1 files changed, 154 insertions, 0 deletions
diff --git a/compiler/exo/src/Pass/FoldTransposeOfConstPass.cpp b/compiler/exo/src/Pass/FoldTransposeOfConstPass.cpp
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+++ b/compiler/exo/src/Pass/FoldTransposeOfConstPass.cpp
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+/*
+ * Copyright (c) 2019 Samsung Electronics Co., Ltd. All Rights Reserved
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "FoldTransposeOfConstPass.h"
+
+#include "Check.h"
+
+#include "Dialect/IR/TFLNodes.h"
+#include "Dialect/IR/TFLNodeVisitor.h"
+
+// TODO remove dependency to angkor
+#include <nncc/core/ADT/tensor/IndexEnumerator.h>
+#include <nncc/core/ADT/tensor/LexicalLayout.h>
+
+#include <oops/InternalExn.h>
+
+namespace
+{
+
+/**
+ * @brief   Check if node is TFLTranspose and its input is TFLConst
+ * @return  Casted TFLTranspose for foldable candidate, nullptr otherwise
+ */
+locoex::TFLTranspose *as_candidate(loco::Node *node)
+{
+  auto transpose = dynamic_cast<locoex::TFLTranspose *>(node);
+  if (not transpose)
+    return nullptr;
+
+  // Only accept Constant input of Transpose
+  if (not dynamic_cast<locoex::TFLConst *>(transpose->a()))
+    return nullptr;
+
+  // Only accept Constant permutation of Transpose
+  if (not dynamic_cast<locoex::TFLConst *>(transpose->perm()))
+    return nullptr;
+
+  return transpose;
+}
+
+nncc::core::ADT::tensor::Shape angkor_shape(locoex::TFLConst *node)
+{
+  nncc::core::ADT::tensor::Shape ret;
+
+  ret.resize(node->rank());
+  for (uint32_t axis = 0; axis < node->rank(); ++axis)
+  {
+    ret.dim(axis) = node->dim(axis).value();
+  }
+
+  return ret;
+}
+
+void fold_transpose_of_const(locoex::TFLTranspose *transpose)
+{
+  const loco::DataType FLOAT32 = loco::DataType::FLOAT32;
+  const loco::DataType S32 = loco::DataType::S32;
+
+  auto const_orig = dynamic_cast<locoex::TFLConst *>(transpose->a());
+  auto perm = dynamic_cast<locoex::TFLConst *>(transpose->perm());
+
+  // Exceptions
+  {
+    EXO_ASSERT(const_orig, "Only support for Transpose-Const pair");
+    // TODO support other data types
+    if (const_orig->dtype() != FLOAT32)
+      INTERNAL_EXN_V("NYI for this data type", oops::to_uint32(const_orig->dtype()));
+
+    EXO_ASSERT(perm, "Only support for constant permutation for Transpose");
+    // TODO support other data types
+    if (perm->dtype() != S32)
+      INTERNAL_EXN_V("NYI for this data type", oops::to_uint32(perm->dtype()));
+
+    auto okay = [&]() {
+      if (perm->rank() != 1)
+        return false;
+      if (perm->dim(0).value() != const_orig->rank())
+        return false;
+      return true;
+    };
+    if (not okay())
+      INTERNAL_EXN("Input and permutation for Transpose is not congruent");
+  }
+
+  uint32_t rank = const_orig->rank();
+
+  // TFLConst to replace
+  auto const_new = transpose->graph()->nodes()->create<locoex::TFLConst>();
+
+  const_new->dtype(FLOAT32);
+  const_new->rank(rank);
+  const_new->size<FLOAT32>(const_orig->size<FLOAT32>());
+  for (uint32_t axis = 0; axis < rank; ++axis)
+    const_new->dim(axis) = const_orig->dim(perm->at<S32>(axis)).value();
+
+  // TODO remove dependency to angkor
+  auto shape_orig = angkor_shape(const_orig);
+  auto shape_new = angkor_shape(const_new);
+
+  nncc::core::ADT::tensor::LexicalLayout l;
+  nncc::core::ADT::tensor::IndexEnumerator e{shape_new};
+
+  for (; e.valid(); e.advance())
+  {
+    loco::TensorIndex index_new = e.current();
+    loco::TensorIndex index_orig;
+
+    // Set original index from matching new index
+    index_orig.resize(rank);
+    for (uint32_t axis = 0; axis < rank; ++axis)
+      index_orig.at(perm->at<S32>(axis)) = index_new.at(axis);
+
+    const_new->at<FLOAT32>(l.offset(shape_new, index_new)) =
+        const_orig->at<FLOAT32>(l.offset(shape_orig, index_orig));
+  }
+
+  // replace
+  loco::replace(transpose).with(const_new);
+}
+
+} // namespace
+
+namespace exo
+{
+
+bool FoldTransposeOfConstPass::run(loco::Graph *g)
+{
+  bool changed = false;
+  for (auto node : loco::active_nodes(loco::output_nodes(g)))
+  {
+    if (auto transpose = as_candidate(node))
+    {
+      fold_transpose_of_const(transpose);
+      changed = true;
+    }
+  }
+
+  return changed;
+}
+
+} // namespace exo