llvm-mirror/lib/ExecutionEngine/TargetSelect.cpp
Chandler Carruth ae65e281f3 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

104 lines
3.6 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/ADT/Triple.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/IR/Module.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Target/TargetMachine.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();
}
// FIXME: non-iOS ARM FastISel is broken with MCJIT.
if (TheTriple.getArch() == Triple::arm &&
!TheTriple.isiOS() &&
OptLevel == CodeGenOpt::None) {
OptLevel = CodeGenOpt::Less;
}
// Allocate a target...
TargetMachine *Target =
TheTarget->createTargetMachine(TheTriple.getTriple(), MCPU, FeaturesStr,
Options, RelocModel, CMModel, OptLevel,
/*JIT*/ true);
Target->Options.EmulatedTLS = EmulatedTLS;
Target->Options.ExplicitEmulatedTLS = true;
assert(Target && "Could not allocate target machine!");
return Target;
}