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 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/Support/Streams.h"
19 #include "llvm/Target/SubtargetFeature.h"
20 #include "llvm/Target/TargetMachine.h"
21 #include "llvm/Target/TargetMachineRegistry.h"
24 static cl::opt<const TargetMachineRegistry::entry*, false,
25 TargetMachineRegistry::Parser>
26 MArch("march", cl::desc("Architecture to generate assembly for:"));
28 static cl::opt<std::string>
30 cl::desc("Target a specific cpu type (-mcpu=help for details)"),
31 cl::value_desc("cpu-name"),
34 static cl::list<std::string>
37 cl::desc("Target specific attributes (-mattr=help for details)"),
38 cl::value_desc("a1,+a2,-a3,..."));
40 /// createInternal - Create an return a new JIT compiler if there is one
41 /// available for the current target. Otherwise, return null.
43 ExecutionEngine *JIT::createJIT(ModuleProvider *MP, std::string *ErrorStr,
44 JITMemoryManager *JMM, bool Fast) {
45 const TargetMachineRegistry::entry *TheArch = MArch;
48 TheArch = TargetMachineRegistry::getClosestTargetForJIT(Error);
54 } else if (TheArch->JITMatchQualityFn() == 0) {
55 cerr << "WARNING: This target JIT is not designed for the host you are"
56 << " running. If bad things happen, please choose a different "
57 << "-march switch.\n";
60 // Package up features to be passed to target/subtarget
61 std::string FeaturesStr;
62 if (!MCPU.empty() || !MAttrs.empty()) {
63 SubtargetFeatures Features;
64 Features.setCPU(MCPU);
65 for (unsigned i = 0; i != MAttrs.size(); ++i)
66 Features.AddFeature(MAttrs[i]);
67 FeaturesStr = Features.getString();
70 // Allocate a target...
71 TargetMachine *Target = TheArch->CtorFn(*MP->getModule(), FeaturesStr);
72 assert(Target && "Could not allocate target machine!");
74 // If the target supports JIT code generation, return a new JIT now.
75 if (TargetJITInfo *TJ = Target->getJITInfo())
76 return new JIT(MP, *Target, *TJ, JMM, Fast);
79 *ErrorStr = "target does not support JIT code generation";