1 //===---- CGLoopInfo.h - LLVM CodeGen for loop metadata -*- C++ -*---------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This is the internal state used for llvm translation for loop statement
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CLANG_LIB_CODEGEN_CGLOOPINFO_H
16 #define LLVM_CLANG_LIB_CODEGEN_CGLOOPINFO_H
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"
28 } // end namespace llvm
35 /// \brief Attributes that may be specified on loops.
36 struct LoopAttributes {
37 explicit LoopAttributes(bool IsParallel = false);
40 /// \brief Generate llvm.loop.parallel metadata for loads and stores.
43 /// \brief State of loop vectorization or unrolling.
44 enum LVEnableState { Unspecified, Enable, Disable, Full };
46 /// \brief Value for llvm.loop.vectorize.enable metadata.
47 LVEnableState VectorizeEnable;
49 /// \brief Value for llvm.loop.unroll.* metadata (enable, disable, or full).
50 LVEnableState UnrollEnable;
52 /// \brief Value for llvm.loop.vectorize.width metadata.
53 unsigned VectorizeWidth;
55 /// \brief Value for llvm.loop.interleave.count metadata.
56 unsigned InterleaveCount;
58 /// \brief llvm.unroll.
62 /// \brief Information used when generating a structured loop.
65 /// \brief Construct a new LoopInfo for the loop with entry Header.
66 LoopInfo(llvm::BasicBlock *Header, const LoopAttributes &Attrs);
68 /// \brief Get the loop id metadata for this loop.
69 llvm::MDNode *getLoopID() const { return LoopID; }
71 /// \brief Get the header block of this loop.
72 llvm::BasicBlock *getHeader() const { return Header; }
74 /// \brief Get the set of attributes active for this loop.
75 const LoopAttributes &getAttributes() const { return Attrs; }
78 /// \brief Loop ID metadata.
80 /// \brief Header block of this loop.
81 llvm::BasicBlock *Header;
82 /// \brief The attributes for this loop.
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
90 LoopInfoStack(const LoopInfoStack &) = delete;
91 void operator=(const LoopInfoStack &) = delete;
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);
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);
105 /// \brief End the current loop.
108 /// \brief Return the top loop id metadata.
109 llvm::MDNode *getCurLoopID() const { return getInfo().getLoopID(); }
111 /// \brief Return true if the top loop is parallel.
112 bool getCurLoopParallel() const {
113 return hasInfo() ? getInfo().getAttributes().IsParallel : false;
116 /// \brief Function called by the CodeGenFunction when an instruction is
118 void InsertHelper(llvm::Instruction *I) const;
120 /// \brief Set the next pushed loop as parallel.
121 void setParallel(bool Enable = true) { StagedAttrs.IsParallel = Enable; }
123 /// \brief Set the next pushed loop 'vectorize.enable'
124 void setVectorizeEnable(bool Enable = true) {
125 StagedAttrs.VectorizeEnable =
126 Enable ? LoopAttributes::Enable : LoopAttributes::Disable;
129 /// \brief Set the next pushed loop unroll state.
130 void setUnrollState(const LoopAttributes::LVEnableState &State) {
131 StagedAttrs.UnrollEnable = State;
134 /// \brief Set the vectorize width for the next loop pushed.
135 void setVectorizeWidth(unsigned W) { StagedAttrs.VectorizeWidth = W; }
137 /// \brief Set the interleave count for the next loop pushed.
138 void setInterleaveCount(unsigned C) { StagedAttrs.InterleaveCount = C; }
140 /// \brief Set the unroll count for the next loop pushed.
141 void setUnrollCount(unsigned C) { StagedAttrs.UnrollCount = C; }
144 /// \brief Returns true if there is LoopInfo on the stack.
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.
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;
155 } // end namespace CodeGen
156 } // end namespace clang