mlir/lib/Transforms/CompositePass.cpp

   1 //===- CompositePass.cpp - Composite pass code ----------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // CompositePass allows to run set of passes until fixed point is reached.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "mlir/Transforms/Passes.h"
  14
  15 #include "mlir/Pass/Pass.h"
  16 #include "mlir/Pass/PassManager.h"
  17
  18 namespace mlir {
  19 #define GEN_PASS_DEF_COMPOSITEFIXEDPOINTPASS
  20 #include "mlir/Transforms/Passes.h.inc"
  21 } // namespace mlir
  22
  23 using namespace mlir;
  24
  25 namespace {
  26 struct CompositeFixedPointPass final
  27     : public impl::CompositeFixedPointPassBase<CompositeFixedPointPass> {
  28   using CompositeFixedPointPassBase::CompositeFixedPointPassBase;
  29
  30   CompositeFixedPointPass(
  31       std::string name_, llvm::function_ref<void(OpPassManager &)> populateFunc,
  32       int maxIterations) {
  33     name = std::move(name_);
  34     maxIter = maxIterations;
  35     populateFunc(dynamicPM);
  36
  37     llvm::raw_string_ostream os(pipelineStr);
  38     dynamicPM.printAsTextualPipeline(os);
  39   }
  40
  41   LogicalResult initializeOptions(
  42       StringRef options,
  43       function_ref<LogicalResult(const Twine &)> errorHandler) override {
  44     if (failed(CompositeFixedPointPassBase::initializeOptions(options,
  45                                                               errorHandler)))
  46       return failure();
  47
  48     if (failed(parsePassPipeline(pipelineStr, dynamicPM)))
  49       return errorHandler("Failed to parse composite pass pipeline");
  50
  51     return success();
  52   }
  53
  54   LogicalResult initialize(MLIRContext *context) override {
  55     if (maxIter <= 0)
  56       return emitError(UnknownLoc::get(context))
  57              << "Invalid maxIterations value: " << maxIter << "\n";
  58
  59     return success();
  60   }
  61
  62   void getDependentDialects(DialectRegistry &registry) const override {
  63     dynamicPM.getDependentDialects(registry);
  64   }
  65
  66   void runOnOperation() override {
  67     auto op = getOperation();
  68     OperationFingerPrint fp(op);
  69
  70     int currentIter = 0;
  71     int maxIterVal = maxIter;
  72     while (true) {
  73       if (failed(runPipeline(dynamicPM, op)))
  74         return signalPassFailure();
  75
  76       if (currentIter++ >= maxIterVal) {
  77         op->emitWarning("Composite pass \"" + llvm::Twine(name) +
  78                         "\"+ didn't converge in " + llvm::Twine(maxIterVal) +
  79                         " iterations");
  80         break;
  81       }
  82
  83       OperationFingerPrint newFp(op);
  84       if (newFp == fp)
  85         break;
  86
  87       fp = newFp;
  88     }
  89   }
  90
  91 protected:
  92   llvm::StringRef getName() const override { return name; }
  93
  94 private:
  95   OpPassManager dynamicPM;
  96 };
  97 } // namespace
  98
  99 std::unique_ptr<Pass> mlir::createCompositeFixedPointPass(
 100     std::string name, llvm::function_ref<void(OpPassManager &)> populateFunc,
 101     int maxIterations) {
 102
 103   return std::make_unique<CompositeFixedPointPass>(std::move(name),
 104                                                    populateFunc, maxIterations);
 105 }