1 //===-- TargetSelect.cpp - Target Chooser Code ----------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This just asks the TargetMachineRegistry for the appropriate JIT to use, and
11 // allows the user to specify a specific one on the commandline with -march=x.
13 //===----------------------------------------------------------------------===//
16 #include "llvm/Module.h"
17 #include "llvm/ModuleProvider.h"
18 #include "llvm/Target/SubtargetFeature.h"
19 #include "llvm/Target/TargetMachine.h"
20 #include "llvm/Target/TargetMachineRegistry.h"
23 static cl::opt<const TargetMachineRegistry::Entry*, false, TargetNameParser>
24 MArch("march", cl::desc("Architecture to generate assembly for:"));
26 static cl::opt<std::string>
28 cl::desc("Target a specific cpu type (-mcpu=help for details)"),
29 cl::value_desc("cpu-name"),
32 static cl::list<std::string>
35 cl::desc("Target specific attributes (-mattr=help for details)"),
36 cl::value_desc("a1,+a2,-a3,..."));
38 /// create - Create an return a new JIT compiler if there is one available
39 /// for the current target. Otherwise, return null.
41 ExecutionEngine *JIT::create(ModuleProvider *MP) {
44 MArch = TargetMachineRegistry::getClosestTargetForJIT(Error);
45 if (MArch == 0) return 0;
46 } else if (MArch->JITMatchQualityFn() == 0) {
47 cerr << "WARNING: This target JIT is not designed for the host you are"
48 << " running. If bad things happen, please choose a different "
49 << "-march switch.\n";
52 // Package up features to be passed to target/subtarget
53 std::string FeaturesStr;
54 if (MCPU.size() || MAttrs.size()) {
55 SubtargetFeatures Features;
56 Features.setCPU(MCPU);
57 for (unsigned i = 0; i != MAttrs.size(); ++i)
58 Features.AddFeature(MAttrs[i]);
59 FeaturesStr = Features.getString();
62 // Allocate a target...
63 TargetMachine *Target = MArch->CtorFn(*MP->getModule(), FeaturesStr);
64 assert(Target && "Could not allocate target machine!");
66 // If the target supports JIT code generation, return a new JIT now.
67 if (TargetJITInfo *TJ = Target->getJITInfo())
68 return new JIT(MP, *Target, *TJ);