Home | History | Annotate | Line # | Download | only in lib 
      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/Host.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 Target *const TheTarget = TargetRegistry::lookupTarget(Triple, Error);
     29   assert(TheTarget && "unknown target for host");
     30   const TargetOptions Options;
     31   TheTargetMachine.reset(
     32       static_cast<LLVMTargetMachine *>(TheTarget->createTargetMachine(
     33           Triple, CpuName, Features, Options, Reloc::Model::Static)));
     34   assert(TheTargetMachine && "unable to create target machine");
     35   TheExegesisTarget = ExegesisTarget::lookup(TheTargetMachine->getTargetTriple());
     36   if (!TheExegesisTarget) {
     37     errs() << "no exegesis target for " << Triple << ", using default\n";
     38     TheExegesisTarget = &ExegesisTarget::getDefault();
     39   }
     40   PfmCounters = &TheExegesisTarget->getPfmCounters(CpuName);
     41 
     42   BitVector ReservedRegs = getFunctionReservedRegs(getTargetMachine());
     43   for (const unsigned Reg : TheExegesisTarget->getUnavailableRegisters())
     44     ReservedRegs.set(Reg);
     45   RATC.reset(
     46       new RegisterAliasingTrackerCache(getRegInfo(), std::move(ReservedRegs)));
     47   IC.reset(new InstructionsCache(getInstrInfo(), getRATC()));
     48 }
     49 
     50 LLVMState::LLVMState(const std::string &CpuName)
     51     : LLVMState(sys::getProcessTriple(),
     52                 CpuName.empty() ? sys::getHostCPUName().str() : CpuName, "") {}
     53 
     54 std::unique_ptr<LLVMTargetMachine> LLVMState::createTargetMachine() const {
     55   return std::unique_ptr<LLVMTargetMachine>(static_cast<LLVMTargetMachine *>(
     56       TheTargetMachine->getTarget().createTargetMachine(
     57           TheTargetMachine->getTargetTriple().normalize(),
     58           TheTargetMachine->getTargetCPU(),
     59           TheTargetMachine->getTargetFeatureString(), TheTargetMachine->Options,
     60           Reloc::Model::Static)));
     61 }
     62 
     63 bool LLVMState::canAssemble(const MCInst &Inst) const {
     64   MCContext Context(TheTargetMachine->getTargetTriple(),
     65                     TheTargetMachine->getMCAsmInfo(),
     66                     TheTargetMachine->getMCRegisterInfo(),
     67                     TheTargetMachine->getMCSubtargetInfo());
     68   std::unique_ptr<const MCCodeEmitter> CodeEmitter(
     69       TheTargetMachine->getTarget().createMCCodeEmitter(
     70           *TheTargetMachine->getMCInstrInfo(), *TheTargetMachine->getMCRegisterInfo(),
     71           Context));
     72   assert(CodeEmitter && "unable to create code emitter");
     73   SmallVector<char, 16> Tmp;
     74   raw_svector_ostream OS(Tmp);
     75   SmallVector<MCFixup, 4> Fixups;
     76   CodeEmitter->encodeInstruction(Inst, OS, Fixups,
     77                                  *TheTargetMachine->getMCSubtargetInfo());
     78   return Tmp.size() > 0;
     79 }
     80 
     81 } // namespace exegesis
     82 } // namespace llvm
     83