A request, not a problem…
Many numerical models require tests against machine precision (eg. error controlled Runge Kuttas). It would be really, really useful to have access in device subroutines/functions to the standard F90/95 numeric enquiry functions and elemental functions to manipulate reals:
digits, epsilon, huge, maxexponent, minexponent, precision, radix, range, tiny, exponent, fraction, nearest, rrspacing, scale, set_exponent and spacing.
This is particularly the case as most GPUs are currently single precision, meaning that truncation errors etc. have a habbit of creeping up on you.
No rest for the wicked eh? Seriously though, these would be really, really useful…