https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89208
--- Comment #12 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Bernd Edlinger from comment #11) > (In reply to Andrew Pinski from comment #10) > > This is documented this way: > > https://gcc.gnu.org/onlinedocs/gcc-8.2.0/gcc/Standards.html#index- > > ffreestanding > > > > Most of the compiler support routines used by GCC are present in libgcc, but > > there are a few exceptions. GCC requires the freestanding environment > > provide memcpy, memmove, memset and memcmp. Finally, if __builtin_trap is > > used, and the target does not implement the trap pattern, then GCC emits a > > call to abort. > > but this still transforms valid to invalid code, > since as Alexander pointer out, one can call "f(a,a);" which > gets translated to "memcpy(a,a,8);" which is not valid when > src, and dst overlaps, while *a = *a is. That is PR 32667 already.
