🗒️ Description

EIP-7883: ModExp Gas Cost Increase

This EIP changes the gas cost, so it falls under this category in the checklist. While this category is meant specifically for gas cost changes, I’ve added a broader set of scenarios, similar to what would be done for a new precompile, since the existing tests from Byzantium are incomplete.

Call contexts

• CALL / DELEGATECALL / STATICCALL / CALLCODE
• Transaction Entry-point
• Initcode call: IMO this is unnecessary, since we still need to use *CALL to trigger the precompile in the create/create2 initcode, it is exactly the same testing scenario as the call context one.
• Precompile as Set-code Delegated Address: please check this in eip-7702 test, it is not located in eip-7883 test.

Inputs

• precompile/test/inputs/valid
• precompile/test/inputs/valid/boundary
• precompile/test/inputs/valid/crypto
• precompile/test/inputs/all_zeros
• precompile/test/inputs/max_values
• precompile/test/inputs/invalid
• precompile/test/inputs/invalid/crypto
• precompile/test/inputs/invalid/corrupted

Value Transfer

• Minimum Fee Precompile
• No-Fee Precompile: Do not need this one, as Modexp is not no-fee precompile

Out-of-bounds checks

• precompile/test/out_of_bounds/max
• precompile/test/out_of_bounds/max_plus_one

Input Lengths

• Zero-length Input
• Static Required Input Length: The input length is dynamic
• Dynamic Required Input Length

Gas usage

• Constant Gas Cost: We do not need this one, as the gas cost is dynamic
• Variable Gas Cost: See analysis below
• Excessive Gas: Already have this in benchmark test

Fork transition

• Pre-fork Block Call
• Cold/Warm Precompile Address State: We do not need this one as the Modexp is not a new precompile.

🔗 Related Issues or PRs

Issue #1791, #1790, #1971

✅ Checklist

• All: Ran fast tox checks to avoid unnecessary CI fails, see also Code Standards and Enabling Pre-commit Checks:

  uvx --with=tox-uv tox -e lint,typecheck,spellcheck,markdownlint

• All: PR title adheres to the repo standard - it will be used as the squash commit message and should start type(scope):.
• All: Considered adding an entry to CHANGELOG.md.
• All: Considered updating the online docs in the ./docs/ directory.
• All: Set appropriate labels for the changes (only maintainers can apply labels).
• Tests: Ran mkdocs serve locally and verified the auto-generated docs for new tests in the Test Case Reference are correctly formatted.
• Tests: For PRs implementing a missed test case, update the post-mortem document to add an entry the list.
• Ported Tests: All converted JSON/YML tests from ethereum/tests or tests/static have been assigned @ported_from marker.