[Bug middle-end/71514] ICE on C11 code with atomic exchange at -O1 and above on x86_64-linux-gnu: in copy_reference_ops_from_ref, at tree-ssa-sccvn.c:879

[rguenth at gcc dot gnu.org]

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