EVM Immediates

[frangio]

I’ve added templates for specifying instructions with approaches 2.2.1:

@frangio

The spec for an instruction I with a one-byte immediate using this approach would consist of a function DECODE_I, with domain DOMAIN_I that excludes at least 5b and 60, …, 7f, and the following addition to the EVM interpreter loop:

When code[pc] is OP_I:

1. Let x = code[pc + 1].
2. If x is not in DOMAIN_I, halt with exceptional failure.
3. Let y = DECODE_I(x).
4. Apply instruction I(y).
5. Set pc = pc + 2.

and 2.2.3:

@frangio

The spec for an instruction I with a one-byte immediate using this approach would consist of the following addition to the EVM interpreter loop:

When code[pc] is OP_I:

1. If code[pc + 1] != OP_PUSH1, halt with exceptional failure.
2. Let x = code[pc + 2].
3. Apply instruction I(x).
4. Set pc = pc + 3.