(Checked for gcc-2.96-54, gcc-2.96-60 and CVS mainline gcc version 2.97
20001009 (experimental), but not a bug in 2.95.2)

The enclosed code (which is little more than a "Hello World" program)
generates incorrect code when compiled with -O2.  For some reason,
g++ is generating code that tramples that function arguments.
Because the code doesn't seem to be particularly unusual or arcane,
this seems like a very serious bug.

rh7% g++ -O -o not-buggy buggy.cc && ./not-buggy
* Shouldn't segfault *
rh7% g++ -O2 -DAVOID_BUG -o not-buggy buggy.cc && ./not-buggy
* Shouldn't segfault *
rh7% g++ -O2 -o buggy buggy.cc && ./buggy
Segmentation fault

I hope this one won't be too hard to find and fix...

    M.E.O.

Enc.

#include <iostream>

ostream& put (char * str, ostream& out) {
    #if !AVOID_BUG
	return out << "* " << str << " *\n";
    #else
	out << "* " << str << " *\n";
	return out;
    #endif
}

int main () {
    put("Shouldn't segfault", cout);
}