[GHC] #13344: Core string literal patch regresses compiler performance considerably

[GHC]

#13344: Core string literal patch regresses compiler performance considerably
-------------------------------------+-------------------------------------
        Reporter:  bgamari           |                Owner:  bgamari
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.2.1
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by gridaphobe):

 * cc: gridaphobe (added)


Comment:

 Replying to [comment:3 bgamari]:
 > I asked David look into this a few weeks back; he says that he may have
 seen duplicated strings in Core.
 >
 > `T5837` looks like it would be a good testcase to evaluate this issue
 with.

 FWIW, I noticed this weekend that Phab:D2605 did not enable CSE on the
 floated literals. I think the latest 1% decrease in binary sizes in my
 Phab:D1259 is largely due to enabling CSE on the floated strings.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13344#comment:11>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler