Add EXP and SIGNEXTEND.

[tcrypt25519]

No description provided.

[semanticdiff-com]

Review changes with  

Changed Files

File	Status
.github/workflows/ci.yml	19% smaller
crates/jet/tests/test_roms.rs	1% smaller
Cargo.lock	Unsupported file format
crates/jet/src/builder/env.rs	0% smaller
crates/jet/src/builder/ops.rs	0% smaller
crates/jet/src/engine/mod.rs	0% smaller
crates/jet/tests/roms/mod.rs	0% smaller
crates/jet_runtime/Cargo.toml	Unsupported file format
crates/jet_runtime/src/builtins.rs	0% smaller
crates/jet_runtime/src/runtime_builder.rs	0% smaller
crates/jet_runtime/src/symbols.rs	0% smaller
docs/process/new-opcode.md	Unsupported file format
scripts/install-llvm.sh	Unsupported file format

[gemini-code-assist]

Summary of Changes

Hello @tcrypt25519, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly enhances the arithmetic capabilities of the system by adding a new EXP (exponentiation) operation and completing the implementation of the SIGNEXTEND operation. These changes enable more complex mathematical computations, particularly involving large integers, within the JIT execution environment. The integration of the ruint library underpins these new functionalities, providing robust support for arbitrary-precision arithmetic.

Highlights

• New EXP (Exponentiation) Operation: Introduced a new EXP operation to perform modular exponentiation on 256-bit integers within the JIT execution environment.
• SIGNEXTEND Implementation: The SIGNEXTEND operation, previously a placeholder, has been fully implemented to correctly handle sign extension for 256-bit integers.
• Ruint Library Integration: Integrated the ruint library for arbitrary-precision unsigned integers, which is fundamental for handling large number arithmetic in the new EXP operation.

Changelog

• Cargo.lock
  • Added numerous new dependencies, including alloy-rlp, ark-ff (multiple versions), bitvec, bytes, fastrlp (multiple versions), num-bigint, num-traits, parity-scale-codec, proptest, rand (multiple versions), ruint, uint, and zerocopy, to support the new arithmetic operations.
  • Updated several syn and semver related dependencies to specific versions (e.g., syn 2.0.114, semver 0.11.0, semver 1.0.27).
• crates/jet/src/builder/env.rs
  • Added exp: FunctionValue<'ctx> to the Symbols struct.
  • Initialized the exp function by retrieving jet_runtime::symbols::FN_EXP from the module.
  • Provided a public getter exp() for the new exponentiation function.
• crates/jet/src/builder/ops.rs
  • Implemented the exp function to pop base and exponent from the stack, call the runtime exp function, and push the result.
  • Provided a full implementation for the signextend function, including logic for clamping and arithmetic shifts to achieve proper sign extension for 256-bit integers.
• crates/jet/src/engine/mod.rs
  • Mapped the exp symbol to the builtins::jet_ops_exp runtime function within the JIT engine.
• crates/jet_runtime/Cargo.toml
  • Added ruint = "1" as a direct dependency to enable arbitrary-precision integer arithmetic.
• crates/jet_runtime/src/builtins.rs
  • Implemented the jet_ops_exp extern "C" function, which performs exponentiation using ruint::aliases::U256 and stores the result in a 32-byte array.
• crates/jet_runtime/src/runtime_builder.rs
  • Added the jet.ops.exp function to the LLVM module with its specified signature.
• crates/jet_runtime/src/symbols.rs
  • Defined the symbolic constant FN_EXP as 'jet.ops.exp'.

Activity

• The pull request introduces a new EXP operation and completes the SIGNEXTEND implementation.
• Significant changes were made to dependency management, particularly the addition of the ruint library and its transitive dependencies, to support large integer arithmetic.
• Modifications span across the jet and jet_runtime crates, affecting the JIT builder, engine, runtime functions, and symbol definitions.

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[gemini-code-assist]

Code Review

This pull request introduces implementations for the EXP and SIGNEXTEND EVM opcodes. While the SIGNEXTEND implementation appears correct, a critical endianness mismatch has been identified in the jet_ops_exp builtin function. The EXP implementation incorrectly treats values as big-endian, despite the VM using host-endianness (little-endian) for stack and memory. This will lead to incorrect results for the EXP instruction on little-endian platforms and must be addressed. The overall structure of the changes is good, with one minor suggestion for readability.

[Copilot]

Pull request overview

Adds runtime/JIT plumbing to support the EVM EXP opcode by introducing a new runtime symbol and builtin, wiring it into the JIT symbol map, and updating the IR builder to call it. The PR also includes an implementation of SIGNEXTEND in the IR builder.

Changes:

• Add new runtime symbol jet.ops.exp and declare it in the runtime LLVM module.
• Implement jet_ops_exp builtin and link it into the JIT symbol mapping.
• Implement SIGNEXTEND IR generation in crates/jet/src/builder/ops.rs.

Reviewed changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
crates/jet_runtime/src/symbols.rs	Adds FN_EXP symbol name for runtime lookup.
crates/jet_runtime/src/runtime_builder.rs	Declares external builtin jet.ops.exp in the runtime module.
crates/jet_runtime/src/builtins.rs	Adds jet_ops_exp runtime implementation.
crates/jet_runtime/Cargo.toml	Introduces ruint dependency for U256 math.
crates/jet/src/engine/mod.rs	Maps jet.ops.exp symbol to the Rust builtin in the JIT engine.
crates/jet/src/builder/ops.rs	Emits IR to call EXP builtin and implements SIGNEXTEND in IR.
crates/jet/src/builder/env.rs	Loads and exposes the new exp runtime function symbol.
Cargo.lock	Updates lockfile for the new dependency graph.