[ikken]

This is because running code on Ethereum VM and storing data is hugely expensive (rightly so, as it's being done on all nodes in the world). Therefore Solidity will try to compile into a VM code that uses the least numbers of cheapest instructions and pack data into as small memory package as possible.

[simias]

Most of the issues pointed out by int_19h would be handled at compile time during static analysis and wouldn't change much to the generated bytecode. I'm talking about strong typing, immutability by default, less error-prone syntax, tail calls, evaluation order etc...

Even replacing 256bit ints with arbitrary precision "bigints" wouldn't add too much of a cost if it's a native type of the underlying VM (as it should be for such an application IMO). It might even reduce code size by removing overflow tests.

[int_19h]

It's about costing the operations reliably.

But I would still expect arithmetic to be overflow-checked by default, as in e.g. VB.NET. This would mean that careless arithmetic on unvalidated inputs could still cause the contract to fail - but at least it would be a controllable failure, with all state changes being reversed, and hence not exploitable.

[earlz]

In the rationale document they explain that arbitrary length integers were too difficult to determine a reasonable gas cost around for math etc.

[bigdubs]

"Normal" and "secure" languages don't do this already?