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Re: About the is_gimple_min_invariant predicate
On 7/5/07, Eric Botcazou <ebotcazou@adacore.com> wrote:
> 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:
We never insert expressions for FRE, and the replacement we do will
only replace the entire RHS with an SSA_NAME or a constant.
/* 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. */
Also, this should be !do_fre these days. The comment/test is from a
bygone era long past :)