GEUVSpan stored the four 64-bit plane values, and the reciprocal table's
entries, to arrays one by one and loaded them as vectors, a store
forwarding stall each time, which took most of its time on x86.
CrossSIMD gets LoadS64Low (the low halves of four 64-bit values) and
LoadPairs (four pairs of 32-bit values split into two vectors) to do it
without memory. Wipeout runs about 2% faster.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>