clang  6.0.0svn
CGLoopInfo.h
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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 /// \brief Attributes that may be specified on loops.
37  explicit LoopAttributes(bool IsParallel = false);
38  void clear();
39 
40  /// \brief Generate llvm.loop.parallel metadata for loads and stores.
41  bool IsParallel;
42 
43  /// \brief State of loop vectorization or unrolling.
44  enum LVEnableState { Unspecified, Enable, Disable, Full };
45 
46  /// \brief Value for llvm.loop.vectorize.enable metadata.
48 
49  /// \brief Value for llvm.loop.unroll.* metadata (enable, disable, or full).
51 
52  /// \brief Value for llvm.loop.vectorize.width metadata.
53  unsigned VectorizeWidth;
54 
55  /// \brief Value for llvm.loop.interleave.count metadata.
56  unsigned InterleaveCount;
57 
58  /// \brief llvm.unroll.
59  unsigned UnrollCount;
60 
61  /// \brief Value for llvm.loop.distribute.enable metadata.
63 };
64 
65 /// \brief Information used when generating a structured loop.
66 class LoopInfo {
67 public:
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);
71 
72  /// \brief Get the loop id metadata for this loop.
73  llvm::MDNode *getLoopID() const { return LoopID; }
74 
75  /// \brief Get the header block of this loop.
76  llvm::BasicBlock *getHeader() const { return Header; }
77 
78  /// \brief Get the set of attributes active for this loop.
79  const LoopAttributes &getAttributes() const { return Attrs; }
80 
81 private:
82  /// \brief Loop ID metadata.
83  llvm::MDNode *LoopID;
84  /// \brief Header block of this loop.
85  llvm::BasicBlock *Header;
86  /// \brief The attributes for this loop.
87  LoopAttributes Attrs;
88 };
89 
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
92 /// is emitted.
94  LoopInfoStack(const LoopInfoStack &) = delete;
95  void operator=(const LoopInfoStack &) = delete;
96 
97 public:
99 
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);
104 
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);
110 
111  /// \brief End the current loop.
112  void pop();
113 
114  /// \brief Return the top loop id metadata.
115  llvm::MDNode *getCurLoopID() const { return getInfo().getLoopID(); }
116 
117  /// \brief Return true if the top loop is parallel.
118  bool getCurLoopParallel() const {
119  return hasInfo() ? getInfo().getAttributes().IsParallel : false;
120  }
121 
122  /// \brief Function called by the CodeGenFunction when an instruction is
123  /// created.
124  void InsertHelper(llvm::Instruction *I) const;
125 
126  /// \brief Set the next pushed loop as parallel.
127  void setParallel(bool Enable = true) { StagedAttrs.IsParallel = Enable; }
128 
129  /// \brief Set the next pushed loop 'vectorize.enable'
130  void setVectorizeEnable(bool Enable = true) {
131  StagedAttrs.VectorizeEnable =
132  Enable ? LoopAttributes::Enable : LoopAttributes::Disable;
133  }
134 
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;
139  }
140 
141  /// \brief Set the next pushed loop unroll state.
143  StagedAttrs.UnrollEnable = State;
144  }
145 
146  /// \brief Set the vectorize width for the next loop pushed.
147  void setVectorizeWidth(unsigned W) { StagedAttrs.VectorizeWidth = W; }
148 
149  /// \brief Set the interleave count for the next loop pushed.
150  void setInterleaveCount(unsigned C) { StagedAttrs.InterleaveCount = C; }
151 
152  /// \brief Set the unroll count for the next loop pushed.
153  void setUnrollCount(unsigned C) { StagedAttrs.UnrollCount = C; }
154 
155 private:
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.
165 };
166 
167 } // end namespace CodeGen
168 } // end namespace clang
169 
170 #endif
void setUnrollCount(unsigned C)
Set the unroll count for the next loop pushed.
Definition: CGLoopInfo.h:153
DominatorTree GraphTraits specialization so the DominatorTree can be iterable by generic graph iterat...
Definition: Dominators.h:26
Attributes that may be specified on loops.
Definition: CGLoopInfo.h:36
Information used when generating a structured loop.
Definition: CGLoopInfo.h:66
virtual void clear()
LVEnableState UnrollEnable
Value for llvm.loop.unroll.* metadata (enable, disable, or full).
Definition: CGLoopInfo.h:50
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:128
LineState State
unsigned InterleaveCount
Value for llvm.loop.interleave.count metadata.
Definition: CGLoopInfo.h:56
LVEnableState VectorizeEnable
Value for llvm.loop.vectorize.enable metadata.
Definition: CGLoopInfo.h:47
void setVectorizeWidth(unsigned W)
Set the vectorize width for the next loop pushed.
Definition: CGLoopInfo.h:147
bool IsParallel
Generate llvm.loop.parallel metadata for loads and stores.
Definition: CGLoopInfo.h:41
void setInterleaveCount(unsigned C)
Set the interleave count for the next loop pushed.
Definition: CGLoopInfo.h:150
unsigned UnrollCount
llvm.unroll.
Definition: CGLoopInfo.h:59
void setParallel(bool Enable=true)
Set the next pushed loop as parallel.
Definition: CGLoopInfo.h:127
LVEnableState DistributeEnable
Value for llvm.loop.distribute.enable metadata.
Definition: CGLoopInfo.h:62
llvm::MDNode * getLoopID() const
Get the loop id metadata for this loop.
Definition: CGLoopInfo.h:73
llvm::MDNode * getCurLoopID() const
Return the top loop id metadata.
Definition: CGLoopInfo.h:115
void setDistributeState(bool Enable=true)
Set the next pushed loop as a distribution candidate.
Definition: CGLoopInfo.h:136
Dataflow Directional Tag Classes.
static const TypeInfo & getInfo(unsigned id)
Definition: Types.cpp:34
A stack of loop information corresponding to loop nesting levels.
Definition: CGLoopInfo.h:93
bool getCurLoopParallel() const
Return true if the top loop is parallel.
Definition: CGLoopInfo.h:118
LVEnableState
State of loop vectorization or unrolling.
Definition: CGLoopInfo.h:44
void setUnrollState(const LoopAttributes::LVEnableState &State)
Set the next pushed loop unroll state.
Definition: CGLoopInfo.h:142
void setVectorizeEnable(bool Enable=true)
Set the next pushed loop &#39;vectorize.enable&#39;.
Definition: CGLoopInfo.h:130
unsigned VectorizeWidth
Value for llvm.loop.vectorize.width metadata.
Definition: CGLoopInfo.h:53
llvm::BasicBlock * getHeader() const
Get the header block of this loop.
Definition: CGLoopInfo.h:76
const LoopAttributes & getAttributes() const
Get the set of attributes active for this loop.
Definition: CGLoopInfo.h:79