[Bug c/59193] Unused postfix operator temporaries

["mtewoodbury at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59193

Max TenEyck Woodbury <mtewoodbury at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
         Resolution|INVALID                     |---

--- Comment #10 from Max TenEyck Woodbury <mtewoodbury at gmail dot com> ---
There is no VARIABLE, just a TEMPORARY r-value like  all the others that hold
intermediate results.

Also, the LANGUAGE semantics has the operator produce a result, an r-value,
that
has to be represented in some manner, that is, it has a store of some kind.
The machine code generated without optimization is required to put that result
into the store before incrementing the specified l-value. (sub-clause 6.2.5.4)
Optimization is allowed to, but not required to, remove such operations as long
as the change produces no detectable change in the program's results.

Now, stop misrepresenting the standard.  It makes your other pronouncements
less credible.

To go over this again, if a piece of code specifies a postfix operation
conceptually, the original value is stored somewhere.  That stored value is
then
discarded.   Those steps are extraneous and the code would be conceptually
cleaner without them.  As such, their present is a defect, a trivial defect,
but
still a defect.  Using the prefix operator in its place improves to code, again
trivially, but it does improve it.  Such changes may want to cite something as
justification for the change.  This report is such a justification.  Until all
such defects have been removed, it should stay open.