xref: /llvm-project-15.0.7/mlir/lib/IR/MLIRContext.cpp (revision b8ff0dae)

//===- MLIRContext.cpp - MLIR Type Classes --------------------------------===//
//
// 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 "mlir/IR/MLIRContext.h"
#include "AffineExprDetail.h"
#include "AffineMapDetail.h"
#include "AttributeDetail.h"
#include "IntegerSetDetail.h"
#include "LocationDetail.h"
#include "TypeDetail.h"
#include "mlir/IR/AffineExpr.h"
#include "mlir/IR/AffineMap.h"
#include "mlir/IR/Attributes.h"
#include "mlir/IR/Diagnostics.h"
#include "mlir/IR/Dialect.h"
#include "mlir/IR/Function.h"
#include "mlir/IR/Identifier.h"
#include "mlir/IR/IntegerSet.h"
#include "mlir/IR/Location.h"
#include "mlir/IR/Module.h"
#include "mlir/IR/Types.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/RWMutex.h"
#include "llvm/Support/raw_ostream.h"
#include <memory>

using namespace mlir;
using namespace mlir::detail;

using llvm::hash_combine;
using llvm::hash_combine_range;

//===----------------------------------------------------------------------===//
// MLIRContext CommandLine Options
//===----------------------------------------------------------------------===//

namespace {
/// This struct contains command line options that can be used to initialize
/// various bits of an MLIRContext. This uses a struct wrapper to avoid the need
/// for global command line options.
struct MLIRContextOptions {
  llvm::cl::opt<bool> disableThreading{
      "mlir-disable-threading",
      llvm::cl::desc("Disabling multi-threading within MLIR")};

  llvm::cl::opt<bool> printOpOnDiagnostic{
      "mlir-print-op-on-diagnostic",
      llvm::cl::desc("When a diagnostic is emitted on an operation, also print "
                     "the operation as an attached note"),
      llvm::cl::init(true)};

  llvm::cl::opt<bool> printStackTraceOnDiagnostic{
      "mlir-print-stacktrace-on-diagnostic",
      llvm::cl::desc("When a diagnostic is emitted, also print the stack trace "
                     "as an attached note")};
};
} // end anonymous namespace

static llvm::ManagedStatic<MLIRContextOptions> clOptions;

/// Register a set of useful command-line options that can be used to configure
/// various flags within the MLIRContext. These flags are used when constructing
/// an MLIR context for initialization.
void mlir::registerMLIRContextCLOptions() {
  // Make sure that the options struct has been initialized.
  *clOptions;
}

//===----------------------------------------------------------------------===//
// Builtin Dialect
//===----------------------------------------------------------------------===//

namespace {
/// A builtin dialect to define types/etc that are necessary for the validity of
/// the IR.
struct BuiltinDialect : public Dialect {
  BuiltinDialect(MLIRContext *context)
      : Dialect(/*name=*/"", context, TypeID::get<BuiltinDialect>()) {
    addAttributes<AffineMapAttr, ArrayAttr, DenseIntOrFPElementsAttr,
                  DenseStringElementsAttr, DictionaryAttr, FloatAttr,
                  SymbolRefAttr, IntegerAttr, IntegerSetAttr, OpaqueAttr,
                  OpaqueElementsAttr, SparseElementsAttr, StringAttr, TypeAttr,
                  UnitAttr>();
    addAttributes<CallSiteLoc, FileLineColLoc, FusedLoc, NameLoc, OpaqueLoc,
                  UnknownLoc>();

    addTypes<ComplexType, FloatType, FunctionType, IndexType, IntegerType,
             MemRefType, UnrankedMemRefType, NoneType, OpaqueType,
             RankedTensorType, TupleType, UnrankedTensorType, VectorType>();

    // TODO: These operations should be moved to a different dialect when they
    // have been fully decoupled from the core.
    addOperations<FuncOp, ModuleOp, ModuleTerminatorOp>();
  }
  static StringRef getDialectNamespace() { return ""; }
};
} // end anonymous namespace.

//===----------------------------------------------------------------------===//
// Locking Utilities
//===----------------------------------------------------------------------===//

namespace {
/// Utility reader lock that takes a runtime flag that specifies if we really
/// need to lock.
struct ScopedReaderLock {
  ScopedReaderLock(llvm::sys::SmartRWMutex<true> &mutexParam, bool shouldLock)
      : mutex(shouldLock ? &mutexParam : nullptr) {
    if (mutex)
      mutex->lock_shared();
  }
  ~ScopedReaderLock() {
    if (mutex)
      mutex->unlock_shared();
  }
  llvm::sys::SmartRWMutex<true> *mutex;
};
/// Utility writer lock that takes a runtime flag that specifies if we really
/// need to lock.
struct ScopedWriterLock {
  ScopedWriterLock(llvm::sys::SmartRWMutex<true> &mutexParam, bool shouldLock)
      : mutex(shouldLock ? &mutexParam : nullptr) {
    if (mutex)
      mutex->lock();
  }
  ~ScopedWriterLock() {
    if (mutex)
      mutex->unlock();
  }
  llvm::sys::SmartRWMutex<true> *mutex;
};
} // end anonymous namespace.

//===----------------------------------------------------------------------===//
// AffineMap and IntegerSet hashing
//===----------------------------------------------------------------------===//

/// A utility function to safely get or create a uniqued instance within the
/// given set container.
template <typename ValueT, typename DenseInfoT, typename KeyT,
          typename ConstructorFn>
static ValueT safeGetOrCreate(DenseSet<ValueT, DenseInfoT> &container,
                              KeyT &&key, llvm::sys::SmartRWMutex<true> &mutex,
                              bool threadingIsEnabled,
                              ConstructorFn &&constructorFn) {
  // Check for an existing instance in read-only mode.
  if (threadingIsEnabled) {
    llvm::sys::SmartScopedReader<true> instanceLock(mutex);
    auto it = container.find_as(key);
    if (it != container.end())
      return *it;
  }

  // Acquire a writer-lock so that we can safely create the new instance.
  ScopedWriterLock instanceLock(mutex, threadingIsEnabled);

  // Check for an existing instance again here, because another writer thread
  // may have already created one. Otherwise, construct a new instance.
  auto existing = container.insert_as(ValueT(), key);
  if (existing.second)
    return *existing.first = constructorFn();
  return *existing.first;
}

namespace {
struct AffineMapKeyInfo : DenseMapInfo<AffineMap> {
  // Affine maps are uniqued based on their dim/symbol counts and affine
  // expressions.
  using KeyTy = std::tuple<unsigned, unsigned, ArrayRef<AffineExpr>>;
  using DenseMapInfo<AffineMap>::isEqual;

  static unsigned getHashValue(const AffineMap &key) {
    return getHashValue(
        KeyTy(key.getNumDims(), key.getNumSymbols(), key.getResults()));
  }

  static unsigned getHashValue(KeyTy key) {
    return hash_combine(
        std::get<0>(key), std::get<1>(key),
        hash_combine_range(std::get<2>(key).begin(), std::get<2>(key).end()));
  }

  static bool isEqual(const KeyTy &lhs, AffineMap rhs) {
    if (rhs == getEmptyKey() || rhs == getTombstoneKey())
      return false;
    return lhs == std::make_tuple(rhs.getNumDims(), rhs.getNumSymbols(),
                                  rhs.getResults());
  }
};

struct IntegerSetKeyInfo : DenseMapInfo<IntegerSet> {
  // Integer sets are uniqued based on their dim/symbol counts, affine
  // expressions appearing in the LHS of constraints, and eqFlags.
  using KeyTy =
      std::tuple<unsigned, unsigned, ArrayRef<AffineExpr>, ArrayRef<bool>>;
  using DenseMapInfo<IntegerSet>::isEqual;

  static unsigned getHashValue(const IntegerSet &key) {
    return getHashValue(KeyTy(key.getNumDims(), key.getNumSymbols(),
                              key.getConstraints(), key.getEqFlags()));
  }

  static unsigned getHashValue(KeyTy key) {
    return hash_combine(
        std::get<0>(key), std::get<1>(key),
        hash_combine_range(std::get<2>(key).begin(), std::get<2>(key).end()),
        hash_combine_range(std::get<3>(key).begin(), std::get<3>(key).end()));
  }

  static bool isEqual(const KeyTy &lhs, IntegerSet rhs) {
    if (rhs == getEmptyKey() || rhs == getTombstoneKey())
      return false;
    return lhs == std::make_tuple(rhs.getNumDims(), rhs.getNumSymbols(),
                                  rhs.getConstraints(), rhs.getEqFlags());
  }
};
} // end anonymous namespace.

//===----------------------------------------------------------------------===//
// MLIRContextImpl
//===----------------------------------------------------------------------===//

namespace mlir {
/// This is the implementation of the MLIRContext class, using the pImpl idiom.
/// This class is completely private to this file, so everything is public.
class MLIRContextImpl {
public:
  //===--------------------------------------------------------------------===//
  // Identifier uniquing
  //===--------------------------------------------------------------------===//

  // Identifier allocator and mutex for thread safety.
  llvm::BumpPtrAllocator identifierAllocator;
  llvm::sys::SmartRWMutex<true> identifierMutex;

  //===--------------------------------------------------------------------===//
  // Diagnostics
  //===--------------------------------------------------------------------===//
  DiagnosticEngine diagEngine;

  //===--------------------------------------------------------------------===//
  // Options
  //===--------------------------------------------------------------------===//

  /// In most cases, creating operation in unregistered dialect is not desired
  /// and indicate a misconfiguration of the compiler. This option enables to
  /// detect such use cases
  bool allowUnregisteredDialects = false;

  /// Enable support for multi-threading within MLIR.
  bool threadingIsEnabled = true;

  /// If the operation should be attached to diagnostics printed via the
  /// Operation::emit methods.
  bool printOpOnDiagnostic = true;

  /// If the current stack trace should be attached when emitting diagnostics.
  bool printStackTraceOnDiagnostic = false;

  //===--------------------------------------------------------------------===//
  // Other
  //===--------------------------------------------------------------------===//

  /// This is a list of dialects that are created referring to this context.
  /// The MLIRContext owns the objects.
  std::vector<std::unique_ptr<Dialect>> dialects;

  /// This is a mapping from operation name to AbstractOperation for registered
  /// operations.
  llvm::StringMap<AbstractOperation> registeredOperations;

  /// These are identifiers uniqued into this MLIRContext.
  llvm::StringSet<llvm::BumpPtrAllocator &> identifiers;

  /// An allocator used for AbstractAttribute and AbstractType objects.
  llvm::BumpPtrAllocator abstractDialectSymbolAllocator;

  //===--------------------------------------------------------------------===//
  // Affine uniquing
  //===--------------------------------------------------------------------===//

  // Affine allocator and mutex for thread safety.
  llvm::BumpPtrAllocator affineAllocator;
  llvm::sys::SmartRWMutex<true> affineMutex;

  // Affine map uniquing.
  using AffineMapSet = DenseSet<AffineMap, AffineMapKeyInfo>;
  AffineMapSet affineMaps;

  // Integer set uniquing.
  using IntegerSets = DenseSet<IntegerSet, IntegerSetKeyInfo>;
  IntegerSets integerSets;

  // Affine expression uniquing.
  StorageUniquer affineUniquer;

  //===--------------------------------------------------------------------===//
  // Type uniquing
  //===--------------------------------------------------------------------===//

  DenseMap<TypeID, const AbstractType *> registeredTypes;
  StorageUniquer typeUniquer;

  /// Cached Type Instances.
  FloatType bf16Ty, f16Ty, f32Ty, f64Ty;
  IndexType indexTy;
  IntegerType int1Ty, int8Ty, int16Ty, int32Ty, int64Ty, int128Ty;
  NoneType noneType;

  //===--------------------------------------------------------------------===//
  // Attribute uniquing
  //===--------------------------------------------------------------------===//

  DenseMap<TypeID, const AbstractAttribute *> registeredAttributes;
  StorageUniquer attributeUniquer;

  /// Cached Attribute Instances.
  BoolAttr falseAttr, trueAttr;
  UnitAttr unitAttr;
  UnknownLoc unknownLocAttr;
  DictionaryAttr emptyDictionaryAttr;

public:
  MLIRContextImpl() : identifiers(identifierAllocator) {}
  ~MLIRContextImpl() {
    for (auto typeMapping : registeredTypes)
      typeMapping.second->~AbstractType();
    for (auto attrMapping : registeredAttributes)
      attrMapping.second->~AbstractAttribute();
  }
};
} // end namespace mlir

MLIRContext::MLIRContext() : impl(new MLIRContextImpl()) {
  // Initialize values based on the command line flags if they were provided.
  if (clOptions.isConstructed()) {
    disableMultithreading(clOptions->disableThreading);
    printOpOnDiagnostic(clOptions->printOpOnDiagnostic);
    printStackTraceOnDiagnostic(clOptions->printStackTraceOnDiagnostic);
  }

  // Register dialects with this context.
  getOrCreateDialect<BuiltinDialect>();
  registerAllDialects(this);

  // Initialize several common attributes and types to avoid the need to lock
  // the context when accessing them.

  //// Types.
  /// Floating-point Types.
  impl->bf16Ty = TypeUniquer::get<FloatType>(this, StandardTypes::BF16);
  impl->f16Ty = TypeUniquer::get<FloatType>(this, StandardTypes::F16);
  impl->f32Ty = TypeUniquer::get<FloatType>(this, StandardTypes::F32);
  impl->f64Ty = TypeUniquer::get<FloatType>(this, StandardTypes::F64);
  /// Index Type.
  impl->indexTy = TypeUniquer::get<IndexType>(this, StandardTypes::Index);
  /// Integer Types.
  impl->int1Ty = TypeUniquer::get<IntegerType>(this, StandardTypes::Integer, 1,
                                               IntegerType::Signless);
  impl->int8Ty = TypeUniquer::get<IntegerType>(this, StandardTypes::Integer, 8,
                                               IntegerType::Signless);
  impl->int16Ty = TypeUniquer::get<IntegerType>(this, StandardTypes::Integer,
                                                16, IntegerType::Signless);
  impl->int32Ty = TypeUniquer::get<IntegerType>(this, StandardTypes::Integer,
                                                32, IntegerType::Signless);
  impl->int64Ty = TypeUniquer::get<IntegerType>(this, StandardTypes::Integer,
                                                64, IntegerType::Signless);
  impl->int128Ty = TypeUniquer::get<IntegerType>(this, StandardTypes::Integer,
                                                 128, IntegerType::Signless);
  /// None Type.
  impl->noneType = TypeUniquer::get<NoneType>(this, StandardTypes::None);

  //// Attributes.
  //// Note: These must be registered after the types as they may generate one
  //// of the above types internally.
  /// Bool Attributes.
  impl->falseAttr = AttributeUniquer::get<IntegerAttr>(
                        this, StandardAttributes::Integer, impl->int1Ty,
                        APInt(/*numBits=*/1, false))
                        .cast<BoolAttr>();
  impl->trueAttr = AttributeUniquer::get<IntegerAttr>(
                       this, StandardAttributes::Integer, impl->int1Ty,
                       APInt(/*numBits=*/1, true))
                       .cast<BoolAttr>();
  /// Unit Attribute.
  impl->unitAttr =
      AttributeUniquer::get<UnitAttr>(this, StandardAttributes::Unit);
  /// Unknown Location Attribute.
  impl->unknownLocAttr = AttributeUniquer::get<UnknownLoc>(
      this, StandardAttributes::UnknownLocation);
  /// The empty dictionary attribute.
  impl->emptyDictionaryAttr = AttributeUniquer::get<DictionaryAttr>(
      this, StandardAttributes::Dictionary, ArrayRef<NamedAttribute>());

  // Register the affine storage objects with the uniquer.
  impl->affineUniquer.registerStorageType(
      TypeID::get<AffineBinaryOpExprStorage>());
  impl->affineUniquer.registerStorageType(
      TypeID::get<AffineConstantExprStorage>());
  impl->affineUniquer.registerStorageType(TypeID::get<AffineDimExprStorage>());
}

MLIRContext::~MLIRContext() {}

/// Copy the specified array of elements into memory managed by the provided
/// bump pointer allocator.  This assumes the elements are all PODs.
template <typename T>
static ArrayRef<T> copyArrayRefInto(llvm::BumpPtrAllocator &allocator,
                                    ArrayRef<T> elements) {
  auto result = allocator.Allocate<T>(elements.size());
  std::uninitialized_copy(elements.begin(), elements.end(), result);
  return ArrayRef<T>(result, elements.size());
}

//===----------------------------------------------------------------------===//
// Diagnostic Handlers
//===----------------------------------------------------------------------===//

/// Returns the diagnostic engine for this context.
DiagnosticEngine &MLIRContext::getDiagEngine() { return getImpl().diagEngine; }

//===----------------------------------------------------------------------===//
// Dialect and Operation Registration
//===----------------------------------------------------------------------===//

/// Return information about all registered IR dialects.
std::vector<Dialect *> MLIRContext::getRegisteredDialects() {
  std::vector<Dialect *> result;
  result.reserve(impl->dialects.size());
  for (auto &dialect : impl->dialects)
    result.push_back(dialect.get());
  return result;
}

/// Get a registered IR dialect with the given namespace. If none is found,
/// then return nullptr.
Dialect *MLIRContext::getRegisteredDialect(StringRef name) {
  // Dialects are sorted by name, so we can use binary search for lookup.
  auto it = llvm::lower_bound(
      impl->dialects, name,
      [](const auto &lhs, StringRef rhs) { return lhs->getNamespace() < rhs; });
  return (it != impl->dialects.end() && (*it)->getNamespace() == name)
             ? (*it).get()
             : nullptr;
}

/// Get a dialect for the provided namespace and TypeID: abort the program if a
/// dialect exist for this namespace with different TypeID. Returns a pointer to
/// the dialect owned by the context.
Dialect *
MLIRContext::getOrCreateDialect(StringRef dialectNamespace, TypeID dialectID,
                                function_ref<std::unique_ptr<Dialect>()> ctor) {
  auto &impl = getImpl();
  // Get the correct insertion position sorted by namespace.
  auto insertPt =
      llvm::lower_bound(impl.dialects, nullptr,
                        [&](const std::unique_ptr<Dialect> &lhs,
                            const std::unique_ptr<Dialect> &rhs) {
                          if (!lhs)
                            return dialectNamespace < rhs->getNamespace();
                          return lhs->getNamespace() < dialectNamespace;
                        });

  // Abort if dialect with namespace has already been registered.
  if (insertPt != impl.dialects.end() &&
      (*insertPt)->getNamespace() == dialectNamespace) {
    if ((*insertPt)->getTypeID() == dialectID)
      return insertPt->get();
    llvm::report_fatal_error("a dialect with namespace '" + dialectNamespace +
                             "' has already been registered");
  }
  auto it = impl.dialects.insert(insertPt, ctor());
  return &**it;
}

bool MLIRContext::allowsUnregisteredDialects() {
  return impl->allowUnregisteredDialects;
}

void MLIRContext::allowUnregisteredDialects(bool allowing) {
  impl->allowUnregisteredDialects = allowing;
}

/// Return true if multi-threading is disabled by the context.
bool MLIRContext::isMultithreadingEnabled() {
  return impl->threadingIsEnabled && llvm::llvm_is_multithreaded();
}

/// Set the flag specifying if multi-threading is disabled by the context.
void MLIRContext::disableMultithreading(bool disable) {
  impl->threadingIsEnabled = !disable;

  // Update the threading mode for each of the uniquers.
  impl->affineUniquer.disableMultithreading(disable);
  impl->attributeUniquer.disableMultithreading(disable);
  impl->typeUniquer.disableMultithreading(disable);
}

/// Return true if we should attach the operation to diagnostics emitted via
/// Operation::emit.
bool MLIRContext::shouldPrintOpOnDiagnostic() {
  return impl->printOpOnDiagnostic;
}

/// Set the flag specifying if we should attach the operation to diagnostics
/// emitted via Operation::emit.
void MLIRContext::printOpOnDiagnostic(bool enable) {
  impl->printOpOnDiagnostic = enable;
}

/// Return true if we should attach the current stacktrace to diagnostics when
/// emitted.
bool MLIRContext::shouldPrintStackTraceOnDiagnostic() {
  return impl->printStackTraceOnDiagnostic;
}

/// Set the flag specifying if we should attach the current stacktrace when
/// emitting diagnostics.
void MLIRContext::printStackTraceOnDiagnostic(bool enable) {
  impl->printStackTraceOnDiagnostic = enable;
}

/// Return information about all registered operations.  This isn't very
/// efficient, typically you should ask the operations about their properties
/// directly.
std::vector<AbstractOperation *> MLIRContext::getRegisteredOperations() {
  // We just have the operations in a non-deterministic hash table order. Dump
  // into a temporary array, then sort it by operation name to get a stable
  // ordering.
  llvm::StringMap<AbstractOperation> &registeredOps =
      impl->registeredOperations;

  std::vector<AbstractOperation *> result;
  result.reserve(registeredOps.size());
  for (auto &elt : registeredOps)
    result.push_back(&elt.second);
  llvm::array_pod_sort(
      result.begin(), result.end(),
      [](AbstractOperation *const *lhs, AbstractOperation *const *rhs) {
        return (*lhs)->name.compare((*rhs)->name);
      });

  return result;
}

bool MLIRContext::isOperationRegistered(StringRef name) {
  return impl->registeredOperations.count(name);
}

void Dialect::addOperation(AbstractOperation opInfo) {
  assert((getNamespace().empty() || opInfo.dialect.name == getNamespace()) &&
         "op name doesn't start with dialect namespace");
  assert(&opInfo.dialect == this && "Dialect object mismatch");
  auto &impl = context->getImpl();
  StringRef opName = opInfo.name;
  if (!impl.registeredOperations.insert({opName, std::move(opInfo)}).second) {
    llvm::errs() << "error: operation named '" << opInfo.name
                 << "' is already registered.\n";
    abort();
  }
}

void Dialect::addType(TypeID typeID, AbstractType &&typeInfo) {
  auto &impl = context->getImpl();
  auto *newInfo =
      new (impl.abstractDialectSymbolAllocator.Allocate<AbstractType>())
          AbstractType(std::move(typeInfo));
  if (!impl.registeredTypes.insert({typeID, newInfo}).second)
    llvm::report_fatal_error("Dialect Type already registered.");
  impl.typeUniquer.registerStorageType(typeID);
}

void Dialect::addAttribute(TypeID typeID, AbstractAttribute &&attrInfo) {
  auto &impl = context->getImpl();
  auto *newInfo =
      new (impl.abstractDialectSymbolAllocator.Allocate<AbstractAttribute>())
          AbstractAttribute(std::move(attrInfo));
  if (!impl.registeredAttributes.insert({typeID, newInfo}).second)
    llvm::report_fatal_error("Dialect Attribute already registered.");
  impl.attributeUniquer.registerStorageType(typeID);
}

/// Get the dialect that registered the attribute with the provided typeid.
const AbstractAttribute &AbstractAttribute::lookup(TypeID typeID,
                                                   MLIRContext *context) {
  auto &impl = context->getImpl();
  auto it = impl.registeredAttributes.find(typeID);
  if (it == impl.registeredAttributes.end())
    llvm::report_fatal_error("Trying to create an Attribute that was not "
                             "registered in this MLIRContext.");
  return *it->second;
}

/// Look up the specified operation in the operation set and return a pointer
/// to it if present.  Otherwise, return a null pointer.
const AbstractOperation *AbstractOperation::lookup(StringRef opName,
                                                   MLIRContext *context) {
  auto &impl = context->getImpl();
  auto it = impl.registeredOperations.find(opName);
  if (it != impl.registeredOperations.end())
    return &it->second;
  return nullptr;
}

/// Get the dialect that registered the type with the provided typeid.
const AbstractType &AbstractType::lookup(TypeID typeID, MLIRContext *context) {
  auto &impl = context->getImpl();
  auto it = impl.registeredTypes.find(typeID);
  if (it == impl.registeredTypes.end())
    llvm::report_fatal_error(
        "Trying to create a Type that was not registered in this MLIRContext.");
  return *it->second;
}

//===----------------------------------------------------------------------===//
// Identifier uniquing
//===----------------------------------------------------------------------===//

/// Return an identifier for the specified string.
Identifier Identifier::get(StringRef str, MLIRContext *context) {
  auto &impl = context->getImpl();

  // Check for an existing identifier in read-only mode.
  if (context->isMultithreadingEnabled()) {
    llvm::sys::SmartScopedReader<true> contextLock(impl.identifierMutex);
    auto it = impl.identifiers.find(str);
    if (it != impl.identifiers.end())
      return Identifier(&*it);
  }

  // Check invariants after seeing if we already have something in the
  // identifier table - if we already had it in the table, then it already
  // passed invariant checks.
  assert(!str.empty() && "Cannot create an empty identifier");
  assert(str.find('\0') == StringRef::npos &&
         "Cannot create an identifier with a nul character");

  // Acquire a writer-lock so that we can safely create the new instance.
  ScopedWriterLock contextLock(impl.identifierMutex, impl.threadingIsEnabled);
  auto it = impl.identifiers.insert(str).first;
  return Identifier(&*it);
}

//===----------------------------------------------------------------------===//
// Type uniquing
//===----------------------------------------------------------------------===//

/// Returns the storage uniquer used for constructing type storage instances.
/// This should not be used directly.
StorageUniquer &MLIRContext::getTypeUniquer() { return getImpl().typeUniquer; }

FloatType FloatType::get(StandardTypes::Kind kind, MLIRContext *context) {
  switch (kind) {
  case StandardTypes::BF16:
    return context->getImpl().bf16Ty;
  case StandardTypes::F16:
    return context->getImpl().f16Ty;
  case StandardTypes::F32:
    return context->getImpl().f32Ty;
  case StandardTypes::F64:
    return context->getImpl().f64Ty;
  default:
    llvm_unreachable("unexpected floating-point kind");
  }
}

/// Get an instance of the IndexType.
IndexType IndexType::get(MLIRContext *context) {
  return context->getImpl().indexTy;
}

/// Return an existing integer type instance if one is cached within the
/// context.
static IntegerType
getCachedIntegerType(unsigned width,
                     IntegerType::SignednessSemantics signedness,
                     MLIRContext *context) {
  if (signedness != IntegerType::Signless)
    return IntegerType();

  switch (width) {
  case 1:
    return context->getImpl().int1Ty;
  case 8:
    return context->getImpl().int8Ty;
  case 16:
    return context->getImpl().int16Ty;
  case 32:
    return context->getImpl().int32Ty;
  case 64:
    return context->getImpl().int64Ty;
  case 128:
    return context->getImpl().int128Ty;
  default:
    return IntegerType();
  }
}

IntegerType IntegerType::get(unsigned width, MLIRContext *context) {
  return get(width, IntegerType::Signless, context);
}

IntegerType IntegerType::get(unsigned width,
                             IntegerType::SignednessSemantics signedness,
                             MLIRContext *context) {
  if (auto cached = getCachedIntegerType(width, signedness, context))
    return cached;
  return Base::get(context, StandardTypes::Integer, width, signedness);
}

IntegerType IntegerType::getChecked(unsigned width, Location location) {
  return getChecked(width, IntegerType::Signless, location);
}

IntegerType IntegerType::getChecked(unsigned width,
                                    SignednessSemantics signedness,
                                    Location location) {
  if (auto cached =
          getCachedIntegerType(width, signedness, location->getContext()))
    return cached;
  return Base::getChecked(location, StandardTypes::Integer, width, signedness);
}

/// Get an instance of the NoneType.
NoneType NoneType::get(MLIRContext *context) {
  return context->getImpl().noneType;
}

//===----------------------------------------------------------------------===//
// Attribute uniquing
//===----------------------------------------------------------------------===//

/// Returns the storage uniquer used for constructing attribute storage
/// instances. This should not be used directly.
StorageUniquer &MLIRContext::getAttributeUniquer() {
  return getImpl().attributeUniquer;
}

/// Initialize the given attribute storage instance.
void AttributeUniquer::initializeAttributeStorage(AttributeStorage *storage,
                                                  MLIRContext *ctx,
                                                  TypeID attrID) {
  storage->initialize(AbstractAttribute::lookup(attrID, ctx));

  // If the attribute did not provide a type, then default to NoneType.
  if (!storage->getType())
    storage->setType(NoneType::get(ctx));
}

BoolAttr BoolAttr::get(bool value, MLIRContext *context) {
  return value ? context->getImpl().trueAttr : context->getImpl().falseAttr;
}

UnitAttr UnitAttr::get(MLIRContext *context) {
  return context->getImpl().unitAttr;
}

Location UnknownLoc::get(MLIRContext *context) {
  return context->getImpl().unknownLocAttr;
}

/// Return empty dictionary.
DictionaryAttr DictionaryAttr::getEmpty(MLIRContext *context) {
  return context->getImpl().emptyDictionaryAttr;
}

//===----------------------------------------------------------------------===//
// AffineMap uniquing
//===----------------------------------------------------------------------===//

StorageUniquer &MLIRContext::getAffineUniquer() {
  return getImpl().affineUniquer;
}

AffineMap AffineMap::getImpl(unsigned dimCount, unsigned symbolCount,
                             ArrayRef<AffineExpr> results,
                             MLIRContext *context) {
  auto &impl = context->getImpl();
  auto key = std::make_tuple(dimCount, symbolCount, results);

  // Safely get or create an AffineMap instance.
  return safeGetOrCreate(
      impl.affineMaps, key, impl.affineMutex, impl.threadingIsEnabled, [&] {
        auto *res = impl.affineAllocator.Allocate<detail::AffineMapStorage>();

        // Copy the results into the bump pointer.
        results = copyArrayRefInto(impl.affineAllocator, results);

        // Initialize the memory using placement new.
        new (res)
            detail::AffineMapStorage{dimCount, symbolCount, results, context};
        return AffineMap(res);
      });
}

AffineMap AffineMap::get(MLIRContext *context) {
  return getImpl(/*dimCount=*/0, /*symbolCount=*/0, /*results=*/{}, context);
}

AffineMap AffineMap::get(unsigned dimCount, unsigned symbolCount,
                         MLIRContext *context) {
  return getImpl(dimCount, symbolCount, /*results=*/{}, context);
}

AffineMap AffineMap::get(unsigned dimCount, unsigned symbolCount,
                         AffineExpr result) {
  return getImpl(dimCount, symbolCount, {result}, result.getContext());
}

AffineMap AffineMap::get(unsigned dimCount, unsigned symbolCount,
                         ArrayRef<AffineExpr> results, MLIRContext *context) {
  return getImpl(dimCount, symbolCount, results, context);
}

//===----------------------------------------------------------------------===//
// Integer Sets: these are allocated into the bump pointer, and are immutable.
// Unlike AffineMap's, these are uniqued only if they are small.
//===----------------------------------------------------------------------===//

IntegerSet IntegerSet::get(unsigned dimCount, unsigned symbolCount,
                           ArrayRef<AffineExpr> constraints,
                           ArrayRef<bool> eqFlags) {
  // The number of constraints can't be zero.
  assert(!constraints.empty());
  assert(constraints.size() == eqFlags.size());

  auto &impl = constraints[0].getContext()->getImpl();

  // A utility function to construct a new IntegerSetStorage instance.
  auto constructorFn = [&] {
    auto *res = impl.affineAllocator.Allocate<detail::IntegerSetStorage>();

    // Copy the results and equality flags into the bump pointer.
    constraints = copyArrayRefInto(impl.affineAllocator, constraints);
    eqFlags = copyArrayRefInto(impl.affineAllocator, eqFlags);

    // Initialize the memory using placement new.
    new (res)
        detail::IntegerSetStorage{dimCount, symbolCount, constraints, eqFlags};
    return IntegerSet(res);
  };

  // If this instance is uniqued, then we handle it separately so that multiple
  // threads may simultaneously access existing instances.
  if (constraints.size() < IntegerSet::kUniquingThreshold) {
    auto key = std::make_tuple(dimCount, symbolCount, constraints, eqFlags);
    return safeGetOrCreate(impl.integerSets, key, impl.affineMutex,
                           impl.threadingIsEnabled, constructorFn);
  }

  // Otherwise, acquire a writer-lock so that we can safely create the new
  // instance.
  ScopedWriterLock affineLock(impl.affineMutex, impl.threadingIsEnabled);
  return constructorFn();
}

//===----------------------------------------------------------------------===//
// StorageUniquerSupport
//===----------------------------------------------------------------------===//

/// Utility method to generate a default location for use when checking the
/// construction invariants of a storage object. This is defined out-of-line to
/// avoid the need to include Location.h.
const AttributeStorage *
mlir::detail::generateUnknownStorageLocation(MLIRContext *ctx) {
  return reinterpret_cast<const AttributeStorage *>(
      ctx->getImpl().unknownLocAttr.getAsOpaquePointer());
}