[GHC] #11808: nofib's cryptarithm1 regresses due to deferred inlining of Int's Ord operations

[GHC]

#11808: nofib's cryptarithm1 regresses due to deferred inlining of Int's Ord
operations
-------------------------------------+-------------------------------------
        Reporter:  bgamari           |                Owner:
            Type:  task              |               Status:  new
        Priority:  highest           |            Milestone:  8.0.1
       Component:  Compiler          |              Version:  8.0.1-rc3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by bgamari):

 I have not been able to reproduce the regression locally, unfortunately. I
 did a nofib run prior to merging the commit which as far as I remember
 didn't show any major regressions; moreover my attempt at reproducing the
 issue this morning came up (or rather, the change supposedly **improved**
 runtime by 1.7%, although I don't believe this is significant).

 Regardless, according to ghc-speed (which you can reveal by clicking on
 the `=` button in the top right corner) the patch didn't change
 allocations. Judging by the
 [[https://perf.haskell.org/ghc/#graph/nofib/time/cryptarithm1;hl=d1179c4bff6d05cc9e86eee3e2d2cee707983c90|history]]
 of this benchmark it seems to be quite unstable. This could be due to a
 number of things, including caching effects.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11808#comment:2>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler