[GHC] #13220: Performance regressions in testsuite from join points

[GHC]

#13220: Performance regressions in testsuite from join points
-------------------------------------+-------------------------------------
        Reporter:  lukemaurer        |                Owner:  lukemaurer
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:  JoinPoints
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by simonpj):

 > Gipeda shows that the build time for GHC itself went up by 13%

 Well that is new and very unwelcome information.

 Some of the `compiler/perf` tests went down quite a bit, a couple
 increased. So I was under the impression that compile time impact was
 slight, and some runtime improvements were jolly big.

 But a 13% increase across the entire build is massive.

 Can we get any insight into what is increasing?   It's hard to konw where
 to start with a single number across the entire build.  A good place to
 look might be binary sizes: if we generate more code then that'll take
 longer to compile.

 Bother.

 Still, there is no good reason that any of this join point stuff should
 cost much more.  Yes, the occurrence analyser is doing a bit more work,
 but not much.  If occ-anal cost 13% more I'd be surprised.  But it'd have
 to cost 100% more to make the entire build take 13% more.  Something is
 fishy.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13220#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler