GCC optimization bugs -- still there or a historic artifact?

From: Nikos Ntarmos (ntarmos_at_ceid.upatras.gr)
Date: 03/13/04

  • Next message: Christoph P. Kukulies: "Re: off topic - disk crash"
    Date: Sat, 13 Mar 2004 21:23:57 +0200
    To: freebsd-hackers@freebsd.org

    Hi all.

    There was a thread on the CFLAGS knob in make.conf in early Feb.'04
    (the exact subject was "need help on CFLAGS in /etc/make.conf
    please"), where some posters raised the issue of gcc optimization bugs
    that supposedly manifest in optimization levels above -O2. The last
    post on this subject was on Feb. 13th, though, and nothing has come up
    ever since. AFAIK 5.2.1+ and -CURRENT have moved to gcc-3.3.3. Are
    these issues still there?

    I've been making my way around FreeBSD's and GCC's gnat and couldn't
    find anything relevant. Ummm... Actually almost all relevant entries
    in our gnat end with something like "bug the gcc guys for we're too
    overwhelmed to look into gcc issues". The funny thing is there is no
    entry in the gcc's gnat about optimization bugs in 3.3.3. As some very
    specific person noted, "-O gets about an order of magnitude less
    testing than -O2" by the gcc community.

    This whole thing came up in the port-alpha@netbsd list, in a thread
    about Compaq's C compiler (aka ccc) for linux/alpha (lang/compaq-cc in
    our ports tree) and its status in NetBSD. The manpage for make.conf
    states that the issues with levels >1 are even worse on alpha. Well,
    gcc-3.3.3 is as fast as (if not faster than) ccc for optimization
    levels above -O2, and can be used for a much wider part of the C/C++
    source available out there. So the question is: are these gcc issues
    still there or just a historic artifact left lurking around manpages
    "just to be sure"?


     Nikos "Noth" Ntarmos    | < ntarmos at ceid dot upatras dot gr >
     NetCINS Lab. @ C.E.I.D. | [ http://{noth,p2p}.ceid.upatras.gr/ ]
     U. of Patras - Greece   | ( 38.2594N, 21.7428E ) ( 1024D / CF95160A )
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