[llvm-commits] Speeding up instruction selection

[Roman Levenstein]

Hi,

2008/3/27, Evan Cheng <evan.cheng at apple.com>:
>
>  On Mar 26, 2008, at 12:19 PM, Roman Levenstein wrote:
>  >>
>  >
>  > As long as there is a hope, I can wait ;-)
>  > And to use the opportunity, there is my pending patch for
>  > ScheduleDAGRRList.cpp still around (the one, where I suggested to use
>  > std::set instead of priority queues based on heaps, see
>  > http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20080303/059076.html)
>  > .
>  > Evan played with it, but there was a problem with 176.gcc (which is
>  > probably unrelated) and somehow the review is stuck at the moment. It
>  > would be nice to proceed with it. In the meantime, I could commit some
>  > parts of it, that are not related to the std::set and are just obvious
>  > optimizations that cannot break anything, e.g. fix for
>  > SumOfUnscheduledPredsOfSuccs.
>
>
>  Unfortunately your patch is triggering a bug somewhere which breaks
>  176.gcc. Dan is trying to track it down but it's illusive. We don't
>  know what part of your patch is causing this so it's best not to check
>  anything in. I'm sure we'll eventually figure out the issue. Thanks
>  for your patience.

OK. It is a pity that it break the test case, which is not publicly available...
Do you know any other testcases, which are also broken by this patch?
What kind of failure do you have?

> > In the meantime, I could commit some
>  > parts of it, that are not related to the std::set and are just obvious
>  > optimizations that cannot break anything, e.g. fix for
>  > SumOfUnscheduledPredsOfSuccs.

But it is OK to commit this small fix for SumOfUnscheduledPredsOfSuccs
only? This one simply cannot break anything because it does not change
the logic at all. It just stops iterations earlier than in the current
version and thus saves some cycles. And it is so obvious, that you can
immediately see that it is correct.

-Roman