darn

Pseudocode Operation

if 'darn' then
    RT ← random(L)

Programming Note

['The random number generator provides a minimum of 0.5 bits of entropy per bit.', 'For L=0, the random number range is 0:0xFFFFFFFF.', 'For L=1 and L=2, the random number range is 0:0xFFFFFFFF_FFFFFFFE.', 'L=3 is reserved.', 'A raw random number is unconditioned noise source output. A conditioned random number has been processed by hardware to reduce bias.', '32-bit software running in an environment that does not preserve the high-order 32 bits of GPRs across invocations of the system error handler, signal handlers, event-based branch handlers, etc., may use the L=0 variant of darn and interpret the value 0xFFFFFFFF to indicate an error condition.', 'When the error value is obtained, software is expected to repeat the operation. If a non-error value has not been obtained after several attempts, a software random number generation method should be used.']

Example