https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109446
--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to Martin Liška from comment #5) > > It seems Clang disables this optimization and convert memcpy to > > __asan_memcpy calls if -fsanitize=address used: > > > > https://godbolt.org/z/dcfadoMYY > > Yep! Richi, do you know a place where we lower this? gimple_fold_builtin_memory_op not sure if we should prevent all of those transforms. But the question is why ASAN doesn't instrument the generated aggregate copy? Maybe because in C/C++ you cannot write an aggregate array copy?
