3 articles
Llama.cpp's PR #22423 landed a kernel fusion for RMS_NORM + MUL in the ggml CPU backend a few weeks ago. The speedup: 1.60×. Consistently. Across dimension sizes, thread counts, even hardware variatio
I manually unrolled a byte-counting loop with four independent accumulators — the textbook ILP optimization — and it ran 2.08x *slower* than the plain loop. The plain loop that GCC had quietly autovec
That's the whole story. I took a virtual-dispatch interpreter loop — the textbook PGO target — instrumented it, trained it on a representative workload, and recompiled. Both GCC 15.2.1 and Clang 21.1.
