1 //===-- X86TargetMachine.cpp - Define TargetMachine for the X86 -----------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the X86 specific subclass of TargetMachine.
12 //===----------------------------------------------------------------------===//
14 #include "MCTargetDesc/X86MCTargetDesc.h"
16 #include "X86CallLowering.h"
17 #include "X86LegalizerInfo.h"
18 #ifdef LLVM_BUILD_GLOBAL_ISEL
19 #include "X86RegisterBankInfo.h"
21 #include "X86MacroFusion.h"
22 #include "X86Subtarget.h"
23 #include "X86TargetMachine.h"
24 #include "X86TargetObjectFile.h"
25 #include "X86TargetTransformInfo.h"
26 #include "llvm/ADT/Optional.h"
27 #include "llvm/ADT/SmallString.h"
28 #include "llvm/ADT/STLExtras.h"
29 #include "llvm/ADT/StringRef.h"
30 #include "llvm/ADT/Triple.h"
31 #include "llvm/Analysis/TargetTransformInfo.h"
32 #include "llvm/CodeGen/ExecutionDepsFix.h"
33 #include "llvm/CodeGen/GlobalISel/CallLowering.h"
34 #include "llvm/CodeGen/GlobalISel/GISelAccessor.h"
35 #include "llvm/CodeGen/GlobalISel/IRTranslator.h"
36 #include "llvm/CodeGen/GlobalISel/InstructionSelect.h"
37 #include "llvm/CodeGen/GlobalISel/Legalizer.h"
38 #include "llvm/CodeGen/GlobalISel/RegBankSelect.h"
39 #include "llvm/CodeGen/MachineScheduler.h"
40 #include "llvm/CodeGen/Passes.h"
41 #include "llvm/CodeGen/TargetPassConfig.h"
42 #include "llvm/IR/Attributes.h"
43 #include "llvm/IR/DataLayout.h"
44 #include "llvm/IR/Function.h"
45 #include "llvm/Pass.h"
46 #include "llvm/Support/CodeGen.h"
47 #include "llvm/Support/CommandLine.h"
48 #include "llvm/Support/ErrorHandling.h"
49 #include "llvm/Support/TargetRegistry.h"
50 #include "llvm/Target/TargetLoweringObjectFile.h"
51 #include "llvm/Target/TargetOptions.h"
57 static cl::opt<bool> EnableMachineCombinerPass("x86-machine-combiner",
58 cl::desc("Enable the machine combiner pass"),
59 cl::init(true), cl::Hidden);
63 void initializeWinEHStatePassPass(PassRegistry &);
64 void initializeX86ExecutionDepsFixPass(PassRegistry &);
66 } // end namespace llvm
68 extern "C" void LLVMInitializeX86Target() {
69 // Register the target.
70 RegisterTargetMachine<X86TargetMachine> X(getTheX86_32Target());
71 RegisterTargetMachine<X86TargetMachine> Y(getTheX86_64Target());
73 PassRegistry &PR = *PassRegistry::getPassRegistry();
74 initializeGlobalISel(PR);
75 initializeWinEHStatePassPass(PR);
76 initializeFixupBWInstPassPass(PR);
77 initializeEvexToVexInstPassPass(PR);
78 initializeX86ExecutionDepsFixPass(PR);
81 static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
82 if (TT.isOSBinFormatMachO()) {
83 if (TT.getArch() == Triple::x86_64)
84 return llvm::make_unique<X86_64MachoTargetObjectFile>();
85 return llvm::make_unique<TargetLoweringObjectFileMachO>();
89 return llvm::make_unique<X86FreeBSDTargetObjectFile>();
90 if (TT.isOSLinux() || TT.isOSNaCl())
91 return llvm::make_unique<X86LinuxNaClTargetObjectFile>();
93 return llvm::make_unique<X86FuchsiaTargetObjectFile>();
94 if (TT.isOSBinFormatELF())
95 return llvm::make_unique<X86ELFTargetObjectFile>();
96 if (TT.isKnownWindowsMSVCEnvironment() || TT.isWindowsCoreCLREnvironment())
97 return llvm::make_unique<X86WindowsTargetObjectFile>();
98 if (TT.isOSBinFormatCOFF())
99 return llvm::make_unique<TargetLoweringObjectFileCOFF>();
100 llvm_unreachable("unknown subtarget type");
103 static std::string computeDataLayout(const Triple &TT) {
104 // X86 is little endian
105 std::string Ret = "e";
107 Ret += DataLayout::getManglingComponent(TT);
108 // X86 and x32 have 32 bit pointers.
109 if ((TT.isArch64Bit() &&
110 (TT.getEnvironment() == Triple::GNUX32 || TT.isOSNaCl())) ||
114 // Some ABIs align 64 bit integers and doubles to 64 bits, others to 32.
115 if (TT.isArch64Bit() || TT.isOSWindows() || TT.isOSNaCl())
117 else if (TT.isOSIAMCU())
118 Ret += "-i64:32-f64:32";
122 // Some ABIs align long double to 128 bits, others to 32.
123 if (TT.isOSNaCl() || TT.isOSIAMCU())
125 else if (TT.isArch64Bit() || TT.isOSDarwin())
133 // The registers can hold 8, 16, 32 or, in x86-64, 64 bits.
134 if (TT.isArch64Bit())
135 Ret += "-n8:16:32:64";
139 // The stack is aligned to 32 bits on some ABIs and 128 bits on others.
140 if ((!TT.isArch64Bit() && TT.isOSWindows()) || TT.isOSIAMCU())
141 Ret += "-a:0:32-S32";
148 static Reloc::Model getEffectiveRelocModel(const Triple &TT,
149 Optional<Reloc::Model> RM) {
150 bool is64Bit = TT.getArch() == Triple::x86_64;
151 if (!RM.hasValue()) {
152 // Darwin defaults to PIC in 64 bit mode and dynamic-no-pic in 32 bit mode.
153 // Win64 requires rip-rel addressing, thus we force it to PIC. Otherwise we
154 // use static relocation model by default.
155 if (TT.isOSDarwin()) {
158 return Reloc::DynamicNoPIC;
160 if (TT.isOSWindows() && is64Bit)
162 return Reloc::Static;
165 // ELF and X86-64 don't have a distinct DynamicNoPIC model. DynamicNoPIC
166 // is defined as a model for code which may be used in static or dynamic
167 // executables but not necessarily a shared library. On X86-32 we just
168 // compile in -static mode, in x86-64 we use PIC.
169 if (*RM == Reloc::DynamicNoPIC) {
172 if (!TT.isOSDarwin())
173 return Reloc::Static;
176 // If we are on Darwin, disallow static relocation model in X86-64 mode, since
177 // the Mach-O file format doesn't support it.
178 if (*RM == Reloc::Static && TT.isOSDarwin() && is64Bit)
184 /// Create an X86 target.
186 X86TargetMachine::X86TargetMachine(const Target &T, const Triple &TT,
187 StringRef CPU, StringRef FS,
188 const TargetOptions &Options,
189 Optional<Reloc::Model> RM,
190 CodeModel::Model CM, CodeGenOpt::Level OL)
191 : LLVMTargetMachine(T, computeDataLayout(TT), TT, CPU, FS, Options,
192 getEffectiveRelocModel(TT, RM), CM, OL),
193 TLOF(createTLOF(getTargetTriple())) {
194 // Windows stack unwinder gets confused when execution flow "falls through"
195 // after a call to 'noreturn' function.
196 // To prevent that, we emit a trap for 'unreachable' IR instructions.
197 // (which on X86, happens to be the 'ud2' instruction)
198 // On PS4, the "return address" of a 'noreturn' call must still be within
199 // the calling function, and TrapUnreachable is an easy way to get that.
200 // The check here for 64-bit windows is a bit icky, but as we're unlikely
201 // to ever want to mix 32 and 64-bit windows code in a single module
202 // this should be fine.
203 if ((TT.isOSWindows() && TT.getArch() == Triple::x86_64) || TT.isPS4())
204 this->Options.TrapUnreachable = true;
209 X86TargetMachine::~X86TargetMachine() = default;
211 #ifdef LLVM_BUILD_GLOBAL_ISEL
214 struct X86GISelActualAccessor : public GISelAccessor {
215 std::unique_ptr<CallLowering> CallLoweringInfo;
216 std::unique_ptr<LegalizerInfo> Legalizer;
217 std::unique_ptr<RegisterBankInfo> RegBankInfo;
218 std::unique_ptr<InstructionSelector> InstSelector;
220 const CallLowering *getCallLowering() const override {
221 return CallLoweringInfo.get();
224 const InstructionSelector *getInstructionSelector() const override {
225 return InstSelector.get();
228 const LegalizerInfo *getLegalizerInfo() const override {
229 return Legalizer.get();
232 const RegisterBankInfo *getRegBankInfo() const override {
233 return RegBankInfo.get();
237 } // end anonymous namespace
241 X86TargetMachine::getSubtargetImpl(const Function &F) const {
242 Attribute CPUAttr = F.getFnAttribute("target-cpu");
243 Attribute FSAttr = F.getFnAttribute("target-features");
245 StringRef CPU = !CPUAttr.hasAttribute(Attribute::None)
246 ? CPUAttr.getValueAsString()
247 : (StringRef)TargetCPU;
248 StringRef FS = !FSAttr.hasAttribute(Attribute::None)
249 ? FSAttr.getValueAsString()
250 : (StringRef)TargetFS;
252 SmallString<512> Key;
253 Key.reserve(CPU.size() + FS.size());
257 // FIXME: This is related to the code below to reset the target options,
258 // we need to know whether or not the soft float flag is set on the
259 // function before we can generate a subtarget. We also need to use
260 // it as a key for the subtarget since that can be the only difference
261 // between two functions.
263 F.getFnAttribute("use-soft-float").getValueAsString() == "true";
264 // If the soft float attribute is set on the function turn on the soft float
265 // subtarget feature.
267 Key += FS.empty() ? "+soft-float" : ",+soft-float";
269 FS = Key.substr(CPU.size());
271 bool OptForSize = F.optForSize();
272 bool OptForMinSize = F.optForMinSize();
274 Key += std::string(OptForSize ? "+" : "-") + "optforsize";
275 Key += std::string(OptForMinSize ? "+" : "-") + "optforminsize";
277 auto &I = SubtargetMap[Key];
279 // This needs to be done before we create a new subtarget since any
280 // creation will depend on the TM and the code generation flags on the
281 // function that reside in TargetOptions.
282 resetTargetOptions(F);
283 I = llvm::make_unique<X86Subtarget>(TargetTriple, CPU, FS, *this,
284 Options.StackAlignmentOverride,
285 OptForSize, OptForMinSize);
286 #ifndef LLVM_BUILD_GLOBAL_ISEL
287 GISelAccessor *GISel = new GISelAccessor();
289 X86GISelActualAccessor *GISel = new X86GISelActualAccessor();
291 GISel->CallLoweringInfo.reset(new X86CallLowering(*I->getTargetLowering()));
292 GISel->Legalizer.reset(new X86LegalizerInfo(*I, *this));
294 auto *RBI = new X86RegisterBankInfo(*I->getRegisterInfo());
295 GISel->RegBankInfo.reset(RBI);
296 GISel->InstSelector.reset(createX86InstructionSelector(
299 I->setGISelAccessor(*GISel);
304 //===----------------------------------------------------------------------===//
305 // Command line options for x86
306 //===----------------------------------------------------------------------===//
308 UseVZeroUpper("x86-use-vzeroupper", cl::Hidden,
309 cl::desc("Minimize AVX to SSE transition penalty"),
312 //===----------------------------------------------------------------------===//
314 //===----------------------------------------------------------------------===//
316 TargetIRAnalysis X86TargetMachine::getTargetIRAnalysis() {
317 return TargetIRAnalysis([this](const Function &F) {
318 return TargetTransformInfo(X86TTIImpl(this, F));
322 //===----------------------------------------------------------------------===//
323 // Pass Pipeline Configuration
324 //===----------------------------------------------------------------------===//
328 /// X86 Code Generator Pass Configuration Options.
329 class X86PassConfig : public TargetPassConfig {
331 X86PassConfig(X86TargetMachine *TM, PassManagerBase &PM)
332 : TargetPassConfig(TM, PM) {}
334 X86TargetMachine &getX86TargetMachine() const {
335 return getTM<X86TargetMachine>();
339 createMachineScheduler(MachineSchedContext *C) const override {
340 ScheduleDAGMILive *DAG = createGenericSchedLive(C);
341 DAG->addMutation(createX86MacroFusionDAGMutation());
345 void addIRPasses() override;
346 bool addInstSelector() override;
347 #ifdef LLVM_BUILD_GLOBAL_ISEL
348 bool addIRTranslator() override;
349 bool addLegalizeMachineIR() override;
350 bool addRegBankSelect() override;
351 bool addGlobalInstructionSelect() override;
353 bool addILPOpts() override;
354 bool addPreISel() override;
355 void addPreRegAlloc() override;
356 void addPostRegAlloc() override;
357 void addPreEmitPass() override;
358 void addPreSched2() override;
361 class X86ExecutionDepsFix : public ExecutionDepsFix {
364 X86ExecutionDepsFix() : ExecutionDepsFix(ID, X86::VR128XRegClass) {}
365 StringRef getPassName() const override {
366 return "X86 Execution Dependency Fix";
369 char X86ExecutionDepsFix::ID;
371 } // end anonymous namespace
373 INITIALIZE_PASS(X86ExecutionDepsFix, "x86-execution-deps-fix",
374 "X86 Execution Dependency Fix", false, false)
376 TargetPassConfig *X86TargetMachine::createPassConfig(PassManagerBase &PM) {
377 return new X86PassConfig(this, PM);
380 void X86PassConfig::addIRPasses() {
381 addPass(createAtomicExpandPass(&getX86TargetMachine()));
383 TargetPassConfig::addIRPasses();
385 if (TM->getOptLevel() != CodeGenOpt::None)
386 addPass(createInterleavedAccessPass(TM));
389 bool X86PassConfig::addInstSelector() {
390 // Install an instruction selector.
391 addPass(createX86ISelDag(getX86TargetMachine(), getOptLevel()));
393 // For ELF, cleanup any local-dynamic TLS accesses.
394 if (TM->getTargetTriple().isOSBinFormatELF() &&
395 getOptLevel() != CodeGenOpt::None)
396 addPass(createCleanupLocalDynamicTLSPass());
398 addPass(createX86GlobalBaseRegPass());
402 #ifdef LLVM_BUILD_GLOBAL_ISEL
403 bool X86PassConfig::addIRTranslator() {
404 addPass(new IRTranslator());
408 bool X86PassConfig::addLegalizeMachineIR() {
409 addPass(new Legalizer());
413 bool X86PassConfig::addRegBankSelect() {
414 addPass(new RegBankSelect());
418 bool X86PassConfig::addGlobalInstructionSelect() {
419 addPass(new InstructionSelect());
424 bool X86PassConfig::addILPOpts() {
425 addPass(&EarlyIfConverterID);
426 if (EnableMachineCombinerPass)
427 addPass(&MachineCombinerID);
431 bool X86PassConfig::addPreISel() {
432 // Only add this pass for 32-bit x86 Windows.
433 const Triple &TT = TM->getTargetTriple();
434 if (TT.isOSWindows() && TT.getArch() == Triple::x86)
435 addPass(createX86WinEHStatePass());
439 void X86PassConfig::addPreRegAlloc() {
440 if (getOptLevel() != CodeGenOpt::None) {
441 addPass(createX86FixupSetCC());
442 addPass(createX86OptimizeLEAs());
443 addPass(createX86CallFrameOptimization());
446 addPass(createX86WinAllocaExpander());
449 void X86PassConfig::addPostRegAlloc() {
450 addPass(createX86FloatingPointStackifierPass());
453 void X86PassConfig::addPreSched2() { addPass(createX86ExpandPseudoPass()); }
455 void X86PassConfig::addPreEmitPass() {
456 if (getOptLevel() != CodeGenOpt::None)
457 addPass(new X86ExecutionDepsFix());
460 addPass(createX86IssueVZeroUpperPass());
462 if (getOptLevel() != CodeGenOpt::None) {
463 addPass(createX86FixupBWInsts());
464 addPass(createX86PadShortFunctions());
465 addPass(createX86FixupLEAs());
466 addPass(createX86EvexToVexInsts());