Six months after its activation on February 5, 2024, the Spiral network upgrade has proven stable and successful — bringing Ethereum Classic's EVM to parity with Ethereum's Shanghai execution-layer improvements.
What Spiral Delivered
Spiral (ECIP-1109) implemented seven EIPs from Ethereum's Shanghai upgrade:
- EIP-3651 — Warm COINBASE: Reduced gas cost for accessing the block producer's address from 2,600 to 100 gas. Benefits MEV and staking-related contracts.
- EIP-3855 — PUSH0: New opcode that pushes zero onto the stack at minimal cost. Reduces bytecode size across all new deployments.
- EIP-3860 — Limit and Meter initcode: Caps initcode size at 49,152 bytes and charges 2 gas per 32-byte word. Prevents oversized deployment transactions.
- EIP-4200 — Static Relative Jumps: Introduces RJUMP, RJUMPI, and RJUMPV opcodes for more efficient control flow in EVM bytecode.
- EIP-6049 — Deprecate SELFDESTRUCT: Formal deprecation notice for the SELFDESTRUCT opcode.
Omitted EIPs
As with previous upgrades, ETC excluded PoS-specific changes:
- EIP-4399 (PREVRANDAO): Replaces DIFFICULTY with beacon chain randomness — only applicable to proof-of-stake
- EIP-4895 (Beacon Chain Withdrawals): Validator withdrawals — only applicable to proof-of-stake
Network Impact
Stability
Zero chain splits, zero client incompatibilities. All three ETC clients (Core-Geth, Besu, Fukuii) processed the fork boundary without issues.
Developer Experience
EVM parity with Shanghai means developers can use the latest Solidity compiler features when deploying to ETC. Tools like Hardhat, Foundry, and Remix work without special configuration.
Gas Efficiency
PUSH0 and Warm COINBASE have measurably reduced gas costs for common operations, benefiting all users.
Current Status
Spiral represents ETC's current production EVM level. The next planned upgrade, Olympia, will introduce the treasury funding mechanism via EIP-1559 base fee redirection.