Files
clang-p2996/llvm/lib/ExecutionEngine/TargetSelect.cpp
Fangrui Song 0d333bf0e3 Remove ExplicitEmulatedTLS and simplify -femulated-tls handling
Currently clangDriver passes -femulated-tls and -fno-emulated-tls to cc1.
cc1 forwards the option to LLVMCodeGen and ExplicitEmulatedTLS is used
to decide the value. Simplify this by moving the Clang decision to
clangDriver and moving the LLVM decision to InitTargetOptionsFromCodeGenFlags.
2023-04-23 11:55:12 -07:00

96 lines
3.3 KiB
C++

//===-- TargetSelect.cpp - Target Chooser Code ----------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This just asks the TargetRegistry for the appropriate target to use, and
// allows the user to specify a specific one on the commandline with -march=x,
// -mcpu=y, and -mattr=a,-b,+c. Clients should initialize targets prior to
// calling selectTarget().
//
//===----------------------------------------------------------------------===//
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/IR/Module.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/TargetParser/Host.h"
#include "llvm/TargetParser/Triple.h"
using namespace llvm;
TargetMachine *EngineBuilder::selectTarget() {
Triple TT;
// MCJIT can generate code for remote targets, but the old JIT and Interpreter
// must use the host architecture.
if (WhichEngine != EngineKind::Interpreter && M)
TT.setTriple(M->getTargetTriple());
return selectTarget(TT, MArch, MCPU, MAttrs);
}
/// selectTarget - Pick a target either via -march or by guessing the native
/// arch. Add any CPU features specified via -mcpu or -mattr.
TargetMachine *EngineBuilder::selectTarget(const Triple &TargetTriple,
StringRef MArch,
StringRef MCPU,
const SmallVectorImpl<std::string>& MAttrs) {
Triple TheTriple(TargetTriple);
if (TheTriple.getTriple().empty())
TheTriple.setTriple(sys::getProcessTriple());
// Adjust the triple to match what the user requested.
const Target *TheTarget = nullptr;
if (!MArch.empty()) {
auto I = find_if(TargetRegistry::targets(),
[&](const Target &T) { return MArch == T.getName(); });
if (I == TargetRegistry::targets().end()) {
if (ErrorStr)
*ErrorStr = "No available targets are compatible with this -march, "
"see -version for the available targets.\n";
return nullptr;
}
TheTarget = &*I;
// Adjust the triple to match (if known), otherwise stick with the
// requested/host triple.
Triple::ArchType Type = Triple::getArchTypeForLLVMName(MArch);
if (Type != Triple::UnknownArch)
TheTriple.setArch(Type);
} else {
std::string Error;
TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), Error);
if (!TheTarget) {
if (ErrorStr)
*ErrorStr = Error;
return nullptr;
}
}
// Package up features to be passed to target/subtarget
std::string FeaturesStr;
if (!MAttrs.empty()) {
SubtargetFeatures Features;
for (unsigned i = 0; i != MAttrs.size(); ++i)
Features.AddFeature(MAttrs[i]);
FeaturesStr = Features.getString();
}
// Allocate a target...
TargetMachine *Target =
TheTarget->createTargetMachine(TheTriple.getTriple(), MCPU, FeaturesStr,
Options, RelocModel, CMModel, OptLevel,
/*JIT*/ true);
Target->Options.EmulatedTLS = EmulatedTLS;
assert(Target && "Could not allocate target machine!");
return Target;
}