tools/llvm-exegesis/lib/LlvmState.cpp

   1 //===-- LlvmState.cpp -------------------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "LlvmState.h"
  10 #include "Target.h"
  11 #include "llvm/ADT/SmallVector.h"
  12 #include "llvm/MC/MCCodeEmitter.h"
  13 #include "llvm/MC/MCContext.h"
  14 #include "llvm/MC/MCFixup.h"
  15 #include "llvm/MC/MCObjectFileInfo.h"
  16 #include "llvm/Support/TargetRegistry.h"
  17 #include "llvm/Support/raw_ostream.h"
  18 #include "llvm/Target/TargetMachine.h"
  19 #include "llvm/Target/TargetOptions.h"
  20
  21 namespace llvm {
  22 namespace exegesis {
  23
  24 LLVMState::LLVMState(const std::string &Triple, const std::string &CpuName,
  25                      const std::string &Features) {
  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(
  32       static_cast<llvm::LLVMTargetMachine *>(TheTarget->createTargetMachine(
  33           Triple, CpuName, Features, Options, 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   PfmCounters = &TheExegesisTarget->getPfmCounters(CpuName);
  40
  41   BitVector ReservedRegs = getFunctionReservedRegs(getTargetMachine());
  42   for (const unsigned Reg : TheExegesisTarget->getUnavailableRegisters())
  43     ReservedRegs.set(Reg);
  44   RATC.reset(
  45       new RegisterAliasingTrackerCache(getRegInfo(), std::move(ReservedRegs)));
  46   IC.reset(new InstructionsCache(getInstrInfo(), getRATC()));
  47 }
  48
  49 LLVMState::LLVMState(const std::string &CpuName)
  50     : LLVMState(llvm::sys::getProcessTriple(),
  51                 CpuName.empty() ? llvm::sys::getHostCPUName().str() : CpuName,
  52                 "") {}
  53
  54 std::unique_ptr<llvm::LLVMTargetMachine>
  55 LLVMState::createTargetMachine() const {
  56   return std::unique_ptr<llvm::LLVMTargetMachine>(
  57       static_cast<llvm::LLVMTargetMachine *>(
  58           TargetMachine->getTarget().createTargetMachine(
  59               TargetMachine->getTargetTriple().normalize(),
  60               TargetMachine->getTargetCPU(),
  61               TargetMachine->getTargetFeatureString(), TargetMachine->Options,
  62               llvm::Reloc::Model::Static)));
  63 }
  64
  65 bool LLVMState::canAssemble(const llvm::MCInst &Inst) const {
  66   llvm::MCObjectFileInfo ObjectFileInfo;
  67   llvm::MCContext Context(TargetMachine->getMCAsmInfo(),
  68                           TargetMachine->getMCRegisterInfo(), &ObjectFileInfo);
  69   std::unique_ptr<const llvm::MCCodeEmitter> CodeEmitter(
  70       TargetMachine->getTarget().createMCCodeEmitter(
  71           *TargetMachine->getMCInstrInfo(), *TargetMachine->getMCRegisterInfo(),
  72           Context));
  73   llvm::SmallVector<char, 16> Tmp;
  74   llvm::raw_svector_ostream OS(Tmp);
  75   llvm::SmallVector<llvm::MCFixup, 4> Fixups;
  76   CodeEmitter->encodeInstruction(Inst, OS, Fixups,
  77                                  *TargetMachine->getMCSubtargetInfo());
  78   return Tmp.size() > 0;
  79 }
  80
  81 } // namespace exegesis
  82 } // namespace llvm