1 //===-- LLVMTargetMachine.cpp - Implement the LLVMTargetMachine class -----===//
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 file implements the LLVMTargetMachine class.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "llvm/Analysis/Passes.h"
15 #include "llvm/CodeGen/AsmPrinter.h"
16 #include "llvm/CodeGen/BasicTTIImpl.h"
17 #include "llvm/CodeGen/MachineModuleInfo.h"
18 #include "llvm/CodeGen/Passes.h"
19 #include "llvm/CodeGen/TargetPassConfig.h"
20 #include "llvm/IR/LegacyPassManager.h"
21 #include "llvm/MC/MCAsmBackend.h"
22 #include "llvm/MC/MCAsmInfo.h"
23 #include "llvm/MC/MCCodeEmitter.h"
24 #include "llvm/MC/MCContext.h"
25 #include "llvm/MC/MCInstrInfo.h"
26 #include "llvm/MC/MCObjectWriter.h"
27 #include "llvm/MC/MCStreamer.h"
28 #include "llvm/MC/MCSubtargetInfo.h"
29 #include "llvm/Support/CommandLine.h"
30 #include "llvm/Support/ErrorHandling.h"
31 #include "llvm/Support/FormattedStream.h"
32 #include "llvm/Support/TargetRegistry.h"
33 #include "llvm/Target/TargetLoweringObjectFile.h"
34 #include "llvm/Target/TargetMachine.h"
35 #include "llvm/Target/TargetOptions.h"
36 using namespace llvm;
37
38 static cl::opt<bool> EnableTrapUnreachable("trap-unreachable",
39 cl::Hidden, cl::ZeroOrMore, cl::init(false),
40 cl::desc("Enable generating trap for unreachable"));
41
initAsmInfo()42 void LLVMTargetMachine::initAsmInfo() {
43 MRI.reset(TheTarget.createMCRegInfo(getTargetTriple().str()));
44 MII.reset(TheTarget.createMCInstrInfo());
45 // FIXME: Having an MCSubtargetInfo on the target machine is a hack due
46 // to some backends having subtarget feature dependent module level
47 // code generation. This is similar to the hack in the AsmPrinter for
48 // module level assembly etc.
49 STI.reset(TheTarget.createMCSubtargetInfo(
50 getTargetTriple().str(), getTargetCPU(), getTargetFeatureString()));
51
52 MCAsmInfo *TmpAsmInfo =
53 TheTarget.createMCAsmInfo(*MRI, getTargetTriple().str());
54 // TargetSelect.h moved to a different directory between LLVM 2.9 and 3.0,
55 // and if the old one gets included then MCAsmInfo will be NULL and
56 // we'll crash later.
57 // Provide the user with a useful error message about what's wrong.
58 assert(TmpAsmInfo && "MCAsmInfo not initialized. "
59 "Make sure you include the correct TargetSelect.h"
60 "and that InitializeAllTargetMCs() is being invoked!");
61
62 if (Options.DisableIntegratedAS)
63 TmpAsmInfo->setUseIntegratedAssembler(false);
64
65 TmpAsmInfo->setPreserveAsmComments(Options.MCOptions.PreserveAsmComments);
66
67 TmpAsmInfo->setCompressDebugSections(Options.CompressDebugSections);
68
69 TmpAsmInfo->setRelaxELFRelocations(Options.RelaxELFRelocations);
70
71 if (Options.ExceptionModel != ExceptionHandling::None)
72 TmpAsmInfo->setExceptionsType(Options.ExceptionModel);
73
74 AsmInfo.reset(TmpAsmInfo);
75 }
76
LLVMTargetMachine(const Target & T,StringRef DataLayoutString,const Triple & TT,StringRef CPU,StringRef FS,const TargetOptions & Options,Reloc::Model RM,CodeModel::Model CM,CodeGenOpt::Level OL)77 LLVMTargetMachine::LLVMTargetMachine(const Target &T,
78 StringRef DataLayoutString,
79 const Triple &TT, StringRef CPU,
80 StringRef FS, const TargetOptions &Options,
81 Reloc::Model RM, CodeModel::Model CM,
82 CodeGenOpt::Level OL)
83 : TargetMachine(T, DataLayoutString, TT, CPU, FS, Options) {
84 this->RM = RM;
85 this->CMModel = CM;
86 this->OptLevel = OL;
87
88 if (EnableTrapUnreachable)
89 this->Options.TrapUnreachable = true;
90 }
91
92 TargetTransformInfo
getTargetTransformInfo(const Function & F)93 LLVMTargetMachine::getTargetTransformInfo(const Function &F) {
94 return TargetTransformInfo(BasicTTIImpl(this, F));
95 }
96
97 /// addPassesToX helper drives creation and initialization of TargetPassConfig.
98 static TargetPassConfig *
addPassesToGenerateCode(LLVMTargetMachine & TM,PassManagerBase & PM,bool DisableVerify,MachineModuleInfo & MMI)99 addPassesToGenerateCode(LLVMTargetMachine &TM, PassManagerBase &PM,
100 bool DisableVerify, MachineModuleInfo &MMI) {
101 // Targets may override createPassConfig to provide a target-specific
102 // subclass.
103 TargetPassConfig *PassConfig = TM.createPassConfig(PM);
104 // Set PassConfig options provided by TargetMachine.
105 PassConfig->setDisableVerify(DisableVerify);
106 PM.add(PassConfig);
107 PM.add(&MMI);
108
109 if (PassConfig->addISelPasses())
110 return nullptr;
111 PassConfig->addMachinePasses();
112 PassConfig->setInitialized();
113 return PassConfig;
114 }
115
addAsmPrinter(PassManagerBase & PM,raw_pwrite_stream & Out,raw_pwrite_stream * DwoOut,CodeGenFileType FileType,MCContext & Context)116 bool LLVMTargetMachine::addAsmPrinter(PassManagerBase &PM,
117 raw_pwrite_stream &Out,
118 raw_pwrite_stream *DwoOut,
119 CodeGenFileType FileType,
120 MCContext &Context) {
121 if (Options.MCOptions.MCSaveTempLabels)
122 Context.setAllowTemporaryLabels(false);
123
124 const MCSubtargetInfo &STI = *getMCSubtargetInfo();
125 const MCAsmInfo &MAI = *getMCAsmInfo();
126 const MCRegisterInfo &MRI = *getMCRegisterInfo();
127 const MCInstrInfo &MII = *getMCInstrInfo();
128
129 std::unique_ptr<MCStreamer> AsmStreamer;
130
131 switch (FileType) {
132 case CGFT_AssemblyFile: {
133 MCInstPrinter *InstPrinter = getTarget().createMCInstPrinter(
134 getTargetTriple(), MAI.getAssemblerDialect(), MAI, MII, MRI);
135
136 // Create a code emitter if asked to show the encoding.
137 std::unique_ptr<MCCodeEmitter> MCE;
138 if (Options.MCOptions.ShowMCEncoding)
139 MCE.reset(getTarget().createMCCodeEmitter(MII, MRI, Context));
140
141 std::unique_ptr<MCAsmBackend> MAB(
142 getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions));
143 auto FOut = llvm::make_unique<formatted_raw_ostream>(Out);
144 MCStreamer *S = getTarget().createAsmStreamer(
145 Context, std::move(FOut), Options.MCOptions.AsmVerbose,
146 Options.MCOptions.MCUseDwarfDirectory, InstPrinter, std::move(MCE),
147 std::move(MAB), Options.MCOptions.ShowMCInst);
148 AsmStreamer.reset(S);
149 break;
150 }
151 case CGFT_ObjectFile: {
152 // Create the code emitter for the target if it exists. If not, .o file
153 // emission fails.
154 MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(MII, MRI, Context);
155 MCAsmBackend *MAB =
156 getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions);
157 if (!MCE || !MAB)
158 return true;
159
160 // Don't waste memory on names of temp labels.
161 Context.setUseNamesOnTempLabels(false);
162
163 Triple T(getTargetTriple().str());
164 AsmStreamer.reset(getTarget().createMCObjectStreamer(
165 T, Context, std::unique_ptr<MCAsmBackend>(MAB),
166 DwoOut ? MAB->createDwoObjectWriter(Out, *DwoOut)
167 : MAB->createObjectWriter(Out),
168 std::unique_ptr<MCCodeEmitter>(MCE), STI, Options.MCOptions.MCRelaxAll,
169 Options.MCOptions.MCIncrementalLinkerCompatible,
170 /*DWARFMustBeAtTheEnd*/ true));
171 break;
172 }
173 case CGFT_Null:
174 // The Null output is intended for use for performance analysis and testing,
175 // not real users.
176 AsmStreamer.reset(getTarget().createNullStreamer(Context));
177 break;
178 }
179
180 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
181 FunctionPass *Printer =
182 getTarget().createAsmPrinter(*this, std::move(AsmStreamer));
183 if (!Printer)
184 return true;
185
186 PM.add(Printer);
187 return false;
188 }
189
addPassesToEmitFile(PassManagerBase & PM,raw_pwrite_stream & Out,raw_pwrite_stream * DwoOut,CodeGenFileType FileType,bool DisableVerify,MachineModuleInfo * MMI)190 bool LLVMTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
191 raw_pwrite_stream &Out,
192 raw_pwrite_stream *DwoOut,
193 CodeGenFileType FileType,
194 bool DisableVerify,
195 MachineModuleInfo *MMI) {
196 // Add common CodeGen passes.
197 if (!MMI)
198 MMI = new MachineModuleInfo(this);
199 TargetPassConfig *PassConfig =
200 addPassesToGenerateCode(*this, PM, DisableVerify, *MMI);
201 if (!PassConfig)
202 return true;
203
204 if (!TargetPassConfig::willCompleteCodeGenPipeline()) {
205 PM.add(createPrintMIRPass(Out));
206 } else if (addAsmPrinter(PM, Out, DwoOut, FileType, MMI->getContext()))
207 return true;
208
209 PM.add(createFreeMachineFunctionPass());
210 return false;
211 }
212
213 /// addPassesToEmitMC - Add passes to the specified pass manager to get
214 /// machine code emitted with the MCJIT. This method returns true if machine
215 /// code is not supported. It fills the MCContext Ctx pointer which can be
216 /// used to build custom MCStreamer.
217 ///
addPassesToEmitMC(PassManagerBase & PM,MCContext * & Ctx,raw_pwrite_stream & Out,bool DisableVerify)218 bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM, MCContext *&Ctx,
219 raw_pwrite_stream &Out,
220 bool DisableVerify) {
221 // Add common CodeGen passes.
222 MachineModuleInfo *MMI = new MachineModuleInfo(this);
223 TargetPassConfig *PassConfig =
224 addPassesToGenerateCode(*this, PM, DisableVerify, *MMI);
225 if (!PassConfig)
226 return true;
227 assert(TargetPassConfig::willCompleteCodeGenPipeline() &&
228 "Cannot emit MC with limited codegen pipeline");
229
230 Ctx = &MMI->getContext();
231 if (Options.MCOptions.MCSaveTempLabels)
232 Ctx->setAllowTemporaryLabels(false);
233
234 // Create the code emitter for the target if it exists. If not, .o file
235 // emission fails.
236 const MCSubtargetInfo &STI = *getMCSubtargetInfo();
237 const MCRegisterInfo &MRI = *getMCRegisterInfo();
238 MCCodeEmitter *MCE =
239 getTarget().createMCCodeEmitter(*getMCInstrInfo(), MRI, *Ctx);
240 MCAsmBackend *MAB =
241 getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions);
242 if (!MCE || !MAB)
243 return true;
244
245 const Triple &T = getTargetTriple();
246 std::unique_ptr<MCStreamer> AsmStreamer(getTarget().createMCObjectStreamer(
247 T, *Ctx, std::unique_ptr<MCAsmBackend>(MAB), MAB->createObjectWriter(Out),
248 std::unique_ptr<MCCodeEmitter>(MCE), STI, Options.MCOptions.MCRelaxAll,
249 Options.MCOptions.MCIncrementalLinkerCompatible,
250 /*DWARFMustBeAtTheEnd*/ true));
251
252 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
253 FunctionPass *Printer =
254 getTarget().createAsmPrinter(*this, std::move(AsmStreamer));
255 if (!Printer)
256 return true;
257
258 PM.add(Printer);
259 PM.add(createFreeMachineFunctionPass());
260
261 return false; // success!
262 }
263