This is the mail archive of the mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [patch] for PR 18040 (Richard Kenner) writes:

>     Your opinion on my alternative suggestion - hoist the type conversion
>     to the outermost type, thus reducing the nested case to the unnested
>     case - would be appreciated (and please read the whole message before
>     answering the question, because I address another objection below).
> Aside from the issue of possible quadratic behavior, I don't completely
> understand the proposal here, so I can't fully comment on it.  I should
> point out, though, that some of these expressions in practice are
> quite complex: there are lots of implicit conversions and dereferences
> generated by the front end.

If you provide an example which produces a type conversion in the
middle of a chain of dereference expressions, I will endeavor to
clarify what I mean.

>     > This stuff is *very* tricky and, as I said, we've been
>     > throught it before.
>     The PR indicates that the solution which has already been
>     implemented does not work.  Thus, the entire topic is open for
>     reexamination.
> The PR indicates that a particular optimizer has problems with the
> overall approach.  One way of dealing with that is to change the
> approach.  But a more local way is to fix that particular optimizer.

Fair point, however, comments upthread indicate that lots of people
are not happy with the overall approach.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]