[GHC] #11222: Teach strictness analysis about `catch`-like operations

[GHC]

#11222: Teach strictness analysis about `catch`-like operations
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        Reporter:  bgamari           |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:  8.2.1
       Component:  Compiler          |              Version:  7.10.3
      Resolution:                    |             Keywords:  Exceptions
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:                    |
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Changes (by dfeuer):

 * status:  closed => new
 * resolution:  fixed =>


Comment:

 This was semantically shady and has been partially reverted. We would like
 to find a way to recover some of the benefits without the downsides. One
 strong possibility is to add a `catchIO#` primop that only catches
 exceptions thrown by `raiseIO#`. Such a primop could be handled more
 aggressively. See
 https://ghc.haskell.org/trac/ghc/wiki/Exceptions/PreciseExceptions.
 Another direction would be to treat `catch#` forms specially in strictness
 analysis, somewhat like `case` expressions.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11222#comment:6>
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