[GHC] #9406: unexpected failure for T7837(profasm)

[GHC]

#9406: unexpected failure for T7837(profasm)
-------------------------------------+-------------------------------------
        Reporter:  jrp               |                   Owner:
            Type:  bug               |                  Status:  closed
        Priority:  low               |               Milestone:
       Component:  Test Suite        |                 Version:  7.8.3
      Resolution:  worksforme        |                Keywords:  T7837
Operating System:  Unknown/Multiple  |            Architecture:  x86_64
 Type of failure:  Incorrect result  |  (amd64)
  at runtime                         |               Test Case:  T7837
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
-------------------------------------+-------------------------------------
Changes (by thomie):

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


Comment:

 This seems now fixed, `make TEST=T7837 WAY=prof TEST_HC=ghc-7.10.2`
 succeeds.

 For some reason ghc-7.8 and earlier were firing extra rules when compiled
 with `-prof -auto-all`.

 {{{
 module T9406 where

 class (Fractional a) => Norm a where
   norm :: a -> a

 normalize :: (Norm a) => a -> a
 normalize x = x / norm x
 }}}

 {{{
 $ ghc-7.8.4 -c T9406.hs -fforce-recomp -O -ddump-rule-firings -auto-all
 -prof
 Rule fired: Class op $p1Norm
 Rule fired: Class op norm
 Rule fired: Class op /
 $ ghc-7.8.4 -c T9406.hs -fforce-recomp -O -ddump-rule-firings
 $ ghc-7.10.2 -c T9406.hs -fforce-recomp -O -ddump-rule-firings -auto-all
 -prof
 $ ghc-7.10.2 -c T9406.hs -fforce-recomp -O -ddump-rule-firings
 }}}

 I'm not adding this as a test, since we have T7837 already.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9406#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler