Alexandru Chitu

this is biiiig. found by AI 🤖.

a small VM change that Rust contract devs will feel: bulk memory is coming to the MultiversX executor. until now, the VM's opcode list did not allow memory.copy and memory.fill. so when a contract copies or clears a buffer, the WASM does it with a loop of loads and stores. more instructions, more gas, bigger code. the new work in mx-vm-executor-rs does three things: 1. opcode sets are now versioned. V1 is the old list and stays the default. V2 adds memory.copy and memory.fill. memory.init and data.drop stay out. only what is needed. a module using memory.copy is rejected under V1 and accepted under V2, and there is a test for exactly that. 2. the new opcodes get their own gas formula: base cost + bytes × per-byte cost. the base cost is charged even for a zero-byte copy, so nobody gets free calls. 3. the experimental executor moves to Wasmer 7.5, with a shared limit of 4,000 locals per function and boundary tests for both executors. how come it is versioned, and not simply switched on? every validator has to agree on which modules are valid and what each instruction costs, down to the byte. so a new WASM feature arrives as one explicit config that the whole network moves to together. what is still open: integrating the new executor into the Go VM (mx-chain-vm-go #990) is in review. for contract devs: cheaper copies and smaller contracts, once the network and your build target V2.