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//===-- X86TargetMachine.cpp - Define TargetMachine for the X86 -----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the X86 specific subclass of TargetMachine.
//
//===----------------------------------------------------------------------===//
#include "X86TargetMachine.h"
#include "X86.h"
#include "X86TargetObjectFile.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/IR/Function.h"
#include "llvm/PassManager.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
extern "C" void LLVMInitializeX86Target() {
// Register the target.
RegisterTargetMachine<X86TargetMachine> X(TheX86_32Target);
RegisterTargetMachine<X86TargetMachine> Y(TheX86_64Target);
}
static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
if (TT.isOSBinFormatMachO()) {
if (TT.getArch() == Triple::x86_64)
return make_unique<X86_64MachoTargetObjectFile>();
return make_unique<TargetLoweringObjectFileMachO>();
}
if (TT.isOSLinux())
return make_unique<X86LinuxTargetObjectFile>();
if (TT.isOSBinFormatELF())
return make_unique<TargetLoweringObjectFileELF>();
if (TT.isKnownWindowsMSVCEnvironment())
return make_unique<X86WindowsTargetObjectFile>();
if (TT.isOSBinFormatCOFF())
return make_unique<TargetLoweringObjectFileCOFF>();
llvm_unreachable("unknown subtarget type");
}
/// X86TargetMachine ctor - Create an X86 target.
///
X86TargetMachine::X86TargetMachine(const Target &T, StringRef TT, StringRef CPU,
StringRef FS, const TargetOptions &Options,
Reloc::Model RM, CodeModel::Model CM,
CodeGenOpt::Level OL)
: LLVMTargetMachine(T, TT, CPU, FS, Options, RM, CM, OL),
TLOF(createTLOF(Triple(getTargetTriple()))),
Subtarget(TT, CPU, FS, *this, Options.StackAlignmentOverride) {
// default to hard float ABI
if (Options.FloatABIType == FloatABI::Default)
this->Options.FloatABIType = FloatABI::Hard;
// Windows stack unwinder gets confused when execution flow "falls through"
// after a call to 'noreturn' function.
// To prevent that, we emit a trap for 'unreachable' IR instructions.
// (which on X86, happens to be the 'ud2' instruction)
if (Subtarget.isTargetWin64())
this->Options.TrapUnreachable = true;
initAsmInfo();
}
X86TargetMachine::~X86TargetMachine() {}
const X86Subtarget *
X86TargetMachine::getSubtargetImpl(const Function &F) const {
AttributeSet FnAttrs = F.getAttributes();
Attribute CPUAttr =
FnAttrs.getAttribute(AttributeSet::FunctionIndex, "target-cpu");
Attribute FSAttr =
FnAttrs.getAttribute(AttributeSet::FunctionIndex, "target-features");
std::string CPU = !CPUAttr.hasAttribute(Attribute::None)
? CPUAttr.getValueAsString().str()
: TargetCPU;
std::string FS = !FSAttr.hasAttribute(Attribute::None)
? FSAttr.getValueAsString().str()
: TargetFS;
// FIXME: This is related to the code below to reset the target options,
// we need to know whether or not the soft float flag is set on the
// function before we can generate a subtarget. We also need to use
// it as a key for the subtarget since that can be the only difference
// between two functions.
Attribute SFAttr =
FnAttrs.getAttribute(AttributeSet::FunctionIndex, "use-soft-float");
bool SoftFloat = !SFAttr.hasAttribute(Attribute::None)
? SFAttr.getValueAsString() == "true"
: Options.UseSoftFloat;
auto &I = SubtargetMap[CPU + FS + (SoftFloat ? "use-soft-float=true"
: "use-soft-float=false")];
if (!I) {
// This needs to be done before we create a new subtarget since any
// creation will depend on the TM and the code generation flags on the
// function that reside in TargetOptions.
resetTargetOptions(F);
I = llvm::make_unique<X86Subtarget>(TargetTriple, CPU, FS, *this,
Options.StackAlignmentOverride);
}
return I.get();
}
//===----------------------------------------------------------------------===//
// Command line options for x86
//===----------------------------------------------------------------------===//
static cl::opt<bool>
UseVZeroUpper("x86-use-vzeroupper", cl::Hidden,
cl::desc("Minimize AVX to SSE transition penalty"),
cl::init(true));
//===----------------------------------------------------------------------===//
// X86 Analysis Pass Setup
//===----------------------------------------------------------------------===//
void X86TargetMachine::addAnalysisPasses(PassManagerBase &PM) {
// Add first the target-independent BasicTTI pass, then our X86 pass. This
// allows the X86 pass to delegate to the target independent layer when
// appropriate.
PM.add(createBasicTargetTransformInfoPass(this));
PM.add(createX86TargetTransformInfoPass(this));
}
//===----------------------------------------------------------------------===//
// Pass Pipeline Configuration
//===----------------------------------------------------------------------===//
namespace {
/// X86 Code Generator Pass Configuration Options.
class X86PassConfig : public TargetPassConfig {
public:
X86PassConfig(X86TargetMachine *TM, PassManagerBase &PM)
: TargetPassConfig(TM, PM) {}
X86TargetMachine &getX86TargetMachine() const {
return getTM<X86TargetMachine>();
}
const X86Subtarget &getX86Subtarget() const {
return *getX86TargetMachine().getSubtargetImpl();
}
void addIRPasses() override;
bool addInstSelector() override;
bool addILPOpts() override;
bool addPreRegAlloc() override;
bool addPostRegAlloc() override;
bool addPreEmitPass() override;
};
} // namespace
TargetPassConfig *X86TargetMachine::createPassConfig(PassManagerBase &PM) {
return new X86PassConfig(this, PM);
}
void X86PassConfig::addIRPasses() {
addPass(createAtomicExpandPass(&getX86TargetMachine()));
TargetPassConfig::addIRPasses();
}
bool X86PassConfig::addInstSelector() {
// Install an instruction selector.
addPass(createX86ISelDag(getX86TargetMachine(), getOptLevel()));
// For ELF, cleanup any local-dynamic TLS accesses.
if (getX86Subtarget().isTargetELF() && getOptLevel() != CodeGenOpt::None)
addPass(createCleanupLocalDynamicTLSPass());
addPass(createX86GlobalBaseRegPass());
return false;
}
bool X86PassConfig::addILPOpts() {
addPass(&EarlyIfConverterID);
return true;
}
bool X86PassConfig::addPreRegAlloc() {
return false; // -print-machineinstr shouldn't print after this.
}
bool X86PassConfig::addPostRegAlloc() {
addPass(createX86FloatingPointStackifierPass());
return true; // -print-machineinstr should print after this.
}
bool X86PassConfig::addPreEmitPass() {
bool ShouldPrint = false;
if (getOptLevel() != CodeGenOpt::None && getX86Subtarget().hasSSE2()) {
addPass(createExecutionDependencyFixPass(&X86::VR128RegClass));
ShouldPrint = true;
}
if (UseVZeroUpper) {
addPass(createX86IssueVZeroUpperPass());
ShouldPrint = true;
}
if (getOptLevel() != CodeGenOpt::None) {
addPass(createX86PadShortFunctions());
addPass(createX86FixupLEAs());
ShouldPrint = true;
}
return ShouldPrint;
}
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