github.com/johnnyeven/libtools@v0.0.0-20191126065708-61829c1adf46/third_party/mlir/lib/Transforms/Utils/RegionUtils.cpp (about)

     1  //===- RegionUtils.cpp - Region-related transformation utilities ----------===//
     2  //
     3  // Copyright 2019 The MLIR Authors.
     4  //
     5  // Licensed under the Apache License, Version 2.0 (the "License");
     6  // you may not use this file except in compliance with the License.
     7  // You may obtain a copy of the License at
     8  //
     9  //   http://www.apache.org/licenses/LICENSE-2.0
    10  //
    11  // Unless required by applicable law or agreed to in writing, software
    12  // distributed under the License is distributed on an "AS IS" BASIS,
    13  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14  // See the License for the specific language governing permissions and
    15  // limitations under the License.
    16  // =============================================================================
    17  
    18  #include "mlir/Transforms/RegionUtils.h"
    19  #include "mlir/IR/Block.h"
    20  #include "mlir/IR/Operation.h"
    21  #include "mlir/IR/Value.h"
    22  
    23  #include "llvm/ADT/SmallSet.h"
    24  
    25  using namespace mlir;
    26  
    27  void mlir::replaceAllUsesInRegionWith(Value *orig, Value *replacement,
    28                                        Region &region) {
    29    for (IROperand &use : llvm::make_early_inc_range(orig->getUses())) {
    30      if (region.isAncestor(use.getOwner()->getParentRegion()))
    31        use.set(replacement);
    32    }
    33  }
    34  
    35  void mlir::getUsedValuesDefinedAbove(Region &region, Region &limit,
    36                                       llvm::SetVector<Value *> &values) {
    37    assert(limit.isAncestor(&region) &&
    38           "expected isolation limit to be an ancestor of the given region");
    39  
    40    // Collect proper ancestors of `limit` upfront to avoid traversing the region
    41    // tree for every value.
    42    llvm::SmallPtrSet<Region *, 4> properAncestors;
    43    for (auto *reg = limit.getParentRegion(); reg != nullptr;
    44         reg = reg->getParentRegion()) {
    45      properAncestors.insert(reg);
    46    }
    47  
    48    region.walk([&values, &properAncestors](Operation *op) {
    49      for (Value *operand : op->getOperands())
    50        // Collect values that are used by an operation and defined in a proper
    51        // ancestor of region.
    52        if (properAncestors.count(operand->getParentRegion()))
    53          values.insert(operand);
    54    });
    55  }