The largest errors over the full binary32 range are after this
patch (on x86_64):
RNDN: libm wrong by up to 9.00e+00 ulp(s) [9] for x=0x1.04c39cp+6
RNDZ: libm wrong by up to 9.00e+00 ulp(s) [9] for x=0x1.04c39cp+6
RNDU: libm wrong by up to 9.00e+00 ulp(s) [9] for x=0x1.04c39cp+6
RNDD: libm wrong by up to 8.98e+00 ulp(s) [9] for x=0x1.4b7066p+7
Inputs that were yielding huge errors have been added to "make check". Reviewed-by: Adhemeral Zanella <adhemerval.zanella@linaro.org>