https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90329
--- Comment #9 from Toon Moene <toon at moene dot org> ---
> So with this suggestion, this procedure would be generated without the hidden
> length argument. The brokenness comes from
> call foo("ab")
> which would generate a call to a procedure WITH the hidden string length
> argument. However, this code is perfectly standard conforming, F2018 15.5.2.4
> says that a character dummy argument must have a length less than or equal to
> the actual argument, which is fulfilled by the above (1 <= 2). That is, we
> can't special case len=1 procedures and calls in any way.
And this happens *a lot* in the LAPACK code itself.
Just do a grep -i sgemm on it and you will see it in action.
Perhaps this is the reason why this occurs in the R -> LAPACK boundary code ...
