pub fn pow2_ceil(v: f32) -> f32
2 ** ceil(log2(v)) for positive normal f32 via the IEEE fields, as fast_log2_ceil / fast_pow2 in kernel.py:22-35 (and _pow2_ceil_log2 in the shims).
2 ** ceil(log2(v))
fast_log2_ceil
fast_pow2
_pow2_ceil_log2