Re: About the is_gimple_min_invariant predicate

[Eric Botcazou <ebotcazou at adacore dot com>]

> Note that TREE_INVARIANT is not going to be useful in an IPA world
> anyway for these users, if it really means that different calls to the
> function could produce different results.

We could test TREE_CONSTANT instead and this would be enough to restore Ada 
bootstrap.  But of course the underlying issue would still be there.

> I'm also not surprised your force_gimple_operand didn't work, since we
> call force_gimple_operand on the expressions we produce already  :)

For PRE only as far I can see, not for FRE:

  /* Insert can get quite slow on an incredibly large number of basic
     blocks due to some quadratic behavior.  Until this behavior is
     fixed, don't run it when he have an incredibly large number of
     bb's.  If we aren't going to run insert, there is no point in
     computing ANTIC, either, even though it's plenty fast.  */
  if (!do_fre && n_basic_blocks < 4000)
    {
      compute_antic_safe ();
      compute_antic ();
      insert ();
    }

-- 
Eric Botcazou