/// Create an WebAssembly architecture model.
///
WebAssemblyTargetMachine::WebAssemblyTargetMachine(
const Target &T, const Triple &TT, StringRef CPU, StringRef FS,
const TargetOptions &Options, Optional<Reloc::Model> RM,
Optional<CodeModel::Model> CM, CodeGenOpt::Level OL, bool JIT)
: LLVMTargetMachine(T,
TT.isArch64Bit() ? "e-m:e-p:64:64-i64:64-n32:64-S128"
: "e-m:e-p:32:32-i64:64-n32:64-S128",
TT, CPU, FS, Options, getEffectiveRelocModel(RM),
CM ? *CM : CodeModel::Large, OL),
TLOF(TT.isOSBinFormatELF() ?
static_cast<TargetLoweringObjectFile*>(
new WebAssemblyTargetObjectFileELF()) :
static_cast<TargetLoweringObjectFile*>(
new WebAssemblyTargetObjectFile())) {
// WebAssembly type-checks instructions, but a noreturn function with a return
// type that doesn't match the context will cause a check failure. So we lower
// LLVM 'unreachable' to ISD::TRAP and then lower that to WebAssembly's
// 'unreachable' instructions which is meant for that case.
this->Options.TrapUnreachable = true;
// WebAssembly treats each function as an independent unit. Force
// -ffunction-sections, effectively, so that we can emit them independently.
if (!TT.isOSBinFormatELF()) {
this->Options.FunctionSections = true;
this->Options.DataSections = true;
this->Options.UniqueSectionNames = true;
}
initAsmInfo();
// Note that we don't use setRequiresStructuredCFG(true). It disables
// optimizations than we're ok with, and want, such as critical edge
// splitting and tail merging.
}
static Reloc::Model getEffectiveRelocModel(const Triple &TT,
Optional<Reloc::Model> RM) {
if (!RM.hasValue())
// Default relocation model on Darwin is PIC.
return TT.isOSBinFormatMachO() ? Reloc::PIC_ : Reloc::Static;
if (*RM == Reloc::ROPI || *RM == Reloc::RWPI || *RM == Reloc::ROPI_RWPI)
assert(TT.isOSBinFormatELF() &&
"ROPI/RWPI currently only supported for ELF");
// DynamicNoPIC is only used on darwin.
if (*RM == Reloc::DynamicNoPIC && !TT.isOSDarwin())
return Reloc::Static;
return *RM;
}
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() || TT.isOSNaCl())
return make_unique<X86LinuxNaClTargetObjectFile>();
if (TT.isOSBinFormatELF())
return make_unique<X86ELFTargetObjectFile>();
if (TT.isKnownWindowsMSVCEnvironment() || TT.isWindowsCoreCLREnvironment())
return make_unique<X86WindowsTargetObjectFile>();
if (TT.isOSBinFormatCOFF())
return make_unique<TargetLoweringObjectFileCOFF>();
llvm_unreachable("unknown subtarget type");
}
static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
if (TT.isOSBinFormatMachO()) {
if (TT.getArch() == Triple::x86_64)
return llvm::make_unique<X86_64MachoTargetObjectFile>();
return llvm::make_unique<TargetLoweringObjectFileMachO>();
}
if (TT.isOSFreeBSD())
return llvm::make_unique<X86FreeBSDTargetObjectFile>();
if (TT.isOSLinux() || TT.isOSNaCl() || TT.isOSIAMCU())
return llvm::make_unique<X86LinuxNaClTargetObjectFile>();
if (TT.isOSSolaris())
return llvm::make_unique<X86SolarisTargetObjectFile>();
if (TT.isOSFuchsia())
return llvm::make_unique<X86FuchsiaTargetObjectFile>();
if (TT.isOSBinFormatELF())
return llvm::make_unique<X86ELFTargetObjectFile>();
if (TT.isOSBinFormatCOFF())
return llvm::make_unique<TargetLoweringObjectFileCOFF>();
llvm_unreachable("unknown subtarget type");
}