[GHC] #15426: `elemIndex` and `findIndex` still can't fuse

[GHC]

#15426: `elemIndex` and `findIndex` still can't fuse
-------------------------------------+-------------------------------------
        Reporter:  kabuhr            |                Owner:  kabuhr
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:  8.8.1
       Component:  libraries/base    |              Version:  8.4.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
                                     |  testsuite/tests/perf/should_run/T15426.hs
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |  https://phabricator.haskell.org/D5063
-------------------------------------+-------------------------------------

Comment (by Ben Gamari <ben@…>):

 In [changeset:"14817621aae2d45f8272a36b171b9ccce8763bba/ghc" 1481762/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="14817621aae2d45f8272a36b171b9ccce8763bba"
 base: Mark `findIndices` as INLINABLE instead of INLINE (fixes #15426)

 If `findIndices` is marked INLINE in `Data.OldList`, then the unfolded
 versions of `elemIndex` and `findIndex` included in the interface file
 are unfusible (even though `findIndices` itself remains fusible).  By
 marking it INLINABLE instead, elemIndex` and `findIndex` will fuse
 properly.

 Test Plan: make TEST=T15426

 Reviewers: hvr, bgamari

 Reviewed By: bgamari

 Subscribers: rwbarton, carter

 GHC Trac Issues: #15426

 Differential Revision: https://phabricator.haskell.org/D5063
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15426#comment:11>
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