; rng on clock · free RNG on native CLOCK · FULL BGF
; LINEAR BGS->BGF->SDF · atoms EZZIE PHI THERMO on BGF · free rides · no duo
; samples a,b + TSC · free · never eaten into SDF
; edi=a esi=b → eax = (a^b^tsc_lo)|1 · edx=tsc_hi raw
        rdtsc
        xor     eax, edi
        xor     eax, esi
        or      eax, 1
        ret