https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63937
Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jakub at gcc dot gnu.org --- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> --- /* PR target/63937 */ /* { dg-do compile { target lp64 } } */ /* { dg-options "-O2" } */ void foo (char *p) { p = __builtin_assume_aligned (p, 64); __builtin_memset (p, 0, 0x100000001ULL); } might be better testcase for the testsuite (or, also use one or both the other ones, but guard them with { i?86-* x86_64-* } && lp64, not sure if all 64-bit targets support huge frames. As for the fix, the right fix agreed on IRC is replace unsigned int type for sizes with unsigned HOST_WIDE_INT in the target hook.