result of pow2_x is never more precise than double 3 results were exact to double the precision 20 largest ulp errors (stored in a double) 0.50008 ulp for pow2_x(-1018.43343033202154) = 2.63626390289935414e-307) 0.50006 ulp for pow2_x(452.550221940071197) = 1.70290863763683895e+136) 0.50006 ulp for pow2_x(-1014.61548226369439) = 3.71796907874864598e-306) 0.50006 ulp for pow2_x(0.542851097300028895) = 1.45684874261355457) 0.50006 ulp for pow2_x(5.70382075300111158) = 52.1220077586827131) 0.50006 ulp for pow2_x(-9.61575561580165861) = 0.00127458595530803142) 0.50006 ulp for pow2_x(-1019.19748648953521) = 1.55233361249817569e-307) 0.50005 ulp for pow2_x(-9.4605698739031947) = 0.00141933427945074896) 0.50005 ulp for pow2_x(-9.41373350869749892) = 0.00146616835839423042) 0.50004 ulp for pow2_x(9.75062363750088146) = 861.450230055834481) 0.50004 ulp for pow2_x(5.70382075299460034) = 52.1220077584474808) 0.50004 ulp for pow2_x(1020.72748560062882) = 1.86033246234004046e+307) 0.50004 ulp for pow2_x(320.451478020044988) = 2.92083509968003166e+96) 0.50004 ulp for pow2_x(0.845871897599592915) = 1.79735065251026693) 0.50004 ulp for pow2_x(6.4612371465020324) = 88.1102006397767639) 0.50004 ulp for pow2_x(-1018.803082864825) = 2.04038622443202056e-307) 0.50004 ulp for pow2_x(1017.74542579708418) = 2.35451311966485302e+306) 0.50003 ulp for pow2_x(6.45889553499798463) = 87.9673066066054616) 0.50003 ulp for pow2_x(6.78795284349562067) = 110.503851465617203) 0.50003 ulp for pow2_x(-9.09655899430199355) = 0.00182668173123542174) pow2_x14670.50008-1018.433430332021542.63626390289935414e-307