llvm/llvm/include/llvm/TargetParser/SubtargetFeature.h

//=== llvm/TargetParser/SubtargetFeature.h - CPU characteristics-*- 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 Defines and manages user or tool specified CPU characteristics.
/// The intent is to be able to package specific features that should or should
/// not be used on a specific target processor.  A tool, such as llc, could, as
/// as example, gather chip info from the command line, a long with features
/// that should be used on that chip.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_TARGETPARSER_SUBTARGETFEATURE_H
#define LLVM_TARGETPARSER_SUBTARGETFEATURE_H

#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/MathExtras.h"
#include <array>
#include <initializer_list>
#include <string>
#include <vector>

namespace llvm {

class raw_ostream;
class Triple;

const unsigned MAX_SUBTARGET_WORDS = …;
const unsigned MAX_SUBTARGET_FEATURES = …;

/// Container class for subtarget features.
/// This is a constexpr reimplementation of a subset of std::bitset. It would be
/// nice to use std::bitset directly, but it doesn't support constant
/// initialization.
class FeatureBitset { … };

/// Class used to store the subtarget bits in the tables created by tablegen.
class FeatureBitArray : public FeatureBitset { … };

//===----------------------------------------------------------------------===//

/// Manages the enabling and disabling of subtarget specific features.
///
/// Features are encoded as a string of the form
///   "+attr1,+attr2,-attr3,...,+attrN"
/// A comma separates each feature from the next (all lowercase.)
/// Each of the remaining features is prefixed with + or - indicating whether
/// that feature should be enabled or disabled contrary to the cpu
/// specification.
class SubtargetFeatures { … };

} // end namespace llvm

#endif // LLVM_TARGETPARSER_SUBTARGETFEATURE_H