Re: Patches to compile the kernel with Intel's C/C++ compiler

From: Alexander Leidinger (Alexander_at_Leidinger.net)
Date: 11/11/03

  • Next message: Alexander Leidinger: "Re: Patches to compile the kernel with Intel's C/C++ compiler"
    Date: Tue, 11 Nov 2003 17:54:51 +0100
    To: Guido van Rooij <guido@gvr.org>, Marius Strobl <marius@alchemy.franken.de>
    
    

    On Tue, 11 Nov 2003 16:31:42 +0100
    Guido van Rooij <guido@gvr.org> wrote:

    > What are the benefits of running an icc compiled kernel?

    The same as every other program gets.

    a) Icc knows better to schedule instructions for a P4 than gcc does.
    b) If you have an application which stresses some critical path in the
    kernel, icc may be able to optimize parts of it and allows you to get a
    little bit more out of it.
    c) Someone is working on getting the icc profiling information out of
    the linux kernel back into icc to optimize the system based upon the
    measured values (think about branch prediction and probabilities). When
    this matures, it's very likely that we also get support for it.
    d) If 2 compilers agree on the behavior of the same code, either both
    compilers a buggy, or your code is fine (yes, an overly optimistic point
    of view, but a pragmatic one). If one of 2 compilers disagrees,
    something is wrong with one of the compilers, or with your code.

    Or perhaps you're just religious and want to use as less (L)GPLed code
    as possible. ;-)

    Obviously not everyone needs to run an icc compiled kernel or userland,
    but it doesn't hurts (modulo bugs in icc (as FreeBSD has a commercial
    license of icc, we get commercial support, and Intel fixed already some
    ICE issues for us) or in the code, but there could be/are bugs in gcc
    too) to run or to be able to run one.

    BTW.: even if Intel doesn't like it, but: icc produces the fastest 32bit
    code for AMD CPUs too (in specific applications of course).

    Bye,
    Alexander.

    -- 
                       It's not a bug, it's tradition!
    http://www.Leidinger.net                       Alexander @ Leidinger.net
      GPG fingerprint = C518 BC70 E67F 143F BE91  3365 79E2 9C60 B006 3FE7
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  • Next message: Alexander Leidinger: "Re: Patches to compile the kernel with Intel's C/C++ compiler"

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