//===--- SyncScope.h - Atomic synchronization scopes ------------*- 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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// Provides definitions for the atomic synchronization scopes.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_BASIC_SYNCSCOPE_H
#define LLVM_CLANG_BASIC_SYNCSCOPE_H
#include "clang/Basic/LangOptions.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringRef.h"
#include <memory>
namespace clang {
/// Defines synch scope values used internally by clang.
///
/// The enum values start from 0 and are contiguous. They are mainly used for
/// enumerating all supported synch scope values and mapping them to LLVM
/// synch scopes. Their numerical values may be different from the corresponding
/// synch scope enums used in source languages.
///
/// In atomic builtin and expressions, language-specific synch scope enums are
/// used. Currently only OpenCL memory scope enums are supported and assumed
/// to be used by all languages. However, in the future, other languages may
/// define their own set of synch scope enums. The language-specific synch scope
/// values are represented by class AtomicScopeModel and its derived classes.
///
/// To add a new enum value:
/// Add the enum value to enum class SyncScope.
/// Update enum value Last if necessary.
/// Update getAsString.
///
enum class SyncScope {
OpenCLWorkGroup,
OpenCLDevice,
OpenCLAllSVMDevices,
OpenCLSubGroup,
Last = OpenCLSubGroup
};
inline llvm::StringRef getAsString(SyncScope S) {
switch (S) {
case SyncScope::OpenCLWorkGroup:
return "opencl_workgroup";
case SyncScope::OpenCLDevice:
return "opencl_device";
case SyncScope::OpenCLAllSVMDevices:
return "opencl_allsvmdevices";
case SyncScope::OpenCLSubGroup:
return "opencl_subgroup";
}
llvm_unreachable("Invalid synch scope");
}
/// Defines the kind of atomic scope models.
enum class AtomicScopeModelKind { None, OpenCL };
/// Defines the interface for synch scope model.
class AtomicScopeModel {
public:
virtual ~AtomicScopeModel() {}
/// Maps language specific synch scope values to internal
/// SyncScope enum.
virtual SyncScope map(unsigned S) const = 0;
/// Check if the compile-time constant synch scope value
/// is valid.
virtual bool isValid(unsigned S) const = 0;
/// Get all possible synch scope values that might be
/// encountered at runtime for the current language.
virtual ArrayRef<unsigned> getRuntimeValues() const = 0;
/// If atomic builtin function is called with invalid
/// synch scope value at runtime, it will fall back to a valid
/// synch scope value returned by this function.
virtual unsigned getFallBackValue() const = 0;
/// Create an atomic scope model by AtomicScopeModelKind.
/// \return an empty std::unique_ptr for AtomicScopeModelKind::None.
static std::unique_ptr<AtomicScopeModel> create(AtomicScopeModelKind K);
};
/// Defines the synch scope model for OpenCL.
class AtomicScopeOpenCLModel : public AtomicScopeModel {
public:
/// The enum values match the pre-defined macros
/// __OPENCL_MEMORY_SCOPE_*, which are used to define memory_scope_*
/// enums in opencl-c-base.h.
enum ID {
WorkGroup = 1,
Device = 2,
AllSVMDevices = 3,
SubGroup = 4,
Last = SubGroup
};
AtomicScopeOpenCLModel() {}
SyncScope map(unsigned S) const override {
switch (static_cast<ID>(S)) {
case WorkGroup:
return SyncScope::OpenCLWorkGroup;
case Device:
return SyncScope::OpenCLDevice;
case AllSVMDevices:
return SyncScope::OpenCLAllSVMDevices;
case SubGroup:
return SyncScope::OpenCLSubGroup;
}
llvm_unreachable("Invalid language synch scope value");
}
bool isValid(unsigned S) const override {
return S >= static_cast<unsigned>(WorkGroup) &&
S <= static_cast<unsigned>(Last);
}
ArrayRef<unsigned> getRuntimeValues() const override {
static_assert(Last == SubGroup, "Does not include all synch scopes");
static const unsigned Scopes[] = {
static_cast<unsigned>(WorkGroup), static_cast<unsigned>(Device),
static_cast<unsigned>(AllSVMDevices), static_cast<unsigned>(SubGroup)};
return llvm::makeArrayRef(Scopes);
}
unsigned getFallBackValue() const override {
return static_cast<unsigned>(AllSVMDevices);
}
};
inline std::unique_ptr<AtomicScopeModel>
AtomicScopeModel::create(AtomicScopeModelKind K) {
switch (K) {
case AtomicScopeModelKind::None:
return std::unique_ptr<AtomicScopeModel>{};
case AtomicScopeModelKind::OpenCL:
return std::make_unique<AtomicScopeOpenCLModel>();
}
llvm_unreachable("Invalid atomic scope model kind");
}
}
#endif