C++ TargetLibraryInfo::getLibFunc方法代码示例

static bool optimizeCall(MachineBasicBlock &MBB, MachineInstr &MI,
                         const MachineRegisterInfo &MRI,
                         MachineDominatorTree &MDT, LiveIntervals &LIS,
                         const WebAssemblyTargetLowering &TLI,
                         const TargetLibraryInfo &LibInfo) {
  MachineOperand &Op1 = MI.getOperand(1);
  if (!Op1.isSymbol())
    return false;

  StringRef Name(Op1.getSymbolName());
  bool callReturnsInput = Name == TLI.getLibcallName(RTLIB::MEMCPY) ||
                          Name == TLI.getLibcallName(RTLIB::MEMMOVE) ||
                          Name == TLI.getLibcallName(RTLIB::MEMSET);
  if (!callReturnsInput)
    return false;

  LibFunc Func;
  if (!LibInfo.getLibFunc(Name, Func))
    return false;

  unsigned FromReg = MI.getOperand(2).getReg();
  unsigned ToReg = MI.getOperand(0).getReg();
  if (MRI.getRegClass(FromReg) != MRI.getRegClass(ToReg))
    report_fatal_error("Store results: call to builtin function with wrong "
                       "signature, from/to mismatch");
  return ReplaceDominatedUses(MBB, MI, FromReg, ToReg, MRI, MDT, LIS);
}

bool PartiallyInlineLibCalls::runOnFunction(Function &F) {
  bool Changed = false;
  Function::iterator CurrBB;
  TargetLibraryInfo *TLI = &getAnalysis<TargetLibraryInfo>();
  const TargetTransformInfo *TTI = &getAnalysis<TargetTransformInfo>();
  for (Function::iterator BB = F.begin(), BE = F.end(); BB != BE;) {
    CurrBB = BB++;

    for (BasicBlock::iterator II = CurrBB->begin(), IE = CurrBB->end();
         II != IE; ++II) {
      CallInst *Call = dyn_cast<CallInst>(&*II);
      Function *CalledFunc;

      if (!Call || !(CalledFunc = Call->getCalledFunction()))
        continue;

      // Skip if function either has local linkage or is not a known library
      // function.
      LibFunc::Func LibFunc;
      if (CalledFunc->hasLocalLinkage() || !CalledFunc->hasName() ||
          !TLI->getLibFunc(CalledFunc->getName(), LibFunc))
        continue;

      switch (LibFunc) {
      case LibFunc::sqrtf:
      case LibFunc::sqrt:
        if (TTI->haveFastSqrt(Call->getType()) &&
            optimizeSQRT(Call, CalledFunc, *CurrBB, BB))
          break;
        continue;
      default:
        continue;
      }

      Changed = true;
      break;
    }
  }

  return Changed;
}

MemoryLocation MemoryLocation::getForArgument(ImmutableCallSite CS,
                                              unsigned ArgIdx,
                                              const TargetLibraryInfo &TLI) {
  AAMDNodes AATags;
  CS->getAAMetadata(AATags);
  const Value *Arg = CS.getArgument(ArgIdx);

  // We may be able to produce an exact size for known intrinsics.
  if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(CS.getInstruction())) {
    const DataLayout &DL = II->getModule()->getDataLayout();

    switch (II->getIntrinsicID()) {
    default:
      break;
    case Intrinsic::memset:
    case Intrinsic::memcpy:
    case Intrinsic::memmove:
      assert((ArgIdx == 0 || ArgIdx == 1) &&
             "Invalid argument index for memory intrinsic");
      if (ConstantInt *LenCI = dyn_cast<ConstantInt>(II->getArgOperand(2)))
        return MemoryLocation(Arg, LenCI->getZExtValue(), AATags);
      break;

    case Intrinsic::lifetime_start:
    case Intrinsic::lifetime_end:
    case Intrinsic::invariant_start:
      assert(ArgIdx == 1 && "Invalid argument index");
      return MemoryLocation(
          Arg, cast<ConstantInt>(II->getArgOperand(0))->getZExtValue(), AATags);

    case Intrinsic::invariant_end:
      // The first argument to an invariant.end is a "descriptor" type (e.g. a
      // pointer to a empty struct) which is never actually dereferenced.
      if (ArgIdx == 0)
        return MemoryLocation(Arg, 0, AATags);
      assert(ArgIdx == 2 && "Invalid argument index");
      return MemoryLocation(
          Arg, cast<ConstantInt>(II->getArgOperand(1))->getZExtValue(), AATags);

    case Intrinsic::arm_neon_vld1:
      assert(ArgIdx == 0 && "Invalid argument index");
      // LLVM's vld1 and vst1 intrinsics currently only support a single
      // vector register.
      return MemoryLocation(Arg, DL.getTypeStoreSize(II->getType()), AATags);

    case Intrinsic::arm_neon_vst1:
      assert(ArgIdx == 0 && "Invalid argument index");
      return MemoryLocation(
          Arg, DL.getTypeStoreSize(II->getArgOperand(1)->getType()), AATags);
    }
  }

  // We can bound the aliasing properties of memset_pattern16 just as we can
  // for memcpy/memset.  This is particularly important because the
  // LoopIdiomRecognizer likes to turn loops into calls to memset_pattern16
  // whenever possible.
  LibFunc F;
  if (CS.getCalledFunction() && TLI.getLibFunc(*CS.getCalledFunction(), F) &&
      F == LibFunc_memset_pattern16 && TLI.has(F)) {
    assert((ArgIdx == 0 || ArgIdx == 1) &&
           "Invalid argument index for memset_pattern16");
    if (ArgIdx == 1)
      return MemoryLocation(Arg, 16, AATags);
    if (const ConstantInt *LenCI = dyn_cast<ConstantInt>(CS.getArgument(2)))
      return MemoryLocation(Arg, LenCI->getZExtValue(), AATags);
  }
  // FIXME: Handle memset_pattern4 and memset_pattern8 also.

  return MemoryLocation(CS.getArgument(ArgIdx), UnknownSize, AATags);
}