1 //===-- X86MCTargetDesc.cpp - X86 Target Descriptions ---------------------===//
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 provides X86 specific target descriptions.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "X86MCTargetDesc.h"
15 #include "InstPrinter/X86ATTInstPrinter.h"
16 #include "InstPrinter/X86IntelInstPrinter.h"
17 #include "X86MCAsmInfo.h"
18 #include "llvm/ADT/Triple.h"
19 #include "llvm/MC/MCCodeGenInfo.h"
20 #include "llvm/MC/MCInstrAnalysis.h"
21 #include "llvm/MC/MCInstrInfo.h"
22 #include "llvm/MC/MCRegisterInfo.h"
23 #include "llvm/MC/MCStreamer.h"
24 #include "llvm/MC/MCSubtargetInfo.h"
25 #include "llvm/MC/MachineLocation.h"
26 #include "llvm/Support/ErrorHandling.h"
27 #include "llvm/Support/Host.h"
28 #include "llvm/Support/TargetRegistry.h"
29 
30 #if _MSC_VER
31 #include <intrin.h>
32 #endif
33 
34 using namespace llvm;
35 
36 #define GET_REGINFO_MC_DESC
37 #include "X86GenRegisterInfo.inc"
38 
39 #define GET_INSTRINFO_MC_DESC
40 #include "X86GenInstrInfo.inc"
41 
42 #define GET_SUBTARGETINFO_MC_DESC
43 #include "X86GenSubtargetInfo.inc"
44 
ParseX86Triple(StringRef TT)45 std::string X86_MC::ParseX86Triple(StringRef TT) {
46   Triple TheTriple(TT);
47   std::string FS;
48   if (TheTriple.getArch() == Triple::x86_64)
49     FS = "+64bit-mode,-32bit-mode,-16bit-mode";
50   else if (TheTriple.getEnvironment() != Triple::CODE16)
51     FS = "-64bit-mode,+32bit-mode,-16bit-mode";
52   else
53     FS = "-64bit-mode,-32bit-mode,+16bit-mode";
54 
55   return FS;
56 }
57 
getDwarfRegFlavour(Triple TT,bool isEH)58 unsigned X86_MC::getDwarfRegFlavour(Triple TT, bool isEH) {
59   if (TT.getArch() == Triple::x86_64)
60     return DWARFFlavour::X86_64;
61 
62   if (TT.isOSDarwin())
63     return isEH ? DWARFFlavour::X86_32_DarwinEH : DWARFFlavour::X86_32_Generic;
64   if (TT.isOSCygMing())
65     // Unsupported by now, just quick fallback
66     return DWARFFlavour::X86_32_Generic;
67   return DWARFFlavour::X86_32_Generic;
68 }
69 
InitLLVM2SEHRegisterMapping(MCRegisterInfo * MRI)70 void X86_MC::InitLLVM2SEHRegisterMapping(MCRegisterInfo *MRI) {
71   // FIXME: TableGen these.
72   for (unsigned Reg = X86::NoRegister+1; Reg < X86::NUM_TARGET_REGS; ++Reg) {
73     unsigned SEH = MRI->getEncodingValue(Reg);
74     MRI->mapLLVMRegToSEHReg(Reg, SEH);
75   }
76 }
77 
createX86MCSubtargetInfo(StringRef TT,StringRef CPU,StringRef FS)78 MCSubtargetInfo *X86_MC::createX86MCSubtargetInfo(StringRef TT, StringRef CPU,
79                                                   StringRef FS) {
80   std::string ArchFS = X86_MC::ParseX86Triple(TT);
81   if (!FS.empty()) {
82     if (!ArchFS.empty())
83       ArchFS = (Twine(ArchFS) + "," + FS).str();
84     else
85       ArchFS = FS;
86   }
87 
88   std::string CPUName = CPU;
89   if (CPUName.empty())
90     CPUName = "generic";
91 
92   MCSubtargetInfo *X = new MCSubtargetInfo();
93   InitX86MCSubtargetInfo(X, TT, CPUName, ArchFS);
94   return X;
95 }
96 
createX86MCInstrInfo()97 static MCInstrInfo *createX86MCInstrInfo() {
98   MCInstrInfo *X = new MCInstrInfo();
99   InitX86MCInstrInfo(X);
100   return X;
101 }
102 
createX86MCRegisterInfo(StringRef TT)103 static MCRegisterInfo *createX86MCRegisterInfo(StringRef TT) {
104   Triple TheTriple(TT);
105   unsigned RA = (TheTriple.getArch() == Triple::x86_64)
106     ? X86::RIP     // Should have dwarf #16.
107     : X86::EIP;    // Should have dwarf #8.
108 
109   MCRegisterInfo *X = new MCRegisterInfo();
110   InitX86MCRegisterInfo(X, RA,
111                         X86_MC::getDwarfRegFlavour(TheTriple, false),
112                         X86_MC::getDwarfRegFlavour(TheTriple, true),
113                         RA);
114   X86_MC::InitLLVM2SEHRegisterMapping(X);
115   return X;
116 }
117 
createX86MCAsmInfo(const MCRegisterInfo & MRI,StringRef TT)118 static MCAsmInfo *createX86MCAsmInfo(const MCRegisterInfo &MRI, StringRef TT) {
119   Triple TheTriple(TT);
120   bool is64Bit = TheTriple.getArch() == Triple::x86_64;
121 
122   MCAsmInfo *MAI;
123   if (TheTriple.isOSBinFormatMachO()) {
124     if (is64Bit)
125       MAI = new X86_64MCAsmInfoDarwin(TheTriple);
126     else
127       MAI = new X86MCAsmInfoDarwin(TheTriple);
128   } else if (TheTriple.isOSBinFormatELF()) {
129     // Force the use of an ELF container.
130     MAI = new X86ELFMCAsmInfo(TheTriple);
131   } else if (TheTriple.isWindowsMSVCEnvironment()) {
132     MAI = new X86MCAsmInfoMicrosoft(TheTriple);
133   } else if (TheTriple.isOSCygMing() ||
134              TheTriple.isWindowsItaniumEnvironment()) {
135     MAI = new X86MCAsmInfoGNUCOFF(TheTriple);
136   } else {
137     // The default is ELF.
138     MAI = new X86ELFMCAsmInfo(TheTriple);
139   }
140 
141   // Initialize initial frame state.
142   // Calculate amount of bytes used for return address storing
143   int stackGrowth = is64Bit ? -8 : -4;
144 
145   // Initial state of the frame pointer is esp+stackGrowth.
146   unsigned StackPtr = is64Bit ? X86::RSP : X86::ESP;
147   MCCFIInstruction Inst = MCCFIInstruction::createDefCfa(
148       nullptr, MRI.getDwarfRegNum(StackPtr, true), -stackGrowth);
149   MAI->addInitialFrameState(Inst);
150 
151   // Add return address to move list
152   unsigned InstPtr = is64Bit ? X86::RIP : X86::EIP;
153   MCCFIInstruction Inst2 = MCCFIInstruction::createOffset(
154       nullptr, MRI.getDwarfRegNum(InstPtr, true), stackGrowth);
155   MAI->addInitialFrameState(Inst2);
156 
157   return MAI;
158 }
159 
createX86MCCodeGenInfo(StringRef TT,Reloc::Model RM,CodeModel::Model CM,CodeGenOpt::Level OL)160 static MCCodeGenInfo *createX86MCCodeGenInfo(StringRef TT, Reloc::Model RM,
161                                              CodeModel::Model CM,
162                                              CodeGenOpt::Level OL) {
163   MCCodeGenInfo *X = new MCCodeGenInfo();
164 
165   Triple T(TT);
166   bool is64Bit = T.getArch() == Triple::x86_64;
167 
168   if (RM == Reloc::Default) {
169     // Darwin defaults to PIC in 64 bit mode and dynamic-no-pic in 32 bit mode.
170     // Win64 requires rip-rel addressing, thus we force it to PIC. Otherwise we
171     // use static relocation model by default.
172     if (T.isOSDarwin()) {
173       if (is64Bit)
174         RM = Reloc::PIC_;
175       else
176         RM = Reloc::DynamicNoPIC;
177     } else if (T.isOSWindows() && is64Bit)
178       RM = Reloc::PIC_;
179     else
180       RM = Reloc::Static;
181   }
182 
183   // ELF and X86-64 don't have a distinct DynamicNoPIC model.  DynamicNoPIC
184   // is defined as a model for code which may be used in static or dynamic
185   // executables but not necessarily a shared library. On X86-32 we just
186   // compile in -static mode, in x86-64 we use PIC.
187   if (RM == Reloc::DynamicNoPIC) {
188     if (is64Bit)
189       RM = Reloc::PIC_;
190     else if (!T.isOSDarwin())
191       RM = Reloc::Static;
192   }
193 
194   // If we are on Darwin, disallow static relocation model in X86-64 mode, since
195   // the Mach-O file format doesn't support it.
196   if (RM == Reloc::Static && T.isOSDarwin() && is64Bit)
197     RM = Reloc::PIC_;
198 
199   // For static codegen, if we're not already set, use Small codegen.
200   if (CM == CodeModel::Default)
201     CM = CodeModel::Small;
202   else if (CM == CodeModel::JITDefault)
203     // 64-bit JIT places everything in the same buffer except external funcs.
204     CM = is64Bit ? CodeModel::Large : CodeModel::Small;
205 
206   X->InitMCCodeGenInfo(RM, CM, OL);
207   return X;
208 }
209 
createX86MCInstPrinter(const Triple & T,unsigned SyntaxVariant,const MCAsmInfo & MAI,const MCInstrInfo & MII,const MCRegisterInfo & MRI)210 static MCInstPrinter *createX86MCInstPrinter(const Triple &T,
211                                              unsigned SyntaxVariant,
212                                              const MCAsmInfo &MAI,
213                                              const MCInstrInfo &MII,
214                                              const MCRegisterInfo &MRI) {
215   if (SyntaxVariant == 0)
216     return new X86ATTInstPrinter(MAI, MII, MRI);
217   if (SyntaxVariant == 1)
218     return new X86IntelInstPrinter(MAI, MII, MRI);
219   return nullptr;
220 }
221 
createX86MCRelocationInfo(StringRef TT,MCContext & Ctx)222 static MCRelocationInfo *createX86MCRelocationInfo(StringRef TT,
223                                                    MCContext &Ctx) {
224   Triple TheTriple(TT);
225   if (TheTriple.isOSBinFormatMachO() && TheTriple.getArch() == Triple::x86_64)
226     return createX86_64MachORelocationInfo(Ctx);
227   else if (TheTriple.isOSBinFormatELF())
228     return createX86_64ELFRelocationInfo(Ctx);
229   // Default to the stock relocation info.
230   return llvm::createMCRelocationInfo(TT, Ctx);
231 }
232 
createX86MCInstrAnalysis(const MCInstrInfo * Info)233 static MCInstrAnalysis *createX86MCInstrAnalysis(const MCInstrInfo *Info) {
234   return new MCInstrAnalysis(Info);
235 }
236 
237 // Force static initialization.
LLVMInitializeX86TargetMC()238 extern "C" void LLVMInitializeX86TargetMC() {
239   for (Target *T : {&TheX86_32Target, &TheX86_64Target}) {
240     // Register the MC asm info.
241     RegisterMCAsmInfoFn X(*T, createX86MCAsmInfo);
242 
243     // Register the MC codegen info.
244     RegisterMCCodeGenInfoFn Y(*T, createX86MCCodeGenInfo);
245 
246     // Register the MC instruction info.
247     TargetRegistry::RegisterMCInstrInfo(*T, createX86MCInstrInfo);
248 
249     // Register the MC register info.
250     TargetRegistry::RegisterMCRegInfo(*T, createX86MCRegisterInfo);
251 
252     // Register the MC subtarget info.
253     TargetRegistry::RegisterMCSubtargetInfo(*T,
254                                             X86_MC::createX86MCSubtargetInfo);
255 
256     // Register the MC instruction analyzer.
257     TargetRegistry::RegisterMCInstrAnalysis(*T, createX86MCInstrAnalysis);
258 
259     // Register the code emitter.
260     TargetRegistry::RegisterMCCodeEmitter(*T, createX86MCCodeEmitter);
261 
262     // Register the object streamer.
263     TargetRegistry::RegisterCOFFStreamer(*T, createX86WinCOFFStreamer);
264 
265     // Register the MCInstPrinter.
266     TargetRegistry::RegisterMCInstPrinter(*T, createX86MCInstPrinter);
267 
268     // Register the MC relocation info.
269     TargetRegistry::RegisterMCRelocationInfo(*T, createX86MCRelocationInfo);
270   }
271 
272   // Register the asm backend.
273   TargetRegistry::RegisterMCAsmBackend(TheX86_32Target,
274                                        createX86_32AsmBackend);
275   TargetRegistry::RegisterMCAsmBackend(TheX86_64Target,
276                                        createX86_64AsmBackend);
277 }
278