SubtargetFeature.h revision e1bff38386b0af24b5564c3d20888c7bbb045099
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 <vector> 22#include "llvm/ADT/Triple.h" 23#include "llvm/Support/DataTypes.h" 24 25namespace 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// 34struct 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 binary search 41 bool operator<(const SubtargetFeatureKV &S) const { 42 return strcmp(Key, S.Key) < 0; 43 } 44}; 45 46//===----------------------------------------------------------------------===// 47/// 48/// SubtargetInfoKV - Used to provide key value pairs for CPU and arbitrary 49/// pointers. 50// 51struct SubtargetInfoKV { 52 const char *Key; // K-V key string 53 void *Value; // K-V pointer value 54 55 // Compare routine for std binary search 56 bool operator<(const SubtargetInfoKV &S) const { 57 return strcmp(Key, S.Key) < 0; 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/// "cpu,+attr1,+attr2,-attr3,...,+attrN" 66/// A comma separates each feature from the next (all lowercase.) 67/// The first feature is always the CPU subtype (eg. pentiumm). If the CPU 68/// value is "generic" then the CPU subtype should be generic for the target. 69/// Each of the remaining features is prefixed with + or - indicating whether 70/// that feature should be enabled or disabled contrary to the cpu 71/// specification. 72/// 73 74class SubtargetFeatures { 75 std::vector<std::string> Features; // Subtarget features as a vector 76public: 77 explicit SubtargetFeatures(const StringRef Initial = ""); 78 79 /// Features string accessors. 80 StringRef getString() const; 81 82 /// Adding Features. 83 void AddFeature(const StringRef String, bool IsEnabled = true); 84 85 /// Get feature bits of a CPU. 86 uint64_t getFeatureBits(const StringRef CPU, 87 const SubtargetFeatureKV *CPUTable, 88 size_t CPUTableSize, 89 const SubtargetFeatureKV *FeatureTable, 90 size_t FeatureTableSize); 91 92 /// Get scheduling itinerary of a CPU. 93 void *getItinerary(const StringRef CPU, 94 const SubtargetInfoKV *Table, size_t TableSize); 95 96 /// Print feature string. 97 void print(raw_ostream &OS) const; 98 99 // Dump feature info. 100 void dump() const; 101 102 /// Retrieve a formatted string of the default features for the specified 103 /// target triple. 104 void getDefaultSubtargetFeatures(const Triple& Triple); 105}; 106 107} // End namespace llvm 108 109#endif 110