/* Copyright 2018 The OpenXLA Authors.

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.
==============================================================================*/

#ifndef XLA_HLO_TRANSFORMS_SIMPLIFIERS_BATCH_DOT_SIMPLIFICATION_H_
#define XLA_HLO_TRANSFORMS_SIMPLIFIERS_BATCH_DOT_SIMPLIFICATION_H_

#include "absl/container/flat_hash_set.h"
#include "absl/status/statusor.h"
#include "absl/strings/string_view.h"
#include "xla/hlo/ir/hlo_instruction.h"
#include "xla/hlo/ir/hlo_module.h"
#include "xla/hlo/pass/hlo_pass_interface.h"

namespace xla {
// Simplifies batch dot operations.
//
// Normally these would live in the algebraic simplifier, but we want to run
// this to fixpoint (this pass reaches fixed point in one execution) before we
// run the DotDecomposer.
class BatchDotSimplification : public HloModulePass {
 public:
  using HloPassInterface::Run;
  absl::StatusOr<bool> Run(
      HloModule* module,
      const absl::flat_hash_set<absl::string_view>& execution_threads) override;
  absl::string_view name() const override { return "batch-dot-simplification"; }

 private:
  absl::StatusOr<bool> ElideDegenerateBatchDimensionFromBatchDot(
      HloInstruction* batch_dot);
};
}  // namespace xla

#endif  // XLA_HLO_TRANSFORMS_SIMPLIFIERS_BATCH_DOT_SIMPLIFICATION_H_