C++ IntrinsicInst::getNumArgOperands方法代码示例

/// CleanupSelectors - Any remaining eh.selector intrinsic calls which still use
/// the "llvm.eh.catch.all.value" call need to convert to using its
/// initializer instead.
bool DwarfEHPrepare::CleanupSelectors(SmallPtrSet<IntrinsicInst*, 32> &Sels) {
  if (!EHCatchAllValue) return false;

  if (!SelectorIntrinsic) {
    SelectorIntrinsic =
      Intrinsic::getDeclaration(F->getParent(), Intrinsic::eh_selector);
    if (!SelectorIntrinsic) return false;
  }

  bool Changed = false;
  for (SmallPtrSet<IntrinsicInst*, 32>::iterator
         I = Sels.begin(), E = Sels.end(); I != E; ++I) {
    IntrinsicInst *Sel = *I;

    // Index of the "llvm.eh.catch.all.value" variable.
    unsigned OpIdx = Sel->getNumArgOperands() - 1;
    GlobalVariable *GV = dyn_cast<GlobalVariable>(Sel->getArgOperand(OpIdx));
    if (GV != EHCatchAllValue) continue;
    Sel->setArgOperand(OpIdx, EHCatchAllValue->getInitializer());
    Changed = true;
  }

  return Changed;
}

//.........这里部分代码省略.........
            ConstantInt::get(op1->getType(), APInt::getSignedMaxValue(bw));
          Value *int_min_s =
            ConstantInt::get(op1->getType(), APInt::getSignedMinValue(bw));
          Value *int_max =
            builder.CreateSExt(int_max_s, IntegerType::get(M.getContext(), bw2));
          Value *int_min =
            builder.CreateSExt(int_min_s, IntegerType::get(M.getContext(), bw2));

          if (ii->getIntrinsicID() == Intrinsic::sadd_with_overflow){
            result_ext = builder.CreateAdd(op1ext, op2ext);
          } else if (ii->getIntrinsicID() == Intrinsic::ssub_with_overflow){
            result_ext = builder.CreateSub(op1ext, op2ext);
          } else if (ii->getIntrinsicID() == Intrinsic::smul_with_overflow){
            result_ext = builder.CreateMul(op1ext, op2ext);
          }
          overflow = builder.CreateOr(builder.CreateICmpSGT(result_ext, int_max),
                                      builder.CreateICmpSLT(result_ext, int_min));
        }

        // This trunc cound be replaced by a more general trunc replacement
        // that allows to detect also undefined behavior in assignments or
        // overflow in operation with integers whose dimension is smaller than
        // int's dimension, e.g.
        //     uint8_t = uint8_t + uint8_t;
        // if one desires the wrapping should write
        //     uint8_t = (uint8_t + uint8_t) & 0xFF;
        // before this, must check if it has side effects on other operations
        result = builder.CreateTrunc(result_ext, op1->getType());
        Value *resultStruct =
          builder.CreateInsertValue(UndefValue::get(ii->getType()), result, 0);
        resultStruct = builder.CreateInsertValue(resultStruct, overflow, 1);
        
        ii->replaceAllUsesWith(resultStruct);
        ii->removeFromParent();
        delete ii;
        dirty = true;
        break;
      }

      case Intrinsic::dbg_value:
      case Intrinsic::dbg_declare:
        // Remove these regardless of lower intrinsics flag. This can
        // be removed once IntrinsicLowering is fixed to not have bad
        // caches.
        ii->eraseFromParent();
        dirty = true;
        break;

      case Intrinsic::trap: {
        // Intrisic instruction "llvm.trap" found. Directly lower it to
        // a call of the abort() function.
        Function *F = cast<Function>(
          M.getOrInsertFunction(
            "abort", Type::getVoidTy(getGlobalContext()), NULL));
        F->setDoesNotReturn();
        F->setDoesNotThrow();

        CallInst::Create(F, Twine(), ii);
        new UnreachableInst(getGlobalContext(), ii);

        ii->eraseFromParent();

        dirty = true;
        break;
      }
      case Intrinsic::objectsize: {
        // We don't know the size of an object in general so we replace
        // with 0 or -1 depending on the second argument to the intrinsic.
        assert(ii->getNumArgOperands() == 2 && "wrong number of arguments");
        Value *minArg = ii->getArgOperand(1);
        assert(minArg && "Failed to get second argument");
        ConstantInt *minArgAsInt = dyn_cast<ConstantInt>(minArg);
        assert(minArgAsInt && "Second arg is not a ConstantInt");
        assert(minArgAsInt->getBitWidth() == 1 && "Second argument is not an i1");
        Value *replacement = NULL;
        LLVM_TYPE_Q IntegerType *intType = dyn_cast<IntegerType>(ii->getType());
        assert(intType && "intrinsic does not have integer return type");
        if (minArgAsInt->isZero()) {
          // min=false
          replacement = ConstantInt::get(intType, -1, /*isSigned=*/true);
        } else {
          // min=true
          replacement = ConstantInt::get(intType, 0, /*isSigned=*/false);
        }
        ii->replaceAllUsesWith(replacement);
        ii->eraseFromParent();
        dirty = true;
        break;
      }
      default:
        if (LowerIntrinsics)
          IL->LowerIntrinsicCall(ii);
        dirty = true;
        break;
      }
    }
  }

  return dirty;
}