> IEEE754 guarantees 0.5 ULPs of accuracy, and even if the mathematical result happens to lie exactly

1) Yes, newer (2008+) version of IEEE-754 is more strict, but its also too new -

there's still plenty of hardware from before that.

2) "Many real-world implementations of the architectures nearly

support IEEE754, but with caveats like not having the full set of NaNs,

forcing denorms to zero, errors of an ULP or two in multiplication /

division results, having multiplication differ by an ULP or two depending

on operand order etc. So "99% of CPUs are IEEE754 compliant" needs a

disclaimer - the spirit is true and for the purposes of the question you

are correct, but in general the devil is often in the detail. More like,

99% of CPUs are 99% IEEE754 compliant."