Method updateGas

lib/llvm/compiler.cpp:4199–4241

  }

  void updateGas() noexcept {
    if (LocalGas) {
      auto CurrBB = Builder.getInsertBlock();
      auto CheckBB = LLVM::BasicBlock::create(LLContext, F.Fn, "gas_check");
      auto OkBB = LLVM::BasicBlock::create(LLContext, F.Fn, "gas_ok");
      auto EndBB = LLVM::BasicBlock::create(LLContext, F.Fn, "gas_end");

      auto Cost = Builder.createLoad(Context.Int64Ty, LocalGas);
      Cost.setAlignment(64);
      auto GasPtr = Context.getGas(Builder, ExecCtx);
      auto GasLimit = Context.getGasLimit(Builder, ExecCtx);
      auto Gas = Builder.createLoad(Context.Int64Ty, GasPtr);
      Gas.setAlignment(64);
      Gas.setOrdering(LLVMAtomicOrderingMonotonic);
      Builder.createBr(CheckBB);
      Builder.positionAtEnd(CheckBB);

      auto PHIOldGas = Builder.createPHI(Context.Int64Ty);
      auto NewGas = Builder.createAdd(PHIOldGas, Cost);
      auto IsGasRemain =
          Builder.createLikely(Builder.createICmpULE(NewGas, GasLimit));
      Builder.createCondBr(IsGasRemain, OkBB,
                           getTrapBB(ErrCode::Value::CostLimitExceeded));
      Builder.positionAtEnd(OkBB);

      auto RGasAndSucceed = Builder.createAtomicCmpXchg(
          GasPtr, PHIOldGas, NewGas, LLVMAtomicOrderingMonotonic,
          LLVMAtomicOrderingMonotonic);
#if LLVM_VERSION_MAJOR >= 13
      RGasAndSucceed.setAlignment(8);
#endif
      RGasAndSucceed.setWeak(true);
      auto RGas = Builder.createExtractValue(RGasAndSucceed, 0);
      auto Succeed = Builder.createExtractValue(RGasAndSucceed, 1);
      Builder.createCondBr(Builder.createLikely(Succeed), EndBB, CheckBB);
      Builder.positionAtEnd(EndBB);

      Builder.createStore(LLContext.getInt64(0), LocalGas);

      PHIOldGas.addIncoming(Gas, CurrBB);
      PHIOldGas.addIncoming(RGas, OkBB);
    }
  }

  void updateGasAtTrap() noexcept {
    if (LocalGas) {