https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/lround-lroundf-lroundl-llround-llroundf-llroundl?view=msvc-170
lround, lroundf, lroundl, llround, llroundf, llroundl | Microsoft Learn
API reference for lround, lroundf, lroundl, llround, llroundf, and llroundl; which rounds a floating-point value to the nearest integer.
llroundfmicrosoftlearn
https://cygwin.com/pipermail/cygwin/2007-August/160512.html
Problem with lroundf()
problem