//===---- CGLoopInfo.h - LLVM CodeGen for loop metadata -*- C++ -*---------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This is the internal state used for llvm translation for loop statement // metadata. // //===----------------------------------------------------------------------===// #ifndef LLVM_CLANG_LIB_CODEGEN_CGLOOPINFO_H #define LLVM_CLANG_LIB_CODEGEN_CGLOOPINFO_H #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/SmallVector.h" #include "llvm/IR/Value.h" #include "llvm/Support/Compiler.h" namespace llvm { class BasicBlock; class Instruction; class MDNode; } // end namespace llvm namespace clang { namespace CodeGen { /// \brief Attributes that may be specified on loops. struct LoopAttributes { explicit LoopAttributes(bool IsParallel = false); void clear(); /// \brief Generate llvm.loop.parallel metadata for loads and stores. bool IsParallel; /// \brief Values of llvm.loop.vectorize.enable metadata. enum LVEnableState { VecUnspecified, VecEnable, VecDisable }; /// \brief llvm.loop.vectorize.enable LVEnableState VectorizerEnable; /// \brief llvm.loop.vectorize.width unsigned VectorizerWidth; /// \brief llvm.loop.interleave.count unsigned VectorizerUnroll; }; /// \brief Information used when generating a structured loop. class LoopInfo { public: /// \brief Construct a new LoopInfo for the loop with entry Header. LoopInfo(llvm::BasicBlock *Header, const LoopAttributes &Attrs); /// \brief Get the loop id metadata for this loop. llvm::MDNode *getLoopID() const { return LoopID; } /// \brief Get the header block of this loop. llvm::BasicBlock *getHeader() const { return Header; } /// \brief Get the set of attributes active for this loop. const LoopAttributes &getAttributes() const { return Attrs; } private: /// \brief Loop ID metadata. llvm::MDNode *LoopID; /// \brief Header block of this loop. llvm::BasicBlock *Header; /// \brief The attributes for this loop. LoopAttributes Attrs; }; /// \brief A stack of loop information corresponding to loop nesting levels. /// This stack can be used to prepare attributes which are applied when a loop /// is emitted. class LoopInfoStack { LoopInfoStack(const LoopInfoStack &) = delete; void operator=(const LoopInfoStack &) = delete; public: LoopInfoStack() {} /// \brief Begin a new structured loop. The set of staged attributes will be /// applied to the loop and then cleared. void push(llvm::BasicBlock *Header); /// \brief End the current loop. void pop(); /// \brief Return the top loop id metadata. llvm::MDNode *getCurLoopID() const { return getInfo().getLoopID(); } /// \brief Return true if the top loop is parallel. bool getCurLoopParallel() const { return hasInfo() ? getInfo().getAttributes().IsParallel : false; } /// \brief Function called by the CodeGenFunction when an instruction is /// created. void InsertHelper(llvm::Instruction *I) const; /// \brief Set the next pushed loop as parallel. void setParallel(bool Enable = true) { StagedAttrs.IsParallel = Enable; } /// \brief Set the next pushed loop 'vectorizer.enable' void setVectorizerEnable(bool Enable = true) { StagedAttrs.VectorizerEnable = Enable ? LoopAttributes::VecEnable : LoopAttributes::VecDisable; } /// \brief Set the vectorizer width for the next loop pushed. void setVectorizerWidth(unsigned W) { StagedAttrs.VectorizerWidth = W; } /// \brief Set the vectorizer unroll for the next loop pushed. void setVectorizerUnroll(unsigned U) { StagedAttrs.VectorizerUnroll = U; } private: /// \brief Returns true if there is LoopInfo on the stack. bool hasInfo() const { return !Active.empty(); } /// \brief Return the LoopInfo for the current loop. HasInfo should be called /// first to ensure LoopInfo is present. const LoopInfo &getInfo() const { return Active.back(); } /// \brief The set of attributes that will be applied to the next pushed loop. LoopAttributes StagedAttrs; /// \brief Stack of active loops. llvm::SmallVector Active; }; } // end namespace CodeGen } // end namespace clang #endif