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, std::string *ErrorStr) {
42 const TargetMachineRegistry::Entry *TheArch = MArch;
45 TheArch = TargetMachineRegistry::getClosestTargetForJIT(Error);
51 } else if (TheArch->JITMatchQualityFn() == 0) {
52 cerr << "WARNING: This target JIT is not designed for the host you are"
53 << " running. If bad things happen, please choose a different "
54 << "-march switch.\n";
57 // Package up features to be passed to target/subtarget
58 std::string FeaturesStr;
59 if (MCPU.size() || MAttrs.size()) {
60 SubtargetFeatures Features;
61 Features.setCPU(MCPU);
62 for (unsigned i = 0; i != MAttrs.size(); ++i)
63 Features.AddFeature(MAttrs[i]);
64 FeaturesStr = Features.getString();
67 // Allocate a target...
68 TargetMachine *Target = TheArch->CtorFn(*MP->getModule(), FeaturesStr);
69 assert(Target && "Could not allocate target machine!");
71 // If the target supports JIT code generation, return a new JIT now.
72 if (TargetJITInfo *TJ = Target->getJITInfo())
73 return new JIT(MP, *Target, *TJ);
76 *ErrorStr = "target does not support JIT code generation";