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