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/DebugLoc.h"
22 #include "llvm/IR/Value.h"
23 #include "llvm/Support/Compiler.h"
29 } // end namespace llvm
36 /// \brief Attributes that may be specified on loops.
37 struct LoopAttributes {
38 explicit LoopAttributes(bool IsParallel = false);
41 /// \brief Generate llvm.loop.parallel metadata for loads and stores.
44 /// \brief State of loop vectorization or unrolling.
45 enum LVEnableState { Unspecified, Enable, Disable, Full };
47 /// \brief Value for llvm.loop.vectorize.enable metadata.
48 LVEnableState VectorizeEnable;
50 /// \brief Value for llvm.loop.unroll.* metadata (enable, disable, or full).
51 LVEnableState UnrollEnable;
53 /// \brief Value for llvm.loop.vectorize.width metadata.
54 unsigned VectorizeWidth;
56 /// \brief Value for llvm.loop.interleave.count metadata.
57 unsigned InterleaveCount;
59 /// \brief llvm.unroll.
62 /// \brief Value for llvm.loop.distribute.enable metadata.
63 LVEnableState DistributeEnable;
66 /// \brief Information used when generating a structured loop.
69 /// \brief Construct a new LoopInfo for the loop with entry Header.
70 LoopInfo(llvm::BasicBlock *Header, const LoopAttributes &Attrs,
71 llvm::DebugLoc Location);
73 /// \brief Get the loop id metadata for this loop.
74 llvm::MDNode *getLoopID() const { return LoopID; }
76 /// \brief Get the header block of this loop.
77 llvm::BasicBlock *getHeader() const { return Header; }
79 /// \brief Get the set of attributes active for this loop.
80 const LoopAttributes &getAttributes() const { return Attrs; }
83 /// \brief Loop ID metadata.
85 /// \brief Header block of this loop.
86 llvm::BasicBlock *Header;
87 /// \brief The attributes for this loop.
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
95 LoopInfoStack(const LoopInfoStack &) = delete;
96 void operator=(const LoopInfoStack &) = delete;
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());
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());
112 /// \brief End the current loop.
115 /// \brief Return the top loop id metadata.
116 llvm::MDNode *getCurLoopID() const { return getInfo().getLoopID(); }
118 /// \brief Return true if the top loop is parallel.
119 bool getCurLoopParallel() const {
120 return hasInfo() ? getInfo().getAttributes().IsParallel : false;
123 /// \brief Function called by the CodeGenFunction when an instruction is
125 void InsertHelper(llvm::Instruction *I) const;
127 /// \brief Set the next pushed loop as parallel.
128 void setParallel(bool Enable = true) { StagedAttrs.IsParallel = Enable; }
130 /// \brief Set the next pushed loop 'vectorize.enable'
131 void setVectorizeEnable(bool Enable = true) {
132 StagedAttrs.VectorizeEnable =
133 Enable ? LoopAttributes::Enable : LoopAttributes::Disable;
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;
142 /// \brief Set the next pushed loop unroll state.
143 void setUnrollState(const LoopAttributes::LVEnableState &State) {
144 StagedAttrs.UnrollEnable = State;
147 /// \brief Set the vectorize width for the next loop pushed.
148 void setVectorizeWidth(unsigned W) { StagedAttrs.VectorizeWidth = W; }
150 /// \brief Set the interleave count for the next loop pushed.
151 void setInterleaveCount(unsigned C) { StagedAttrs.InterleaveCount = C; }
153 /// \brief Set the unroll count for the next loop pushed.
154 void setUnrollCount(unsigned C) { StagedAttrs.UnrollCount = C; }
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;
168 } // end namespace CodeGen
169 } // end namespace clang