[ETHOSU] Add early simplify to fix LoopPartition (apache#9387)

* [ETHOSU] Add early simplify to fix LoopPartition

Certain loops aren't correctly partitioned if the loop
condition hasn't been simplified. This can happen when
a copy loop is split by a non-factor. To fix this, an
additional simplify pass is added to the TIR pipeline
prior to LoopPartition.

Change-Id: Icd4ff14648ccaed41384da50c6d183a122b30048

* Fix linting again

Change-Id: I9c9dc2ee2c679861866b23531e88584b94198e51

Author: mbaret

python/tvm/relay/backend/contrib/ethosu/tir/compiler.py

@@ -78,6 +78,7 @@ def lower_ethosu(sch, args, const_dict, name="main"):
         mod = tvm.tir.transform.Simplify()(mod)
         mod = tvm.tir.transform.StorageFlatten(64)(mod)
         mod = tvm.tir.transform.UnrollLoop()(mod)
+        mod = tvm.tir.transform.Simplify()(mod)
         mod = tvm.tir.transform.LoopPartition()(mod)
         mod = RemoveZeroStores()(mod)
         mod = tvm.tir.transform.Simplify()(mod)

tests/python/contrib/test_ethosu/test_replace_copy.py

@@ -22,7 +22,7 @@
 from tvm import relay
 from tvm.relay.testing import run_opt_pass
 from tvm.relay.backend.contrib.ethosu.tir.compiler import lower_to_tir
-from tvm.relay.backend.contrib.ethosu.tir.scheduler import copy_constants
+from tvm.relay.backend.contrib.ethosu.tir.scheduler import copy_constants, Convolution2DCompute
 
 from .infra import make_ethosu_conv2d
 
@@ -73,5 +73,67 @@ def _get_func():
     tvm.ir.assert_structural_equal(test_mod["main"], reference_mod["main"], True)
 
 
+# fmt: off
+@tvm.script.ir_module
+class WeightStream:
+    @T.prim_func
+    def main(placeholder: T.handle, ethosu_write: T.handle, placeholder_1: T.handle, placeholder_2: T.handle, placeholder_3: T.handle, placeholder_4: T.handle) -> None:
+        # function attr dict
+        T.func_attr({"from_legacy_te_schedule": True, "global_symbol": "main", "tir.noalias": True})
+        placeholder_5 = T.match_buffer(placeholder, [1, 16, 16, 32], dtype="int8")
+        ethosu_write_1 = T.match_buffer(ethosu_write, [1, 16, 16, 16], dtype="int8")
+        buffer = T.match_buffer(placeholder_1, [416], dtype="uint8")
+        buffer_1 = T.match_buffer(placeholder_2, [112], dtype="uint8")
+        buffer_2 = T.match_buffer(placeholder_3, [272], dtype="uint8")
+        buffer_3 = T.match_buffer(placeholder_4, [64], dtype="uint8")
+        # body
+        placeholder_global = T.allocate([416], "uint8", "global")
+        placeholder_d_global = T.allocate([112], "uint8", "global")
+        T.evaluate(T.call_extern("ethosu_copy", T.load("uint8", buffer.data, 0), 416, T.load("uint8", placeholder_global, 0), dtype="handle"))
+        T.evaluate(T.call_extern("ethosu_copy", T.load("uint8", buffer_1.data, 0), 112, T.load("uint8", placeholder_d_global, 0), dtype="handle"))
+        T.evaluate(T.call_extern("ethosu_conv2d", "int8", 16, 16, 32, 16, 0, 16, T.load("int8", placeholder_5.data, 0), 0, 0, 0, T.float32(0.5), 10, "NHWC", 512, 32, 1, "int8", 16, 16, 10, 16, 0, 16, T.load("int8", ethosu_write_1.data, 0), 0, 0, 0, T.float32(0.25), 14, "NHWC", 256, 16, 1, 1, 1, 1, 1, 1, 1, T.load("uint8", placeholder_global, 0), 416, 12, T.load("uint8", placeholder_d_global, 0), 112, 0, 0, 0, 0, "NONE", 0, 0, "NONE", dtype="handle"))
+        T.evaluate(T.call_extern("ethosu_copy", T.load("uint8", buffer_2.data, 0), 272, T.load("uint8", placeholder_global, 0), dtype="handle"))
+        T.evaluate(T.call_extern("ethosu_copy", T.load("uint8", buffer_3.data, 0), 64, T.load("uint8", placeholder_d_global, 0), dtype="handle"))
+        T.evaluate(T.call_extern("ethosu_conv2d", "int8", 16, 16, 32, 16, 0, 16, T.load("int8", placeholder_5.data, 0), 0, 0, 0, T.float32(0.5), 10, "NHWC", 512, 32, 1, "int8", 16, 16, 6, 16, 0, 16, T.load("int8", ethosu_write_1.data, 10), 0, 0, 0, T.float32(0.25), 14, "NHWC", 256, 16, 1, 1, 1, 1, 1, 1, 1, T.load("uint8", placeholder_global, 0), 272, 12, T.load("uint8", placeholder_d_global, 0), 64, 0, 0, 0, 0, "NONE", 0, 0, "NONE", dtype="handle"))
+    __tvm_meta__ = None
+# fmt: on
+
+
+def test_weight_stream():
+    def _cascader(cached_func, const_dict, sch):
+        weight = cached_func.inputs[1]
+        scale_bias = cached_func.inputs[2]
+        out = cached_func.outputs[0]
+        conv_compute = Convolution2DCompute.from_output(out)
+        co = conv_compute.split(sch, 3, 10)
+        cache_weight = sch.cache_read(weight, "global", [conv_compute.conv2d])
+        cache_scale_bias = sch.cache_read(scale_bias, "global", [conv_compute.conv2d])
+        sch[cache_weight].compute_at(sch[out], co)
+        sch[cache_scale_bias].compute_at(sch[out], co)
+
+    def _get_func():
+        ifm = relay.var("ifm", shape=(1, 16, 16, 32), dtype="int8")
+        conv = make_ethosu_conv2d(
+            ifm,
+            32,
+            16,
+            (1, 1),
+            (0, 0),
+            (1, 1),
+            (1, 1),
+        )
+        func = relay.Function(relay.analysis.free_vars(conv), conv)
+        func = run_opt_pass(func, relay.transform.InferType())
+        return func
+
+    func = _get_func()
+    mod, _ = lower_to_tir(func, cascader=_cascader)
+
+    script = mod.script(show_meta=True)
+    test_mod = tvm.script.from_source(script)
+    reference_mod = WeightStream
+    tvm.ir.assert_structural_equal(test_mod["main"], reference_mod["main"], True)
+
+
 if __name__ == "__main__":
     pytest.main([__file__])