identity

Question

Who uses the identity precompile and what data sizes are being copied?

Background

identity (0x04) just returns its input data unchanged. It exists as a cheap way to copy data in memory. Gas cost: 15 base + 3 per 32-byte word.

With 14.6 million calls, identity is #3 by call count. But at an average of just 27 gas per call, it's only 0.2% of precompile gas. Most calls copy very small amounts of data.

Investigation

Gas distribution

Since gas scales with input size, the distribution shows how much data is being copied per call.

Top callers

Note: The callers data below covers a smaller window (~6,000 blocks) because the self-join query needed to resolve parent contracts is too expensive to run over the full range. The gas distribution above uses the full 426K-block range.

Takeaways

• identity is #3 by call count (14.6M) but negligible gas (0.2% of total)
• Average 27 gas per call means most copies are tiny (1 word or less)