1 //===-- LLVMTargetMachine.cpp - Implement the LLVMTargetMachine class -----===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the LLVMTargetMachine class.
12 //===----------------------------------------------------------------------===//
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"
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"));
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());
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
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!");
64 if (Options.DisableIntegratedAS)
65 TmpAsmInfo->setUseIntegratedAssembler(false);
67 if (Options.CompressDebugSections)
68 TmpAsmInfo->setCompressDebugSections(true);
70 TmpAsmInfo->finishInit(*this);
74 LLVMTargetMachine::LLVMTargetMachine(const Target &T,
75 StringRef DataLayoutString,
76 StringRef Triple, StringRef CPU,
77 StringRef FS, TargetOptions Options,
78 Reloc::Model RM, CodeModel::Model CM,
80 : TargetMachine(T, DataLayoutString, Triple, CPU, FS, Options) {
81 CodeGenInfo = T.createMCCodeGenInfo(Triple, RM, CM, OL);
84 TargetIRAnalysis LLVMTargetMachine::getTargetIRAnalysis() {
85 return TargetIRAnalysis([this](Function &F) {
86 return TargetTransformInfo(BasicTTIImpl(this, F));
90 /// addPassesToX helper drives creation and initialization of TargetPassConfig.
91 static MCContext *addPassesToGenerateCode(LLVMTargetMachine *TM,
94 AnalysisID StartAfter,
95 AnalysisID StopAfter) {
97 // Add internal analysis passes from the target machine.
98 PM.add(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis()));
100 // Targets may override createPassConfig to provide a target-specific
102 TargetPassConfig *PassConfig = TM->createPassConfig(PM);
103 PassConfig->setStartStopPasses(StartAfter, StopAfter);
105 // Set PassConfig options provided by TargetMachine.
106 PassConfig->setDisableVerify(DisableVerify);
110 PassConfig->addIRPasses();
112 PassConfig->addCodeGenPrepare();
114 PassConfig->addPassesToHandleExceptions();
116 PassConfig->addISelPrepare();
118 // Install a MachineModuleInfo class, which is an immutable pass that holds
119 // all the per-module stuff we're generating, including MCContext.
120 MachineModuleInfo *MMI = new MachineModuleInfo(
121 *TM->getMCAsmInfo(), *TM->getMCRegisterInfo(), TM->getObjFileLowering());
124 // Set up a MachineFunction for the rest of CodeGen to work on.
125 PM.add(new MachineFunctionAnalysis(*TM));
127 // Enable FastISel with -fast, but allow that to be overridden.
128 if (EnableFastISelOption == cl::BOU_TRUE ||
129 (TM->getOptLevel() == CodeGenOpt::None &&
130 EnableFastISelOption != cl::BOU_FALSE))
131 TM->setFastISel(true);
133 // Ask the target for an isel.
134 if (PassConfig->addInstSelector())
137 PassConfig->addMachinePasses();
139 PassConfig->setInitialized();
141 return &MMI->getContext();
144 bool LLVMTargetMachine::addPassesToEmitFile(
145 PassManagerBase &PM, raw_pwrite_stream &Out, CodeGenFileType FileType,
146 bool DisableVerify, AnalysisID StartAfter, AnalysisID StopAfter) {
147 // Add common CodeGen passes.
148 MCContext *Context = addPassesToGenerateCode(this, PM, DisableVerify,
149 StartAfter, StopAfter);
154 // FIXME: The intent is that this should eventually write out a YAML file,
155 // containing the LLVM IR, the machine-level IR (when stopping after a
156 // machine-level pass), and whatever other information is needed to
157 // deserialize the code and resume compilation. For now, just write the
159 PM.add(createPrintModulePass(Out));
163 if (Options.MCOptions.MCSaveTempLabels)
164 Context->setAllowTemporaryLabels(false);
166 const MCSubtargetInfo &STI = *getMCSubtargetInfo();
167 const MCAsmInfo &MAI = *getMCAsmInfo();
168 const MCRegisterInfo &MRI = *getMCRegisterInfo();
169 const MCInstrInfo &MII = *getMCInstrInfo();
171 std::unique_ptr<MCStreamer> AsmStreamer;
174 case CGFT_AssemblyFile: {
175 MCInstPrinter *InstPrinter = getTarget().createMCInstPrinter(
176 Triple(getTargetTriple()), MAI.getAssemblerDialect(), MAI, MII, MRI);
178 // Create a code emitter if asked to show the encoding.
179 MCCodeEmitter *MCE = nullptr;
180 if (Options.MCOptions.ShowMCEncoding)
181 MCE = getTarget().createMCCodeEmitter(MII, MRI, *Context);
183 MCAsmBackend *MAB = getTarget().createMCAsmBackend(MRI, getTargetTriple(),
185 auto FOut = llvm::make_unique<formatted_raw_ostream>(Out);
186 MCStreamer *S = getTarget().createAsmStreamer(
187 *Context, std::move(FOut), Options.MCOptions.AsmVerbose,
188 Options.MCOptions.MCUseDwarfDirectory, InstPrinter, MCE, MAB,
189 Options.MCOptions.ShowMCInst);
190 AsmStreamer.reset(S);
193 case CGFT_ObjectFile: {
194 // Create the code emitter for the target if it exists. If not, .o file
196 MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(MII, MRI, *Context);
197 MCAsmBackend *MAB = getTarget().createMCAsmBackend(MRI, getTargetTriple(),
202 // Don't waste memory on names of temp labels.
203 Context->setUseNamesOnTempLabels(false);
205 Triple T(getTargetTriple());
206 AsmStreamer.reset(getTarget().createMCObjectStreamer(
207 T, *Context, *MAB, Out, MCE, STI, Options.MCOptions.MCRelaxAll,
208 /*DWARFMustBeAtTheEnd*/ true));
212 // The Null output is intended for use for performance analysis and testing,
214 AsmStreamer.reset(getTarget().createNullStreamer(*Context));
218 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
219 FunctionPass *Printer =
220 getTarget().createAsmPrinter(*this, std::move(AsmStreamer));
229 /// addPassesToEmitMC - Add passes to the specified pass manager to get
230 /// machine code emitted with the MCJIT. This method returns true if machine
231 /// code is not supported. It fills the MCContext Ctx pointer which can be
232 /// used to build custom MCStreamer.
234 bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM, MCContext *&Ctx,
235 raw_pwrite_stream &Out,
236 bool DisableVerify) {
237 // Add common CodeGen passes.
238 Ctx = addPassesToGenerateCode(this, PM, DisableVerify, nullptr, nullptr);
242 if (Options.MCOptions.MCSaveTempLabels)
243 Ctx->setAllowTemporaryLabels(false);
245 // Create the code emitter for the target if it exists. If not, .o file
247 const MCRegisterInfo &MRI = *getMCRegisterInfo();
249 getTarget().createMCCodeEmitter(*getMCInstrInfo(), MRI, *Ctx);
250 MCAsmBackend *MAB = getTarget().createMCAsmBackend(MRI, getTargetTriple(),
255 Triple T(getTargetTriple());
256 const MCSubtargetInfo &STI = *getMCSubtargetInfo();
257 std::unique_ptr<MCStreamer> AsmStreamer(getTarget().createMCObjectStreamer(
258 T, *Ctx, *MAB, Out, MCE, STI, Options.MCOptions.MCRelaxAll,
259 /*DWARFMustBeAtTheEnd*/ true));
261 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
262 FunctionPass *Printer =
263 getTarget().createAsmPrinter(*this, std::move(AsmStreamer));
269 return false; // success!