1 //===-- LlvmState.cpp -------------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "LlvmState.h"
11 #include "Target.h"
12 #include "llvm/ADT/SmallVector.h"
13 #include "llvm/MC/MCCodeEmitter.h"
14 #include "llvm/MC/MCContext.h"
15 #include "llvm/MC/MCFixup.h"
16 #include "llvm/MC/MCObjectFileInfo.h"
17 #include "llvm/Support/TargetRegistry.h"
18 #include "llvm/Support/raw_ostream.h"
19 #include "llvm/Target/TargetMachine.h"
20 #include "llvm/Target/TargetOptions.h"
21 
22 namespace llvm {
23 namespace exegesis {
24 
25 LLVMState::LLVMState(const std::string &Triple, const std::string &CpuName,
26                      const std::string &Features) {
27   std::string Error;
28   const llvm::Target *const TheTarget =
29       llvm::TargetRegistry::lookupTarget(Triple, Error);
30   assert(TheTarget && "unknown target for host");
31   const llvm::TargetOptions Options;
32   TargetMachine.reset(
33       static_cast<llvm::LLVMTargetMachine *>(TheTarget->createTargetMachine(
34           Triple, CpuName, Features, Options, llvm::Reloc::Model::Static)));
35   TheExegesisTarget = ExegesisTarget::lookup(TargetMachine->getTargetTriple());
36   if (!TheExegesisTarget) {
37     llvm::errs() << "no exegesis target for " << Triple << ", using default\n";
38     TheExegesisTarget = &ExegesisTarget::getDefault();
39   }
40   PfmCounters = &TheExegesisTarget->getPfmCounters(CpuName);
41 
42   RATC.reset(new RegisterAliasingTrackerCache(
43       getRegInfo(), getFunctionReservedRegs(getTargetMachine())));
44   IC.reset(new InstructionsCache(getInstrInfo(), getRATC()));
45 }
46 
47 LLVMState::LLVMState(const std::string &CpuName)
48     : LLVMState(llvm::sys::getProcessTriple(),
49                 CpuName.empty() ? llvm::sys::getHostCPUName().str() : CpuName,
50                 "") {}
51 
52 std::unique_ptr<llvm::LLVMTargetMachine>
53 LLVMState::createTargetMachine() const {
54   return std::unique_ptr<llvm::LLVMTargetMachine>(
55       static_cast<llvm::LLVMTargetMachine *>(
56           TargetMachine->getTarget().createTargetMachine(
57               TargetMachine->getTargetTriple().normalize(),
58               TargetMachine->getTargetCPU(),
59               TargetMachine->getTargetFeatureString(), TargetMachine->Options,
60               llvm::Reloc::Model::Static)));
61 }
62 
63 bool LLVMState::canAssemble(const llvm::MCInst &Inst) const {
64   llvm::MCObjectFileInfo ObjectFileInfo;
65   llvm::MCContext Context(TargetMachine->getMCAsmInfo(),
66                           TargetMachine->getMCRegisterInfo(), &ObjectFileInfo);
67   std::unique_ptr<const llvm::MCCodeEmitter> CodeEmitter(
68       TargetMachine->getTarget().createMCCodeEmitter(
69           *TargetMachine->getMCInstrInfo(), *TargetMachine->getMCRegisterInfo(),
70           Context));
71   llvm::SmallVector<char, 16> Tmp;
72   llvm::raw_svector_ostream OS(Tmp);
73   llvm::SmallVector<llvm::MCFixup, 4> Fixups;
74   CodeEmitter->encodeInstruction(Inst, OS, Fixups,
75                                  *TargetMachine->getMCSubtargetInfo());
76   return Tmp.size() > 0;
77 }
78 
79 } // namespace exegesis
80 } // namespace llvm
81