1 //===- MCLinkerOptimizationHint.h - LOH interface ---------------*- C++ -*-===//
4 // The LLVM Compiler Infrastructure
6 // This file is distributed under the University of Illinois Open Source
7 // License. See LICENSE.TXT for details.
9 //===----------------------------------------------------------------------===//
11 // This file declares some helpers classes to handle Linker Optimization Hint
14 // FIXME: LOH interface supports only MachO format at the moment.
15 //===----------------------------------------------------------------------===//
17 #ifndef LLVM_MC_MCLINKEROPTIMIZATIONHINT_H
18 #define LLVM_MC_MCLINKEROPTIMIZATIONHINT_H
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/ADT/StringRef.h"
22 #include "llvm/ADT/StringSwitch.h"
23 #include "llvm/Support/raw_ostream.h"
29 class MachObjectWriter;
33 /// Linker Optimization Hint Type.
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.
45 static inline StringRef MCLOHDirectiveName() {
46 return StringRef(".loh");
49 static inline bool isValidMCLOHType(unsigned Kind) {
50 return Kind >= MCLOH_AdrpAdrp && Kind <= MCLOH_AdrpLdrGot;
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)
67 static inline StringRef MCLOHIdToName(MCLOHType Kind) {
68 #define MCLOHCaseIdToName(Name) case MCLOH_ ## Name: return StringRef(#Name);
70 MCLOHCaseIdToName(AdrpAdrp);
71 MCLOHCaseIdToName(AdrpLdr);
72 MCLOHCaseIdToName(AdrpAddLdr);
73 MCLOHCaseIdToName(AdrpLdrGotLdr);
74 MCLOHCaseIdToName(AdrpAddStr);
75 MCLOHCaseIdToName(AdrpLdrGotStr);
76 MCLOHCaseIdToName(AdrpAdd);
77 MCLOHCaseIdToName(AdrpLdrGot);
82 static inline int MCLOHIdToNbArgs(MCLOHType Kind) {
84 // LOH with two arguments
88 case MCLOH_AdrpLdrGot:
90 // LOH with three arguments
91 case MCLOH_AdrpAddLdr:
92 case MCLOH_AdrpLdrGotLdr:
93 case MCLOH_AdrpAddStr:
94 case MCLOH_AdrpLdrGotStr:
100 /// Store Linker Optimization Hint information (LOH).
101 class MCLOHDirective {
104 /// Arguments of this directive. Order matters.
105 SmallVector<MCSymbol *, 3> Args;
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;
114 using LOHArgs = SmallVectorImpl<MCSymbol *>;
116 MCLOHDirective(MCLOHType Kind, const LOHArgs &Args)
117 : Kind(Kind), Args(Args.begin(), Args.end()) {
118 assert(isValidMCLOHType(Kind) && "Invalid LOH directive type!");
121 MCLOHType getKind() const { return Kind; }
123 const LOHArgs &getArgs() const { return Args; }
125 /// Emit this directive as:
126 /// <kind, numArgs, addr1, ..., addrN>
127 void emit(MachObjectWriter &ObjWriter, const MCAsmLayout &Layout) const;
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;
135 class MCLOHContainer {
136 /// Keep track of the emit size of all the LOHs.
137 mutable uint64_t EmitSize = 0;
139 /// Keep track of all LOH directives.
140 SmallVector<MCLOHDirective, 32> Directives;
143 using LOHDirectives = SmallVectorImpl<MCLOHDirective>;
145 MCLOHContainer() = default;
147 /// Const accessor to the directives.
148 const LOHDirectives &getDirectives() const {
152 /// Add the directive of the given kind \p Kind with the given arguments
153 /// \p Args to the container.
154 void addDirective(MCLOHType Kind, const MCLOHDirective::LOHArgs &Args) {
155 Directives.push_back(MCLOHDirective(Kind, Args));
158 /// Get the size of the directives if emitted.
159 uint64_t getEmitSize(const MachObjectWriter &ObjWriter,
160 const MCAsmLayout &Layout) const {
162 for (const MCLOHDirective &D : Directives)
163 EmitSize += D.getEmitSize(ObjWriter, Layout);
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);
181 // Add types for specialized template using MCSymbol.
182 using MCLOHArgs = MCLOHDirective::LOHArgs;
183 using MCLOHDirectives = MCLOHContainer::LOHDirectives;
185 } // end namespace llvm
187 #endif // LLVM_MC_MCLINKEROPTIMIZATIONHINT_H