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 exegesis {
  23
  24 LLVMState::LLVMState(const std::string &Triple, const std::string &CpuName) {
  25   std::string Error;
  26   const llvm::Target *const TheTarget =
  27       llvm::TargetRegistry::lookupTarget(Triple, Error);
  28   assert(TheTarget && "unknown target for host");
  29   const llvm::TargetOptions Options;
  30   TargetMachine.reset(static_cast<llvm::LLVMTargetMachine *>(
  31       TheTarget->createTargetMachine(Triple, CpuName, /*Features*/ "", Options,
  32                                      llvm::Reloc::Model::Static)));
  33   TheExegesisTarget = ExegesisTarget::lookup(TargetMachine->getTargetTriple());
  34   if (!TheExegesisTarget) {
  35     llvm::errs() << "no exegesis target for " << Triple << ", using default\n";
  36     TheExegesisTarget = &ExegesisTarget::getDefault();
  37   }
  38   RATC.reset(new RegisterAliasingTrackerCache(
  39       getRegInfo(), getFunctionReservedRegs(getTargetMachine())));
  40 }
  41
  42 LLVMState::LLVMState()
  43     : LLVMState(llvm::sys::getProcessTriple(),
  44                 llvm::sys::getHostCPUName().str()) {}
  45
  46 std::unique_ptr<llvm::LLVMTargetMachine>
  47 LLVMState::createTargetMachine() const {
  48   return std::unique_ptr<llvm::LLVMTargetMachine>(
  49       static_cast<llvm::LLVMTargetMachine *>(
  50           TargetMachine->getTarget().createTargetMachine(
  51               TargetMachine->getTargetTriple().normalize(),
  52               TargetMachine->getTargetCPU(),
  53               TargetMachine->getTargetFeatureString(), TargetMachine->Options,
  54               llvm::Reloc::Model::Static)));
  55 }
  56
  57 bool LLVMState::canAssemble(const llvm::MCInst &Inst) const {
  58   llvm::MCObjectFileInfo ObjectFileInfo;
  59   llvm::MCContext Context(TargetMachine->getMCAsmInfo(),
  60                           TargetMachine->getMCRegisterInfo(), &ObjectFileInfo);
  61   std::unique_ptr<const llvm::MCCodeEmitter> CodeEmitter(
  62       TargetMachine->getTarget().createMCCodeEmitter(
  63           *TargetMachine->getMCInstrInfo(), *TargetMachine->getMCRegisterInfo(),
  64           Context));
  65   llvm::SmallVector<char, 16> Tmp;
  66   llvm::raw_svector_ostream OS(Tmp);
  67   llvm::SmallVector<llvm::MCFixup, 4> Fixups;
  68   CodeEmitter->encodeInstruction(Inst, OS, Fixups,
  69                                  *TargetMachine->getMCSubtargetInfo());
  70   return Tmp.size() > 0;
  71 }
  72
  73 } // namespace exegesis