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 private: 88 /// Loop ID metadata. 89 llvm::MDNode *LoopID; 90 /// Header block of this loop. 91 llvm::BasicBlock *Header; 92 /// The attributes for this loop. 93 LoopAttributes Attrs; 94 }; 95 96 /// A stack of loop information corresponding to loop nesting levels. 97 /// This stack can be used to prepare attributes which are applied when a loop 98 /// is emitted. 99 class LoopInfoStack { 100 LoopInfoStack(const LoopInfoStack &) = delete; 101 void operator=(const LoopInfoStack &) = delete; 102 103 public: 104 LoopInfoStack() {} 105 106 /// Begin a new structured loop. The set of staged attributes will be 107 /// applied to the loop and then cleared. 108 void push(llvm::BasicBlock *Header, const llvm::DebugLoc &StartLoc, 109 const llvm::DebugLoc &EndLoc); 110 111 /// Begin a new structured loop. Stage attributes from the Attrs list. 112 /// The staged attributes are applied to the loop and then cleared. 113 void push(llvm::BasicBlock *Header, clang::ASTContext &Ctx, 114 llvm::ArrayRef<const Attr *> Attrs, const llvm::DebugLoc &StartLoc, 115 const llvm::DebugLoc &EndLoc); 116 117 /// End the current loop. 118 void pop(); 119 120 /// Return the top loop id metadata. 121 llvm::MDNode *getCurLoopID() const { return getInfo().getLoopID(); } 122 123 /// Return true if the top loop is parallel. 124 bool getCurLoopParallel() const { 125 return hasInfo() ? getInfo().getAttributes().IsParallel : false; 126 } 127 128 /// Function called by the CodeGenFunction when an instruction is 129 /// created. 130 void InsertHelper(llvm::Instruction *I) const; 131 132 /// Set the next pushed loop as parallel. 133 void setParallel(bool Enable = true) { StagedAttrs.IsParallel = Enable; } 134 135 /// Set the next pushed loop 'vectorize.enable' 136 void setVectorizeEnable(bool Enable = true) { 137 StagedAttrs.VectorizeEnable = 138 Enable ? LoopAttributes::Enable : LoopAttributes::Disable; 139 } 140 141 /// Set the next pushed loop as a distribution candidate. 142 void setDistributeState(bool Enable = true) { 143 StagedAttrs.DistributeEnable = 144 Enable ? LoopAttributes::Enable : LoopAttributes::Disable; 145 } 146 147 /// Set the next pushed loop unroll state. 148 void setUnrollState(const LoopAttributes::LVEnableState &State) { 149 StagedAttrs.UnrollEnable = State; 150 } 151 152 /// Set the next pushed loop unroll_and_jam state. 153 void setUnrollAndJamState(const LoopAttributes::LVEnableState &State) { 154 StagedAttrs.UnrollAndJamEnable = State; 155 } 156 157 /// Set the vectorize width for the next loop pushed. 158 void setVectorizeWidth(unsigned W) { StagedAttrs.VectorizeWidth = W; } 159 160 /// Set the interleave count for the next loop pushed. 161 void setInterleaveCount(unsigned C) { StagedAttrs.InterleaveCount = C; } 162 163 /// Set the unroll count for the next loop pushed. 164 void setUnrollCount(unsigned C) { StagedAttrs.UnrollCount = C; } 165 166 /// \brief Set the unroll count for the next loop pushed. 167 void setUnrollAndJamCount(unsigned C) { StagedAttrs.UnrollAndJamCount = C; } 168 169 private: 170 /// Returns true if there is LoopInfo on the stack. 171 bool hasInfo() const { return !Active.empty(); } 172 /// Return the LoopInfo for the current loop. HasInfo should be called 173 /// first to ensure LoopInfo is present. 174 const LoopInfo &getInfo() const { return Active.back(); } 175 /// The set of attributes that will be applied to the next pushed loop. 176 LoopAttributes StagedAttrs; 177 /// Stack of active loops. 178 llvm::SmallVector<LoopInfo, 4> Active; 179 }; 180 181 } // end namespace CodeGen 182 } // end namespace clang 183 184 #endif 185