Re: [libvirt] [PATCH 1/8] Add virRandom() API to generate numbers with non-power-of-2 limit

> The alternative I wanted to use was drand48_t() which returns a double

> in the range 0.0 -> 1.0, with 48 bits of entropy. You could multiply by > 'max', and cast to int. But this isn't portable and is not fixed by > GNULIB. Might not be too hard to make drand48_r into a gnulib module (harder than clz, but not intractible, so I'll take a shot at it, but no promises). Using drand48_r does still hit non-uniformity due to rounding, but with much smaller fuzz factor (that is, instead of my example of 50/25/25, you'd be more like 25.000004, 24.999993, 24.999993), which I can live with as being in the noise.

No need to do that. -lm already gives us a very nice function: ldexp(). Basically, you take an integer in the range [0,1<<48), then multiply that by 2**-48 using ldexp().