The author discovered a performance quirk while refining a quicksort routine in Clang. The compiler aggressively optimizes loops that use branch‑free logic, so the code adopts a style that eliminates conditional jumps.

The implementation relies on a series of macros—sort2 through sort12—to build sorting networks for up to twelve elements. Partitioning functions use a median‑of‑five selector (med5) and thresholds like SMALLPART 1024, UNROLL 16, and SWSZ 512 to decide between recursive quicksort and in‑place sorting networks. Unrolled loops process chunks of 16 elements, while a small partition routine copies a buffer of size 1024 for local sorting.

Because the algorithm avoids branch mispredictions, it delivers predictable latency on modern CPUs. The code is MIT‑licensed and compiles cleanly with -O3 in Clang, making it a drop‑in replacement for standard library sort functions in performance‑critical paths.

The technique demonstrates that microπόoptimizing loops—čina unrolling, branch‑free predicates, and custom sorting networks—can yield measurable throughput gains in tight loops, encouraging developers to profile branchողների behavior before relying on compiler defaults.