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/Target/TargetMachine.h"
15 #include "llvm/Analysis/Passes.h"
16 #include "llvm/CodeGen/AsmPrinter.h"
17 #include "llvm/CodeGen/BasicTTIImpl.h"
18 #include "llvm/CodeGen/MachineFunctionAnalysis.h"
19 #include "llvm/CodeGen/MachineModuleInfo.h"
20 #include "llvm/CodeGen/Passes.h"
21 #include "llvm/IR/IRPrintingPasses.h"
22 #include "llvm/IR/LegacyPassManager.h"
23 #include "llvm/IR/Verifier.h"
24 #include "llvm/MC/MCAsmInfo.h"
25 #include "llvm/MC/MCContext.h"
26 #include "llvm/MC/MCInstrInfo.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/TargetOptions.h"
35 #include "llvm/Transforms/Scalar.h"
36 using namespace llvm;
37
38 // Enable or disable FastISel. Both options are needed, because
39 // FastISel is enabled by default with -fast, and we wish to be
40 // able to enable or disable fast-isel independently from -O0.
41 static cl::opt<cl::boolOrDefault>
42 EnableFastISelOption("fast-isel", cl::Hidden,
43 cl::desc("Enable the \"fast\" instruction selector"));
44
initAsmInfo()45 void LLVMTargetMachine::initAsmInfo() {
46 MRI = TheTarget.createMCRegInfo(getTargetTriple());
47 MII = TheTarget.createMCInstrInfo();
48 // FIXME: Having an MCSubtargetInfo on the target machine is a hack due
49 // to some backends having subtarget feature dependent module level
50 // code generation. This is similar to the hack in the AsmPrinter for
51 // module level assembly etc.
52 STI = TheTarget.createMCSubtargetInfo(getTargetTriple(), getTargetCPU(),
53 getTargetFeatureString());
54
55 MCAsmInfo *TmpAsmInfo = TheTarget.createMCAsmInfo(*MRI, getTargetTriple());
56 // TargetSelect.h moved to a different directory between LLVM 2.9 and 3.0,
57 // and if the old one gets included then MCAsmInfo will be NULL and
58 // we'll crash later.
59 // Provide the user with a useful error message about what's wrong.
60 assert(TmpAsmInfo && "MCAsmInfo not initialized. "
61 "Make sure you include the correct TargetSelect.h"
62 "and that InitializeAllTargetMCs() is being invoked!");
63
64 if (Options.DisableIntegratedAS)
65 TmpAsmInfo->setUseIntegratedAssembler(false);
66
67 if (Options.CompressDebugSections)
68 TmpAsmInfo->setCompressDebugSections(true);
69
70 AsmInfo = TmpAsmInfo;
71 }
72
LLVMTargetMachine(const Target & T,StringRef DataLayoutString,StringRef Triple,StringRef CPU,StringRef FS,TargetOptions Options,Reloc::Model RM,CodeModel::Model CM,CodeGenOpt::Level OL)73 LLVMTargetMachine::LLVMTargetMachine(const Target &T,
74 StringRef DataLayoutString,
75 StringRef Triple, StringRef CPU,
76 StringRef FS, TargetOptions Options,
77 Reloc::Model RM, CodeModel::Model CM,
78 CodeGenOpt::Level OL)
79 : TargetMachine(T, DataLayoutString, Triple, CPU, FS, Options) {
80 CodeGenInfo = T.createMCCodeGenInfo(Triple, RM, CM, OL);
81 }
82
getTargetIRAnalysis()83 TargetIRAnalysis LLVMTargetMachine::getTargetIRAnalysis() {
84 return TargetIRAnalysis([this](Function &F) {
85 return TargetTransformInfo(BasicTTIImpl(this, F));
86 });
87 }
88
89 /// addPassesToX helper drives creation and initialization of TargetPassConfig.
addPassesToGenerateCode(LLVMTargetMachine * TM,PassManagerBase & PM,bool DisableVerify,AnalysisID StartAfter,AnalysisID StopAfter)90 static MCContext *addPassesToGenerateCode(LLVMTargetMachine *TM,
91 PassManagerBase &PM,
92 bool DisableVerify,
93 AnalysisID StartAfter,
94 AnalysisID StopAfter) {
95
96 // Add internal analysis passes from the target machine.
97 PM.add(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis()));
98
99 // Targets may override createPassConfig to provide a target-specific
100 // subclass.
101 TargetPassConfig *PassConfig = TM->createPassConfig(PM);
102 PassConfig->setStartStopPasses(StartAfter, StopAfter);
103
104 // Set PassConfig options provided by TargetMachine.
105 PassConfig->setDisableVerify(DisableVerify);
106
107 PM.add(PassConfig);
108
109 PassConfig->addIRPasses();
110
111 PassConfig->addCodeGenPrepare();
112
113 PassConfig->addPassesToHandleExceptions();
114
115 PassConfig->addISelPrepare();
116
117 // Install a MachineModuleInfo class, which is an immutable pass that holds
118 // all the per-module stuff we're generating, including MCContext.
119 MachineModuleInfo *MMI = new MachineModuleInfo(
120 *TM->getMCAsmInfo(), *TM->getMCRegisterInfo(), TM->getObjFileLowering());
121 PM.add(MMI);
122
123 // Set up a MachineFunction for the rest of CodeGen to work on.
124 PM.add(new MachineFunctionAnalysis(*TM));
125
126 // Enable FastISel with -fast, but allow that to be overridden.
127 if (EnableFastISelOption == cl::BOU_TRUE ||
128 (TM->getOptLevel() == CodeGenOpt::None &&
129 EnableFastISelOption != cl::BOU_FALSE))
130 TM->setFastISel(true);
131
132 // Ask the target for an isel.
133 if (PassConfig->addInstSelector())
134 return nullptr;
135
136 PassConfig->addMachinePasses();
137
138 PassConfig->setInitialized();
139
140 return &MMI->getContext();
141 }
142
addPassesToEmitFile(PassManagerBase & PM,raw_pwrite_stream & Out,CodeGenFileType FileType,bool DisableVerify,AnalysisID StartAfter,AnalysisID StopAfter)143 bool LLVMTargetMachine::addPassesToEmitFile(
144 PassManagerBase &PM, raw_pwrite_stream &Out, CodeGenFileType FileType,
145 bool DisableVerify, AnalysisID StartAfter, AnalysisID StopAfter) {
146 // Add common CodeGen passes.
147 MCContext *Context = addPassesToGenerateCode(this, PM, DisableVerify,
148 StartAfter, StopAfter);
149 if (!Context)
150 return true;
151
152 if (StopAfter) {
153 // FIXME: The intent is that this should eventually write out a YAML file,
154 // containing the LLVM IR, the machine-level IR (when stopping after a
155 // machine-level pass), and whatever other information is needed to
156 // deserialize the code and resume compilation. For now, just write the
157 // LLVM IR.
158 PM.add(createPrintModulePass(Out));
159 return false;
160 }
161
162 if (Options.MCOptions.MCSaveTempLabels)
163 Context->setAllowTemporaryLabels(false);
164
165 const MCSubtargetInfo &STI = *getMCSubtargetInfo();
166 const MCAsmInfo &MAI = *getMCAsmInfo();
167 const MCRegisterInfo &MRI = *getMCRegisterInfo();
168 const MCInstrInfo &MII = *getMCInstrInfo();
169
170 std::unique_ptr<MCStreamer> AsmStreamer;
171
172 switch (FileType) {
173 case CGFT_AssemblyFile: {
174 MCInstPrinter *InstPrinter = getTarget().createMCInstPrinter(
175 Triple(getTargetTriple()), MAI.getAssemblerDialect(), MAI, MII, MRI);
176
177 // Create a code emitter if asked to show the encoding.
178 MCCodeEmitter *MCE = nullptr;
179 if (Options.MCOptions.ShowMCEncoding)
180 MCE = getTarget().createMCCodeEmitter(MII, MRI, *Context);
181
182 MCAsmBackend *MAB = getTarget().createMCAsmBackend(MRI, getTargetTriple(),
183 TargetCPU);
184 auto FOut = llvm::make_unique<formatted_raw_ostream>(Out);
185 MCStreamer *S = getTarget().createAsmStreamer(
186 *Context, std::move(FOut), Options.MCOptions.AsmVerbose,
187 Options.MCOptions.MCUseDwarfDirectory, InstPrinter, MCE, MAB,
188 Options.MCOptions.ShowMCInst);
189 AsmStreamer.reset(S);
190 break;
191 }
192 case CGFT_ObjectFile: {
193 // Create the code emitter for the target if it exists. If not, .o file
194 // emission fails.
195 MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(MII, MRI, *Context);
196 MCAsmBackend *MAB = getTarget().createMCAsmBackend(MRI, getTargetTriple(),
197 TargetCPU);
198 if (!MCE || !MAB)
199 return true;
200
201 Triple T(getTargetTriple());
202 AsmStreamer.reset(getTarget().createMCObjectStreamer(
203 T, *Context, *MAB, Out, MCE, STI, Options.MCOptions.MCRelaxAll,
204 /*DWARFMustBeAtTheEnd*/ true));
205 break;
206 }
207 case CGFT_Null:
208 // The Null output is intended for use for performance analysis and testing,
209 // not real users.
210 AsmStreamer.reset(getTarget().createNullStreamer(*Context));
211 break;
212 }
213
214 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
215 FunctionPass *Printer =
216 getTarget().createAsmPrinter(*this, std::move(AsmStreamer));
217 if (!Printer)
218 return true;
219
220 PM.add(Printer);
221
222 return false;
223 }
224
225 /// addPassesToEmitMC - Add passes to the specified pass manager to get
226 /// machine code emitted with the MCJIT. This method returns true if machine
227 /// code is not supported. It fills the MCContext Ctx pointer which can be
228 /// used to build custom MCStreamer.
229 ///
addPassesToEmitMC(PassManagerBase & PM,MCContext * & Ctx,raw_pwrite_stream & Out,bool DisableVerify)230 bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM, MCContext *&Ctx,
231 raw_pwrite_stream &Out,
232 bool DisableVerify) {
233 // Add common CodeGen passes.
234 Ctx = addPassesToGenerateCode(this, PM, DisableVerify, nullptr, nullptr);
235 if (!Ctx)
236 return true;
237
238 if (Options.MCOptions.MCSaveTempLabels)
239 Ctx->setAllowTemporaryLabels(false);
240
241 // Create the code emitter for the target if it exists. If not, .o file
242 // emission fails.
243 const MCRegisterInfo &MRI = *getMCRegisterInfo();
244 MCCodeEmitter *MCE =
245 getTarget().createMCCodeEmitter(*getMCInstrInfo(), MRI, *Ctx);
246 MCAsmBackend *MAB = getTarget().createMCAsmBackend(MRI, getTargetTriple(),
247 TargetCPU);
248 if (!MCE || !MAB)
249 return true;
250
251 Triple T(getTargetTriple());
252 const MCSubtargetInfo &STI = *getMCSubtargetInfo();
253 std::unique_ptr<MCStreamer> AsmStreamer(getTarget().createMCObjectStreamer(
254 T, *Ctx, *MAB, Out, MCE, STI, Options.MCOptions.MCRelaxAll,
255 /*DWARFMustBeAtTheEnd*/ true));
256
257 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
258 FunctionPass *Printer =
259 getTarget().createAsmPrinter(*this, std::move(AsmStreamer));
260 if (!Printer)
261 return true;
262
263 PM.add(Printer);
264
265 return false; // success!
266 }
267