SpecializeOption.cpp

Go to the documentation of this file.

//===- SpecializeOption.cpp -------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
 
#include "circt/Dialect/FIRRTL/FIRRTLOps.h"
#include "circt/Dialect/FIRRTL/Passes.h"
#include "mlir/IR/ImplicitLocOpBuilder.h"
#include "mlir/IR/SymbolTable.h"
#include "mlir/IR/Threading.h"
#include "mlir/Pass/Pass.h"
 
namespace circt {
namespace firrtl {
#define GEN_PASS_DEF_SPECIALIZEOPTION
#include "circt/Dialect/FIRRTL/Passes.h.inc"
} // namespace firrtl
} // namespace circt
 
using namespace mlir;
using namespace circt;
using namespace firrtl;
 
namespace {
struct SpecializeOptionPass
    : public circt::firrtl::impl::SpecializeOptionBase<SpecializeOptionPass> {
  using Base::Base;
 
  void runOnOperation() override {
    auto circuit = getOperation();
    auto &symTbl = getAnalysis<SymbolTable>();
 
    DenseMap<StringAttr, OptionCaseOp> selected;
    if (auto choiceAttr = circuit.getSelectInstChoiceAttr()) {
      for (auto attr : choiceAttr.getAsRange<StringAttr>()) {
        const auto optionAndCase = attr.getValue().str();
        size_t eq = optionAndCase.find("=");
        if (eq == std::string::npos) {
          mlir::emitError(circuit.getLoc(),
                          "invalid option format: \"" + optionAndCase + '"');
          return signalPassFailure();
        }
 
        std::string optionName = optionAndCase.substr(0, eq);
        // If the option is specified with `?=`, allow the absence of option.
        bool allowNonExistent = !optionName.empty() && optionName.back() == '?';
        if (allowNonExistent)
          optionName.pop_back();
        auto optionOp = symTbl.lookup<OptionOp>(optionName);
        if (!optionOp) {
          if (allowNonExistent)
            continue;
          mlir::emitError(circuit.getLoc(), "unknown option \"")
              << optionName << '"';
          return signalPassFailure();
        }
 
        std::string caseName = optionAndCase.substr(eq + 1);
        if (caseName == "<default>") {
          selected[StringAttr::get(&getContext(), optionName)] = {};
          continue;
        }
 
        auto caseOp = optionOp.lookupSymbol<OptionCaseOp>(caseName);
        if (!caseOp) {
          mlir::emitError(circuit.getLoc(), "invalid option case \"")
              << caseName << '"';
          return signalPassFailure();
        }
        selected[StringAttr::get(&getContext(), optionName)] = caseOp;
      }
    }
 
    bool failed = false;
    mlir::parallelForEach(
        &getContext(), circuit.getOps<FModuleOp>(), [&](auto module) {
          module.walk([&](firrtl::InstanceChoiceOp inst) {
            auto it = selected.find(inst.getOptionNameAttr());
            FlatSymbolRefAttr target;
            if (it == selected.end()) {
              if (selectDefaultInstanceChoice)
                target = inst.getDefaultTargetAttr();
              else
                return;
            } else {
              if (it->second)
                target = inst.getTargetOrDefaultAttr(it->second);
              else
                target = inst.getDefaultTargetAttr();
            }
 
            ImplicitLocOpBuilder builder(inst.getLoc(), inst);
            auto newInst = InstanceOp::create(
                builder, inst->getResultTypes(), target, inst.getNameAttr(),
                inst.getNameKindAttr(), inst.getPortDirectionsAttr(),
                inst.getPortNamesAttr(), inst.getDomainInfoAttr(),
                inst.getAnnotationsAttr(), inst.getPortAnnotationsAttr(),
                builder.getArrayAttr({}), UnitAttr{}, UnitAttr{},
                inst.getInnerSymAttr());
            inst.replaceAllUsesWith(newInst);
            inst.erase();
 
            ++numInstances;
          });
        });
 
    bool analysisPreserved = numInstances == 0;
    circuit->walk([&](OptionOp optionOp) {
      // When selectDefaultInstanceChoice is true, all instance choices are
      // specialized (either to a selected case or to the default), so we can
      // erase all options. Otherwise, only erase options that were selected.
      if (!selectDefaultInstanceChoice &&
          !selected.contains(optionOp.getSymNameAttr()))
        return;
      optionOp->erase();
      analysisPreserved = false;
    });
    if (analysisPreserved)
      markAllAnalysesPreserved();
 
    if (failed)
      signalPassFailure();
  }
};
} // namespace