[luci/pass] Trim RemoveUnnecessaryTransposesNetPass (#14187)

This PR trims RemoveUnnecessaryTransposesNetPass.
- enhance some comements
- rename a varaible
- replace 'if(not cond) return false' with macro

ONE-DCO-1.0-Signed-off-by: seunghui youn <[email protected]>

compiler/luci/pass/src/RemoveUnnecessaryTransposeNetPass.cpp

@@ -191,6 +191,8 @@ void TaggedShapeAnalyzer::analyze_transpose(const std::vector<int32_t> &perm)
  *
  * @return False, if it fails to update _shape
  *
+ * @note It only support analyzing reshape that combines N consecutive dims into one dims.
+ *
  * @example Let's assume new_shape={1, 448, 49} is given to [before] _shape.
  *
  *  [before]  _shape :
@@ -233,16 +235,16 @@ bool TaggedShapeAnalyzer::analyze_reshape(const std::vector<int32_t> &new_shape)
   // Create 'new_tagged_shape' based on 'new_shape'
   TagShape new_tagged_shape;
 
-  uint32_t new_shape_idx = 0;
-  while (new_shape_idx < new_shape.size())
+  uint32_t target_idx = 0;
+  while (target_idx < new_shape.size())
   {
-    auto target_dim = new_shape[new_shape_idx];
+    auto target_dim = new_shape[target_idx];
 
     // Ignore dim == 1
     if (target_dim == 1)
     {
       new_tagged_shape.emplace_back(1);
-      new_shape_idx++;
+      target_idx++;
       continue;
     }
 
@@ -265,7 +267,7 @@ bool TaggedShapeAnalyzer::analyze_reshape(const std::vector<int32_t> &new_shape)
     }
     new_tagged_shape.push_back(dim);
 
-    new_shape_idx++;
+    target_idx++;
     move_to_next_range();
   }
   _shape = new_tagged_shape;
@@ -293,8 +295,8 @@ bool TaggedShapeAnalyzer::verify_tag() const
  * @brief Initialize the class members and check under conditions
  *
  *  Condtiions that have to be met for analyzer
- *    c2: The 'perm' of tranpose should be a CircleConst* type
- *    c3: All extracted shapes (named as '*_shape_v' in member variable) should be known
+ *    c1: The 'perm' of tranpose should be a CircleConst* type
+ *    c2: All extracted shapes (named as '*_shape_v' in member variable) should be known
  *
  * @return True, if all conditions are satisfied and class members are initialized successfully
  *         False, otherwise
@@ -311,7 +313,7 @@ bool TaggedShapeAnalyzer::init(const luci::CircleTranspose *front_transpose,
   const auto front_perm = dynamic_cast<luci::CircleConst *>(_front_transpose->perm());
   const auto back_perm = dynamic_cast<luci::CircleConst *>(_back_transpose->perm());
 
-  // check c2
+  // check c1
   CHECK_OR_FALSE(front_perm != nullptr);
   CHECK_OR_FALSE(back_perm != nullptr);
 
@@ -329,7 +331,7 @@ bool TaggedShapeAnalyzer::init(const luci::CircleTranspose *front_transpose,
     return true;
   };
 
-  // check c3
+  // check c2
   CHECK_OR_FALSE(all_known(_in_shape_v));
   CHECK_OR_FALSE(all_known(_front_shape_v));
   CHECK_OR_FALSE(all_known(_mid_shape_v));
@@ -467,24 +469,16 @@ bool remove_unnecessary_transpose(luci::CircleTranspose *node)
 {
   // find 'front_transpose - mid_reshape - back_transpose' pattern
   const auto back_transpose = node;
+
   const auto mid_reshape = dynamic_cast<luci::CircleReshape *>(back_transpose->a());
-  {
-    if (mid_reshape == nullptr)
-      return false;
-  }
+  CHECK_OR_FALSE(mid_reshape != nullptr);
+
   const auto front_transpose = dynamic_cast<luci::CircleTranspose *>(mid_reshape->tensor());
-  {
-    if (not front_transpose)
-      return false;
-  }
+  CHECK_OR_FALSE(front_transpose != nullptr);
 
   TaggedShapeAnalyzer analyzer;
-
-  if (not analyzer.init(front_transpose, mid_reshape, back_transpose))
-    return false;
-
-  if (not analyzer.can_remove_transposes())
-    return false;
+  CHECK_OR_FALSE(analyzer.init(front_transpose, mid_reshape, back_transpose));
+  CHECK_OR_FALSE(analyzer.can_remove_transposes());
 
   // repalce with new_node
   luci::CircleReshape *new_node = create_reshape_node<loco::DataType::S32>(