| //===-- 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/MC/TargetRegistry.h" |
| #include "llvm/Support/Host.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(); |
| } |
| |
| // 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; |
| } |