X86TargetMachine.cpp revision 207618 
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/Support/FormattedStream.h"
21#include "llvm/Target/TargetOptions.h"
22#include "llvm/Target/TargetRegistry.h"
23#include "llvm/Support/CommandLine.h"
24
25using namespace llvm;
26
27static cl::opt<bool> DisableSSEDomain("disable-sse-domain",
28    cl::init(false), cl::Hidden,
29    cl::desc("Disable SSE Domain Fixing"));
30
31static MCAsmInfo *createMCAsmInfo(const Target &T, StringRef TT) {
32  Triple TheTriple(TT);
33  switch (TheTriple.getOS()) {
34  case Triple::Darwin:
35    return new X86MCAsmInfoDarwin(TheTriple);
36  case Triple::MinGW32:
37  case Triple::MinGW64:
38  case Triple::Cygwin:
39  case Triple::Win32:
40    return new X86MCAsmInfoCOFF(TheTriple);
41  default:
42    return new X86ELFMCAsmInfo(TheTriple);
43  }
44}
45
46extern "C" void LLVMInitializeX86Target() {
47  // Register the target.
48  RegisterTargetMachine<X86_32TargetMachine> X(TheX86_32Target);
49  RegisterTargetMachine<X86_64TargetMachine> Y(TheX86_64Target);
50
51  // Register the target asm info.
52  RegisterAsmInfoFn A(TheX86_32Target, createMCAsmInfo);
53  RegisterAsmInfoFn B(TheX86_64Target, createMCAsmInfo);
54
55  // Register the code emitter.
56  TargetRegistry::RegisterCodeEmitter(TheX86_32Target,
57                                      createX86_32MCCodeEmitter);
58  TargetRegistry::RegisterCodeEmitter(TheX86_64Target,
59                                      createX86_64MCCodeEmitter);
60
61  // Register the asm backend.
62  TargetRegistry::RegisterAsmBackend(TheX86_32Target,
63                                     createX86_32AsmBackend);
64  TargetRegistry::RegisterAsmBackend(TheX86_64Target,
65                                     createX86_64AsmBackend);
66}
67
68
69X86_32TargetMachine::X86_32TargetMachine(const Target &T, const std::string &TT,
70                                         const std::string &FS)
71  : X86TargetMachine(T, TT, FS, false) {
72}
73
74
75X86_64TargetMachine::X86_64TargetMachine(const Target &T, const std::string &TT,
76                                         const std::string &FS)
77  : X86TargetMachine(T, TT, FS, true) {
78}
79
80/// X86TargetMachine ctor - Create an X86 target.
81///
82X86TargetMachine::X86TargetMachine(const Target &T, const std::string &TT,
83                                   const std::string &FS, bool is64Bit)
84  : LLVMTargetMachine(T, TT),
85    Subtarget(TT, FS, is64Bit),
86    DataLayout(Subtarget.getDataLayout()),
87    FrameInfo(TargetFrameInfo::StackGrowsDown,
88              Subtarget.getStackAlignment(),
89              (Subtarget.isTargetWin64() ? -40 :
90               (Subtarget.is64Bit() ? -8 : -4))),
91    InstrInfo(*this), JITInfo(*this), TLInfo(*this), ELFWriterInfo(*this) {
92  DefRelocModel = getRelocationModel();
93
94  // If no relocation model was picked, default as appropriate for the target.
95  if (getRelocationModel() == Reloc::Default) {
96    if (!Subtarget.isTargetDarwin())
97      setRelocationModel(Reloc::Static);
98    else if (Subtarget.is64Bit())
99      setRelocationModel(Reloc::PIC_);
100    else
101      setRelocationModel(Reloc::DynamicNoPIC);
102  }
103
104  assert(getRelocationModel() != Reloc::Default &&
105         "Relocation mode not picked");
106
107  // ELF and X86-64 don't have a distinct DynamicNoPIC model.  DynamicNoPIC
108  // is defined as a model for code which may be used in static or dynamic
109  // executables but not necessarily a shared library. On X86-32 we just
110  // compile in -static mode, in x86-64 we use PIC.
111  if (getRelocationModel() == Reloc::DynamicNoPIC) {
112    if (is64Bit)
113      setRelocationModel(Reloc::PIC_);
114    else if (!Subtarget.isTargetDarwin())
115      setRelocationModel(Reloc::Static);
116  }
117
118  // If we are on Darwin, disallow static relocation model in X86-64 mode, since
119  // the Mach-O file format doesn't support it.
120  if (getRelocationModel() == Reloc::Static &&
121      Subtarget.isTargetDarwin() &&
122      is64Bit)
123    setRelocationModel(Reloc::PIC_);
124
125  // Determine the PICStyle based on the target selected.
126  if (getRelocationModel() == Reloc::Static) {
127    // Unless we're in PIC or DynamicNoPIC mode, set the PIC style to None.
128    Subtarget.setPICStyle(PICStyles::None);
129  } else if (Subtarget.isTargetCygMing()) {
130    Subtarget.setPICStyle(PICStyles::None);
131  } else if (Subtarget.isTargetDarwin()) {
132    if (Subtarget.is64Bit())
133      Subtarget.setPICStyle(PICStyles::RIPRel);
134    else if (getRelocationModel() == Reloc::PIC_)
135      Subtarget.setPICStyle(PICStyles::StubPIC);
136    else {
137      assert(getRelocationModel() == Reloc::DynamicNoPIC);
138      Subtarget.setPICStyle(PICStyles::StubDynamicNoPIC);
139    }
140  } else if (Subtarget.isTargetELF()) {
141    if (Subtarget.is64Bit())
142      Subtarget.setPICStyle(PICStyles::RIPRel);
143    else
144      Subtarget.setPICStyle(PICStyles::GOT);
145  }
146
147  // Finally, if we have "none" as our PIC style, force to static mode.
148  if (Subtarget.getPICStyle() == PICStyles::None)
149    setRelocationModel(Reloc::Static);
150}
151
152//===----------------------------------------------------------------------===//
153// Pass Pipeline Configuration
154//===----------------------------------------------------------------------===//
155
156bool X86TargetMachine::addInstSelector(PassManagerBase &PM,
157                                       CodeGenOpt::Level OptLevel) {
158  // Install an instruction selector.
159  PM.add(createX86ISelDag(*this, OptLevel));
160
161  // Install a pass to insert x87 FP_REG_KILL instructions, as needed.
162  PM.add(createX87FPRegKillInserterPass());
163
164  return false;
165}
166
167bool X86TargetMachine::addPreRegAlloc(PassManagerBase &PM,
168                                      CodeGenOpt::Level OptLevel) {
169  PM.add(createX86MaxStackAlignmentHeuristicPass());
170  return false;  // -print-machineinstr shouldn't print after this.
171}
172
173bool X86TargetMachine::addPostRegAlloc(PassManagerBase &PM,
174                                       CodeGenOpt::Level OptLevel) {
175  PM.add(createX86FloatingPointStackifierPass());
176  return true;  // -print-machineinstr should print after this.
177}
178
179bool X86TargetMachine::addPreEmitPass(PassManagerBase &PM,
180                                      CodeGenOpt::Level OptLevel) {
181  if (OptLevel != CodeGenOpt::None && Subtarget.hasSSE2() &&
182      !DisableSSEDomain) {
183    PM.add(createSSEDomainFixPass());
184    return true;
185  }
186  return false;
187}
188
189bool X86TargetMachine::addCodeEmitter(PassManagerBase &PM,
190                                      CodeGenOpt::Level OptLevel,
191                                      JITCodeEmitter &JCE) {
192  // FIXME: Move this to TargetJITInfo!
193  // On Darwin, do not override 64-bit setting made in X86TargetMachine().
194  if (DefRelocModel == Reloc::Default &&
195      (!Subtarget.isTargetDarwin() || !Subtarget.is64Bit())) {
196    setRelocationModel(Reloc::Static);
197    Subtarget.setPICStyle(PICStyles::None);
198  }
199
200
201  PM.add(createX86JITCodeEmitterPass(*this, JCE));
202
203  return false;
204}
205
206void X86TargetMachine::setCodeModelForStatic() {
207
208    if (getCodeModel() != CodeModel::Default) return;
209
210    // For static codegen, if we're not already set, use Small codegen.
211    setCodeModel(CodeModel::Small);
212}
213
214
215void X86TargetMachine::setCodeModelForJIT() {
216
217  if (getCodeModel() != CodeModel::Default) return;
218
219  // 64-bit JIT places everything in the same buffer except external functions.
220  if (Subtarget.is64Bit())
221    setCodeModel(CodeModel::Large);
222  else
223    setCodeModel(CodeModel::Small);
224}
225