As far as I see, the cosmos source code only defines the number of gas for storage operations. I am not quiet understand the computation you mean here, as cosmos does not support any computationally intensive operations. The reason behind is that smart contract can not run in cosmos and a message can not be divided into atomic operations. You can set a very large gas needed without any limit at will for a newly added type of message (as I see, the amount of gas consumed is defined in message handler and is not related with anything), as long as it is accepted by validators. There is not a standard to evaluate such computation cost even after using gas design, which exists in name only.
Cosmos could work well with absence of gas. To say the least, even if in the future a type of message with high computation is accepted by network, validators could also be capable to evaluate what price they should charge to transaction sender by their own, because operations of all messages are ruled in code . We can leave it to market, and can expect it works better.
Let me restate my point: design of gas is to evaluate cost of transactions better that is hard to know in Turing-complete-smart-contract-supported blockchain. Gas is a standard for the cost evaluation system, while all opeartions is tx can be decomposed into smaller atomic operations that are indivisible units for gas calculation. A miner in Ethereum don’t know what will happen even after he deserializes a transaction, so they should evaluate its price with the help of gas mechanism. However, in cosmos a validator can clearly know the result that a certain kind of message will lead to after receiving and deserializing it. As they have alreay known the price, why should we introduce gas?