Debug Execution Trace Size of Your Code

Motivation

Execution trace size is critical to the performance of generating zk proof. This doc provides a way to print out the execution trace size of any code when running prove.

Example of code in zkWasm-rust sdk:

extern "C" {
    pub fn wasm_dbg(v:u64);
    pub fn wasm_trace_size() -> u64;
}
pub fn zkmain() {
  int traceSize = wasm_trace_size();
  // TODO: Insert your code here
  wasm_dbg(wasm_trace_size() - traceSize);
}

By compiling the code into a WASM image, you can follow here to run prove on the WASM image. The trace size of your code will show up in cli output.

Alternatively, you can submit your prove task to zkwasmhub, and the wasm_dbg info will show up in the Debug Logs section in the task overview page.