[GHC] #15519: Minor code refactoring leads to drastic performance degradation

[GHC]

#15519: Minor code refactoring leads to drastic performance degradation
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        Reporter:  danilo2           |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.8.1
       Component:  Compiler          |              Version:  8.4.3
      Resolution:                    |             Keywords:  SpecConstr
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by sgraf):

 Replying to [comment:21 simonpj]:
 > > Yes, exactly. I'm not happy with doing this (or rather having to
 anticipate doing this), either.
 >
 > I've got lost.  What exactly is "this"? Are you happy with what I
 propose in #15578?

 Sorry, I could have been clearer. TLDR; I'm quite happy, the comment was
 unrelated to anything you wrote.

 In comment:10, I wrote (with a little more context):

 > So, the fix to apply in your situation seems to be to eta-expand test1
 and omit the INLINE pragma.

 That's what @danilo2's comment:15 alludes to when he writes

 >  I strongly disagree with the sentence that the "fix would be to remove
 INLINE pragma" [...] I suspect @sgraf that you didn't mean "fix" but
 instead a "dirty workaround for now", but I preferred to emphasize my
 worries regarding this matter.

 So, by "this" in comment:20, I meant the workaround of manually eta-
 expanding and (more importantly) omitting the INLINE pragma. I'm quite
 happy about #15578 :) Not sure about consequences for library authors
 being used to the old behavior (if they were even aware of it), though.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15519#comment:22>
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