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/JumpInstrTableInfo.h"
16 #include "llvm/Analysis/Passes.h"
17 #include "llvm/CodeGen/AsmPrinter.h"
18 #include "llvm/CodeGen/ForwardControlFlowIntegrity.h"
19 #include "llvm/CodeGen/JumpInstrTables.h"
20 #include "llvm/CodeGen/MachineFunctionAnalysis.h"
21 #include "llvm/CodeGen/MachineModuleInfo.h"
22 #include "llvm/CodeGen/Passes.h"
23 #include "llvm/IR/IRPrintingPasses.h"
24 #include "llvm/IR/Verifier.h"
25 #include "llvm/MC/MCAsmInfo.h"
26 #include "llvm/MC/MCContext.h"
27 #include "llvm/MC/MCInstrInfo.h"
28 #include "llvm/MC/MCStreamer.h"
29 #include "llvm/MC/MCSubtargetInfo.h"
30 #include "llvm/PassManager.h"
31 #include "llvm/Support/CommandLine.h"
32 #include "llvm/Support/ErrorHandling.h"
33 #include "llvm/Support/FormattedStream.h"
34 #include "llvm/Support/TargetRegistry.h"
35 #include "llvm/Target/TargetInstrInfo.h"
36 #include "llvm/Target/TargetLowering.h"
37 #include "llvm/Target/TargetLoweringObjectFile.h"
38 #include "llvm/Target/TargetOptions.h"
39 #include "llvm/Target/TargetRegisterInfo.h"
40 #include "llvm/Target/TargetSubtargetInfo.h"
41 #include "llvm/Transforms/Scalar.h"
42 using namespace llvm;
43
44 // Enable or disable FastISel. Both options are needed, because
45 // FastISel is enabled by default with -fast, and we wish to be
46 // able to enable or disable fast-isel independently from -O0.
47 static cl::opt<cl::boolOrDefault>
48 EnableFastISelOption("fast-isel", cl::Hidden,
49 cl::desc("Enable the \"fast\" instruction selector"));
50
initAsmInfo()51 void LLVMTargetMachine::initAsmInfo() {
52 MCAsmInfo *TmpAsmInfo = TheTarget.createMCAsmInfo(
53 *getSubtargetImpl()->getRegisterInfo(), getTargetTriple());
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 if (Options.CompressDebugSections)
66 TmpAsmInfo->setCompressDebugSections(true);
67
68 AsmInfo = TmpAsmInfo;
69 }
70
LLVMTargetMachine(const Target & T,StringRef Triple,StringRef CPU,StringRef FS,TargetOptions Options,Reloc::Model RM,CodeModel::Model CM,CodeGenOpt::Level OL)71 LLVMTargetMachine::LLVMTargetMachine(const Target &T, StringRef Triple,
72 StringRef CPU, StringRef FS,
73 TargetOptions Options,
74 Reloc::Model RM, CodeModel::Model CM,
75 CodeGenOpt::Level OL)
76 : TargetMachine(T, Triple, CPU, FS, Options) {
77 CodeGenInfo = T.createMCCodeGenInfo(Triple, RM, CM, OL);
78 }
79
addAnalysisPasses(PassManagerBase & PM)80 void LLVMTargetMachine::addAnalysisPasses(PassManagerBase &PM) {
81 PM.add(createBasicTargetTransformInfoPass(this));
82 }
83
84 /// addPassesToX helper drives creation and initialization of TargetPassConfig.
addPassesToGenerateCode(LLVMTargetMachine * TM,PassManagerBase & PM,bool DisableVerify,AnalysisID StartAfter,AnalysisID StopAfter)85 static MCContext *addPassesToGenerateCode(LLVMTargetMachine *TM,
86 PassManagerBase &PM,
87 bool DisableVerify,
88 AnalysisID StartAfter,
89 AnalysisID StopAfter) {
90
91 // Add internal analysis passes from the target machine.
92 TM->addAnalysisPasses(PM);
93
94 // Targets may override createPassConfig to provide a target-specific
95 // subclass.
96 TargetPassConfig *PassConfig = TM->createPassConfig(PM);
97 PassConfig->setStartStopPasses(StartAfter, StopAfter);
98
99 // Set PassConfig options provided by TargetMachine.
100 PassConfig->setDisableVerify(DisableVerify);
101
102 PM.add(PassConfig);
103
104 PassConfig->addIRPasses();
105
106 PassConfig->addCodeGenPrepare();
107
108 PassConfig->addPassesToHandleExceptions();
109
110 PassConfig->addISelPrepare();
111
112 // Install a MachineModuleInfo class, which is an immutable pass that holds
113 // all the per-module stuff we're generating, including MCContext.
114 MachineModuleInfo *MMI = new MachineModuleInfo(
115 *TM->getMCAsmInfo(), *TM->getSubtargetImpl()->getRegisterInfo(),
116 &TM->getSubtargetImpl()->getTargetLowering()->getObjFileLowering());
117 PM.add(MMI);
118
119 // Set up a MachineFunction for the rest of CodeGen to work on.
120 PM.add(new MachineFunctionAnalysis(*TM));
121
122 // Enable FastISel with -fast, but allow that to be overridden.
123 if (EnableFastISelOption == cl::BOU_TRUE ||
124 (TM->getOptLevel() == CodeGenOpt::None &&
125 EnableFastISelOption != cl::BOU_FALSE))
126 TM->setFastISel(true);
127
128 // Ask the target for an isel.
129 if (PassConfig->addInstSelector())
130 return nullptr;
131
132 PassConfig->addMachinePasses();
133
134 PassConfig->setInitialized();
135
136 return &MMI->getContext();
137 }
138
addPassesToEmitFile(PassManagerBase & PM,formatted_raw_ostream & Out,CodeGenFileType FileType,bool DisableVerify,AnalysisID StartAfter,AnalysisID StopAfter)139 bool LLVMTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
140 formatted_raw_ostream &Out,
141 CodeGenFileType FileType,
142 bool DisableVerify,
143 AnalysisID StartAfter,
144 AnalysisID StopAfter) {
145 // Passes to handle jumptable function annotations. These can't be handled at
146 // JIT time, so we don't add them directly to addPassesToGenerateCode.
147 PM.add(createJumpInstrTableInfoPass(
148 getSubtargetImpl()->getInstrInfo()->getJumpInstrTableEntryBound()));
149 PM.add(createJumpInstrTablesPass(Options.JTType));
150 if (Options.FCFI)
151 PM.add(createForwardControlFlowIntegrityPass(
152 Options.JTType, Options.CFIType, Options.CFIEnforcing,
153 Options.getCFIFuncName()));
154
155 // Add common CodeGen passes.
156 MCContext *Context = addPassesToGenerateCode(this, PM, DisableVerify,
157 StartAfter, StopAfter);
158 if (!Context)
159 return true;
160
161 if (StopAfter) {
162 // FIXME: The intent is that this should eventually write out a YAML file,
163 // containing the LLVM IR, the machine-level IR (when stopping after a
164 // machine-level pass), and whatever other information is needed to
165 // deserialize the code and resume compilation. For now, just write the
166 // LLVM IR.
167 PM.add(createPrintModulePass(Out));
168 return false;
169 }
170
171 if (Options.MCOptions.MCSaveTempLabels)
172 Context->setAllowTemporaryLabels(false);
173
174 const MCSubtargetInfo &STI = getSubtarget<MCSubtargetInfo>();
175 const MCAsmInfo &MAI = *getMCAsmInfo();
176 const MCRegisterInfo &MRI = *getSubtargetImpl()->getRegisterInfo();
177 const MCInstrInfo &MII = *getSubtargetImpl()->getInstrInfo();
178 std::unique_ptr<MCStreamer> AsmStreamer;
179
180 switch (FileType) {
181 case CGFT_AssemblyFile: {
182 MCInstPrinter *InstPrinter =
183 getTarget().createMCInstPrinter(MAI.getAssemblerDialect(), MAI,
184 MII, MRI, STI);
185
186 // Create a code emitter if asked to show the encoding.
187 MCCodeEmitter *MCE = nullptr;
188 if (Options.MCOptions.ShowMCEncoding)
189 MCE = getTarget().createMCCodeEmitter(MII, MRI, STI, *Context);
190
191 MCAsmBackend *MAB = getTarget().createMCAsmBackend(MRI, getTargetTriple(),
192 TargetCPU);
193 MCStreamer *S = getTarget().createAsmStreamer(
194 *Context, Out, Options.MCOptions.AsmVerbose,
195 Options.MCOptions.MCUseDwarfDirectory, InstPrinter, MCE, MAB,
196 Options.MCOptions.ShowMCInst);
197 AsmStreamer.reset(S);
198 break;
199 }
200 case CGFT_ObjectFile: {
201 // Create the code emitter for the target if it exists. If not, .o file
202 // emission fails.
203 MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(MII, MRI, STI,
204 *Context);
205 MCAsmBackend *MAB = getTarget().createMCAsmBackend(MRI, getTargetTriple(),
206 TargetCPU);
207 if (!MCE || !MAB)
208 return true;
209
210 AsmStreamer.reset(
211 getTarget()
212 .createMCObjectStreamer(getTargetTriple(), *Context, *MAB, Out, MCE,
213 STI, Options.MCOptions.MCRelaxAll));
214 break;
215 }
216 case CGFT_Null:
217 // The Null output is intended for use for performance analysis and testing,
218 // not real users.
219 AsmStreamer.reset(getTarget().createNullStreamer(*Context));
220 break;
221 }
222
223 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
224 FunctionPass *Printer = getTarget().createAsmPrinter(*this, *AsmStreamer);
225 if (!Printer)
226 return true;
227
228 // If successful, createAsmPrinter took ownership of AsmStreamer.
229 AsmStreamer.release();
230
231 PM.add(Printer);
232
233 return false;
234 }
235
236 /// addPassesToEmitMC - Add passes to the specified pass manager to get
237 /// machine code emitted with the MCJIT. This method returns true if machine
238 /// code is not supported. It fills the MCContext Ctx pointer which can be
239 /// used to build custom MCStreamer.
240 ///
addPassesToEmitMC(PassManagerBase & PM,MCContext * & Ctx,raw_ostream & Out,bool DisableVerify)241 bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM,
242 MCContext *&Ctx,
243 raw_ostream &Out,
244 bool DisableVerify) {
245 // Add common CodeGen passes.
246 Ctx = addPassesToGenerateCode(this, PM, DisableVerify, nullptr, nullptr);
247 if (!Ctx)
248 return true;
249
250 if (Options.MCOptions.MCSaveTempLabels)
251 Ctx->setAllowTemporaryLabels(false);
252
253 // Create the code emitter for the target if it exists. If not, .o file
254 // emission fails.
255 const MCRegisterInfo &MRI = *getSubtargetImpl()->getRegisterInfo();
256 const MCSubtargetInfo &STI = getSubtarget<MCSubtargetInfo>();
257 MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(
258 *getSubtargetImpl()->getInstrInfo(), MRI, STI, *Ctx);
259 MCAsmBackend *MAB = getTarget().createMCAsmBackend(MRI, getTargetTriple(),
260 TargetCPU);
261 if (!MCE || !MAB)
262 return true;
263
264 std::unique_ptr<MCStreamer> AsmStreamer;
265 AsmStreamer.reset(getTarget()
266 .createMCObjectStreamer(getTargetTriple(), *Ctx, *MAB,
267 Out, MCE, STI,
268 Options.MCOptions.MCRelaxAll));
269
270 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
271 FunctionPass *Printer = getTarget().createAsmPrinter(*this, *AsmStreamer);
272 if (!Printer)
273 return true;
274
275 // If successful, createAsmPrinter took ownership of AsmStreamer.
276 AsmStreamer.release();
277
278 PM.add(Printer);
279
280 return false; // success!
281 }
282