DATA_ALIGNMENT vs. DECL_USER_ALIGNMENT

[Robert Dewar]

>         Interpret "type" as "primitive type" in your nomenclature.  As
> long as the user does not explicitly override the default alignment of the
> primitive type (probably the natural alignment, or whatever the language
> or target ABI specifies), the compiler should not need to annotate the GCC
> type information with an explicit user type.

Wel then there is some other funny behavior, which is that it is widely
understood that provinding a confirming rep clause shoud have no effect
at all on the generated code.

So if it should make no difference to the code whether a confirming rep
clause is given, how can it be possbiule in some cases that it should be
omitted.