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/MC/MCMachObjectWriter.h"
24 #include "llvm/Support/raw_ostream.h"
28 // Forward declarations.
32 /// Linker Optimization Hint Type.
34 MCLOH_AdrpAdrp
= 0x1u
, ///< Adrp xY, _v1@PAGE -> Adrp xY, _v2@PAGE.
35 MCLOH_AdrpLdr
= 0x2u
, ///< Adrp _v@PAGE -> Ldr _v@PAGEOFF.
36 MCLOH_AdrpAddLdr
= 0x3u
, ///< Adrp _v@PAGE -> Add _v@PAGEOFF -> Ldr.
37 MCLOH_AdrpLdrGotLdr
= 0x4u
, ///< Adrp _v@GOTPAGE -> Ldr _v@GOTPAGEOFF -> Ldr.
38 MCLOH_AdrpAddStr
= 0x5u
, ///< Adrp _v@PAGE -> Add _v@PAGEOFF -> Str.
39 MCLOH_AdrpLdrGotStr
= 0x6u
, ///< Adrp _v@GOTPAGE -> Ldr _v@GOTPAGEOFF -> Str.
40 MCLOH_AdrpAdd
= 0x7u
, ///< Adrp _v@PAGE -> Add _v@PAGEOFF.
41 MCLOH_AdrpLdrGot
= 0x8u
///< Adrp _v@GOTPAGE -> Ldr _v@GOTPAGEOFF.
44 static inline StringRef
MCLOHDirectiveName() {
45 return StringRef(".loh");
48 static inline bool isValidMCLOHType(unsigned Kind
) {
49 return Kind
>= MCLOH_AdrpAdrp
&& Kind
<= MCLOH_AdrpLdrGot
;
52 static inline int MCLOHNameToId(StringRef Name
) {
53 #define MCLOHCaseNameToId(Name) .Case(#Name, MCLOH_ ## Name)
54 return StringSwitch
<int>(Name
)
55 MCLOHCaseNameToId(AdrpAdrp
)
56 MCLOHCaseNameToId(AdrpLdr
)
57 MCLOHCaseNameToId(AdrpAddLdr
)
58 MCLOHCaseNameToId(AdrpLdrGotLdr
)
59 MCLOHCaseNameToId(AdrpAddStr
)
60 MCLOHCaseNameToId(AdrpLdrGotStr
)
61 MCLOHCaseNameToId(AdrpAdd
)
62 MCLOHCaseNameToId(AdrpLdrGot
)
66 static inline StringRef
MCLOHIdToName(MCLOHType Kind
) {
67 #define MCLOHCaseIdToName(Name) case MCLOH_ ## Name: return StringRef(#Name);
69 MCLOHCaseIdToName(AdrpAdrp
);
70 MCLOHCaseIdToName(AdrpLdr
);
71 MCLOHCaseIdToName(AdrpAddLdr
);
72 MCLOHCaseIdToName(AdrpLdrGotLdr
);
73 MCLOHCaseIdToName(AdrpAddStr
);
74 MCLOHCaseIdToName(AdrpLdrGotStr
);
75 MCLOHCaseIdToName(AdrpAdd
);
76 MCLOHCaseIdToName(AdrpLdrGot
);
81 static inline int MCLOHIdToNbArgs(MCLOHType Kind
) {
83 // LOH with two arguments
87 case MCLOH_AdrpLdrGot
:
89 // LOH with three arguments
90 case MCLOH_AdrpAddLdr
:
91 case MCLOH_AdrpLdrGotLdr
:
92 case MCLOH_AdrpAddStr
:
93 case MCLOH_AdrpLdrGotStr
:
99 /// Store Linker Optimization Hint information (LOH).
100 class MCLOHDirective
{
103 /// Arguments of this directive. Order matters.
104 SmallVector
<MCSymbol
*, 3> Args
;
106 /// Emit this directive in @p OutStream using the information available
107 /// in the given @p ObjWriter and @p Layout to get the address of the
108 /// arguments within the object file.
109 void Emit_impl(raw_ostream
&OutStream
, const MachObjectWriter
&ObjWriter
,
110 const MCAsmLayout
&Layout
) const;
113 typedef SmallVectorImpl
<MCSymbol
*> LOHArgs
;
115 MCLOHDirective(MCLOHType Kind
, const LOHArgs
&Args
)
116 : Kind(Kind
), Args(Args
.begin(), Args
.end()) {
117 assert(isValidMCLOHType(Kind
) && "Invalid LOH directive type!");
120 MCLOHType
getKind() const { return Kind
; }
122 const LOHArgs
&getArgs() const { return Args
; }
124 /// Emit this directive as:
125 /// <kind, numArgs, addr1, ..., addrN>
126 void Emit(MachObjectWriter
&ObjWriter
, const MCAsmLayout
&Layout
) const {
127 raw_ostream
&OutStream
= ObjWriter
.getStream();
128 Emit_impl(OutStream
, ObjWriter
, Layout
);
131 /// Get the size in bytes of this directive if emitted in @p ObjWriter with
132 /// the given @p Layout.
133 uint64_t getEmitSize(const MachObjectWriter
&ObjWriter
,
134 const MCAsmLayout
&Layout
) const {
135 class raw_counting_ostream
: public raw_ostream
{
138 void write_impl(const char *, size_t size
) override
{ Count
+= size
; }
140 uint64_t current_pos() const override
{ return Count
; }
143 raw_counting_ostream() : Count(0) {}
144 ~raw_counting_ostream() { flush(); }
147 raw_counting_ostream OutStream
;
148 Emit_impl(OutStream
, ObjWriter
, Layout
);
149 return OutStream
.tell();
153 class MCLOHContainer
{
154 /// Keep track of the emit size of all the LOHs.
155 mutable uint64_t EmitSize
;
157 /// Keep track of all LOH directives.
158 SmallVector
<MCLOHDirective
, 32> Directives
;
161 typedef SmallVectorImpl
<MCLOHDirective
> LOHDirectives
;
163 MCLOHContainer() : EmitSize(0) {};
165 /// Const accessor to the directives.
166 const LOHDirectives
&getDirectives() const {
170 /// Add the directive of the given kind @p Kind with the given arguments
171 /// @p Args to the container.
172 void addDirective(MCLOHType Kind
, const MCLOHDirective::LOHArgs
&Args
) {
173 Directives
.push_back(MCLOHDirective(Kind
, Args
));
176 /// Get the size of the directives if emitted.
177 uint64_t getEmitSize(const MachObjectWriter
&ObjWriter
,
178 const MCAsmLayout
&Layout
) const {
180 for (const MCLOHDirective
&D
: Directives
)
181 EmitSize
+= D
.getEmitSize(ObjWriter
, Layout
);
186 /// Emit all Linker Optimization Hint in one big table.
187 /// Each line of the table is emitted by LOHDirective::Emit.
188 void Emit(MachObjectWriter
&ObjWriter
, const MCAsmLayout
&Layout
) const {
189 for (const MCLOHDirective
&D
: Directives
)
190 D
.Emit(ObjWriter
, Layout
);
199 // Add types for specialized template using MCSymbol.
200 typedef MCLOHDirective::LOHArgs MCLOHArgs
;
201 typedef MCLOHContainer::LOHDirectives MCLOHDirectives
;
203 } // end namespace llvm