1 //===---- CGLoopInfo.h - LLVM CodeGen for loop metadata -*- 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 is the internal state used for llvm translation for loop statement 11 // metadata. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_CLANG_LIB_CODEGEN_CGLOOPINFO_H 16 #define LLVM_CLANG_LIB_CODEGEN_CGLOOPINFO_H 17 18 #include "llvm/ADT/ArrayRef.h" 19 #include "llvm/ADT/SmallVector.h" 20 #include "llvm/IR/DebugLoc.h" 21 #include "llvm/IR/Value.h" 22 #include "llvm/Support/Compiler.h" 23 24 namespace llvm { 25 class BasicBlock; 26 class Instruction; 27 class MDNode; 28 } // end namespace llvm 29 30 namespace clang { 31 class Attr; 32 class ASTContext; 33 namespace CodeGen { 34 35 /// Attributes that may be specified on loops. 36 struct LoopAttributes { 37 explicit LoopAttributes(bool IsParallel = false); 38 void clear(); 39 40 /// Generate llvm.loop.parallel metadata for loads and stores. 41 bool IsParallel; 42 43 /// State of loop vectorization or unrolling. 44 enum LVEnableState { Unspecified, Enable, Disable, Full }; 45 46 /// Value for llvm.loop.vectorize.enable metadata. 47 LVEnableState VectorizeEnable; 48 49 /// Value for llvm.loop.unroll.* metadata (enable, disable, or full). 50 LVEnableState UnrollEnable; 51 52 /// Value for llvm.loop.unroll_and_jam.* metadata (enable, disable, or full). 53 LVEnableState UnrollAndJamEnable; 54 55 /// Value for llvm.loop.vectorize.width metadata. 56 unsigned VectorizeWidth; 57 58 /// Value for llvm.loop.interleave.count metadata. 59 unsigned InterleaveCount; 60 61 /// llvm.unroll. 62 unsigned UnrollCount; 63 64 /// llvm.unroll. 65 unsigned UnrollAndJamCount; 66 67 /// Value for llvm.loop.distribute.enable metadata. 68 LVEnableState DistributeEnable; 69 }; 70 71 /// Information used when generating a structured loop. 72 class LoopInfo { 73 public: 74 /// Construct a new LoopInfo for the loop with entry Header. 75 LoopInfo(llvm::BasicBlock *Header, const LoopAttributes &Attrs, 76 const llvm::DebugLoc &StartLoc, const llvm::DebugLoc &EndLoc); 77 78 /// Get the loop id metadata for this loop. 79 llvm::MDNode *getLoopID() const { return LoopID; } 80 81 /// Get the header block of this loop. 82 llvm::BasicBlock *getHeader() const { return Header; } 83 84 /// Get the set of attributes active for this loop. 85 const LoopAttributes &getAttributes() const { return Attrs; } 86 87 /// Return this loop's access group or nullptr if it does not have one. 88 llvm::MDNode *getAccessGroup() const { return AccGroup; } 89 90 private: 91 /// Loop ID metadata. 92 llvm::MDNode *LoopID; 93 /// Header block of this loop. 94 llvm::BasicBlock *Header; 95 /// The attributes for this loop. 96 LoopAttributes Attrs; 97 /// The access group for memory accesses parallel to this loop. 98 llvm::MDNode *AccGroup = nullptr; 99 }; 100 101 /// A stack of loop information corresponding to loop nesting levels. 102 /// This stack can be used to prepare attributes which are applied when a loop 103 /// is emitted. 104 class LoopInfoStack { 105 LoopInfoStack(const LoopInfoStack &) = delete; 106 void operator=(const LoopInfoStack &) = delete; 107 108 public: 109 LoopInfoStack() {} 110 111 /// Begin a new structured loop. The set of staged attributes will be 112 /// applied to the loop and then cleared. 113 void push(llvm::BasicBlock *Header, const llvm::DebugLoc &StartLoc, 114 const llvm::DebugLoc &EndLoc); 115 116 /// Begin a new structured loop. Stage attributes from the Attrs list. 117 /// The staged attributes are applied to the loop and then cleared. 118 void push(llvm::BasicBlock *Header, clang::ASTContext &Ctx, 119 llvm::ArrayRef<const Attr *> Attrs, const llvm::DebugLoc &StartLoc, 120 const llvm::DebugLoc &EndLoc); 121 122 /// End the current loop. 123 void pop(); 124 125 /// Return the top loop id metadata. 126 llvm::MDNode *getCurLoopID() const { return getInfo().getLoopID(); } 127 128 /// Return true if the top loop is parallel. 129 bool getCurLoopParallel() const { 130 return hasInfo() ? getInfo().getAttributes().IsParallel : false; 131 } 132 133 /// Function called by the CodeGenFunction when an instruction is 134 /// created. 135 void InsertHelper(llvm::Instruction *I) const; 136 137 /// Set the next pushed loop as parallel. 138 void setParallel(bool Enable = true) { StagedAttrs.IsParallel = Enable; } 139 140 /// Set the next pushed loop 'vectorize.enable' 141 void setVectorizeEnable(bool Enable = true) { 142 StagedAttrs.VectorizeEnable = 143 Enable ? LoopAttributes::Enable : LoopAttributes::Disable; 144 } 145 146 /// Set the next pushed loop as a distribution candidate. 147 void setDistributeState(bool Enable = true) { 148 StagedAttrs.DistributeEnable = 149 Enable ? LoopAttributes::Enable : LoopAttributes::Disable; 150 } 151 152 /// Set the next pushed loop unroll state. 153 void setUnrollState(const LoopAttributes::LVEnableState &State) { 154 StagedAttrs.UnrollEnable = State; 155 } 156 157 /// Set the next pushed loop unroll_and_jam state. 158 void setUnrollAndJamState(const LoopAttributes::LVEnableState &State) { 159 StagedAttrs.UnrollAndJamEnable = State; 160 } 161 162 /// Set the vectorize width for the next loop pushed. 163 void setVectorizeWidth(unsigned W) { StagedAttrs.VectorizeWidth = W; } 164 165 /// Set the interleave count for the next loop pushed. 166 void setInterleaveCount(unsigned C) { StagedAttrs.InterleaveCount = C; } 167 168 /// Set the unroll count for the next loop pushed. 169 void setUnrollCount(unsigned C) { StagedAttrs.UnrollCount = C; } 170 171 /// \brief Set the unroll count for the next loop pushed. 172 void setUnrollAndJamCount(unsigned C) { StagedAttrs.UnrollAndJamCount = C; } 173 174 private: 175 /// Returns true if there is LoopInfo on the stack. 176 bool hasInfo() const { return !Active.empty(); } 177 /// Return the LoopInfo for the current loop. HasInfo should be called 178 /// first to ensure LoopInfo is present. 179 const LoopInfo &getInfo() const { return Active.back(); } 180 /// The set of attributes that will be applied to the next pushed loop. 181 LoopAttributes StagedAttrs; 182 /// Stack of active loops. 183 llvm::SmallVector<LoopInfo, 4> Active; 184 }; 185 186 } // end namespace CodeGen 187 } // end namespace clang 188 189 #endif 190