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Re: i386 backend
- To: "David Rasmussen" <pinkfloydhomer at yahoo dot com>
- Subject: Re: i386 backend
- From: Lee Iverson <leei at AI dot SRI dot COM>
- Date: Mon, 19 Mar 2001 13:28:32 -0800
- cc: dewar at gnat dot com, gcc at gcc dot gnu dot org
In message <ELECLDHLONNAHNIBCAEIIEOFCBAA.pinkfloydhomer@yahoo.com>, "David Rasm
ussen" writes:
>
>Even if I can't be very precise in pointing out _where_ the problems is, it
>should still be recognized as a problem. A very simplistic way of putting it
>is: "Why is gcc producing slower code than MSVC++ or Intel C++?". I know
>that it is not always the case, but from all the different types of programs
>I've compiled, and all the people who I have talked to, it is almost always
>the case. So there is room for improvement.
But that *is* the point. You can be *much* more precise in reporting
*where* the problem is. If you have been serious about benchmarking
your code in any way, then it should be clear to you what parts of
your code are having slowdown problems. That is what is being asked of
you, and frankly, it is not too much to ask since this is exactly the
kind of analysis you should be doing anyway if you are at all worried
about performance.
The compiler developers know of many places in which the compiler can
be improved and the vagaries of the 1386 architecture make it a
particularly nasty test case for a general purpose compiler targeted
at a wide variety of machine architectures. Whether or not the
problems you are experiencing are known or unknown, simple or complex
is something that can only be answered if and when you do at least
some of the work to identify specifics.
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Lee Iverson SRI International
leei@ai.sri.com 333 Ravenswood Ave., Menlo Park CA 94025
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