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"
38using 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.
43static cl::opt<cl::boolOrDefault>
44EnableFastISelOption("fast-isel", cl::Hidden,
45  cl::desc("Enable the \"fast\" instruction selector"));
46
47static cl::opt<bool> ShowMCEncoding("show-mc-encoding", cl::Hidden,
48    cl::desc("Show encoding in .s output"));
49static cl::opt<bool> ShowMCInst("show-mc-inst", cl::Hidden,
50    cl::desc("Show instruction structure in .s output"));
51
52static cl::opt<cl::boolOrDefault>
53AsmVerbose("asm-verbose", cl::desc("Add comments to directives."),
54           cl::init(cl::BOU_UNSET));
55
56static 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
65LLVMTargetMachine::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.
83static 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
131bool 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///
232bool 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///
251bool 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