Hubert, If you have a couple of minutes, can you explain why you multiply the absolute error by cosh(x) in the asinh tests: T y = sinh(x); T z = asinh(y); T absolute_error = abs(z-x); T relative_error = absolute_error*cosh(x); // Why???? T scaled_error = relative_error/epsilon; Without that and using the usual definition of relative error in this case: fabs(z-x)/x Then I see an error of 0.5eps for the case that fails on Linux/AMD64. However with the multiplication by cosh(x) in place (which is a largish value for some of the test inputs) I believe the test will only pass if the error is zero, which is not the case on Linux AMD64. BTW, I'm not familiar with the term "scaled error", I don't see anything useful with a web search either? Thanks, John.