# Branch Loop Benchmark Scaffold

Release: `exp-40`; Common Lisp/SBCL comparison added by `exp-41`; hot-loop
mode added by `exp-42`.

This benchmark compares a deterministic branch-heavy integer loop across
Slovo, C, Rust, Python, Clojure, and Common Lisp/SBCL on the same machine.

It is not a published benchmark result, performance threshold, optimizer
claim, or cross-machine comparison.

All implementations print checksum `1185071` for loop count `1000000`.
Hot-loop mode uses loop count `10000000` and checksum `220775`. The runner
supplies the loop count at runtime.

## Comparison Method

- The runner builds each implementation once before timing. The reported
  numbers measure execution only, not compile time.
- Slovo timings use `glagol build`, which currently lowers to LLVM and then
  invokes host `clang -O2` with `runtime/runtime.c`.
- C timings use `clang -O2 -std=c11`.
- Rust timings use `rustc -C opt-level=3 -C debuginfo=0`.

Timing is cold-process local-machine evidence only. Clojure timings include
JVM and Clojure startup, while Common Lisp timings include SBCL script
startup.

Hot-loop mode is startup-amortized local evidence. It reports total time plus
normalized time for the base `1000000` loop count.
