GH-118095: Handle RETURN_GENERATOR in tier 2

[markshannon]

• Issue: Increase the number of micro-ops that we can handle in tier 2 #118095

[gvanrossum]

Why not add a test? E.g.

    def test_return_generator(self):
        def gen():
            yield None
        def testfunc(n):
            for i in range(n):
                gen()
        res, ex = self._run_with_optimizer(testfunc, 20)
        self.assertIsNotNone(ex)
        self.assertIn("_RETURN_GENERATOR", get_opnames(ex))

[gvanrossum]

It's a bit inelegant that all places that treat _PUSH_FRAME and _POP_FRAME special now also have to check for _RETURN_GENERATOR. Not sure what to do about it. :-(

[markshannon]

Once #118095 is done we can add a flag for all uops that push or pop frames.

[gvanrossum]

Am I correct that this is the only line that differs from _POP_FRAME? The duplication of so much code is unfortunate. At the same time I don't see a better solution. Maybe add a comment to both explaining they need to be kept in sync?

[markshannon]

A good candidate for refactoring, but I'd like to get #118095 done first so that we more easily see the common patterns.

[iritkatriel]

I'd assert the value of res as well.

[markshannon]

done

[markshannon]

The four failing tests are the usual suspects.