No openmp, no openacc, though that would all be trivial. For linking, my own linker still has a lot of regressions, but is at least 10x faster than shelling out to gcc/ld. Similar to tcc. No linker scripts, no LTO via the native linker. rcc can easily fallback to the gcc linker for such features.

Auto vectorization would need extensive -O3 opts, which I dont do yet. No ssa, no escape analysis. The compiler should stay fast. And I prefer manual vectorization via attributes. Still better than using the insane and platform dependent SSE/neon apis, everyone else is using. See the torture/vect/ tests. They all pass