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/SmallVector.h"
20 #include "llvm/IR/DebugLoc.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.
61 /// \brief Value for llvm.loop.distribute.enable metadata.
62 LVEnableState DistributeEnable;
65 /// \brief Information used when generating a structured loop.
68 /// \brief Construct a new LoopInfo for the loop with entry Header.
69 LoopInfo(llvm::BasicBlock *Header, const LoopAttributes &Attrs,
70 const llvm::DebugLoc &StartLoc, const llvm::DebugLoc &EndLoc);
72 /// \brief Get the loop id metadata for this loop.
73 llvm::MDNode *getLoopID() const { return LoopID; }
75 /// \brief Get the header block of this loop.
76 llvm::BasicBlock *getHeader() const { return Header; }
78 /// \brief Get the set of attributes active for this loop.
79 const LoopAttributes &getAttributes() const { return Attrs; }
82 /// \brief Loop ID metadata.
84 /// \brief Header block of this loop.
85 llvm::BasicBlock *Header;
86 /// \brief The attributes for this loop.
90 /// \brief A stack of loop information corresponding to loop nesting levels.
91 /// This stack can be used to prepare attributes which are applied when a loop
94 LoopInfoStack(const LoopInfoStack &) = delete;
95 void operator=(const LoopInfoStack &) = delete;
100 /// \brief Begin a new structured loop. The set of staged attributes will be
101 /// applied to the loop and then cleared.
102 void push(llvm::BasicBlock *Header, const llvm::DebugLoc &StartLoc,
103 const llvm::DebugLoc &EndLoc);
105 /// \brief Begin a new structured loop. Stage attributes from the Attrs list.
106 /// The staged attributes are applied to the loop and then cleared.
107 void push(llvm::BasicBlock *Header, clang::ASTContext &Ctx,
108 llvm::ArrayRef<const Attr *> Attrs, const llvm::DebugLoc &StartLoc,
109 const llvm::DebugLoc &EndLoc);
111 /// \brief End the current loop.
114 /// \brief Return the top loop id metadata.
115 llvm::MDNode *getCurLoopID() const { return getInfo().getLoopID(); }
117 /// \brief Return true if the top loop is parallel.
118 bool getCurLoopParallel() const {
119 return hasInfo() ? getInfo().getAttributes().IsParallel : false;
122 /// \brief Function called by the CodeGenFunction when an instruction is
124 void InsertHelper(llvm::Instruction *I) const;
126 /// \brief Set the next pushed loop as parallel.
127 void setParallel(bool Enable = true) { StagedAttrs.IsParallel = Enable; }
129 /// \brief Set the next pushed loop 'vectorize.enable'
130 void setVectorizeEnable(bool Enable = true) {
131 StagedAttrs.VectorizeEnable =
132 Enable ? LoopAttributes::Enable : LoopAttributes::Disable;
135 /// \brief Set the next pushed loop as a distribution candidate.
136 void setDistributeState(bool Enable = true) {
137 StagedAttrs.DistributeEnable =
138 Enable ? LoopAttributes::Enable : LoopAttributes::Disable;
141 /// \brief Set the next pushed loop unroll state.
142 void setUnrollState(const LoopAttributes::LVEnableState &State) {
143 StagedAttrs.UnrollEnable = State;
146 /// \brief Set the vectorize width for the next loop pushed.
147 void setVectorizeWidth(unsigned W) { StagedAttrs.VectorizeWidth = W; }
149 /// \brief Set the interleave count for the next loop pushed.
150 void setInterleaveCount(unsigned C) { StagedAttrs.InterleaveCount = C; }
152 /// \brief Set the unroll count for the next loop pushed.
153 void setUnrollCount(unsigned C) { StagedAttrs.UnrollCount = C; }
156 /// \brief Returns true if there is LoopInfo on the stack.
157 bool hasInfo() const { return !Active.empty(); }
158 /// \brief Return the LoopInfo for the current loop. HasInfo should be called
159 /// first to ensure LoopInfo is present.
160 const LoopInfo &getInfo() const { return Active.back(); }
161 /// \brief The set of attributes that will be applied to the next pushed loop.
162 LoopAttributes StagedAttrs;
163 /// \brief Stack of active loops.
164 llvm::SmallVector<LoopInfo, 4> Active;
167 } // end namespace CodeGen
168 } // end namespace clang