Why does "Normalize" take so long?

Could the “Normalize” module be accelerated to multicore CPU or even GPU calculation (okay, 32-bit accuracy might be a problem there)?

Filesize 1,4 GB
Timing:
Wavelab 12.0.40 → 3 seconds
Audacity 3.7 → 4 seconds
Spectral Layers 11.0.40 → 38 seconds

Even though Wavelab and Audacity also seem only single tasking the normalization, but they are a lot faster (around 10 times faster!), than Spectral Layers.