, and i seriously doubt he's
wrong, it might generate invalid code)?
I could also do some more analysis if you could make that particular
test available to me.

--Dan

-- 
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