| //===- llvm/MC/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_MC_SUBTARGETFEATURE_H |
| #define LLVM_MC_SUBTARGETFEATURE_H |
| |
| #include "llvm/ADT/StringRef.h" |
| #include <bitset> |
| #include <initializer_list> |
| #include <string> |
| #include <vector> |
| |
| namespace llvm { |
| |
| template <typename T> class ArrayRef; |
| class raw_ostream; |
| class Triple; |
| |
| const unsigned MAX_SUBTARGET_FEATURES = 192; |
| /// Container class for subtarget features. |
| /// This is convenient because std::bitset does not have a constructor |
| /// with an initializer list of set bits. |
| class FeatureBitset : public std::bitset<MAX_SUBTARGET_FEATURES> { |
| public: |
| // Cannot inherit constructors because it's not supported by VC++.. |
| FeatureBitset() = default; |
| |
| FeatureBitset(const bitset<MAX_SUBTARGET_FEATURES>& B) : bitset(B) {} |
| |
| FeatureBitset(std::initializer_list<unsigned> Init) { |
| for (auto I : Init) |
| set(I); |
| } |
| }; |
| |
| //===----------------------------------------------------------------------===// |
| |
| /// Used to provide key value pairs for feature and CPU bit flags. |
| struct SubtargetFeatureKV { |
| const char *Key; ///< K-V key string |
| const char *Desc; ///< Help descriptor |
| FeatureBitset Value; ///< K-V integer value |
| FeatureBitset Implies; ///< K-V bit mask |
| |
| /// Compare routine for std::lower_bound |
| bool operator<(StringRef S) const { |
| return StringRef(Key) < S; |
| } |
| |
| /// Compare routine for std::is_sorted. |
| bool operator<(const SubtargetFeatureKV &Other) const { |
| return StringRef(Key) < StringRef(Other.Key); |
| } |
| }; |
| |
| //===----------------------------------------------------------------------===// |
| |
| /// Used to provide key value pairs for CPU and arbitrary pointers. |
| struct SubtargetInfoKV { |
| const char *Key; ///< K-V key string |
| const void *Value; ///< K-V pointer value |
| |
| /// Compare routine for std::lower_bound |
| bool operator<(StringRef S) const { |
| return StringRef(Key) < S; |
| } |
| }; |
| |
| //===----------------------------------------------------------------------===// |
| |
| /// 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 { |
| std::vector<std::string> Features; ///< Subtarget features as a vector |
| |
| public: |
| explicit SubtargetFeatures(StringRef Initial = ""); |
| |
| /// Returns features as a string. |
| std::string getString() const; |
| |
| /// Adds Features. |
| void AddFeature(StringRef String, bool Enable = true); |
| |
| /// Toggles a feature and update the feature bits. |
| static void ToggleFeature(FeatureBitset &Bits, StringRef String, |
| ArrayRef<SubtargetFeatureKV> FeatureTable); |
| |
| /// Applies the feature flag and update the feature bits. |
| static void ApplyFeatureFlag(FeatureBitset &Bits, StringRef Feature, |
| ArrayRef<SubtargetFeatureKV> FeatureTable); |
| |
| /// Returns feature bits of a CPU. |
| FeatureBitset getFeatureBits(StringRef CPU, |
| ArrayRef<SubtargetFeatureKV> CPUTable, |
| ArrayRef<SubtargetFeatureKV> FeatureTable); |
| |
| /// Returns the vector of individual subtarget features. |
| const std::vector<std::string> &getFeatures() const { return Features; } |
| |
| /// Prints feature string. |
| void print(raw_ostream &OS) const; |
| |
| // Dumps feature info. |
| void dump() const; |
| |
| /// Adds the default features for the specified target triple. |
| void getDefaultSubtargetFeatures(const Triple& Triple); |
| }; |
| |
| } // end namespace llvm |
| |
| #endif // LLVM_MC_SUBTARGETFEATURE_H |