Martin Storsjö authored Nov 16, 2016 and Henrik Gramner committed Nov 21, 2016

On iOS, vcmp.f64 can behave as if the register was zero, if the
register (interpreted as a f64), was a denormal number.

The vcmp.f64 (and other VFP instructions) will trap to the kernel
(which is supposed to implement the FP operation, which it apparently
doesn't do properly on iOS) if the value is a denormal. If this happens,
the whole comparison ends up way more costly.