https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118544
--- Comment #3 from Tibor Győri <tiborgyri at gmail dot com> --- (In reply to Andrew Pinski from comment #2) > The unroll 2 is correct, it was unrolled one time; likewise 3 is unrolled > twice, etc. I suspect you are missunderstanding what the diagnostic is > saying, it is saying unrolled the loop one extra iteration. OK, I guess that does make sense, but it is unexpected that it does not follow the same "counting convention" as the pragma. In the pragma one requests an unroll factor, while the opt-info messages say how many iterations are unrolled. For what its worth, clang reports the unroll factor in its opt-info messages, which feels like the more natural choice of "counting convention" to me.