https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71514
--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> --- The following ICEs int a, b; int main (int n) { int foo[n]; __atomic_exchange (&a, &foo, &b, __ATOMIC_RELAXED); return 0; } t.c:8:5: internal compiler error: in tree_to_uhwi, at tree.c:7343 __atomic_exchange (&a, &foo, &b, __ATOMIC_RELAXED); ^~~~~~~~~~~~~~~~~ 0x11c50be tree_to_uhwi(tree_node const*) /space/rguenther/src/svn/trunk/gcc/tree.c:7343 0x857a48 get_atomic_generic_size /space/rguenther/src/svn/trunk/gcc/c-family/c-common.c:10988 0x857db1 resolve_overloaded_atomic_exchange /space/rguenther/src/svn/trunk/gcc/c-family/c-common.c:11098 0x858594 resolve_overloaded_builtin(unsigned int, tree_node*, vec<tree_node*, va_gc, vl_embed>*) /space/rguenther/src/svn/trunk/gcc/c-family/c-common.c:11394 0x7a0708 c_build_function_call_vec(unsigned int, vec<unsigned int, va_heap, vl_ptr>, tree_node*, vec<tree_node*, va_gc, vl_embed>*, vec<tree_node*, va_gc, vl_embed>*) /space/rguenther/src/svn/trunk/gcc/c/c-typeck.c:3150