// Copyright (c) 2019 Google LLC.
//
// 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 "source/opt/legalize_vector_shuffle_pass.h"

#include "source/opt/ir_context.h"

namespace spvtools {
namespace opt {

Pass::Status LegalizeVectorShufflePass::Process() {
  bool changed = false;
  context()->module()->ForEachInst([&changed](Instruction* inst) {
    if (inst->opcode() != SpvOpVectorShuffle) return;

    for (uint32_t idx = 2; idx < inst->NumInOperands(); ++idx) {
      auto literal = inst->GetSingleWordInOperand(idx);
      if (literal != 0xFFFFFFFF) continue;
      changed = true;
      inst->SetInOperand(idx, {0});
    }
  });

  return changed ? Status::SuccessWithChange : Status::SuccessWithoutChange;
}

}  // namespace opt
}  // namespace spvtools