https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97571
--- Comment #5 from Mark J Olah <molah at ucar dot edu> --- I reported this in bug #100235, where it was suggested this would be treated as WONTFIX. It seems this bug is reporting on the same issue arising from rttov: https://nwp-saf.eumetsat.int/site/software/rttov/ Whatever is happening inside the AST evaluation in this case is not only extraordinarily inefficient, but also apparently exponential with the size of the fixed array. This can be demonstrated by adjusting N in the test case I added to bug #100235. IMHO, 2000sec is not a reasonable compile time for *any* code, especially something this simple (and arguably correct code that is used in production packages). A quick test shows I can compute ACOS of 10^8 elements in less than a second on any reasonable hardware. We are talking about only 32k elements here, which should be trivial. In any case is there a flag I can add to the compiler to disable this new behavior?
