FIRRTLOpInterfaces.cpp

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//===- FIRRTLOpInterfaces.cpp - Implement the FIRRTL op interfaces --------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file implement the FIRRTL operation interfaces.
//
//===----------------------------------------------------------------------===//
 
#include "circt/Dialect/FIRRTL/FIRRTLAttributes.h"
#include "circt/Dialect/FIRRTL/FIRRTLOps.h"
#include "mlir/IR/BuiltinAttributes.h"
#include "mlir/IR/BuiltinTypes.h"
#include "mlir/IR/PatternMatch.h"
#include "llvm/ADT/SmallBitVector.h"
#include "llvm/ADT/StringRef.h"
 
using namespace mlir;
using namespace llvm;
using namespace circt::firrtl;
 
static LogicalResult verifyNoInputProbes(FModuleLike module) {
  // Helper to check for input-oriented refs.
  std::function<bool(Type, bool)> hasInputRef = [&](Type type,
                                                    bool output) -> bool {
    auto ftype = type_dyn_cast<FIRRTLType>(type);
    if (!ftype || !ftype.containsReference())
      return false;
    return FIRRTLTypeSwitch<FIRRTLType, bool>(ftype)
        .Case<RefType>([&](auto reftype) { return !output; })
        .Case<OpenVectorType>([&](OpenVectorType ovt) {
          return hasInputRef(ovt.getElementType(), output);
        })
        .Case<OpenBundleType>([&](OpenBundleType obt) {
          for (auto field : obt.getElements())
            if (hasInputRef(field.type, field.isFlip ^ output))
              return true;
          return false;
        });
  };
 
  for (auto &pi : module.getPorts())
    if (hasInputRef(pi.type, pi.isOutput()))
      return emitError(pi.loc, "input probe not allowed");
  return success();
}
 
LogicalResult circt::firrtl::verifyModuleLikeOpInterface(FModuleLike module) {
  // Verify port types first.  This is used as the basis for the number of
  // ports required everywhere else.
  auto portTypes = module.getPortTypesAttr();
  if (!portTypes || llvm::any_of(portTypes.getValue(), [](Attribute attr) {
        return !isa<TypeAttr>(attr);
      }))
    return module.emitOpError("requires valid port types");
 
  auto numPorts = portTypes.size();
 
  // Verify the port dirctions.
  auto portDirections = module.getPortDirectionsAttr();
  if (!portDirections)
    return module.emitOpError("requires valid port direction");
  // TODO: bitwidth is 1 when there are no ports, since APInt previously did not
  // support 0 bit widths.
  auto bitWidth = portDirections.size();
  if (static_cast<size_t>(bitWidth) != numPorts)
    return module.emitOpError("requires ") << numPorts << " port directions";
 
  // Verify the port names.
  auto portNames = module.getPortNamesAttr();
  if (!portNames)
    return module.emitOpError("requires valid port names");
  if (portNames.size() != numPorts)
    return module.emitOpError("requires ") << numPorts << " port names";
  if (llvm::any_of(portNames.getValue(),
                   [](Attribute attr) { return !isa<StringAttr>(attr); }))
    return module.emitOpError("port names should all be string attributes");
 
  // Verify the port annotations.
  auto portAnnotations = module.getPortAnnotationsAttr();
  if (!portAnnotations)
    return module.emitOpError("requires valid port annotations");
  // TODO: it seems weird to allow empty port annotations.
  if (!portAnnotations.empty() && portAnnotations.size() != numPorts)
    return module.emitOpError("requires ") << numPorts << " port annotations";
  // TODO: Move this into an annotation verifier.
  for (auto annos : portAnnotations.getValue()) {
    auto arrayAttr = dyn_cast<ArrayAttr>(annos);
    if (!arrayAttr)
      return module.emitOpError(
          "requires port annotations be array attributes");
    if (llvm::any_of(arrayAttr.getValue(),
                     [](Attribute attr) { return !isa<DictionaryAttr>(attr); }))
      return module.emitOpError(
          "annotations must be dictionaries or subannotations");
  }
 
  // Verify the port symbols.
  auto portSymbols = module.getPortSymbolsAttr();
  if (!portSymbols)
    return module.emitOpError("requires valid port symbols");
  if (!portSymbols.empty() && portSymbols.size() != numPorts)
    return module.emitOpError("requires ") << numPorts << " port symbols";
  if (llvm::any_of(portSymbols.getValue(), [](Attribute attr) {
        return !attr || !isa<hw::InnerSymAttr>(attr);
      }))
    return module.emitOpError("port symbols should all be InnerSym attributes");
 
  // Verify the port locations.
  auto portLocs = module.getPortLocationsAttr();
  if (!portLocs)
    return module.emitOpError("requires valid port locations");
  if (portLocs.size() != numPorts)
    return module.emitOpError("requires ") << numPorts << " port locations";
  if (llvm::any_of(portLocs.getValue(), [](Attribute attr) {
        return !attr || !isa<LocationAttr>(attr);
      }))
    return module.emitOpError("port symbols should all be location attributes");
 
  // Verify the port domains.  This can be either:
  //   1. An empty ArrayAttr.
  //   2. An ArrayAttr, one entry-per-port, of:
  //      a. SymbolRefAttrs if the port is a domain type
  //      b. IntegerAttrs if the port is a non-domain type
  //
  // Note: error handling here intentionally does _not_ use port info locations.
  // This is because if any of these fail, this is almost always a
  // CIRCT-internal bug.  These code paths are essoentially inaccessible from
  // FIRRTL text.
  auto domains = module.getDomainInfoAttr();
  // Domain info cannot be null.
  if (!domains)
    return module.emitOpError("requires valid port domains");
  // If non-empty, the one-entry-per-port.
  if (!domains.empty() && domains.size() != numPorts)
    return module.emitOpError("requires ")
           << numPorts << " port domains, but has " << domains.size();
 
  for (auto [index, port] : llvm::enumerate(module.getPorts())) {
    auto type = cast<TypeAttr>(portTypes[index]).getValue();
    // If this is a domain type port, then it _must_ refer to a domain.  This
    // cannot be empty.
    if (isa<DomainType>(type)) {
      if (domains.empty())
        return module.emitOpError() << "has domain port '" << port.getName()
                                    << "', but no domain information";
      if (!isa<FlatSymbolRefAttr>(domains[index]))
        return module.emitOpError() << "domain information for domain port '"
                                    << module.getPortName(index)
                                    << "' must be a 'FlatSymbolRefAttr'";
      continue;
    }
 
    // Non-domain type ports can have no domain information.
    if (domains.empty())
      continue;
 
    // If they do have domain information, then the domain info must be an array
    // of integers and each integer must point to a domain type port.
    auto domain = domains[index];
    auto arrayAttr = dyn_cast<ArrayAttr>(domain);
    if (!arrayAttr)
      return module.emitOpError()
             << "domain information for non-domain port '"
             << module.getPortName(index) << "' must be an 'ArrayAttr'";
    for (auto attr : arrayAttr) {
      auto association = dyn_cast<IntegerAttr>(attr);
      if (!association)
        return module.emitOpError()
               << "domain information for non-domain port '"
               << module.getPortName(index)
               << "' must be an 'ArrayAttr<IntegerAttr>'";
      auto associationIdx = association.getValue().getZExtValue();
      if (associationIdx >= numPorts)
        return module.emitOpError()
               << "has domain association " << associationIdx << " for port '"
               << module.getPortName(index) << "', but the module only has "
               << numPorts << " ports";
      if (!type_isa<DomainType>(module.getPortType(associationIdx)))
        return module.emitOpError()
               << "has port '" << module.getPortName(index)
               << "' which has a domain association with non-domain port '"
               << module.getPortName(associationIdx) << "'";
    }
  }
 
  // Verify the body.
  if (module->getNumRegions() != 1)
    return module.emitOpError("requires one region");
 
  if (failed(verifyNoInputProbes(module)))
    return failure();
 
  return success();
}
 
//===----------------------------------------------------------------------===//
// Forceable
//===----------------------------------------------------------------------===//
 
RefType circt::firrtl::detail::getForceableResultType(bool forceable,
                                                      Type type) {
  auto base = dyn_cast_or_null<FIRRTLBaseType>(type);
  // TODO: Find a way to not check same things RefType::get/verify does.
  if (!forceable || !base || base.containsConst())
    return {};
  return circt::firrtl::RefType::get(base.getPassiveType(), forceable);
}
 
LogicalResult circt::firrtl::detail::verifyForceableOp(Forceable op) {
  bool forceable = op.isForceable();
  auto ref = op.getDataRef();
  if ((bool)ref != forceable)
    return op.emitOpError("must have ref result iff marked forceable");
  if (!forceable)
    return success();
  auto data = op.getDataRaw();
  auto baseType = type_dyn_cast<FIRRTLBaseType>(data.getType());
  if (!baseType)
    return op.emitOpError("has data that is not a base type");
  if (baseType.containsConst())
    return op.emitOpError("cannot force a declaration of constant type");
  auto expectedRefType = getForceableResultType(forceable, baseType);
  if (ref.getType() != expectedRefType)
    return op.emitOpError("reference result of incorrect type, found ")
           << ref.getType() << ", expected " << expectedRefType;
  return success();
}
 
namespace {
/// Simple wrapper to allow construction from a context for local use.
class TrivialPatternRewriter : public PatternRewriter {
public:
  explicit TrivialPatternRewriter(MLIRContext *context)
      : PatternRewriter(context) {}
};
} // end namespace
 
Forceable
circt::firrtl::detail::replaceWithNewForceability(Forceable op, bool forceable,
                                                  PatternRewriter *rewriter) {
  if (forceable == op.isForceable())
    return op;
 
  assert(op->getNumRegions() == 0);
 
  // Create copy of this operation with/without the forceable marker + result
  // type.
 
  TrivialPatternRewriter localRewriter(op.getContext());
  PatternRewriter &rw = rewriter ? *rewriter : localRewriter;
 
  // Grab the current operation's results and attributes.
  SmallVector<Type, 8> resultTypes(op->getResultTypes());
  SmallVector<NamedAttribute, 16> attributes(op->getAttrs());
 
  // Add/remove the optional ref result.
  auto refType = firrtl::detail::getForceableResultType(true, op.getDataType());
  if (forceable)
    resultTypes.push_back(refType);
  else {
    assert(resultTypes.back() == refType &&
           "expected forceable type as last result");
    resultTypes.pop_back();
  }
 
  // Add/remove the forceable marker.
  auto forceableMarker =
      rw.getNamedAttr(op.getForceableAttrName(), rw.getUnitAttr());
  if (forceable)
    attributes.push_back(forceableMarker);
  else {
    llvm::erase(attributes, forceableMarker);
    assert(attributes.size() != op->getAttrs().size());
  }
 
  // Create the replacement operation.
  OperationState state(op.getLoc(), op->getName(), op->getOperands(),
                       resultTypes, attributes, op->getSuccessors());
  rw.setInsertionPoint(op);
  auto *replace = rw.create(state);
 
  // Dropping forceability (!forceable) -> no uses of forceable ref handle.
  assert(forceable || op.getDataRef().use_empty());
 
  // Replace results.
  for (auto result : llvm::drop_end(op->getResults(), forceable ? 0 : 1))
    rw.replaceAllUsesWith(result, replace->getResult(result.getResultNumber()));
  rw.eraseOp(op);
  return cast<Forceable>(replace);
}
 
#include "circt/Dialect/FIRRTL/FIRRTLOpInterfaces.cpp.inc"