Cancun support

[RomarQ]

What does it do?

Adds support for a few EIP's included in CANCUN hard-fork.

• Adds 2 new opcodes (TLOAD and TSTORE) for manipulating state that behaves almost identically to storage but is discarded after every transaction.

  • These new instructions were introduced by EIP-1153 and included in Cancun fork.

• Adds a new opcode (MCOPY) for copying memory. Implementing this change will be important in ensuring that the same solidity/vyper contract compiles down to the same bytecode.´

  • This new instruction was introduced by EIP-5656 and included in Cancun fork.

• Changes the behaviour of the self destruct opcode.

  • EIP-6780: SELFDESTRUCT only in same transaction

Are there relevant PRs or issues in other repositories (Polkadot-SDK, Frontier)?

rust-ethereum/evm#278
rust-ethereum/evm#279
rust-ethereum/evm#281
moonbeam-foundation/evm#3
moonbeam-foundation/frontier#205

[github-actions]

Coverage Report

@@                Coverage Diff                 @@
##           master   cancun-support      +/-   ##
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- Coverage   72.87%           72.83%   -0.04%     
  Files         229              229              
+ Lines       70028            70073      +45     
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  Hits        51031            51031              
+ Misses      18997            19042      +45     

Files Changed	Coverage

Coverage generated Fri May 24 10:50:10 UTC 2024

[RomarQ]

Reason for the gas cost decreases in this PR:

The new opcode MCOPY has optimised memory copying.

As example use case, copying 256 bytes costs:

• at least 757 gas pre-EIP-2929 using the identity precompile
• at least 157 gas post-EIP-2929 using the identity precompile
• at least 96 gas using unrolled MLOAD/MSTORE instructions
• 27 gas using EIP-5656 (The changes included in this PR)

According to an analysis of blocks 10537502 to 10538702 on ethereum, roughly 10.5% of memory copies would have had improved performance with the availability of an MCOPY instruction.

Memory copying is used by languages like Solidity and Vyper, where we expect this improvement to provide efficient means of building data structures, including efficient sliced access and copies of memory objects. Having a dedicated MCOPY instruction would also add forward protection against future gas cost changes to CALL instructions in general.