The never decreasing list of things to do:
------------------------------------------

- Fix the memory leak when running the queen problem... (MMX-emu bug ?)
  Seems that %esp is touched by the emulation, when it shouldn't...

- Test Cyrix' EMMX, and AMD's 3DNow! (especially transcendental functions).

- Use a union type (cf mmx_types.h) in the emulation functions ?

- About the look-ahead, should it be disabled automatically when tracing ?
  NB:   FPU_lookahead = 1;
        if (current->flags & PF_PTRACED)
          FPU_lookahead = 0;

- What about support for multi-threaded code ?  Is the emulator re-entrant ?
  Anyway, which thread[s] gets the SIGILL in this case ?

- About "struct sigcontext[_struct]".  With Glibc2, we only need:
  #include <sigcontext.h>
  without   asm/...
  But it breaks compatibility with libc5, so we keep the current solution.

- Extend the emulation to MMX2 ?  FPU ?

- Port MMX-Emu to FreeBSD.  It should not be too hard I guess.
  First install the beast ;-)

- Finish the detection of the 3 features correctly (if CPUID doesn't
  exist, nothing exists...).


For speed:
----------
- Benchmark the thing, give indicative timings.
- Tune CFLAGS in the Makefile.
