On a hunch, I went back and checked some 2000 C source files that I wrote over 30+years for instances of 'abs' that should have been 'fabs'. To my embarrassment, found more than 20 instances.

That could explain quite a few frustrating experiences with numerical software, such as improper stopping of iterations.

They could have been detected with the gcc -Wfloat-conversion switch, but it took me a decade or two to learn about it...

☹️ #Programming #FloatingPoint #CLibrary #LanguageDesign