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 "X86TargetAsmInfo.h"
15 #include "X86TargetMachine.h"
16 #include "X86.h"
17 #include "llvm/Module.h"
18 #include "llvm/PassManager.h"
19 #include "llvm/CodeGen/MachineFunction.h"
20 #include "llvm/CodeGen/Passes.h"
21 #include "llvm/Support/raw_ostream.h"
22 #include "llvm/Target/TargetOptions.h"
23 #include "llvm/Target/TargetMachineRegistry.h"
24 using namespace llvm;
25 
26 /// X86TargetMachineModule - Note that this is used on hosts that cannot link
27 /// in a library unless there are references into the library.  In particular,
28 /// it seems that it is not possible to get things to work on Win32 without
29 /// this.  Though it is unused, do not remove it.
30 extern "C" int X86TargetMachineModule;
31 int X86TargetMachineModule = 0;
32 
33 // Register the target.
34 static RegisterTarget<X86_32TargetMachine>
35 X("x86",    "32-bit X86: Pentium-Pro and above");
36 static RegisterTarget<X86_64TargetMachine>
37 Y("x86-64", "64-bit X86: EM64T and AMD64");
38 
39 // Force static initialization.
40 extern "C" void LLVMInitializeX86Target() { }
41 
42 // No assembler printer by default
43 X86TargetMachine::AsmPrinterCtorFn X86TargetMachine::AsmPrinterCtor = 0;
44 
45 const TargetAsmInfo *X86TargetMachine::createTargetAsmInfo() const {
46   if (Subtarget.isFlavorIntel())
47     return new X86WinTargetAsmInfo(*this);
48   else
49     switch (Subtarget.TargetType) {
50      case X86Subtarget::isDarwin:
51       return new X86DarwinTargetAsmInfo(*this);
52      case X86Subtarget::isELF:
53       return new X86ELFTargetAsmInfo(*this);
54      case X86Subtarget::isMingw:
55      case X86Subtarget::isCygwin:
56       return new X86COFFTargetAsmInfo(*this);
57      case X86Subtarget::isWindows:
58       return new X86WinTargetAsmInfo(*this);
59      default:
60       return new X86GenericTargetAsmInfo(*this);
61     }
62 }
63 
64 unsigned X86_32TargetMachine::getJITMatchQuality() {
65 #if defined(i386) || defined(__i386__) || defined(__x86__) || defined(_M_IX86)
66   return 10;
67 #endif
68   return 0;
69 }
70 
71 unsigned X86_64TargetMachine::getJITMatchQuality() {
72 #if defined(__x86_64__) || defined(_M_AMD64)
73   return 10;
74 #endif
75   return 0;
76 }
77 
78 unsigned X86_32TargetMachine::getModuleMatchQuality(const Module &M) {
79   // We strongly match "i[3-9]86-*".
80   std::string TT = M.getTargetTriple();
81   if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
82       TT[4] == '-' && TT[1] - '3' < 6)
83     return 20;
84   // If the target triple is something non-X86, we don't match.
85   if (!TT.empty()) return 0;
86 
87   if (M.getEndianness()  == Module::LittleEndian &&
88       M.getPointerSize() == Module::Pointer32)
89     return 10;                                   // Weak match
90   else if (M.getEndianness() != Module::AnyEndianness ||
91            M.getPointerSize() != Module::AnyPointerSize)
92     return 0;                                    // Match for some other target
93 
94   return getJITMatchQuality()/2;
95 }
96 
97 unsigned X86_64TargetMachine::getModuleMatchQuality(const Module &M) {
98   // We strongly match "x86_64-*".
99   std::string TT = M.getTargetTriple();
100   if (TT.size() >= 7 && TT[0] == 'x' && TT[1] == '8' && TT[2] == '6' &&
101       TT[3] == '_' && TT[4] == '6' && TT[5] == '4' && TT[6] == '-')
102     return 20;
103 
104   // We strongly match "amd64-*".
105   if (TT.size() >= 6 && TT[0] == 'a' && TT[1] == 'm' && TT[2] == 'd' &&
106       TT[3] == '6' && TT[4] == '4' && TT[5] == '-')
107     return 20;
108 
109   // If the target triple is something non-X86-64, we don't match.
110   if (!TT.empty()) return 0;
111 
112   if (M.getEndianness()  == Module::LittleEndian &&
113       M.getPointerSize() == Module::Pointer64)
114     return 10;                                   // Weak match
115   else if (M.getEndianness() != Module::AnyEndianness ||
116            M.getPointerSize() != Module::AnyPointerSize)
117     return 0;                                    // Match for some other target
118 
119   return getJITMatchQuality()/2;
120 }
121 
122 X86_32TargetMachine::X86_32TargetMachine(const Module &M, const std::string &FS)
123   : X86TargetMachine(M, FS, false) {
124 }
125 
126 
127 X86_64TargetMachine::X86_64TargetMachine(const Module &M, const std::string &FS)
128   : X86TargetMachine(M, FS, true) {
129 }
130 
131 /// X86TargetMachine ctor - Create an X86 target.
132 ///
133 X86TargetMachine::X86TargetMachine(const Module &M, const std::string &FS,
134                                    bool is64Bit)
135   : Subtarget(M, FS, is64Bit),
136     DataLayout(Subtarget.getDataLayout()),
137     FrameInfo(TargetFrameInfo::StackGrowsDown,
138               Subtarget.getStackAlignment(), Subtarget.is64Bit() ? -8 : -4),
139     InstrInfo(*this), JITInfo(*this), TLInfo(*this), ELFWriterInfo(*this) {
140   DefRelocModel = getRelocationModel();
141 
142   // If no relocation model was picked, default as appropriate for the target.
143   if (getRelocationModel() == Reloc::Default) {
144     if (!Subtarget.isTargetDarwin())
145       setRelocationModel(Reloc::Static);
146     else if (Subtarget.is64Bit())
147       setRelocationModel(Reloc::PIC_);
148     else
149       setRelocationModel(Reloc::DynamicNoPIC);
150   }
151 
152   assert(getRelocationModel() != Reloc::Default &&
153          "Relocation mode not picked");
154 
155   // If no code model is picked, default to small.
156   if (getCodeModel() == CodeModel::Default)
157     setCodeModel(CodeModel::Small);
158 
159   // ELF and X86-64 don't have a distinct DynamicNoPIC model.  DynamicNoPIC
160   // is defined as a model for code which may be used in static or dynamic
161   // executables but not necessarily a shared library. On X86-32 we just
162   // compile in -static mode, in x86-64 we use PIC.
163   if (getRelocationModel() == Reloc::DynamicNoPIC) {
164     if (is64Bit)
165       setRelocationModel(Reloc::PIC_);
166     else if (!Subtarget.isTargetDarwin())
167       setRelocationModel(Reloc::Static);
168   }
169 
170   // If we are on Darwin, disallow static relocation model in X86-64 mode, since
171   // the Mach-O file format doesn't support it.
172   if (getRelocationModel() == Reloc::Static &&
173       Subtarget.isTargetDarwin() &&
174       is64Bit)
175     setRelocationModel(Reloc::PIC_);
176 
177   // Determine the PICStyle based on the target selected.
178   if (getRelocationModel() == Reloc::Static) {
179     // Unless we're in PIC or DynamicNoPIC mode, set the PIC style to None.
180     Subtarget.setPICStyle(PICStyles::None);
181   } else if (Subtarget.isTargetCygMing()) {
182     Subtarget.setPICStyle(PICStyles::None);
183   } else if (Subtarget.isTargetDarwin()) {
184     if (Subtarget.is64Bit())
185       Subtarget.setPICStyle(PICStyles::RIPRel);
186     else
187       Subtarget.setPICStyle(PICStyles::Stub);
188   } else if (Subtarget.isTargetELF()) {
189     if (Subtarget.is64Bit())
190       Subtarget.setPICStyle(PICStyles::RIPRel);
191     else
192       Subtarget.setPICStyle(PICStyles::GOT);
193   }
194 
195   // Finally, if we have "none" as our PIC style, force to static mode.
196   if (Subtarget.getPICStyle() == PICStyles::None)
197     setRelocationModel(Reloc::Static);
198 }
199 
200 //===----------------------------------------------------------------------===//
201 // Pass Pipeline Configuration
202 //===----------------------------------------------------------------------===//
203 
204 bool X86TargetMachine::addInstSelector(PassManagerBase &PM,
205                                        CodeGenOpt::Level OptLevel) {
206   // Install an instruction selector.
207   PM.add(createX86ISelDag(*this, OptLevel));
208 
209   // If we're using Fast-ISel, clean up the mess.
210   if (EnableFastISel)
211     PM.add(createDeadMachineInstructionElimPass());
212 
213   // Install a pass to insert x87 FP_REG_KILL instructions, as needed.
214   PM.add(createX87FPRegKillInserterPass());
215 
216   return false;
217 }
218 
219 bool X86TargetMachine::addPreRegAlloc(PassManagerBase &PM,
220                                       CodeGenOpt::Level OptLevel) {
221   // Calculate and set max stack object alignment early, so we can decide
222   // whether we will need stack realignment (and thus FP).
223   PM.add(createX86MaxStackAlignmentCalculatorPass());
224   return false;  // -print-machineinstr shouldn't print after this.
225 }
226 
227 bool X86TargetMachine::addPostRegAlloc(PassManagerBase &PM,
228                                        CodeGenOpt::Level OptLevel) {
229   PM.add(createX86FloatingPointStackifierPass());
230   return true;  // -print-machineinstr should print after this.
231 }
232 
233 bool X86TargetMachine::addAssemblyEmitter(PassManagerBase &PM,
234                                           CodeGenOpt::Level OptLevel,
235                                           bool Verbose,
236                                           raw_ostream &Out) {
237   assert(AsmPrinterCtor && "AsmPrinter was not linked in");
238   if (AsmPrinterCtor)
239     PM.add(AsmPrinterCtor(Out, *this, Verbose));
240   return false;
241 }
242 
243 bool X86TargetMachine::addCodeEmitter(PassManagerBase &PM,
244                                       CodeGenOpt::Level OptLevel,
245                                       bool DumpAsm,
246                                       MachineCodeEmitter &MCE) {
247   // FIXME: Move this to TargetJITInfo!
248   // On Darwin, do not override 64-bit setting made in X86TargetMachine().
249   if (DefRelocModel == Reloc::Default &&
250       (!Subtarget.isTargetDarwin() || !Subtarget.is64Bit())) {
251     setRelocationModel(Reloc::Static);
252     Subtarget.setPICStyle(PICStyles::None);
253   }
254 
255   // 64-bit JIT places everything in the same buffer except external functions.
256   // On Darwin, use small code model but hack the call instruction for
257   // externals.  Elsewhere, do not assume globals are in the lower 4G.
258   if (Subtarget.is64Bit()) {
259     if (Subtarget.isTargetDarwin())
260       setCodeModel(CodeModel::Small);
261     else
262       setCodeModel(CodeModel::Large);
263   }
264 
265   PM.add(createX86CodeEmitterPass(*this, MCE));
266   if (DumpAsm) {
267     assert(AsmPrinterCtor && "AsmPrinter was not linked in");
268     if (AsmPrinterCtor)
269       PM.add(AsmPrinterCtor(errs(), *this, true));
270   }
271 
272   return false;
273 }
274 
275 bool X86TargetMachine::addCodeEmitter(PassManagerBase &PM,
276                                       CodeGenOpt::Level OptLevel,
277                                       bool DumpAsm,
278                                       JITCodeEmitter &JCE) {
279   // FIXME: Move this to TargetJITInfo!
280   // On Darwin, do not override 64-bit setting made in X86TargetMachine().
281   if (DefRelocModel == Reloc::Default &&
282       (!Subtarget.isTargetDarwin() || !Subtarget.is64Bit())) {
283     setRelocationModel(Reloc::Static);
284     Subtarget.setPICStyle(PICStyles::None);
285   }
286 
287   // 64-bit JIT places everything in the same buffer except external functions.
288   // On Darwin, use small code model but hack the call instruction for
289   // externals.  Elsewhere, do not assume globals are in the lower 4G.
290   if (Subtarget.is64Bit()) {
291     if (Subtarget.isTargetDarwin())
292       setCodeModel(CodeModel::Small);
293     else
294       setCodeModel(CodeModel::Large);
295   }
296 
297   PM.add(createX86JITCodeEmitterPass(*this, JCE));
298   if (DumpAsm) {
299     assert(AsmPrinterCtor && "AsmPrinter was not linked in");
300     if (AsmPrinterCtor)
301       PM.add(AsmPrinterCtor(errs(), *this, true));
302   }
303 
304   return false;
305 }
306 
307 bool X86TargetMachine::addCodeEmitter(PassManagerBase &PM,
308                                       CodeGenOpt::Level OptLevel,
309                                       bool DumpAsm,
310                                       ObjectCodeEmitter &OCE) {
311   PM.add(createX86ObjectCodeEmitterPass(*this, OCE));
312   if (DumpAsm) {
313     assert(AsmPrinterCtor && "AsmPrinter was not linked in");
314     if (AsmPrinterCtor)
315       PM.add(AsmPrinterCtor(errs(), *this, true));
316   }
317 
318   return false;
319 }
320 
321 bool X86TargetMachine::addSimpleCodeEmitter(PassManagerBase &PM,
322                                             CodeGenOpt::Level OptLevel,
323                                             bool DumpAsm,
324                                             MachineCodeEmitter &MCE) {
325   PM.add(createX86CodeEmitterPass(*this, MCE));
326   if (DumpAsm) {
327     assert(AsmPrinterCtor && "AsmPrinter was not linked in");
328     if (AsmPrinterCtor)
329       PM.add(AsmPrinterCtor(errs(), *this, true));
330   }
331 
332   return false;
333 }
334 
335 bool X86TargetMachine::addSimpleCodeEmitter(PassManagerBase &PM,
336                                             CodeGenOpt::Level OptLevel,
337                                             bool DumpAsm,
338                                             JITCodeEmitter &JCE) {
339   PM.add(createX86JITCodeEmitterPass(*this, JCE));
340   if (DumpAsm) {
341     assert(AsmPrinterCtor && "AsmPrinter was not linked in");
342     if (AsmPrinterCtor)
343       PM.add(AsmPrinterCtor(errs(), *this, true));
344   }
345 
346   return false;
347 }
348 
349 bool X86TargetMachine::addSimpleCodeEmitter(PassManagerBase &PM,
350                                             CodeGenOpt::Level OptLevel,
351                                             bool DumpAsm,
352                                             ObjectCodeEmitter &OCE) {
353   PM.add(createX86ObjectCodeEmitterPass(*this, OCE));
354   if (DumpAsm) {
355     assert(AsmPrinterCtor && "AsmPrinter was not linked in");
356     if (AsmPrinterCtor)
357       PM.add(AsmPrinterCtor(errs(), *this, true));
358   }
359 
360   return false;
361 }
362