Ethereum proposals target 64-bit EVM math and AA solvers

Two Ethereum proposals landed on Ethereum Magicians on October 15: EIP-8442, targeting 64-bit opcodes, and ERC-8420, proposing an AA-Compatible Solver. One goes after computation inside the EVM; the other deals with how account-abstraction transactions get coordinated. The proposals address different layers and were posted on the same date.

EIP-8442 proposes 28 new instructions, each operating on the low 64 bits of its operands. Every new instruction is paired with something already in the EVM, placed at the existing opcode plus 0xC0.

Twenty-eight instructions across 256 possible one-byte opcode values is 10.9375% of the one-byte opcode space.

The rationale is about fit between data types and execution costs. “Not every computation needs 256 bits. Counters, offsets, lengths, and the inner loops of hashes and big-number arithmetic fit in 64, and the EVM makes them pay for 256 at every step,” gcolvin wrote on Ethereum Magicians.

There’s prior art worth flagging. EIP-7937 previously proposed an EVM64 instruction set carrying the same operations and costs as EIP-8442, but encoded behind a prefix byte. EIP-8442 drops the prefix and places each instruction at an existing opcode plus 0xC0 instead. Same stated operation set and costs, different encoding choice.

ERC-8420 is a coordination proposal. Its abstract calls for “a general-purpose Solver that coordinates the execution of User Intents while remaining fully backward-compatible with existing smart wallets.” Users submitUserEnvelopeTx objects containingenvelopeTx; under the proposal’s policies, no changes to wallet interfaces or signing mechanisms would be required.

That compatibility claim puts existing smart-wallet users directly in scope — their interfaces and signing flows would stay unchanged while a Solver coordinates execution of their intents. ERC-7521 is cited among its related Intent standards.