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/DenseMap.h" 20 #include "llvm/ADT/SmallVector.h" 21 #include "llvm/IR/DebugLoc.h" 22 #include "llvm/IR/Value.h" 23 #include "llvm/Support/Compiler.h" 24 25 namespace llvm { 26 class BasicBlock; 27 class Instruction; 28 class MDNode; 29 } // end namespace llvm 30 31 namespace clang { 32 class Attr; 33 class ASTContext; 34 namespace CodeGen { 35 36 /// \brief Attributes that may be specified on loops. 37 struct LoopAttributes { 38 explicit LoopAttributes(bool IsParallel = false); 39 void clear(); 40 41 /// \brief Generate llvm.loop.parallel metadata for loads and stores. 42 bool IsParallel; 43 44 /// \brief State of loop vectorization or unrolling. 45 enum LVEnableState { Unspecified, Enable, Disable, Full }; 46 47 /// \brief Value for llvm.loop.vectorize.enable metadata. 48 LVEnableState VectorizeEnable; 49 50 /// \brief Value for llvm.loop.unroll.* metadata (enable, disable, or full). 51 LVEnableState UnrollEnable; 52 53 /// \brief Value for llvm.loop.vectorize.width metadata. 54 unsigned VectorizeWidth; 55 56 /// \brief Value for llvm.loop.interleave.count metadata. 57 unsigned InterleaveCount; 58 59 /// \brief llvm.unroll. 60 unsigned UnrollCount; 61 62 /// \brief Value for llvm.loop.distribute.enable metadata. 63 LVEnableState DistributeEnable; 64 }; 65 66 /// \brief Information used when generating a structured loop. 67 class LoopInfo { 68 public: 69 /// \brief Construct a new LoopInfo for the loop with entry Header. 70 LoopInfo(llvm::BasicBlock *Header, const LoopAttributes &Attrs, 71 llvm::DebugLoc Location); 72 73 /// \brief Get the loop id metadata for this loop. 74 llvm::MDNode *getLoopID() const { return LoopID; } 75 76 /// \brief Get the header block of this loop. 77 llvm::BasicBlock *getHeader() const { return Header; } 78 79 /// \brief Get the set of attributes active for this loop. 80 const LoopAttributes &getAttributes() const { return Attrs; } 81 82 private: 83 /// \brief Loop ID metadata. 84 llvm::MDNode *LoopID; 85 /// \brief Header block of this loop. 86 llvm::BasicBlock *Header; 87 /// \brief The attributes for this loop. 88 LoopAttributes Attrs; 89 }; 90 91 /// \brief A stack of loop information corresponding to loop nesting levels. 92 /// This stack can be used to prepare attributes which are applied when a loop 93 /// is emitted. 94 class LoopInfoStack { 95 LoopInfoStack(const LoopInfoStack &) = delete; 96 void operator=(const LoopInfoStack &) = delete; 97 98 public: 99 LoopInfoStack() {} 100 101 /// \brief Begin a new structured loop. The set of staged attributes will be 102 /// applied to the loop and then cleared. 103 void push(llvm::BasicBlock *Header, 104 llvm::DebugLoc Location = llvm::DebugLoc()); 105 106 /// \brief Begin a new structured loop. Stage attributes from the Attrs list. 107 /// The staged attributes are applied to the loop and then cleared. 108 void push(llvm::BasicBlock *Header, clang::ASTContext &Ctx, 109 llvm::ArrayRef<const Attr *> Attrs, 110 llvm::DebugLoc Location = llvm::DebugLoc()); 111 112 /// \brief End the current loop. 113 void pop(); 114 115 /// \brief Return the top loop id metadata. 116 llvm::MDNode *getCurLoopID() const { return getInfo().getLoopID(); } 117 118 /// \brief Return true if the top loop is parallel. 119 bool getCurLoopParallel() const { 120 return hasInfo() ? getInfo().getAttributes().IsParallel : false; 121 } 122 123 /// \brief Function called by the CodeGenFunction when an instruction is 124 /// created. 125 void InsertHelper(llvm::Instruction *I) const; 126 127 /// \brief Set the next pushed loop as parallel. 128 void setParallel(bool Enable = true) { StagedAttrs.IsParallel = Enable; } 129 130 /// \brief Set the next pushed loop 'vectorize.enable' 131 void setVectorizeEnable(bool Enable = true) { 132 StagedAttrs.VectorizeEnable = 133 Enable ? LoopAttributes::Enable : LoopAttributes::Disable; 134 } 135 136 /// \brief Set the next pushed loop as a distribution candidate. 137 void setDistributeState(bool Enable = true) { 138 StagedAttrs.DistributeEnable = 139 Enable ? LoopAttributes::Enable : LoopAttributes::Disable; 140 } 141 142 /// \brief Set the next pushed loop unroll state. 143 void setUnrollState(const LoopAttributes::LVEnableState &State) { 144 StagedAttrs.UnrollEnable = State; 145 } 146 147 /// \brief Set the vectorize width for the next loop pushed. 148 void setVectorizeWidth(unsigned W) { StagedAttrs.VectorizeWidth = W; } 149 150 /// \brief Set the interleave count for the next loop pushed. 151 void setInterleaveCount(unsigned C) { StagedAttrs.InterleaveCount = C; } 152 153 /// \brief Set the unroll count for the next loop pushed. 154 void setUnrollCount(unsigned C) { StagedAttrs.UnrollCount = C; } 155 156 private: 157 /// \brief Returns true if there is LoopInfo on the stack. 158 bool hasInfo() const { return !Active.empty(); } 159 /// \brief Return the LoopInfo for the current loop. HasInfo should be called 160 /// first to ensure LoopInfo is present. 161 const LoopInfo &getInfo() const { return Active.back(); } 162 /// \brief The set of attributes that will be applied to the next pushed loop. 163 LoopAttributes StagedAttrs; 164 /// \brief Stack of active loops. 165 llvm::SmallVector<LoopInfo, 4> Active; 166 }; 167 168 } // end namespace CodeGen 169 } // end namespace clang 170 171 #endif 172
