1 //===-- TargetSelect.cpp - Target Chooser Code ----------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This just asks the TargetRegistry for the appropriate target to use, and
11 // allows the user to specify a specific one on the commandline with -march=x,
12 // -mcpu=y, and -mattr=a,-b,+c. Clients should initialize targets prior to
13 // calling selectTarget().
15 //===----------------------------------------------------------------------===//
17 #include "llvm/ExecutionEngine/ExecutionEngine.h"
18 #include "llvm/Module.h"
19 #include "llvm/ADT/Triple.h"
20 #include "llvm/MC/SubtargetFeature.h"
21 #include "llvm/Target/TargetMachine.h"
22 #include "llvm/Support/CommandLine.h"
23 #include "llvm/Support/Host.h"
24 #include "llvm/Support/TargetRegistry.h"
28 TargetMachine *EngineBuilder::selectTarget() {
31 SmallVector<std::string, 1> MAttrs;
32 Triple TT(M->getTargetTriple());
34 return selectTarget(TT, MArch, MCPU, MAttrs);
37 /// selectTarget - Pick a target either via -march or by guessing the native
38 /// arch. Add any CPU features specified via -mcpu or -mattr.
39 TargetMachine *EngineBuilder::selectTarget(const Triple &TargetTriple,
42 const SmallVectorImpl<std::string>& MAttrs) {
43 Triple TheTriple(TargetTriple);
44 if (TheTriple.getTriple().empty())
45 TheTriple.setTriple(sys::getDefaultTargetTriple());
47 // Adjust the triple to match what the user requested.
48 const Target *TheTarget = 0;
50 for (TargetRegistry::iterator it = TargetRegistry::begin(),
51 ie = TargetRegistry::end(); it != ie; ++it) {
52 if (MArch == it->getName()) {
60 *ErrorStr = "No available targets are compatible with this -march, "
61 "see -version for the available targets.\n";
65 // Adjust the triple to match (if known), otherwise stick with the
66 // requested/host triple.
67 Triple::ArchType Type = Triple::getArchTypeForLLVMName(MArch);
68 if (Type != Triple::UnknownArch)
69 TheTriple.setArch(Type);
72 TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), Error);
80 // Package up features to be passed to target/subtarget
81 std::string FeaturesStr;
82 if (!MAttrs.empty()) {
83 SubtargetFeatures Features;
84 for (unsigned i = 0; i != MAttrs.size(); ++i)
85 Features.AddFeature(MAttrs[i]);
86 FeaturesStr = Features.getString();
89 // Allocate a target...
90 TargetMachine *Target = TheTarget->createTargetMachine(TheTriple.getTriple(),
95 assert(Target && "Could not allocate target machine!");