Added V4 vector helpers (loadV3, storeV3, dot3) and rewrote several
functions to use @Vector(4, f32) operations instead of scalar f64:
- planeNormal: 0.7x -> 1.7x (79 -> 33 cyc) -- V4 cross + normalize
- transformAABox: 0.7x -> 1.2x (118 -> 69 cyc) -- f32 + @min/@max
- evaluatePolynomial: 0.4x -> 0.6x (24 -> 16 cyc) -- drop f64 promotion
- vec3MulScalar: 0.7x -> 0.8x -- V4 splat multiply
- dotProduct/squaredMagnitude: rewritten with dot3 helper
crossProduct reverted from shuffle-SIMD back to scalar -- shuffles added
latency that the x87 pipeline doesn't have (16 vs 13 cyc).
Remaining losers (dotProduct 0.4x, evalPoly 0.6x) are at the function
call overhead floor -- the original x87 is 5-11 cycles, which is close
to bare call/ret cost.
MarcelineVQ
0671ffce02