1 //===-- X86TargetMachine.cpp - Define TargetMachine for the X86 -----------===//
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 defines the X86 specific subclass of TargetMachine.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "X86MCAsmInfo.h"
15 #include "X86TargetMachine.h"
16 #include "X86.h"
17 #include "llvm/PassManager.h"
18 #include "llvm/CodeGen/MachineFunction.h"
19 #include "llvm/CodeGen/Passes.h"
20 #include "llvm/MC/MCCodeEmitter.h"
21 #include "llvm/MC/MCStreamer.h"
22 #include "llvm/Support/FormattedStream.h"
23 #include "llvm/Target/TargetOptions.h"
24 #include "llvm/Target/TargetRegistry.h"
25 using namespace llvm;
26 
27 static MCAsmInfo *createMCAsmInfo(const Target &T, StringRef TT) {
28   Triple TheTriple(TT);
29   switch (TheTriple.getOS()) {
30   case Triple::Darwin:
31     return new X86MCAsmInfoDarwin(TheTriple);
32   case Triple::MinGW32:
33   case Triple::Cygwin:
34   case Triple::Win32:
35     if (TheTriple.getEnvironment() == Triple::MachO)
36       return new X86MCAsmInfoDarwin(TheTriple);
37     else
38       return new X86MCAsmInfoCOFF(TheTriple);
39   default:
40     return new X86ELFMCAsmInfo(TheTriple);
41   }
42 }
43 
44 static MCStreamer *createMCStreamer(const Target &T, const std::string &TT,
45                                     MCContext &Ctx, TargetAsmBackend &TAB,
46                                     raw_ostream &_OS,
47                                     MCCodeEmitter *_Emitter,
48                                     bool RelaxAll,
49                                     bool NoExecStack) {
50   Triple TheTriple(TT);
51   switch (TheTriple.getOS()) {
52   case Triple::Darwin:
53     return createMachOStreamer(Ctx, TAB, _OS, _Emitter, RelaxAll);
54   case Triple::MinGW32:
55   case Triple::Cygwin:
56   case Triple::Win32:
57     if (TheTriple.getEnvironment() == Triple::MachO)
58       return createMachOStreamer(Ctx, TAB, _OS, _Emitter, RelaxAll);
59     else
60       return createWinCOFFStreamer(Ctx, TAB, *_Emitter, _OS, RelaxAll);
61   default:
62     return createELFStreamer(Ctx, TAB, _OS, _Emitter, RelaxAll, NoExecStack);
63   }
64 }
65 
66 extern "C" void LLVMInitializeX86Target() {
67   // Register the target.
68   RegisterTargetMachine<X86_32TargetMachine> X(TheX86_32Target);
69   RegisterTargetMachine<X86_64TargetMachine> Y(TheX86_64Target);
70 
71   // Register the target asm info.
72   RegisterAsmInfoFn A(TheX86_32Target, createMCAsmInfo);
73   RegisterAsmInfoFn B(TheX86_64Target, createMCAsmInfo);
74 
75   // Register the code emitter.
76   TargetRegistry::RegisterCodeEmitter(TheX86_32Target,
77                                       createX86_32MCCodeEmitter);
78   TargetRegistry::RegisterCodeEmitter(TheX86_64Target,
79                                       createX86_64MCCodeEmitter);
80 
81   // Register the asm backend.
82   TargetRegistry::RegisterAsmBackend(TheX86_32Target,
83                                      createX86_32AsmBackend);
84   TargetRegistry::RegisterAsmBackend(TheX86_64Target,
85                                      createX86_64AsmBackend);
86 
87   // Register the object streamer.
88   TargetRegistry::RegisterObjectStreamer(TheX86_32Target,
89                                          createMCStreamer);
90   TargetRegistry::RegisterObjectStreamer(TheX86_64Target,
91                                          createMCStreamer);
92 }
93 
94 
95 X86_32TargetMachine::X86_32TargetMachine(const Target &T, const std::string &TT,
96                                          const std::string &FS)
97   : X86TargetMachine(T, TT, FS, false),
98     DataLayout(getSubtargetImpl()->isTargetDarwin() ?
99                "e-p:32:32-f64:32:64-i64:32:64-f80:128:128-f128:128:128-n8:16:32" :
100                (getSubtargetImpl()->isTargetCygMing() ||
101                 getSubtargetImpl()->isTargetWindows()) ?
102                "e-p:32:32-f64:64:64-i64:64:64-f80:32:32-f128:128:128-n8:16:32" :
103                "e-p:32:32-f64:32:64-i64:32:64-f80:32:32-f128:128:128-n8:16:32"),
104     InstrInfo(*this),
105     TSInfo(*this),
106     TLInfo(*this),
107     JITInfo(*this) {
108 }
109 
110 
111 X86_64TargetMachine::X86_64TargetMachine(const Target &T, const std::string &TT,
112                                          const std::string &FS)
113   : X86TargetMachine(T, TT, FS, true),
114     DataLayout("e-p:64:64-s:64-f64:64:64-i64:64:64-f80:128:128-f128:128:128-n8:16:32:64"),
115     InstrInfo(*this),
116     TSInfo(*this),
117     TLInfo(*this),
118     JITInfo(*this) {
119 }
120 
121 /// X86TargetMachine ctor - Create an X86 target.
122 ///
123 X86TargetMachine::X86TargetMachine(const Target &T, const std::string &TT,
124                                    const std::string &FS, bool is64Bit)
125   : LLVMTargetMachine(T, TT),
126     Subtarget(TT, FS, is64Bit),
127     FrameLowering(*this, Subtarget),
128     ELFWriterInfo(is64Bit, true) {
129   DefRelocModel = getRelocationModel();
130 
131   // If no relocation model was picked, default as appropriate for the target.
132   if (getRelocationModel() == Reloc::Default) {
133     // Darwin defaults to PIC in 64 bit mode and dynamic-no-pic in 32 bit mode.
134     // Win64 requires rip-rel addressing, thus we force it to PIC. Otherwise we
135     // use static relocation model by default.
136     if (Subtarget.isTargetDarwin()) {
137       if (Subtarget.is64Bit())
138         setRelocationModel(Reloc::PIC_);
139       else
140         setRelocationModel(Reloc::DynamicNoPIC);
141     } else if (Subtarget.isTargetWin64())
142       setRelocationModel(Reloc::PIC_);
143     else
144       setRelocationModel(Reloc::Static);
145   }
146 
147   assert(getRelocationModel() != Reloc::Default &&
148          "Relocation mode not picked");
149 
150   // ELF and X86-64 don't have a distinct DynamicNoPIC model.  DynamicNoPIC
151   // is defined as a model for code which may be used in static or dynamic
152   // executables but not necessarily a shared library. On X86-32 we just
153   // compile in -static mode, in x86-64 we use PIC.
154   if (getRelocationModel() == Reloc::DynamicNoPIC) {
155     if (is64Bit)
156       setRelocationModel(Reloc::PIC_);
157     else if (!Subtarget.isTargetDarwin())
158       setRelocationModel(Reloc::Static);
159   }
160 
161   // If we are on Darwin, disallow static relocation model in X86-64 mode, since
162   // the Mach-O file format doesn't support it.
163   if (getRelocationModel() == Reloc::Static &&
164       Subtarget.isTargetDarwin() &&
165       is64Bit)
166     setRelocationModel(Reloc::PIC_);
167 
168   // Determine the PICStyle based on the target selected.
169   if (getRelocationModel() == Reloc::Static) {
170     // Unless we're in PIC or DynamicNoPIC mode, set the PIC style to None.
171     Subtarget.setPICStyle(PICStyles::None);
172   } else if (Subtarget.is64Bit()) {
173     // PIC in 64 bit mode is always rip-rel.
174     Subtarget.setPICStyle(PICStyles::RIPRel);
175   } else if (Subtarget.isTargetCygMing()) {
176     Subtarget.setPICStyle(PICStyles::None);
177   } else if (Subtarget.isTargetDarwin()) {
178     if (getRelocationModel() == Reloc::PIC_)
179       Subtarget.setPICStyle(PICStyles::StubPIC);
180     else {
181       assert(getRelocationModel() == Reloc::DynamicNoPIC);
182       Subtarget.setPICStyle(PICStyles::StubDynamicNoPIC);
183     }
184   } else if (Subtarget.isTargetELF()) {
185     Subtarget.setPICStyle(PICStyles::GOT);
186   }
187 
188   // Finally, if we have "none" as our PIC style, force to static mode.
189   if (Subtarget.getPICStyle() == PICStyles::None)
190     setRelocationModel(Reloc::Static);
191 }
192 
193 //===----------------------------------------------------------------------===//
194 // Pass Pipeline Configuration
195 //===----------------------------------------------------------------------===//
196 
197 bool X86TargetMachine::addInstSelector(PassManagerBase &PM,
198                                        CodeGenOpt::Level OptLevel) {
199   // Install an instruction selector.
200   PM.add(createX86ISelDag(*this, OptLevel));
201 
202   // For 32-bit, prepend instructions to set the "global base reg" for PIC.
203   if (!Subtarget.is64Bit())
204     PM.add(createGlobalBaseRegPass());
205 
206   return false;
207 }
208 
209 bool X86TargetMachine::addPreRegAlloc(PassManagerBase &PM,
210                                       CodeGenOpt::Level OptLevel) {
211   PM.add(createX86MaxStackAlignmentHeuristicPass());
212   return false;  // -print-machineinstr shouldn't print after this.
213 }
214 
215 bool X86TargetMachine::addPostRegAlloc(PassManagerBase &PM,
216                                        CodeGenOpt::Level OptLevel) {
217   PM.add(createX86FloatingPointStackifierPass());
218   return true;  // -print-machineinstr should print after this.
219 }
220 
221 bool X86TargetMachine::addPreEmitPass(PassManagerBase &PM,
222                                       CodeGenOpt::Level OptLevel) {
223   if (OptLevel != CodeGenOpt::None && Subtarget.hasSSE2()) {
224     PM.add(createSSEDomainFixPass());
225     return true;
226   }
227   return false;
228 }
229 
230 bool X86TargetMachine::addCodeEmitter(PassManagerBase &PM,
231                                       CodeGenOpt::Level OptLevel,
232                                       JITCodeEmitter &JCE) {
233   // FIXME: Move this to TargetJITInfo!
234   // On Darwin, do not override 64-bit setting made in X86TargetMachine().
235   if (DefRelocModel == Reloc::Default &&
236       (!Subtarget.isTargetDarwin() || !Subtarget.is64Bit())) {
237     setRelocationModel(Reloc::Static);
238     Subtarget.setPICStyle(PICStyles::None);
239   }
240 
241 
242   PM.add(createX86JITCodeEmitterPass(*this, JCE));
243 
244   return false;
245 }
246 
247 void X86TargetMachine::setCodeModelForStatic() {
248 
249     if (getCodeModel() != CodeModel::Default) return;
250 
251     // For static codegen, if we're not already set, use Small codegen.
252     setCodeModel(CodeModel::Small);
253 }
254 
255 
256 void X86TargetMachine::setCodeModelForJIT() {
257 
258   if (getCodeModel() != CodeModel::Default) return;
259 
260   // 64-bit JIT places everything in the same buffer except external functions.
261   if (Subtarget.is64Bit())
262     setCodeModel(CodeModel::Large);
263   else
264     setCodeModel(CodeModel::Small);
265 }
266