| // include/strata/kernels/dequant_s2.hpp - the S2 decode, host-callable. | |
| // | |
| // S2 is Q2_0's canonical form and 31.64 GiB of the artifact is Q2_0, so this is the hottest decode in the | |
| // engine. Plane layout is docs/pack-format.md's: codes packed 4 per byte LSB-first (element i at byte i/4, | |
| // bits (i%4)*2) and one FP32 scale per group of 64. Decode is `(code - 1) * scale` with the subtraction in | |
| // the INTEGER domain, which is what makes it bit-exact (docs/pack-format.md §3.1). | |
| namespace strata::kernels { | |
| // Decode `n_blocks` S2 blocks. `codes` is n_blocks*16 bytes, `scales` n_blocks floats, `out` n_blocks*64 | |
| // floats. All device pointers. Synchronises before returning, so a caller can read `out` immediately - | |
| // correctness first; overlap is a Phase 3 concern. | |
| void dequant_s2(const uint8_t* codes, const float* scales, float* out, int64_t n_blocks); | |
| } // namespace strata::kernels | |