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/Transforms/Scalar.h"
15 #include "llvm/PassManager.h"
16 #include "llvm/Assembly/PrintModulePass.h"
17 #include "llvm/CodeGen/AsmPrinter.h"
18 #include "llvm/CodeGen/Passes.h"
19 #include "llvm/CodeGen/MachineFunctionAnalysis.h"
20 #include "llvm/CodeGen/MachineModuleInfo.h"
21 #include "llvm/Target/TargetInstrInfo.h"
22 #include "llvm/Target/TargetLowering.h"
23 #include "llvm/Target/TargetLoweringObjectFile.h"
24 #include "llvm/Target/TargetMachine.h"
25 #include "llvm/Target/TargetOptions.h"
26 #include "llvm/Target/TargetSubtargetInfo.h"
27 #include "llvm/Target/TargetRegisterInfo.h"
28 #include "llvm/MC/MCAsmInfo.h"
29 #include "llvm/MC/MCContext.h"
30 #include "llvm/MC/MCInstrInfo.h"
31 #include "llvm/MC/MCStreamer.h"
32 #include "llvm/MC/MCSubtargetInfo.h"
33 #include "llvm/ADT/OwningPtr.h"
34 #include "llvm/Support/CommandLine.h"
35 #include "llvm/Support/FormattedStream.h"
36 #include "llvm/Support/ErrorHandling.h"
37 #include "llvm/Support/TargetRegistry.h"
38 using namespace llvm;
39
40 // Enable or disable FastISel. Both options are needed, because
41 // FastISel is enabled by default with -fast, and we wish to be
42 // able to enable or disable fast-isel independently from -O0.
43 static cl::opt<cl::boolOrDefault>
44 EnableFastISelOption("fast-isel", cl::Hidden,
45 cl::desc("Enable the \"fast\" instruction selector"));
46
47 static cl::opt<bool> ShowMCEncoding("show-mc-encoding", cl::Hidden,
48 cl::desc("Show encoding in .s output"));
49 static cl::opt<bool> ShowMCInst("show-mc-inst", cl::Hidden,
50 cl::desc("Show instruction structure in .s output"));
51
52 static cl::opt<cl::boolOrDefault>
53 AsmVerbose("asm-verbose", cl::desc("Add comments to directives."),
54 cl::init(cl::BOU_UNSET));
55
getVerboseAsm()56 static bool getVerboseAsm() {
57 switch (AsmVerbose) {
58 case cl::BOU_UNSET: return TargetMachine::getAsmVerbosityDefault();
59 case cl::BOU_TRUE: return true;
60 case cl::BOU_FALSE: return false;
61 }
62 llvm_unreachable("Invalid verbose asm state");
63 }
64
LLVMTargetMachine(const Target & T,StringRef Triple,StringRef CPU,StringRef FS,TargetOptions Options,Reloc::Model RM,CodeModel::Model CM,CodeGenOpt::Level OL)65 LLVMTargetMachine::LLVMTargetMachine(const Target &T, StringRef Triple,
66 StringRef CPU, StringRef FS,
67 TargetOptions Options,
68 Reloc::Model RM, CodeModel::Model CM,
69 CodeGenOpt::Level OL)
70 : TargetMachine(T, Triple, CPU, FS, Options) {
71 CodeGenInfo = T.createMCCodeGenInfo(Triple, RM, CM, OL);
72 AsmInfo = T.createMCAsmInfo(Triple);
73 // TargetSelect.h moved to a different directory between LLVM 2.9 and 3.0,
74 // and if the old one gets included then MCAsmInfo will be NULL and
75 // we'll crash later.
76 // Provide the user with a useful error message about what's wrong.
77 assert(AsmInfo && "MCAsmInfo not initialized."
78 "Make sure you include the correct TargetSelect.h"
79 "and that InitializeAllTargetMCs() is being invoked!");
80 }
81
82 /// addPassesToX helper drives creation and initialization of TargetPassConfig.
addPassesToGenerateCode(LLVMTargetMachine * TM,PassManagerBase & PM,bool DisableVerify,AnalysisID StartAfter,AnalysisID StopAfter)83 static MCContext *addPassesToGenerateCode(LLVMTargetMachine *TM,
84 PassManagerBase &PM,
85 bool DisableVerify,
86 AnalysisID StartAfter,
87 AnalysisID StopAfter) {
88 // Targets may override createPassConfig to provide a target-specific sublass.
89 TargetPassConfig *PassConfig = TM->createPassConfig(PM);
90 PassConfig->setStartStopPasses(StartAfter, StopAfter);
91
92 // Set PassConfig options provided by TargetMachine.
93 PassConfig->setDisableVerify(DisableVerify);
94
95 PM.add(PassConfig);
96
97 PassConfig->addIRPasses();
98
99 PassConfig->addPassesToHandleExceptions();
100
101 PassConfig->addISelPrepare();
102
103 // Install a MachineModuleInfo class, which is an immutable pass that holds
104 // all the per-module stuff we're generating, including MCContext.
105 MachineModuleInfo *MMI =
106 new MachineModuleInfo(*TM->getMCAsmInfo(), *TM->getRegisterInfo(),
107 &TM->getTargetLowering()->getObjFileLowering());
108 PM.add(MMI);
109 MCContext *Context = &MMI->getContext(); // Return the MCContext by-ref.
110
111 // Set up a MachineFunction for the rest of CodeGen to work on.
112 PM.add(new MachineFunctionAnalysis(*TM));
113
114 // Enable FastISel with -fast, but allow that to be overridden.
115 if (EnableFastISelOption == cl::BOU_TRUE ||
116 (TM->getOptLevel() == CodeGenOpt::None &&
117 EnableFastISelOption != cl::BOU_FALSE))
118 TM->setFastISel(true);
119
120 // Ask the target for an isel.
121 if (PassConfig->addInstSelector())
122 return NULL;
123
124 PassConfig->addMachinePasses();
125
126 PassConfig->setInitialized();
127
128 return Context;
129 }
130
addPassesToEmitFile(PassManagerBase & PM,formatted_raw_ostream & Out,CodeGenFileType FileType,bool DisableVerify,AnalysisID StartAfter,AnalysisID StopAfter)131 bool LLVMTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
132 formatted_raw_ostream &Out,
133 CodeGenFileType FileType,
134 bool DisableVerify,
135 AnalysisID StartAfter,
136 AnalysisID StopAfter) {
137 // Add common CodeGen passes.
138 MCContext *Context = addPassesToGenerateCode(this, PM, DisableVerify,
139 StartAfter, StopAfter);
140 if (!Context)
141 return true;
142
143 if (StopAfter) {
144 // FIXME: The intent is that this should eventually write out a YAML file,
145 // containing the LLVM IR, the machine-level IR (when stopping after a
146 // machine-level pass), and whatever other information is needed to
147 // deserialize the code and resume compilation. For now, just write the
148 // LLVM IR.
149 PM.add(createPrintModulePass(&Out));
150 return false;
151 }
152
153 if (hasMCSaveTempLabels())
154 Context->setAllowTemporaryLabels(false);
155
156 const MCAsmInfo &MAI = *getMCAsmInfo();
157 const MCRegisterInfo &MRI = *getRegisterInfo();
158 const MCSubtargetInfo &STI = getSubtarget<MCSubtargetInfo>();
159 OwningPtr<MCStreamer> AsmStreamer;
160
161 switch (FileType) {
162 case CGFT_AssemblyFile: {
163 MCInstPrinter *InstPrinter =
164 getTarget().createMCInstPrinter(MAI.getAssemblerDialect(), MAI,
165 *getInstrInfo(),
166 Context->getRegisterInfo(), STI);
167
168 // Create a code emitter if asked to show the encoding.
169 MCCodeEmitter *MCE = 0;
170 MCAsmBackend *MAB = 0;
171 if (ShowMCEncoding) {
172 const MCSubtargetInfo &STI = getSubtarget<MCSubtargetInfo>();
173 MCE = getTarget().createMCCodeEmitter(*getInstrInfo(), MRI, STI,
174 *Context);
175 MAB = getTarget().createMCAsmBackend(getTargetTriple());
176 }
177
178 MCStreamer *S = getTarget().createAsmStreamer(*Context, Out,
179 getVerboseAsm(),
180 hasMCUseLoc(),
181 hasMCUseCFI(),
182 hasMCUseDwarfDirectory(),
183 InstPrinter,
184 MCE, MAB,
185 ShowMCInst);
186 AsmStreamer.reset(S);
187 break;
188 }
189 case CGFT_ObjectFile: {
190 // Create the code emitter for the target if it exists. If not, .o file
191 // emission fails.
192 MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(*getInstrInfo(), MRI,
193 STI, *Context);
194 MCAsmBackend *MAB = getTarget().createMCAsmBackend(getTargetTriple());
195 if (MCE == 0 || MAB == 0)
196 return true;
197
198 AsmStreamer.reset(getTarget().createMCObjectStreamer(getTargetTriple(),
199 *Context, *MAB, Out,
200 MCE, hasMCRelaxAll(),
201 hasMCNoExecStack()));
202 AsmStreamer.get()->InitSections();
203 break;
204 }
205 case CGFT_Null:
206 // The Null output is intended for use for performance analysis and testing,
207 // not real users.
208 AsmStreamer.reset(createNullStreamer(*Context));
209 break;
210 }
211
212 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
213 FunctionPass *Printer = getTarget().createAsmPrinter(*this, *AsmStreamer);
214 if (Printer == 0)
215 return true;
216
217 // If successful, createAsmPrinter took ownership of AsmStreamer.
218 AsmStreamer.take();
219
220 PM.add(Printer);
221
222 PM.add(createGCInfoDeleter());
223 return false;
224 }
225
226 /// addPassesToEmitMachineCode - Add passes to the specified pass manager to
227 /// get machine code emitted. This uses a JITCodeEmitter object to handle
228 /// actually outputting the machine code and resolving things like the address
229 /// of functions. This method should returns true if machine code emission is
230 /// not supported.
231 ///
addPassesToEmitMachineCode(PassManagerBase & PM,JITCodeEmitter & JCE,bool DisableVerify)232 bool LLVMTargetMachine::addPassesToEmitMachineCode(PassManagerBase &PM,
233 JITCodeEmitter &JCE,
234 bool DisableVerify) {
235 // Add common CodeGen passes.
236 MCContext *Context = addPassesToGenerateCode(this, PM, DisableVerify, 0, 0);
237 if (!Context)
238 return true;
239
240 addCodeEmitter(PM, JCE);
241 PM.add(createGCInfoDeleter());
242
243 return false; // success!
244 }
245
246 /// addPassesToEmitMC - Add passes to the specified pass manager to get
247 /// machine code emitted with the MCJIT. This method returns true if machine
248 /// code is not supported. It fills the MCContext Ctx pointer which can be
249 /// used to build custom MCStreamer.
250 ///
addPassesToEmitMC(PassManagerBase & PM,MCContext * & Ctx,raw_ostream & Out,bool DisableVerify)251 bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM,
252 MCContext *&Ctx,
253 raw_ostream &Out,
254 bool DisableVerify) {
255 // Add common CodeGen passes.
256 Ctx = addPassesToGenerateCode(this, PM, DisableVerify, 0, 0);
257 if (!Ctx)
258 return true;
259
260 if (hasMCSaveTempLabels())
261 Ctx->setAllowTemporaryLabels(false);
262
263 // Create the code emitter for the target if it exists. If not, .o file
264 // emission fails.
265 const MCRegisterInfo &MRI = *getRegisterInfo();
266 const MCSubtargetInfo &STI = getSubtarget<MCSubtargetInfo>();
267 MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(*getInstrInfo(), MRI,
268 STI, *Ctx);
269 MCAsmBackend *MAB = getTarget().createMCAsmBackend(getTargetTriple());
270 if (MCE == 0 || MAB == 0)
271 return true;
272
273 OwningPtr<MCStreamer> AsmStreamer;
274 AsmStreamer.reset(getTarget().createMCObjectStreamer(getTargetTriple(), *Ctx,
275 *MAB, Out, MCE,
276 hasMCRelaxAll(),
277 hasMCNoExecStack()));
278 AsmStreamer.get()->InitSections();
279
280 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
281 FunctionPass *Printer = getTarget().createAsmPrinter(*this, *AsmStreamer);
282 if (Printer == 0)
283 return true;
284
285 // If successful, createAsmPrinter took ownership of AsmStreamer.
286 AsmStreamer.take();
287
288 PM.add(Printer);
289
290 return false; // success!
291 }
292