tools/llvm-exegesis/lib/LlvmState.cpp

   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   std::string Error;
  27   const llvm::Target *const TheTarget =
  28       llvm::TargetRegistry::lookupTarget(Triple, Error);
  29   assert(TheTarget && "unknown target for host");
  30   const llvm::TargetOptions Options;
  31   TargetMachine.reset(static_cast<llvm::LLVMTargetMachine *>(
  32       TheTarget->createTargetMachine(Triple, CpuName, /*Features*/ "", Options,
  33                                      llvm::Reloc::Model::Static)));
  34   TheExegesisTarget = ExegesisTarget::lookup(TargetMachine->getTargetTriple());
  35   if (!TheExegesisTarget) {
  36     llvm::errs() << "no exegesis target for " << Triple << ", using default\n";
  37     TheExegesisTarget = &ExegesisTarget::getDefault();
  38   }
  39   RATC.reset(new RegisterAliasingTrackerCache(
  40       getRegInfo(), getFunctionReservedRegs(getTargetMachine())));
  41   IC.reset(new InstructionsCache(getInstrInfo(), getRATC()));
  42 }
  43
  44 LLVMState::LLVMState()
  45     : LLVMState(llvm::sys::getProcessTriple(),
  46                 llvm::sys::getHostCPUName().str()) {}
  47
  48 std::unique_ptr<llvm::LLVMTargetMachine>
  49 LLVMState::createTargetMachine() const {
  50   return std::unique_ptr<llvm::LLVMTargetMachine>(
  51       static_cast<llvm::LLVMTargetMachine *>(
  52           TargetMachine->getTarget().createTargetMachine(
  53               TargetMachine->getTargetTriple().normalize(),
  54               TargetMachine->getTargetCPU(),
  55               TargetMachine->getTargetFeatureString(), TargetMachine->Options,
  56               llvm::Reloc::Model::Static)));
  57 }
  58
  59 bool LLVMState::canAssemble(const llvm::MCInst &Inst) const {
  60   llvm::MCObjectFileInfo ObjectFileInfo;
  61   llvm::MCContext Context(TargetMachine->getMCAsmInfo(),
  62                           TargetMachine->getMCRegisterInfo(), &ObjectFileInfo);
  63   std::unique_ptr<const llvm::MCCodeEmitter> CodeEmitter(
  64       TargetMachine->getTarget().createMCCodeEmitter(
  65           *TargetMachine->getMCInstrInfo(), *TargetMachine->getMCRegisterInfo(),
  66           Context));
  67   llvm::SmallVector<char, 16> Tmp;
  68   llvm::raw_svector_ostream OS(Tmp);
  69   llvm::SmallVector<llvm::MCFixup, 4> Fixups;
  70   CodeEmitter->encodeInstruction(Inst, OS, Fixups,
  71                                  *TargetMachine->getMCSubtargetInfo());
  72   return Tmp.size() > 0;
  73 }
  74
  75 } // namespace exegesis
  76 } // namespace llvm