NVIDIA's enc1 and enc2 clamp the patch merge's result to ±2π (as f16) before
its e4m3 encoding (max.f16x2 / min.f16x2 with 0fC0C90FDB / 0f40C90FDB after the
merge's last MMA). The native layers did not, in either template or set:
merge_clamp (swin_common.h) now does, at the three sites that encode the merged
tokens (swin_block.h's e4m3-activation and f16 paths, swin_tok.h), and
swin_check.py's model clamps the same way.
Measured on an RX 9070 XT against a run with no native kernels (preset L,
accuracy set, the flags of Ghost of Tsushima, 1280x720 -> 3840x2160, one
frame): native enc1 alone 34 dB and enc2 alone 31 dB from the translated
kernels before, byte-identical after; the whole native set 28 -> 80 dB (the
rest is dec1, 0.09% of the output values). Preset M's fast set against
translated M: 30.8 -> 35.1 dB after 30 frames. The gfx11 path has the same
change and was not run on hardware.
The repo's tests pass (36, 3 skipped).
woutermans
934fb486c7