Hi, I confirm the patch from Fabian [1] fixes the large error for powf. With that patch applied on top of Newlib 4.0.0, the largest error I get so far is about 160 ulps after a quick test: x,y=0x1.f4fcdap-1,0x1.ee1fe4p+11 [1.61e+02] 160.483 Best regards, Paul [1] https://sourceware.org/pipermail/newlib/2020/018187.html