bad C code or bad object code ?

[Andrew Haley]

Mike Frysinger writes:
 > we noticed that xterm in Gentoo started to produce broken color display when 
 > compiled with gcc-4.1 and -Os ... one of our devs ripped apart a small test 
 > case to illustrate the issue at hand (Debian shows the same issues)
 > 
 > the trouble centers around a matrix declared as static volatile and is never 
 > initialized ... xterm expects the matrix to be zero set already, but when 
 > compiled with -Os, this just doesnt work
 > 
 > example code attached ... to reproduce on an x86 host:

Compile with -save-temps.  Look at the declaration of s:

        .local  s.1776
        .comm   s.1776,768,32

Tell us what you find.

Andrew.