[GHC] #6135: Unboxed Booleans

[GHC]

#6135: Unboxed Booleans
-------------------------------------+-------------------------------------
              Reporter:  benl        |            Owner:
                  Type:  feature     |           Status:  new
  request                            |        Milestone:  7.8.1
              Priority:  normal      |          Version:  7.4.1
             Component:  Compiler    |         Keywords:
            Resolution:              |     Architecture:  Unknown/Multiple
      Operating System:              |       Difficulty:  Unknown
  Unknown/Multiple                   |       Blocked By:  8103, 8103
       Type of failure:              |  Related Tickets:  #605
  None/Unknown                       |
             Test Case:              |
  primops/should_run/T6135           |
              Blocking:              |
Differential Revisions:              |
-------------------------------------+-------------------------------------
Changes (by dfeuer):

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


Comment:

 It appears that this works as intended for `<#`, `>#`, `<=#`, and `>=#`,
 but not for `==#`. If I write something like

 {{{#!hs
 foo x = tagToEnum# ((x <# 3#) `orI#` (x ># 100#) `orI#`
                     (x ==# 12#) `orI#` (x ==# 15#))
 }}}

 I get (in 7.8.3) Core doing something like

 {{{#!hs
 foo x = case x of
           12# -> True
           15# -> True
           _   -> tagToEnum# ((x <# 3#) `orI#` (x ># 100#))
 }}}

 (with different syntax, or course) and branching assembly to match. If
 this transformation is important in some other context, it would be great
 to have something that acts just like `==#` but that doesn't do that, for
 the  times when we actually don't want it.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6135#comment:93>
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