nnc::CombineTransposes Class Reference

This pass combines sequential transposes and removes identity transposes if the combination results in an identity permutation. More...

#include <CombineTransposes.h>

Collaboration diagram for nnc::CombineTransposes:

Public Member Functions
PassData	run (PassData data) override
	run compiler pass
std::string	getName () override
Public Member Functions inherited from nnc::Pass
virtual void	cleanup ()
	clean compiler pass data
virtual	~Pass ()=default

Detailed Description

This pass combines sequential transposes and removes identity transposes if the combination results in an identity permutation.

Definition at line 30 of file CombineTransposes.h.

Member Function Documentation

getName()

std::string nnc::CombineTransposes::getName ( )

inlineoverridevirtual

Reimplemented from nnc::Pass.

Definition at line 35 of file CombineTransposes.h.

{ return "opt_combine_transposes"; };

run()

nnc::PassData nnc::CombineTransposes::run ( PassData  data )

overridevirtual

run compiler pass

Parameters

data	- data that pass is taken

Returns

data that can be passed to the next pass

Exceptions

PassException

object if errors occured

Implements nnc::Pass.

Definition at line 52 of file CombineTransposes.cpp.

{
  auto g = static_cast<Graph *>(data);
  assert(g);
  GraphPatternMatcher matcher(g);
  auto is_tr = [](const Operation *op1) { return op1->getType() == Operation::Type::transpose; };
  std::vector<std::pair<Operation *, Operation *>> matches = matcher.matchEdge(is_tr, is_tr);
  std::unordered_set<Operation *> deleted_nodes;
  while (!matches.empty())
  {
    for (std::pair<Operation *, Operation *> match : matches)
    {
      if (deleted_nodes.find(match.first) != deleted_nodes.end())
      {
        break;
      };
      auto *top_transpose = dynamic_cast<mir::ops::TransposeOp *>(match.first);
      if (deleted_nodes.find(match.second) != deleted_nodes.end())
      {
        break;
      };
      auto *bottom_transpose = dynamic_cast<mir::ops::TransposeOp *>(match.second);
      auto combined_axis_order =
        combineAxisOrders(top_transpose->getAxisOrder(), bottom_transpose->getAxisOrder());
 
      if (!isIdentityTranspose(combined_axis_order))
      {
        auto new_tr_op =
          g->create<mir::ops::TransposeOp>(top_transpose->getInput(0), combined_axis_order);
 
        g->replaceNode(bottom_transpose, new_tr_op);
      }
      else
      {
        // Connect top input to all outputs of bottom
        Operation *top = top_transpose->getInput(0)->getNode();
        g->replaceNode(bottom_transpose, top);
      }
      deleted_nodes.emplace(bottom_transpose);
      if (top_transpose->getOutput(0)->getUses().empty())
      {
        g->removeNode(top_transpose);
        deleted_nodes.emplace(top_transpose);
      }
    }
    matches = matcher.matchEdge(is_tr, is_tr);
  };
  return g;
}

References nnc::combineAxisOrders(), mir::Operation::getInput(), mir::Operation::Output::getNode(), and mir::GraphPatternMatcher::matchEdge().

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The documentation for this class was generated from the following files:

• compiler/nnc/include/passes/optimizations/CombineTransposes.h
• compiler/nnc/passes/optimizations/CombineTransposes.cpp