New opcodes: RETURNDATASIZE and RETURNDATACOPY

The five-minute read

One action, walked through

1. Open EIP 211 and read the status line before the examples.
2. Write down the rule in one sentence. A fair version of that sentence is: A mechanism to allow returning arbitrary-length data inside the EVM has been requested for quite a while now.
3. Name the object that changes: EVM, RETURNDATASIZE, RETURNDATACOPY.
4. Ask what an old client, an old contract, or an offline counterparty does. If the document is silent, the silence is part of the design.

The argument, unpacked

What has to be true

• You are implementing EIP 211 at the status the text itself states: Final.
• The object that has to change is EVM, RETURNDATASIZE, RETURNDATACOPY. A neighbouring document with a similar name is not this one.
• Constants in the text can be superseded by a later fork. Cite the EIP number and the fork you mean.

What happened after the paper

The source marks this final. That is a statement about the text, not a promise that every wallet or node has shipped it. Later documents can narrow, replace, or ignore this one. Cite the number you mean.

What to check before you use the idea

• What does New opcodes: RETURNDATASIZE and RETURNDATACOPY charge, reject, or redefine on the first touch versus a later one?
• Does a reverted subcall roll the change back?
• Can you point at the object in a client: EVM, RETURNDATASIZE, RETURNDATACOPY?

Terms

EIP 211

The public text titled New opcodes: RETURNDATASIZE and RETURNDATACOPY.

Final

The document's own label for how finished the text is. It is not a market fact.

The problem the paper names

An underpriced or ambiguous EVM rule is not a feature. It is a block that takes longer than the gas limit claimed, or a client that disagrees about the result.

What the design proposes

• A mechanism to allow returning arbitrary-length data inside the EVM has been requested for quite a while now.
• Existing proposals always had very intricate problems associated with charging gas.
• This proposal solves the same problem while at the same time, it has a very simple gas charging mechanism and requires minimal changes to the call opcodes.

How the mechanism is specified

• Taken from the specification, the next constraint is: Existing proposals always had very intricate problems associated with charging gas.
• Locate EVM, RETURNDATASIZE, RETURNDATACOPY in EIP 211 and apply it to one transaction or call.
• Then check the failure the class of rule always has: a node that did not upgrade, a reverted call, a replayed signature, or a peer that does not speak the message.

What this page does not treat as proven

• A gas or opcode change is not a throughput benchmark. It is a relative price and a validity rule.
• Constants in the text can be superseded by a later fork. Cite the EIP number and the fork you mean.
• The source marks this final. That is a statement about the text, not a promise that every wallet or node has shipped it.

Why a venture studio still reads it

Use EIP 211 when a pitch says 'New opcodes: RETURNDATASIZE and RETURNDATACOPY' without saying whether the rule is consensus, policy, or an interface. The number is the citation. The pitch is not.