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/CodeGen/AsmPrinter.h"
17 #include "llvm/CodeGen/Passes.h"
18 #include "llvm/CodeGen/MachineFunctionAnalysis.h"
19 #include "llvm/CodeGen/MachineModuleInfo.h"
20 #include "llvm/Target/TargetInstrInfo.h"
21 #include "llvm/Target/TargetLowering.h"
22 #include "llvm/Target/TargetLoweringObjectFile.h"
23 #include "llvm/Target/TargetMachine.h"
24 #include "llvm/Target/TargetOptions.h"
25 #include "llvm/Target/TargetSubtargetInfo.h"
26 #include "llvm/Target/TargetRegisterInfo.h"
27 #include "llvm/MC/MCAsmInfo.h"
28 #include "llvm/MC/MCContext.h"
29 #include "llvm/MC/MCInstrInfo.h"
30 #include "llvm/MC/MCStreamer.h"
31 #include "llvm/MC/MCSubtargetInfo.h"
32 #include "llvm/ADT/OwningPtr.h"
33 #include "llvm/Support/CommandLine.h"
34 #include "llvm/Support/FormattedStream.h"
35 #include "llvm/Support/ErrorHandling.h"
36 #include "llvm/Support/TargetRegistry.h"
37 using namespace llvm;
38
39 // Enable or disable FastISel. Both options are needed, because
40 // FastISel is enabled by default with -fast, and we wish to be
41 // able to enable or disable fast-isel independently from -O0.
42 static cl::opt<cl::boolOrDefault>
43 EnableFastISelOption("fast-isel", cl::Hidden,
44 cl::desc("Enable the \"fast\" instruction selector"));
45
46 static cl::opt<bool> ShowMCEncoding("show-mc-encoding", cl::Hidden,
47 cl::desc("Show encoding in .s output"));
48 static cl::opt<bool> ShowMCInst("show-mc-inst", cl::Hidden,
49 cl::desc("Show instruction structure in .s output"));
50
51 static cl::opt<cl::boolOrDefault>
52 AsmVerbose("asm-verbose", cl::desc("Add comments to directives."),
53 cl::init(cl::BOU_UNSET));
54
getVerboseAsm()55 static bool getVerboseAsm() {
56 switch (AsmVerbose) {
57 case cl::BOU_UNSET: return TargetMachine::getAsmVerbosityDefault();
58 case cl::BOU_TRUE: return true;
59 case cl::BOU_FALSE: return false;
60 }
61 llvm_unreachable("Invalid verbose asm state");
62 }
63
LLVMTargetMachine(const Target & T,StringRef Triple,StringRef CPU,StringRef FS,TargetOptions Options,Reloc::Model RM,CodeModel::Model CM,CodeGenOpt::Level OL)64 LLVMTargetMachine::LLVMTargetMachine(const Target &T, StringRef Triple,
65 StringRef CPU, StringRef FS,
66 TargetOptions Options,
67 Reloc::Model RM, CodeModel::Model CM,
68 CodeGenOpt::Level OL)
69 : TargetMachine(T, Triple, CPU, FS, Options) {
70 CodeGenInfo = T.createMCCodeGenInfo(Triple, RM, CM, OL);
71 AsmInfo = T.createMCAsmInfo(Triple);
72 // TargetSelect.h moved to a different directory between LLVM 2.9 and 3.0,
73 // and if the old one gets included then MCAsmInfo will be NULL and
74 // we'll crash later.
75 // Provide the user with a useful error message about what's wrong.
76 assert(AsmInfo && "MCAsmInfo not initialized."
77 "Make sure you include the correct TargetSelect.h"
78 "and that InitializeAllTargetMCs() is being invoked!");
79 }
80
81 /// Turn exception handling constructs into something the code generators can
82 /// handle.
addPassesToHandleExceptions(TargetMachine * TM,PassManagerBase & PM)83 static void addPassesToHandleExceptions(TargetMachine *TM,
84 PassManagerBase &PM) {
85 switch (TM->getMCAsmInfo()->getExceptionHandlingType()) {
86 case ExceptionHandling::SjLj:
87 // SjLj piggy-backs on dwarf for this bit. The cleanups done apply to both
88 // Dwarf EH prepare needs to be run after SjLj prepare. Otherwise,
89 // catch info can get misplaced when a selector ends up more than one block
90 // removed from the parent invoke(s). This could happen when a landing
91 // pad is shared by multiple invokes and is also a target of a normal
92 // edge from elsewhere.
93 PM.add(createSjLjEHPreparePass(TM->getTargetLowering()));
94 // FALLTHROUGH
95 case ExceptionHandling::DwarfCFI:
96 case ExceptionHandling::ARM:
97 case ExceptionHandling::Win64:
98 PM.add(createDwarfEHPass(TM));
99 break;
100 case ExceptionHandling::None:
101 PM.add(createLowerInvokePass(TM->getTargetLowering()));
102
103 // The lower invoke pass may create unreachable code. Remove it.
104 PM.add(createUnreachableBlockEliminationPass());
105 break;
106 }
107 }
108
109 /// addPassesToX helper drives creation and initialization of TargetPassConfig.
addPassesToGenerateCode(LLVMTargetMachine * TM,PassManagerBase & PM,bool DisableVerify)110 static MCContext *addPassesToGenerateCode(LLVMTargetMachine *TM,
111 PassManagerBase &PM,
112 bool DisableVerify) {
113 // Targets may override createPassConfig to provide a target-specific sublass.
114 TargetPassConfig *PassConfig = TM->createPassConfig(PM);
115
116 // Set PassConfig options provided by TargetMachine.
117 PassConfig->setDisableVerify(DisableVerify);
118
119 PM.add(PassConfig);
120
121 PassConfig->addIRPasses();
122
123 addPassesToHandleExceptions(TM, PM);
124
125 PassConfig->addISelPrepare();
126
127 // Install a MachineModuleInfo class, which is an immutable pass that holds
128 // all the per-module stuff we're generating, including MCContext.
129 MachineModuleInfo *MMI =
130 new MachineModuleInfo(*TM->getMCAsmInfo(), *TM->getRegisterInfo(),
131 &TM->getTargetLowering()->getObjFileLowering());
132 PM.add(MMI);
133 MCContext *Context = &MMI->getContext(); // Return the MCContext by-ref.
134
135 // Set up a MachineFunction for the rest of CodeGen to work on.
136 PM.add(new MachineFunctionAnalysis(*TM));
137
138 // Enable FastISel with -fast, but allow that to be overridden.
139 if (EnableFastISelOption == cl::BOU_TRUE ||
140 (TM->getOptLevel() == CodeGenOpt::None &&
141 EnableFastISelOption != cl::BOU_FALSE))
142 TM->setFastISel(true);
143
144 // Ask the target for an isel.
145 if (PassConfig->addInstSelector())
146 return NULL;
147
148 PassConfig->addMachinePasses();
149
150 PassConfig->setInitialized();
151
152 return Context;
153 }
154
addPassesToEmitFile(PassManagerBase & PM,formatted_raw_ostream & Out,CodeGenFileType FileType,bool DisableVerify)155 bool LLVMTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
156 formatted_raw_ostream &Out,
157 CodeGenFileType FileType,
158 bool DisableVerify) {
159 // Add common CodeGen passes.
160 MCContext *Context = addPassesToGenerateCode(this, PM, DisableVerify);
161 if (!Context)
162 return true;
163
164 if (hasMCSaveTempLabels())
165 Context->setAllowTemporaryLabels(false);
166
167 const MCAsmInfo &MAI = *getMCAsmInfo();
168 const MCSubtargetInfo &STI = getSubtarget<MCSubtargetInfo>();
169 OwningPtr<MCStreamer> AsmStreamer;
170
171 switch (FileType) {
172 case CGFT_AssemblyFile: {
173 MCInstPrinter *InstPrinter =
174 getTarget().createMCInstPrinter(MAI.getAssemblerDialect(), MAI,
175 *getInstrInfo(),
176 Context->getRegisterInfo(), STI);
177
178 // Create a code emitter if asked to show the encoding.
179 MCCodeEmitter *MCE = 0;
180 MCAsmBackend *MAB = 0;
181 if (ShowMCEncoding) {
182 const MCSubtargetInfo &STI = getSubtarget<MCSubtargetInfo>();
183 MCE = getTarget().createMCCodeEmitter(*getInstrInfo(), STI, *Context);
184 MAB = getTarget().createMCAsmBackend(getTargetTriple());
185 }
186
187 MCStreamer *S = getTarget().createAsmStreamer(*Context, Out,
188 getVerboseAsm(),
189 hasMCUseLoc(),
190 hasMCUseCFI(),
191 hasMCUseDwarfDirectory(),
192 InstPrinter,
193 MCE, MAB,
194 ShowMCInst);
195 AsmStreamer.reset(S);
196 break;
197 }
198 case CGFT_ObjectFile: {
199 // Create the code emitter for the target if it exists. If not, .o file
200 // emission fails.
201 MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(*getInstrInfo(), STI,
202 *Context);
203 MCAsmBackend *MAB = getTarget().createMCAsmBackend(getTargetTriple());
204 if (MCE == 0 || MAB == 0)
205 return true;
206
207 AsmStreamer.reset(getTarget().createMCObjectStreamer(getTargetTriple(),
208 *Context, *MAB, Out,
209 MCE, hasMCRelaxAll(),
210 hasMCNoExecStack()));
211 AsmStreamer.get()->InitSections();
212 break;
213 }
214 case CGFT_Null:
215 // The Null output is intended for use for performance analysis and testing,
216 // not real users.
217 AsmStreamer.reset(createNullStreamer(*Context));
218 break;
219 }
220
221 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
222 FunctionPass *Printer = getTarget().createAsmPrinter(*this, *AsmStreamer);
223 if (Printer == 0)
224 return true;
225
226 // If successful, createAsmPrinter took ownership of AsmStreamer.
227 AsmStreamer.take();
228
229 PM.add(Printer);
230
231 PM.add(createGCInfoDeleter());
232 return false;
233 }
234
235 /// addPassesToEmitMachineCode - Add passes to the specified pass manager to
236 /// get machine code emitted. This uses a JITCodeEmitter object to handle
237 /// actually outputting the machine code and resolving things like the address
238 /// of functions. This method should returns true if machine code emission is
239 /// not supported.
240 ///
addPassesToEmitMachineCode(PassManagerBase & PM,JITCodeEmitter & JCE,bool DisableVerify)241 bool LLVMTargetMachine::addPassesToEmitMachineCode(PassManagerBase &PM,
242 JITCodeEmitter &JCE,
243 bool DisableVerify) {
244 // Add common CodeGen passes.
245 MCContext *Context = addPassesToGenerateCode(this, PM, DisableVerify);
246 if (!Context)
247 return true;
248
249 addCodeEmitter(PM, JCE);
250 PM.add(createGCInfoDeleter());
251
252 return false; // success!
253 }
254
255 /// addPassesToEmitMC - Add passes to the specified pass manager to get
256 /// machine code emitted with the MCJIT. This method returns true if machine
257 /// code is not supported. It fills the MCContext Ctx pointer which can be
258 /// used to build custom MCStreamer.
259 ///
addPassesToEmitMC(PassManagerBase & PM,MCContext * & Ctx,raw_ostream & Out,bool DisableVerify)260 bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM,
261 MCContext *&Ctx,
262 raw_ostream &Out,
263 bool DisableVerify) {
264 // Add common CodeGen passes.
265 Ctx = addPassesToGenerateCode(this, PM, DisableVerify);
266 if (!Ctx)
267 return true;
268
269 if (hasMCSaveTempLabels())
270 Ctx->setAllowTemporaryLabels(false);
271
272 // Create the code emitter for the target if it exists. If not, .o file
273 // emission fails.
274 const MCSubtargetInfo &STI = getSubtarget<MCSubtargetInfo>();
275 MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(*getInstrInfo(),STI,
276 *Ctx);
277 MCAsmBackend *MAB = getTarget().createMCAsmBackend(getTargetTriple());
278 if (MCE == 0 || MAB == 0)
279 return true;
280
281 OwningPtr<MCStreamer> AsmStreamer;
282 AsmStreamer.reset(getTarget().createMCObjectStreamer(getTargetTriple(), *Ctx,
283 *MAB, Out, MCE,
284 hasMCRelaxAll(),
285 hasMCNoExecStack()));
286 AsmStreamer.get()->InitSections();
287
288 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
289 FunctionPass *Printer = getTarget().createAsmPrinter(*this, *AsmStreamer);
290 if (Printer == 0)
291 return true;
292
293 // If successful, createAsmPrinter took ownership of AsmStreamer.
294 AsmStreamer.take();
295
296 PM.add(Printer);
297
298 return false; // success!
299 }
300