Re: Testsuite failure ?

[Jeffrey A Law <law at cygnus dot com>]

  In message <200008251906.PAA21047@onsager.chem.mcgill.ca>you write:
  > Alexandre Oliva replied:
  > 
  > 
  > 	On Aug 25, 2000, David Ronis wrote:
  > 	
  > 	> -malign-double
  > 	
  > 	> triggers all the problems on an i686-linux-gnu box.
  > 	
  > 	This is likely to be the source of the problem.  Make sure you build
  > 	not only libgcc, but also libio, libstdc++ and probably also glibc
  > 	with this flag.
  > 
  > I did a complete bootstrap build, which takes care of libio and libstc++; I
  >  
  > haven't rebuilt libc in quite some time and frankly, I don't remember which
  >  
  > flags I used there, although I can rebuild it with -malign-double and see w
  > hat 
  > happens.  Before doing this, I'll try lowering the optimization and keeping
  >  
  > -malign-double in gcc.
  > 
  > BTW: I routinely add -malign-double for all apps on an i[56]86.  I've not 
  > encountered this problem elsewhere.
-malign-double CHANGES THE ABI.

This means that if you use it, you have to make sure everything is compiled
with that flag.  Otherwise bad things will happen.  Depending on the code
you write, it might go unnoticed for weeks, months or even years, but
eventually you'll get nailed.

And when we say everything, we mean it.  It includes glibc, every library,
and every application.

-malign-double is evil.  Do not use it.

jeff