tests/python/relax/test_kill_after_last_use.py

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import tvm
import tvm.relax
import tvm.testing

from tvm.script import ir as I, relax as R

from tvm.relax.transform import KillAfterLastUse


def test_basic():
    @I.ir_module
    class Before:
        @R.function(pure=False)
        def main(x: R.Tensor([16, 32], "float32")):
            storage = R.memory.alloc_storage(R.shape([2048]), 0, "global", "uint8")
            y = R.memory.alloc_tensor(storage, 0, R.shape([16, 32]), "float32")
            _dummy = R.call_packed("add_tensors", [x, y], sinfo_args=(R.Tuple,))
            z = R.add(x, y)
            return z

    @I.ir_module
    class Expected:
        @R.function(pure=False)
        def main(x: R.Tensor([16, 32], "float32")):
            storage = R.memory.alloc_storage(R.shape([2048]), 0, "global", "uint8")
            y = R.memory.alloc_tensor(storage, 0, R.shape([16, 32]), "float32")
            _ = R.memory.kill_storage(storage)
            _dummy = R.call_packed("add_tensors", [x, y], sinfo_args=(R.Tuple,))
            z = R.add(x, y)
            _ = R.memory.kill_tensor(y)
            return z

    After = KillAfterLastUse()(Before)
    tvm.ir.assert_structural_equal(Expected, After)


def test_track_usage_across_trivial_rebindings():
    """To work around VM de-duplication of register usage"""

    @I.ir_module
    class Before:
        @R.function(pure=False)
        def main(w: R.Tensor([16, 32], "float32")):
            x = R.add(w, R.const(1, "float32"))
            y = x
            z = R.add(y, R.const(1, "float32"))
            return z

    @I.ir_module
    class Expected:
        @R.function(pure=False)
        def main(w: R.Tensor([16, 32], "float32")):
            x = R.add(w, R.const(1, "float32"))
            z = R.add(x, R.const(1, "float32"))
            _ = R.memory.kill_tensor(x)
            return z

    After = KillAfterLastUse()(Before)
    tvm.ir.assert_structural_equal(Expected, After)


def test_track_usage_across_trivial_rebindings_in_match_cast():
    """To work around VM de-duplication of register usage"""

    @I.ir_module
    class Before:
        @R.function(pure=False)
        def main(w: R.Tensor([16, 32], "float32")):
            x = R.add(w, R.const(1, "float32"))
            y = R.match_cast(x, R.Tensor([16, 32]))
            z = R.add(y, R.const(1, "float32"))
            return z

    @I.ir_module
    class Expected:
        @R.function(pure=False)
        def main(w: R.Tensor([16, 32], "float32")):
            x = R.add(w, R.const(1, "float32"))
            y = R.match_cast(x, R.Tensor([16, 32]))
            _ = R.memory.kill_tensor(x)
            z = R.add(y, R.const(1, "float32"))
            _ = R.memory.kill_tensor(y)
            return z

    After = KillAfterLastUse()(Before)
    tvm.ir.assert_structural_equal(Expected, After)


if __name__ == "__main__":
    tvm.testing.main()