https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100363
--- Comment #14 from Linus Torvalds <torva...@linux-foundation.org> --- (In reply to Vineet Gupta from comment #13) > Sorry the workaround proposed by Alexander doesn't seem to cure it (patch > attached), outcome is the same Vineet - it's not the ldd/std that is necessarily buggy, it's the earlier tests of the address that guard that vectorized path. So your quoted parts of the code generation aren't necessarily the problematic ones. Did you actually test the code and check whether it has the same issue? Maybe it changed the address limit guards before that ldd/std? I also sent you a separate patch to test if just upgrading to a newer version of the zlib code helps. Although that may be buggy for other reasons, it's not like I actually tested the end result.. But it would be interesting to hear if that one works for you (again, ldd/std might be a valid end result of trying to vectorize that code assuming the aliasing tests are done correctly in the vectorized loop headers).