constant_addr
bool constant_addr(const tnode_t *, const sym_t **, ptrdiff_t *);
if (constant_addr(tn, &unused_sym, &unused_offs))
return constant_addr(tn->u.ops.right, symp, offsp);
if (!constant_addr(tn->u.ops.right, &sym, &offs2))
if (!constant_addr(tn->u.ops.left, &sym, &offs1))
return constant_addr(tn->u.ops.left, symp, offsp);