On Sun, Apr 25, 2004 at 06:30:20AM +1000, Kevin Ryde wrote: > You could change some of those printfs to %a to show the exact bits > coming out, which should show which answer is right. With %a, I get : | mpfr_sqrt_ui differs from sqrt for a=891885598, rnd_mode=GMP_RNDZ | sqrt gives 0x1.d2a1d0a4c79b2p+14, mpfr_sqrt_ui gives | 0x1.d2a1d0a4c79b1p+14 (-1 ulp)