[GHC] #14103: Retypechecking the loop in --make mode is super-linear when there are many .hs-boot modules

[GHC]

#14103: Retypechecking the loop in --make mode is super-linear when there are many
.hs-boot modules
-------------------------------------+-------------------------------------
           Reporter:  duog           |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.3
           Keywords:  hs-boot        |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 At time of writing master is at commit
 14457cf6a50f708eecece8f286f08687791d51f7.

 In GhcMake.hs, both upsweep and parUpsweep call getModLoop for each
 module. getModLoop is (at least) linear when called on a .hs-boot
 ModSummary. See comments in Phab:3646.

 This isn't a big deal in practice, since .hs-boot modules are uncommon,
 but it does irk me, and it will be easy to fix. Fixing this would also be
 an opportunity to de-duplicate some logic in upsweep and parUpsweep.

 ccing niteria as he has worked with this code recently.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14103>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler