1 //===-- TargetSelect.cpp - Target Chooser Code ----------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This just asks the TargetRegistry for the appropriate JIT to use, and allows 11 // the user to specify a specific one on the commandline with -march=x. Clients 12 // should initialize targets prior to calling createJIT. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #include "llvm/ExecutionEngine/ExecutionEngine.h" 17 #include "llvm/Module.h" 18 #include "llvm/ADT/Triple.h" 19 #include "llvm/MC/SubtargetFeature.h" 20 #include "llvm/Support/CommandLine.h" 21 #include "llvm/Support/raw_ostream.h" 22 #include "llvm/Support/Host.h" 23 #include "llvm/Target/TargetMachine.h" 24 #include "llvm/Target/TargetRegistry.h" 25 using namespace llvm; 26 27 /// selectTarget - Pick a target either via -march or by guessing the native 28 /// arch. Add any CPU features specified via -mcpu or -mattr. 29 TargetMachine *EngineBuilder::selectTarget(Module *Mod, 30 StringRef MArch, 31 StringRef MCPU, 32 const SmallVectorImpl<std::string>& MAttrs, 33 Reloc::Model RM, 34 std::string *ErrorStr) { 35 Triple TheTriple(Mod->getTargetTriple()); 36 if (TheTriple.getTriple().empty()) 37 TheTriple.setTriple(sys::getHostTriple()); 38 39 // Adjust the triple to match what the user requested. 40 const Target *TheTarget = 0; 41 if (!MArch.empty()) { 42 for (TargetRegistry::iterator it = TargetRegistry::begin(), 43 ie = TargetRegistry::end(); it != ie; ++it) { 44 if (MArch == it->getName()) { 45 TheTarget = &*it; 46 break; 47 } 48 } 49 50 if (!TheTarget) { 51 *ErrorStr = "No available targets are compatible with this -march, " 52 "see -version for the available targets.\n"; 53 return 0; 54 } 55 56 // Adjust the triple to match (if known), otherwise stick with the 57 // module/host triple. 58 Triple::ArchType Type = Triple::getArchTypeForLLVMName(MArch); 59 if (Type != Triple::UnknownArch) 60 TheTriple.setArch(Type); 61 } else { 62 std::string Error; 63 TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), Error); 64 if (TheTarget == 0) { 65 if (ErrorStr) 66 *ErrorStr = Error; 67 return 0; 68 } 69 } 70 71 if (!TheTarget->hasJIT()) { 72 errs() << "WARNING: This target JIT is not designed for the host you are" 73 << " running. If bad things happen, please choose a different " 74 << "-march switch.\n"; 75 } 76 77 // Package up features to be passed to target/subtarget 78 std::string FeaturesStr; 79 if (!MAttrs.empty()) { 80 SubtargetFeatures Features; 81 for (unsigned i = 0; i != MAttrs.size(); ++i) 82 Features.AddFeature(MAttrs[i]); 83 FeaturesStr = Features.getString(); 84 } 85 86 // Allocate a target... 87 TargetMachine *Target = TheTarget->createTargetMachine(TheTriple.getTriple(), 88 MCPU, FeaturesStr, RM); 89 assert(Target && "Could not allocate target machine!"); 90 return Target; 91 } 92
