Enable -fomit-frame-pointer on i386

[Andrew Haley]

Jan Hubicka writes:
 > > Jan Hubicka writes:
 > >  > > Jan Hubicka writes:
 > >  > >  > Perhaps we can simply replace use of backtrace() in libjava by
 > >  > >  > the Jakub's unwind based implementation to break the dependency on
 > >  > >  > targets where unwind info shall be available (ia-64/x86-64/i386/s390 at
 > >  > >  > least)
 > >  > > 
 > >  > > That's a good idea.  Bryce is working on such a patch, I believe.
 > >  > > 
 > >  > > In the meantime, this is what we do with x86-64 
 > >  > > 
 > >  > > in configure.in:
 > >  > > 
 > >  > > BACKTRACESPEC=
 > >  > > case "${host}" in
 > >  > >  x86_64*-*-linux*)
 > >  > >     BACKTRACESPEC=-fno-omit-frame-pointer
 > >  > >     ;;
 > >  > > esac
 > >  > > 
 > >  > > And configure.host:
 > >  > > 
 > >  > >   x86_64-*)
 > >  > > 	CHECKREFSPEC="%{m32:-fcheck-references}"
 > >  > > 	sysdeps_dir=x86-64
 > >  > > 	libgcj_flags="${libgcj_flags} -ffloat-store -fno-omit-frame-pointer"
 > >  > 
 > >  > I this still important?  x86-64 glibc can do unwinding without frame
 > >  > pointer for some time already.
 > > 
 > > It's important until no-one uses an earlier glibc.  Leave it 'til 3.5.
 > 
 > When the glibc switched to dwarf2 unwinding?  I was under impressions
 > that all released glibcs does it.  At least glibc CVS apparently never
 > contained some other implementation

AFAICS x86_64 used sysdeps/generic/backtrace.c until 2003/10/05.

2003-10-05  Jakub Jelinek  <jakub@redhat.com>

	* sysdeps/ia64/backtrace.c: New file.
	* sysdeps/x86_64/backtrace.c: New file.
	* sysdeps/generic/unwind.h (_Unwind_Trace_Fn): New type.
	(_Unwind_Backtrace): New prototype.

Andrew.