[GHC] #13085: -fregs-graph is ignored but this is undocumented

[GHC]

#13085: -fregs-graph is ignored but this is undocumented
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        Reporter:  jberryman         |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Documentation     |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #13033, #7192     |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by bgamari):

 * related:   => #13033, #7192


Comment:

 Indeed `-fregs-graph` has been a bit of a state of disarray since the
 merge of the new code generator, at which point it regressed in
 performance to the point of being worse than the linear allocator in some
 cases (#7192). At this point the flag was disabled.

 tjakway has been interested in dusting it off so I tried to re-enable the
 flag for 8.0.2, but unfortunately this prompted #13033 which forced me to
 revert the change.

 Regardless, I hadn't noticed that `-fregs-graph` lacked documentation;
 thanks for pointing this out. This should be fixed for 8.2.1, when
 `-fregs-graph` should be finally enabled.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13085#comment:1>
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