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 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.
14 //===----------------------------------------------------------------------===//
17 #include "llvm/Module.h"
18 #include "llvm/ModuleProvider.h"
19 #include "llvm/ADT/Triple.h"
20 #include "llvm/Support/CommandLine.h"
21 #include "llvm/Support/raw_ostream.h"
22 #include "llvm/System/Host.h"
23 #include "llvm/Target/SubtargetFeature.h"
24 #include "llvm/Target/TargetMachine.h"
25 #include "llvm/Target/TargetRegistry.h"
28 static cl::opt<std::string>
30 cl::desc("Architecture to generate assembly for (see --version)"));
32 static cl::opt<std::string>
34 cl::desc("Target a specific cpu type (-mcpu=help for details)"),
35 cl::value_desc("cpu-name"),
38 static cl::list<std::string>
41 cl::desc("Target specific attributes (-mattr=help for details)"),
42 cl::value_desc("a1,+a2,-a3,..."));
44 /// selectTarget - Pick a target either via -march or by guessing the native
45 /// arch. Add any CPU features specified via -mcpu or -mattr.
46 TargetMachine *JIT::selectTarget(ModuleProvider *MP, std::string *ErrorStr) {
47 Module &Mod = *MP->getModule();
49 Triple TheTriple(Mod.getTargetTriple());
50 if (TheTriple.getTriple().empty())
51 TheTriple.setTriple(sys::getHostTriple());
53 // Adjust the triple to match what the user requested.
54 const Target *TheTarget = 0;
56 for (TargetRegistry::iterator it = TargetRegistry::begin(),
57 ie = TargetRegistry::end(); it != ie; ++it) {
58 if (MArch == it->getName()) {
65 *ErrorStr = "No available targets are compatible with this -march, "
66 "see -version for the available targets.\n";
70 // Adjust the triple to match (if known), otherwise stick with the
71 // module/host triple.
72 Triple::ArchType Type = Triple::getArchTypeForLLVMName(MArch);
73 if (Type != Triple::UnknownArch)
74 TheTriple.setArch(Type);
77 TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), Error);
85 if (!TheTarget->hasJIT()) {
86 errs() << "WARNING: This target JIT is not designed for the host you are"
87 << " running. If bad things happen, please choose a different "
88 << "-march switch.\n";
91 // Package up features to be passed to target/subtarget
92 std::string FeaturesStr;
93 if (!MCPU.empty() || !MAttrs.empty()) {
94 SubtargetFeatures Features;
95 Features.setCPU(MCPU);
96 for (unsigned i = 0; i != MAttrs.size(); ++i)
97 Features.AddFeature(MAttrs[i]);
98 FeaturesStr = Features.getString();
101 // Allocate a target...
102 TargetMachine *Target =
103 TheTarget->createTargetMachine(TheTriple.getTriple(), FeaturesStr);
104 assert(Target && "Could not allocate target machine!");