Files
revive/CHANGELOG.md
T
98d818f958 The new Yul optimizer toolkit (#519)
This PR introduces powerful code size optimizations. This is achieved
with an additional IR layer in between Yul and LLVM IR. It works quite
well (see below for a comparison) because it captures optimization gains
that neither solc nor LLVM can realize.

The feature is gated behind `--newyork` or a corresponding standard JSON
input setting and **off by default**.

### How it works

We implemented an SSA IR modelled after or inspired by the [MLIR SCF
dialect](https://mlir.llvm.org/docs/Dialects/SCFDialect/). Yul is
translated into this IR and the IR implements mainly the following
optimizations:

- **Type narrowing**: narrows 256-bit values to I1..I160 where provable
(bidirectional + interprocedural), so LLVM emits native 32/64-bit ops
instead
    of software 256-bit arithmetic.
- **FMP range proof**: exposes the `mload(0x40) < heap_size` bound to
LLVM
IPSCCP, eliminating trailing overflow checks on FMP-derived offsets.
Single
    largest code-size contributor.
- **Heap analysis**: skips big-endian byte-swaps where native
little-endian
    layout is safe.
  - **mem_opt / keccak fusion+folding**, **compound outlining** (mapping
sload/sstore), **guard narrowing**, **inlining** tuned for PolkaVM, and
    **exact + fuzzy function dedup**.

### Results
The optimizations implemented with the newyork IR bring substantial code
size improvements.
  - Integration contracts: approximately **-20% to -50%** code size.
  - OpenZeppelin Wizard corpus: around **-47%** code size.

This table shows the code size improvements on various OpenZeppelin ERC
implementations, taken from their [contracts
wizard](https://wizard.openzeppelin.com/), with almost all features
enabled.

| Contract | Default: (bytes) | With `--newyork`: (bytes) | Reduction |
|---|---:|---:|---:|
| erc1155 | 59,206 | 30,649 | -48.2% |
| erc20 | 81,697 | 42,893 | -47.5% |
| erc721 | 92,052 | 49,423 | -46.3% |
| oz_gov | 141,861 | 81,159 | -42.8% |
| oz_rwa | 77,274 | 37,975 | -50.9% |
| oz_simple_erc20 | 29,950 | 16,554 | -44.7% |
| oz_stable | 82,117 | 39,032 | -52.5% |
| **Total** | **564,157** | **297,685** | **-47.2%** |

We believe this to be a reasonably representative dataset and conclude
that the newyork IR achieves drastic code size reductions on real world
dApp implementations.

### Methodology, security and runtime performance

Since the main contributors to these improvements are the FMP range
proofs and the type narrowing, we don't expect big runtime performance
regressions (it may even benefit runtime performance in some cases).

The PR also includes docs
(`book/src/developer_guide/newyork_{optimizer,ir}.md`) and many new
integration tests, including regression tests for known FMP soundness
traps.

The PR was authored collaboratively and reviewed extensively by the
`revive` maintainers, as well as Claude Opus, Claude Fable, Qwen,
Minimax and Deepseek LLMs, over a span of many months.

The `newyork` compiler pipeline introduces no new regressions over our
integration and differential test suites (containing over 30000 test
cases). This was achieved by careful manual reviews and many LLM bughunt
loops. Additionally, a final security review by Anthropic's Fable 5 LLM
found no remaining soundness issues. Nonetheless, like any brand new
software, please consider this an experimental feature upon release.

---------

Signed-off-by: xermicus <bigcyrill@hotmail.com>
Signed-off-by: xermicus <cyrill@parity.io>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: neo <me@90f9.org>
Co-authored-by: LJ <81748770+elle-j@users.noreply.github.com>
2026-06-17 12:35:16 +02:00

14 KiB

Changelog

Unreleased

Supported polkadot-sdk rev: 2604.2.0

Changed

  • Updated polkadot-sdk to 2604.2.0

Added

  • Experimental newyork IR optimization pipeline, selectable via the --newyork CLI flag or the settings.polkavm.newyork standard JSON input field. Off by default. #519

v1.2.0

Supported polkadot-sdk rev: 2603

Changed

  • Updated LLVM from 21.1.8 to LLVM 22.1.4

Added

  • Support for solc v0.8.35.

Fixed

  • A constant folding bug causing incorrect translation of a signed remainder edge case. The affected pattern (Solidity % or Yul smod):
    • SREM over the two constant operands type(int256).min and -1.
    • At least one of the two constants needs folding (i.e. not just type(int256).min % -1), and is written specifically such that solc doesn't fold but LLVM does, resulting in UB (signed-overflow).
  • Fix mulmod returning out-of-range result for large moduli.

v1.1.0

Supported polkadot-sdk rev: 2603

Added

  • Support for solc v0.8.34.
  • Inherit STDERR in recursive processes, allowing debug logs to be printed to the console #485

Fixed

  • npm package: The --bin CLI flag was not producing bytecode because the outputSelection was not updated to explicitly requested it.
  • Yul mode now properly exits when solc reports validation errors (e.g., invalid hex literals), matching --standard-json behavior. #477
  • Fixed a bytecode divergence (yet functionally equivalent) between the resolc Linux/macOS builds and the Windows build for Solidity contracts containing a value multiplied by itself (e.g. via explicit squaring or exponentiation), manifesting primarily when using optimization level -O0. #500
  • Recursive processes use the current executable by default #484
  • Work around some LLVM indeterminism problem #500

Changed

  • Updated LLVM from 18.1.8 to LLVM 21.1.8
  • Updated musl to 1.2.5
  • Updated inkwell to 0.8.0
  • Updated polkavm-* to 0.31.0
  • Updated EMSDK to 5.0.0
  • Switched building LLVM for Windows from Visual Studio to MSVC-compatible Clang (clang-cl) and Ninja. #497
  • Append optnone and noinline for -O0 optlevel #502

v1.0.0

Supported polkadot-sdk rev: unstable2507

Changed

  • Removed the revive-explorer utility.

Fixed

  • OOB access in calldataload and calldatacopy should always produce zero values instead of consuming all gas.
  • The superfluous byte swap in linkersymbol.
  • Compiling with --standard-json now compiles to PolkaVM bytecode only for the contracts explicitly requested in the outputSelection, significantly improving compilation time when none or a subset of files requests bytecode. PR#461
  • Compiling with --standard-json now outputs only the explicitly requested output (e.g. evm.assembly, evm.bytecode, ast, etc.). PR#461
// Example:
{
  "settings": {
    // ...
    "outputSelection": {
      "path/to/my/file1.sol": {
        // Contracts in this file will generate bytecode.
        // Only these fields of the JSON output selection will be in the `contracts` output.
        "*": ["abi", "evm.methodIdentifiers", "metadata", "evm.bytecode"],
        // Only this field of the JSON output selection will be in the `sources` output.
        "": ["ast"]
      },
      "path/to/my/file2.sol": {
        // No contracts in this file will generate bytecode.
        "*": ["abi", "evm.methodIdentifiers", "metadata"],
        // No `ast` will be in the `sources` output (only the automatically added `id`,
        // similar to solc as this is not a configurable output selection).
        "": []
      },
    }
  }
}

v0.6.0

This is a development pre-release.

Supported polkadot-sdk rev: unstable2507

Added

Changed

  • Instruct the LLVM backend and linker to --relax (may lead to smaller contract code size).
  • Standard JSON mode: Don't forward EVM bytecode related output selections to solc.
  • The supported polkadot-sdk release is unstable2507.
  • The INVALID opcode and OOB memory accesses now consume all remaining gas.
  • Emit the call_evm and delegate_call_evm syscalls for contract calls.
  • The revive-runner can execute arbitrarily large contract blobs.
  • Set the default PolkaVM stack and heap size values to 128KB.

Fixed:

  • The missing STOP instruction at the end of code blocks.
  • The missing bounds check in the internal sbrk implementation.
  • The call gas is no longer ignored.
  • The settings.polkavm.memoryConfig object and its fields are now in camelCase.

v0.5.0

This is a development pre-release.

Supported polkadot-sdk rev: 2509.0.0

Added

  • Support for SELFDESTRUCT.

Changed

  • Emulated EVM heap memory accesses of zero length are never out of bounds.
  • Switched to newer and cheaper storage syscalls (omits reads and writes of 0 values).

Fixed

  • Introduced a workaround avoiding compiler crashes caused by a bug in LLVM affecting SDIV.
  • An off-by-one bug affecting SDIV overflow semantics.

v0.4.1

This is a development pre-release.

Supported polkadot-sdk rev: 2503.0.1

Changed

  • The ast output is no longer pruned in standard JSON mode (required for foundry).
  • Support standard_json.output_selection to also look at per file settings.

v0.4.0

This is a development pre-release.

Supported polkadot-sdk rev: 2503.0.1

Changed

  • Remove the broken --llvm-ir mode.
  • Remove the unused fallback for size optimization setting.
  • Unlinked contract binaries are emitted as raw ELF objects.

Added

  • Line debug information per YUL builtin and for if statements.
  • Column numbers in debug information.
  • Support for the YUL optimizer details in the standard json input definition.
  • The revive-explorer compiler utility.
  • revive-yul: The AST visitor interface.
  • The --link deploy time linking mode.

Fixed

  • The debug info source file matches the YUL path in --debug-output-dir, allowing tools to display the source line.
  • Incosistent type forwarding in JSON output (empty string vs. null object).
  • The solc automatic import resolution.
  • Compiler panic on missing libraries definition.

v0.3.0

This is a development pre-release.

Supported polkadot-sdk rev: 2503.0.1

Fixed

  • llvm-context: Bugfix the SAR YUL builtin translation.
  • runtime-api: Add the missing memset builtin.
  • npm package: Bugfix the exports field defined in the package.json.

v0.2.0

This is a development pre-release.

Supported polkadot-sdk rev: 2503.0.1

Changed

  • Removed the license printer from the resolc binary.
  • EVM bytecode is no longer requested from solc (except in test utils) leading to less compilation work in the pipeline.

Fixed

  • solc-json-interface: Serializing of any custom key in the JSON input is only skipped if not provided.
  • npm package resolution no longer fails with an 'ERR_PACKAGE_PATH_NOT_EXPORTED' error for packages defining exports fields in the package.json.

v0.1.0

This is a development pre-release.

Supported polkadot-sdk rev: 2503.0.1

Added

  • Add the PolkaVM heap size, stack size and debug info CLI compiler options to the standard JSON settings. This makes the standard JSON input succint for reproducible builds.

Changed

  • Supported polkadot-sdk version is now 2503.0.1
  • The emsdk version is now 4.0.9

Fixed

v0.1.0-dev.16

This is a development pre-release.

Supported polkadot-sdk rev:c29e72a8628835e34deb6aa7db9a78a2e4eabcee

Added

  • Move the npm package from paritytech/js-revive, into this repo. The package @parity/resolc will be deployed to npm for each release.
  • Support for solc v0.8.30

Changed

  • By default, heavy size optimizations are applied.

Fixed

  • @parity/resolc: The solc dependency package is constrained to the latest supported version, preventing breaking the package ever time a new solc package was released.
  • The resolc npm package no longer ignores the optimizer settings

v0.1.0-dev.14

This is a development pre-release.

Supported polkadot-sdk rev:c29e72a8628835e34deb6aa7db9a78a2e4eabcee

Added

  • The revive-runner helper utility binary which helps to run contracts locally without a blockchain node.
  • Allow configuration of the EVM heap memory size and stack size via CLI flags and JSON input settings.

Changed

  • The default PVM stack memory size was increased from 16kb to 32kb.

Fixed

  • Constructors avoid storing zero sized immutable data on exit.

v0.1.0-dev.13

This is a development pre-release.

Supported polkadot-sdk rev:c29e72a8628835e34deb6aa7db9a78a2e4eabcee

Added

  • Support for solc v0.8.29
  • Decouples the solc JSON-input-output type definitions from the Solidity fronted and expose them via a dedicated crate.
  • --supported-solc-versions for resolc binary to return a semver range of supported solc versions.
  • Support for passing LLVM command line options via the prcoess input or providing one or more --llvm-arg='..' resolc CLI flag. This allows more fine-grained control over the LLVM backend configuration.

Changed

  • Storage keys and values are big endian. This was a pre-mature optimization because for the contract itself it this is a no-op and thus not observable. However we should consider the storage layout as part of the contract ABI. The endianness of transient storage values are still kept as-is.
  • Running resolc using webkit is no longer supported.

Fixed

  • A missing byte swap for the create2 salt value.

v0.1.0-dev.12

This is a development pre-release.

Supported polkadot-sdk rev: 21f6f0705e53c15aa2b8a5706b208200447774a9

Added

  • Per file output selection for --standard-json mode.
  • The ir output selection option for --standard-json mode.

Changed

  • Improved code size: Large contracts compile to smaller code blobs when enabling aggressive size optimizations (-Oz).

Fixed

v0.1.0-dev.11

This is a development pre-release.

Supported polkadot-sdk rev: 274a781e8ca1a9432c7ec87593bd93214abbff50

Added

Changed

Fixed

  • A bug causing incorrect loads from the emulated EVM linear memory.
  • A missing integer truncate after switching to 64bit.

v0.1.0-dev.10

This is a development pre-release.

Supported polkadot-sdk rev: 274a781e8ca1a9432c7ec87593bd93214abbff50

Added

  • Support for the coinbase opcode.
  • The resolc web JS version.

Changed

  • Missing the --overwrite flag emits an error instead of a warning.
  • The resolc executable prints the help by default.
  • Removed support for legacy EVM assembly (EVMLA) translation.
  • integration: identify cached code blobs on source code to fix potential confusions.
  • Setting base, include or allow paths in emscripten is now a hard error.
  • Employ a heuristic to detect address.transfer and address.send calls. If detected, the re-entrant call flag is not set and 0 deposit limit is endowed.

Fixed

  • Solidity: Add the solc --libraries files to sources.
  • A data race in tests.
  • Fix broken pipe errors.
  • llvm-builder: Allow warnings.
  • solidity: Fix the custom compiler warning messages.

v0.1.0-dev.9

This is a development pre-release.

Added

Changed

  • Syscalls with more than 6 arguments now pack them into registers.

Fixed

  • Remove reloading of the resolc.js file (fix issue with relative path in web worker)

v0.1.0-dev.8

This is a development pre-release.

Added

  • The revive-llvm-builder crate with the revive-llvm helper utility for streamlined management of the LLVM framework dependency.
  • Initial support for running resolc in the browser.

Changed

  • Suported contracts runtime is polkadot-sdk git version d62a90c8c729acd98c7e9a5cab9803b8b211ffc5.
  • The minimum supported Rust version is 1.81.0.
  • Error out early instead of invoking solc with invalid base or include path flags.

Fixed

  • Decouple the LLVM target dependency from the LLVM host dependency.
  • Do not error out if no files and no errors were produced. This aligns resolc closer to solc.
  • Fixes input normalization in the Wasm version.

v0.1.0-dev.7

This is a development pre-release.

Added

  • Implement the GASPRICE opcode.
  • Implement the BASEFEE opcode.
  • Implement the GASLIMIT opcode.

Changed

  • The GAS opcode now returns the remaining ref_time.
  • Contracts can now be supplied call data input of arbitrary size.
  • Some syscalls now return the value in a register, slightly improving emitted contract code.
  • Calls forward maximum weight limits instead of 0, anticipating a change in polkadot-sdk where weight limits of 0 no longer interprets as uncapped limit.

Fixed

  • A linker bug which was preventing certain contracts from linking with the PVM linker.
  • JS: Fix encoding conversion from JS string (UTF-16) to UTF-8.
  • The git commit hash slug is always displayed in the version string.

v0.1.0-dev.6

This is a development pre-release.

Added

  • Implement the BLOCKHASH opcode.
  • Implement delegate calls.
  • Implement the GASPRICE opcode. Currently hard-coded to return 1.
  • The ELF shared object contract artifact is dumped into the debug output directory.
  • Initial support for emitting debug info (opt in via the -g flag)

Changed

  • resolc now emits 64bit PolkaVM blobs, reducing contract code size and execution time.
  • The RISC-V bit-manipulation target feature (zbb) is enabled.

Fixed

  • Compilation to Wasm (for usage in node and web browsers)

v0.1.0-dev.5

This is development pre-release.

Added

  • Implement the CODESIZE and EXTCODESIZE opcodes.

Changed

  • Include the full revive version in the contract metadata.

Fixed

v0.1.0-dev-4

This is development pre-release.

Added

  • Support the ORIGIN opcode.

Changed

  • Update polkavm to v0.14.0.
  • Enable the a, fast-unaligned-access and xtheadcondmov LLVM target features, decreasing the code size for some contracts.

Fixed