LLVM  6.0.0svn
MCLinkerOptimizationHint.h
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1 //===- MCLinkerOptimizationHint.h - LOH interface ---------------*- C++ -*-===//
2 //
3 //
4 // The LLVM Compiler Infrastructure
5 //
6 // This file is distributed under the University of Illinois Open Source
7 // License. See LICENSE.TXT for details.
8 //
9 //===----------------------------------------------------------------------===//
10 //
11 // This file declares some helpers classes to handle Linker Optimization Hint
12 // (LOH).
13 //
14 // FIXME: LOH interface supports only MachO format at the moment.
15 //===----------------------------------------------------------------------===//
16 
17 #ifndef LLVM_MC_MCLINKEROPTIMIZATIONHINT_H
18 #define LLVM_MC_MCLINKEROPTIMIZATIONHINT_H
19 
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/ADT/StringRef.h"
22 #include "llvm/ADT/StringSwitch.h"
24 #include <cassert>
25 #include <cstdint>
26 
27 namespace llvm {
28 
29 class MachObjectWriter;
30 class MCAsmLayout;
31 class MCSymbol;
32 
33 /// Linker Optimization Hint Type.
34 enum MCLOHType {
35  MCLOH_AdrpAdrp = 0x1u, ///< Adrp xY, _v1@PAGE -> Adrp xY, _v2@PAGE.
36  MCLOH_AdrpLdr = 0x2u, ///< Adrp _v@PAGE -> Ldr _v@PAGEOFF.
37  MCLOH_AdrpAddLdr = 0x3u, ///< Adrp _v@PAGE -> Add _v@PAGEOFF -> Ldr.
38  MCLOH_AdrpLdrGotLdr = 0x4u, ///< Adrp _v@GOTPAGE -> Ldr _v@GOTPAGEOFF -> Ldr.
39  MCLOH_AdrpAddStr = 0x5u, ///< Adrp _v@PAGE -> Add _v@PAGEOFF -> Str.
40  MCLOH_AdrpLdrGotStr = 0x6u, ///< Adrp _v@GOTPAGE -> Ldr _v@GOTPAGEOFF -> Str.
41  MCLOH_AdrpAdd = 0x7u, ///< Adrp _v@PAGE -> Add _v@PAGEOFF.
42  MCLOH_AdrpLdrGot = 0x8u ///< Adrp _v@GOTPAGE -> Ldr _v@GOTPAGEOFF.
43 };
44 
45 static inline StringRef MCLOHDirectiveName() {
46  return StringRef(".loh");
47 }
48 
49 static inline bool isValidMCLOHType(unsigned Kind) {
50  return Kind >= MCLOH_AdrpAdrp && Kind <= MCLOH_AdrpLdrGot;
51 }
52 
53 static inline int MCLOHNameToId(StringRef Name) {
54 #define MCLOHCaseNameToId(Name) .Case(#Name, MCLOH_ ## Name)
55  return StringSwitch<int>(Name)
56  MCLOHCaseNameToId(AdrpAdrp)
57  MCLOHCaseNameToId(AdrpLdr)
58  MCLOHCaseNameToId(AdrpAddLdr)
59  MCLOHCaseNameToId(AdrpLdrGotLdr)
60  MCLOHCaseNameToId(AdrpAddStr)
61  MCLOHCaseNameToId(AdrpLdrGotStr)
62  MCLOHCaseNameToId(AdrpAdd)
63  MCLOHCaseNameToId(AdrpLdrGot)
64  .Default(-1);
65 }
66 
68 #define MCLOHCaseIdToName(Name) case MCLOH_ ## Name: return StringRef(#Name);
69  switch (Kind) {
70  MCLOHCaseIdToName(AdrpAdrp);
71  MCLOHCaseIdToName(AdrpLdr);
72  MCLOHCaseIdToName(AdrpAddLdr);
73  MCLOHCaseIdToName(AdrpLdrGotLdr);
74  MCLOHCaseIdToName(AdrpAddStr);
75  MCLOHCaseIdToName(AdrpLdrGotStr);
76  MCLOHCaseIdToName(AdrpAdd);
77  MCLOHCaseIdToName(AdrpLdrGot);
78  }
79  return StringRef();
80 }
81 
82 static inline int MCLOHIdToNbArgs(MCLOHType Kind) {
83  switch (Kind) {
84  // LOH with two arguments
85  case MCLOH_AdrpAdrp:
86  case MCLOH_AdrpLdr:
87  case MCLOH_AdrpAdd:
88  case MCLOH_AdrpLdrGot:
89  return 2;
90  // LOH with three arguments
91  case MCLOH_AdrpAddLdr:
93  case MCLOH_AdrpAddStr:
95  return 3;
96  }
97  return -1;
98 }
99 
100 /// Store Linker Optimization Hint information (LOH).
102  MCLOHType Kind;
103 
104  /// Arguments of this directive. Order matters.
106 
107  /// Emit this directive in \p OutStream using the information available
108  /// in the given \p ObjWriter and \p Layout to get the address of the
109  /// arguments within the object file.
110  void emit_impl(raw_ostream &OutStream, const MachObjectWriter &ObjWriter,
111  const MCAsmLayout &Layout) const;
112 
113 public:
115 
116  MCLOHDirective(MCLOHType Kind, const LOHArgs &Args)
117  : Kind(Kind), Args(Args.begin(), Args.end()) {
118  assert(isValidMCLOHType(Kind) && "Invalid LOH directive type!");
119  }
120 
121  MCLOHType getKind() const { return Kind; }
122 
123  const LOHArgs &getArgs() const { return Args; }
124 
125  /// Emit this directive as:
126  /// <kind, numArgs, addr1, ..., addrN>
127  void emit(MachObjectWriter &ObjWriter, const MCAsmLayout &Layout) const;
128 
129  /// Get the size in bytes of this directive if emitted in \p ObjWriter with
130  /// the given \p Layout.
131  uint64_t getEmitSize(const MachObjectWriter &ObjWriter,
132  const MCAsmLayout &Layout) const;
133 };
134 
136  /// Keep track of the emit size of all the LOHs.
137  mutable uint64_t EmitSize = 0;
138 
139  /// Keep track of all LOH directives.
141 
142 public:
144 
145  MCLOHContainer() = default;
146 
147  /// Const accessor to the directives.
148  const LOHDirectives &getDirectives() const {
149  return Directives;
150  }
151 
152  /// Add the directive of the given kind \p Kind with the given arguments
153  /// \p Args to the container.
155  Directives.push_back(MCLOHDirective(Kind, Args));
156  }
157 
158  /// Get the size of the directives if emitted.
159  uint64_t getEmitSize(const MachObjectWriter &ObjWriter,
160  const MCAsmLayout &Layout) const {
161  if (!EmitSize) {
162  for (const MCLOHDirective &D : Directives)
163  EmitSize += D.getEmitSize(ObjWriter, Layout);
164  }
165  return EmitSize;
166  }
167 
168  /// Emit all Linker Optimization Hint in one big table.
169  /// Each line of the table is emitted by LOHDirective::emit.
170  void emit(MachObjectWriter &ObjWriter, const MCAsmLayout &Layout) const {
171  for (const MCLOHDirective &D : Directives)
172  D.emit(ObjWriter, Layout);
173  }
174 
175  void reset() {
176  Directives.clear();
177  EmitSize = 0;
178  }
179 };
180 
181 // Add types for specialized template using MCSymbol.
184 
185 } // end namespace llvm
186 
187 #endif // LLVM_MC_MCLINKEROPTIMIZATIONHINT_H
const_iterator end(StringRef path)
Get end iterator over path.
Definition: Path.cpp:244
const_iterator begin(StringRef path, Style style=Style::native)
Get begin iterator over path.
Definition: Path.cpp:235
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
void emit(MachObjectWriter &ObjWriter, const MCAsmLayout &Layout) const
Emit this directive as: <kind, numArgs, addr1, ..., addrN>
Adrp _v -> Add _v -> Ldr.
Adrp _v -> Ldr _v -> Ldr.
Store Linker Optimization Hint information (LOH).
Encapsulates the layout of an assembly file at a particular point in time.
Definition: MCAsmLayout.h:29
MCLOHDirective(MCLOHType Kind, const LOHArgs &Args)
#define MCLOHCaseIdToName(Name)
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APFloat.h:42
uint64_t getEmitSize(const MachObjectWriter &ObjWriter, const MCAsmLayout &Layout) const
Get the size of the directives if emitted.
uint64_t getEmitSize(const MachObjectWriter &ObjWriter, const MCAsmLayout &Layout) const
Get the size in bytes of this directive if emitted in ObjWriter with the given Layout.
#define MCLOHCaseNameToId(Name)
A switch()-like statement whose cases are string literals.
Definition: StringSwitch.h:43
void emit(MachObjectWriter &ObjWriter, const MCAsmLayout &Layout) const
Emit all Linker Optimization Hint in one big table.
static int MCLOHNameToId(StringRef Name)
MCLOHType
Linker Optimization Hint Type.
const LOHArgs & getArgs() const
Adrp _v -> Add _v -> Str.
void addDirective(MCLOHType Kind, const MCLOHDirective::LOHArgs &Args)
Add the directive of the given kind Kind with the given arguments Args to the container.
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:864
static GCRegistry::Add< StatepointGC > D("statepoint-example", "an example strategy for statepoint")
static StringRef MCLOHDirectiveName()
SmallVectorImpl< MCLOHDirective > LOHDirectives
SmallVectorImpl< MCSymbol * > LOHArgs
Adrp xY, _v1 -> Adrp xY, _v2.
static bool isValidMCLOHType(unsigned Kind)
Adrp _v -> Ldr _v -> Str.
const unsigned Kind
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
static int MCLOHIdToNbArgs(MCLOHType Kind)
static StringRef MCLOHIdToName(MCLOHType Kind)
const LOHDirectives & getDirectives() const
Const accessor to the directives.
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:44
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49