result of erfc is more precise than double 1185 out of 1318 times

5 errors <= 1% worse in accum, 49 <= 10%,67 <= 100%, 7 > 100%

5 results were exact to double the precision

20 largest ulp errors (from result in accumulator)
   0.94971 ulp for erfc(4.09194005615609058) = 7.17069916336737953e-09)
   0.93373 ulp for erfc(4.09194005615511269) = 7.17069916342638976e-09)
   0.93058 ulp for erfc(4.09194005615514733) = 7.17069916342429948e-09)
   0.91039 ulp for erfc(4.09194005618304235) = 7.17069916174098031e-09)
   0.82754 ulp for erfc(8.53581457107666353) = 1.49450255392989289e-33)
   0.82677 ulp for erfc(8.53581457105521402) = 1.49450255448085259e-33)
   0.82628 ulp for erfc(8.53581457105480723) = 1.49450255449130143e-33)
   0.82611 ulp for erfc(8.53581457105102892) = 1.49450255458835247e-33)
   0.82499 ulp for erfc(8.53581457101446617) = 1.49450255552751632e-33)
   0.82498 ulp for erfc(8.53581457105533126) = 1.49450255447784113e-33)
   0.82320 ulp for erfc(8.5358145710554485) = 1.49450255447482967e-33)
   0.80647 ulp for erfc(8.53581457105542718) = 1.49450255447537723e-33)
   0.72674 ulp for erfc(2.51097781562342792) = 0.000383684568027650816)
   0.67645 ulp for erfc(2.51097781562352429) = 0.000383684568027452136)
   0.67431 ulp for erfc(2.51097781562945466) = 0.000383684568015225534)
   0.63784 ulp for erfc(12.407681680745986) = 6.25827240510313581e-69)
   0.62435 ulp for erfc(12.4076816807355268) = 6.25827240673270326e-69)
   0.61573 ulp for erfc(6.34157082491694624) = 3.010290017263913e-19)
   0.61479 ulp for erfc(12.4076816807366068) = 6.25827240656443269e-69)
   0.61414 ulp for erfc(12.407681680893587) = 6.25827238210652935e-69)

20 largest ulp errors (stored in a double)
   0.77254 ulp for erfc(10.2580820608537433) = 1.09212414831558143e-47)
   0.64024 ulp for erfc(13.176291413317939) = 1.70021243427565675e-77)
   0.61195 ulp for erfc(11.3632890321314957) = 4.13302455209145918e-58)
   0.58382 ulp for erfc(8.53581457105542718) = 1.49450255447537723e-33)
   0.57682 ulp for erfc(1.36150067734948577) = 0.0541727451067814184)
   0.57268 ulp for erfc(10.2549076072860981) = 1.16596459744643583e-47)
   0.56719 ulp for erfc(13.2373143203469485) = 3.3767335458631898e-78)
   0.55627 ulp for erfc(13.7514437934095604) = 3.06119641470977001e-84)
   0.55619 ulp for erfc(8.72963152758068262) = 5.14727120854811956e-35)
   0.55273 ulp for erfc(2) = 0.00467773498104726536)
   0.55074 ulp for erfc(12.1195662651077818) = 7.5094932858444076e-66)
   0.54923 ulp for erfc(6.33485142953102276) = 3.28133245644700535e-19)
   0.54855 ulp for erfc(12.6359226632482358) = 2.02381423214758009e-71)
   0.54834 ulp for erfc(8.72963152758071992) = 5.14727120854474546e-35)
   0.54812 ulp for erfc(14.850574318911903) = 6.30361684785769994e-98)
   0.54758 ulp for erfc(2.17263150840727404) = 0.00212227646439986598)
   0.54693 ulp for erfc(1.65786532723541868) = 0.0190487467772775879)
   0.54643 ulp for erfc(8.24542979436522394) = 2.02137420636164946e-31)
   0.54627 ulp for erfc(12.407681680893587) = 6.25827238210652935e-69)
   0.54596 ulp for erfc(8.24542979436521506) = 2.02137420636194767e-31)

<tr><td align=left><a href=erfc.res>erfc</a></td><td align=right>1318</td><td align=right>0.77254</td><td>10.2580820608537433</td><td>1.09212414831558143e-47</td></tr>