[Bug 2228] New: Xorg server unusable when DefaultGcc2i386Opt has both -O and -mXXXX CPU architecture optimizations

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https://bugs.freedesktop.org/show_bug.cgi?id=2228        
   
           Summary: Xorg server unusable when DefaultGcc2i386Opt has both -O
                    and -mXXXX CPU architecture optimizations
           Product: xorg
           Version: 6.8.1
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Server/general
        AssignedTo: xorg-bugzilla-noise@freedesktop.org
        ReportedBy: bjdouma@xs4all.nl


Not really a bug, but a FYI with some compile tests of Xorg-6.8.1.

I know the stock build flags don't use these optimizations together, but
I have seen some host.def's that were modified to have a highly optimized
DefaultGcc2i386Opt.  For me that doesn't work, and here are some of my   
findings.



Static:
-------
System:
        IA32, Pentium4
        Linux-2.6.9; Linux-2.6.10
        custom, homegrown system, no distribution

Glibc:
        glibc-2.3.3 + NPTL (cvs glibc-20041004)

Gcc:
        gcc-3.4.3 (stock)

Graphics driver:
        nvidia-6629 custom compiled

Xorg:
        6.8.1 (stock); 6.8.1 cvs Dec 24 10:38 MET

Window manager:
        vtwm-2.5.6b

Specific xorg.conf options:
        RenderAccel "on"   

Specific Xorg build options:
        DefaultCCOptions:       default
        OptimizedCDebugFlags:   default



Variable:
---------
DefaultGcc2i386Opt:
        gtk progams run without problems when X server is compiled with:
        -I/usr/local/include/freetype2 -O0 -march=pentium3
        -I/usr/local/include/freetype2 -O0 -march=pentium4
        -I/usr/local/include/freetype2 -O0
        -I/usr/local/include/freetype2 -O1
        -I/usr/local/include/freetype2 -O2 -fno-strength-reduce

        gtk programs freeze the X server when X server is compiled with:
        -I/usr/local/include/freetype2 -O2 -fno-strength-reduce -march=pentium4
        -I/usr/local/include/freetype2 -O2 -fno-strength-reduce -mfpmath=sse -msse2
        -I/usr/local/include/freetype2 -O1 -march=pentium4

notes:
- gtk programs are: gqview, gimp, wininfo
- freeze happens when the program in question is
  started, and the pointer moves into the window;
  at that time X freezes, system becomes unusable,
  reboot necessary.


bjd        
   
   
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