[GHC] #8973: Fewer CPSZ: lines with -dshow-passes

[GHC]

#8973: Fewer CPSZ: lines with -dshow-passes
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        Reporter:  simonpj           |            Owner:  simonmar
            Type:  bug               |           Status:  new
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  7.6.3
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
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Comment (by ezyang):

 The cause is we're running mapAccumL, calling the CPSZ pass on each
 `CmmGroup` in the stream. The obvious thing is to hoist the print out, but
 the tradeoff is now your debug output when you dump C-- no longer has
 demarcation markers:

 {{{
 *** CPSZ:

 ==================== Post CPS Cmm ====================
 ...

 ==================== Output Cmm ====================
 ...

 ==================== Cmm produced by new codegen ====================
 ...

 *** CPSZ:

 ==================== Post CPS Cmm ====================
 ...

 ==================== Output Cmm ====================
 ...

 ==================== Cmm produced by new codegen ====================
 ...
 }}}

 Maybe we can do something more clever, or maybe it's OK to not have things
 partitioned up this way.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8973#comment:2>
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