1 //===-- llvm/MC/SubtargetFeature.h - CPU characteristics --------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file defines and manages user or tool specified CPU characteristics. 11 // The intent is to be able to package specific features that should or should 12 // not be used on a specific target processor. A tool, such as llc, could, as 13 // as example, gather chip info from the command line, a long with features 14 // that should be used on that chip. 15 // 16 //===----------------------------------------------------------------------===// 17 18 #ifndef LLVM_MC_SUBTARGETFEATURE_H 19 #define LLVM_MC_SUBTARGETFEATURE_H 20 21 #include "llvm/ADT/ArrayRef.h" 22 #include "llvm/ADT/Triple.h" 23 #include "llvm/Support/DataTypes.h" 24 25 namespace llvm { 26 class raw_ostream; 27 class StringRef; 28 29 //===----------------------------------------------------------------------===// 30 /// 31 /// SubtargetFeatureKV - Used to provide key value pairs for feature and 32 /// CPU bit flags. 33 // 34 struct SubtargetFeatureKV { 35 const char *Key; // K-V key string 36 const char *Desc; // Help descriptor 37 uint64_t Value; // K-V integer value 38 uint64_t Implies; // K-V bit mask 39 40 // Compare routine for std::lower_bound 41 bool operator<(StringRef S) const { 42 return StringRef(Key) < S; 43 } 44 }; 45 46 //===----------------------------------------------------------------------===// 47 /// 48 /// SubtargetInfoKV - Used to provide key value pairs for CPU and arbitrary 49 /// pointers. 50 // 51 struct SubtargetInfoKV { 52 const char *Key; // K-V key string 53 const void *Value; // K-V pointer value 54 55 // Compare routine for std::lower_bound 56 bool operator<(StringRef S) const { 57 return StringRef(Key) < S; 58 } 59 }; 60 61 //===----------------------------------------------------------------------===// 62 /// 63 /// SubtargetFeatures - Manages the enabling and disabling of subtarget 64 /// specific features. Features are encoded as a string of the form 65 /// "+attr1,+attr2,-attr3,...,+attrN" 66 /// A comma separates each feature from the next (all lowercase.) 67 /// Each of the remaining features is prefixed with + or - indicating whether 68 /// that feature should be enabled or disabled contrary to the cpu 69 /// specification. 70 /// 71 72 class SubtargetFeatures { 73 std::vector<std::string> Features; // Subtarget features as a vector 74 public: 75 explicit SubtargetFeatures(const StringRef Initial = ""); 76 77 /// Features string accessors. 78 std::string getString() const; 79 80 /// Adding Features. 81 void AddFeature(const StringRef String); 82 83 /// ToggleFeature - Toggle a feature and returns the newly updated feature 84 /// bits. 85 uint64_t ToggleFeature(uint64_t Bits, const StringRef String, 86 ArrayRef<SubtargetFeatureKV> FeatureTable); 87 88 /// Get feature bits of a CPU. 89 uint64_t getFeatureBits(const StringRef CPU, 90 ArrayRef<SubtargetFeatureKV> CPUTable, 91 ArrayRef<SubtargetFeatureKV> FeatureTable); 92 93 /// Print feature string. 94 void print(raw_ostream &OS) const; 95 96 // Dump feature info. 97 void dump() const; 98 99 /// Adds the default features for the specified target triple. 100 void getDefaultSubtargetFeatures(const Triple& Triple); 101 }; 102 103 } // End namespace llvm 104 105 #endif 106
