[GHC] #7366: Strange data corruption with HEAD

[GHC]

#7366: Strange data corruption with HEAD
---------------------------------+------------------------------------------
 Reporter:  bgamari              |          Owner:                  
     Type:  bug                  |         Status:  new             
 Priority:  normal               |      Component:  Compiler        
  Version:                       |       Keywords:                  
       Os:  Unknown/Multiple     |   Architecture:  Unknown/Multiple
  Failure:  Building GHC failed  |       Testcase:                  
Blockedby:                       |       Blocking:                  
  Related:                       |  
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Comment(by bgamari):

 Here is my bisection log.
 {{{
 git bisect start
 # good: [176a360031e1e7ef4d49ff18f1dd3e32ce4f56d9] Fix typo
 git bisect good 176a360031e1e7ef4d49ff18f1dd3e32ce4f56d9
 # bad: [0b3811c093736950c1d2757fb12dba60f9bf97ca] typo
 git bisect bad 0b3811c093736950c1d2757fb12dba60f9bf97ca
 # good: [2c2be637206cb1d58f4fc8a4a2e717e419c9fa5d] comments only
 git bisect good 2c2be637206cb1d58f4fc8a4a2e717e419c9fa5d
 # bad: [88a6f863d9f127fc1b03a1e2f068fd20ecbe096c] Small optimisation:
 always sink/inline reg1 = reg2 assignments
 git bisect bad 88a6f863d9f127fc1b03a1e2f068fd20ecbe096c
 # good: [2471a6bacccdf4d187aa4b31c382d5a5094b6fa5] Use canned heap checks
 to save a few bytes of code
 git bisect good 2471a6bacccdf4d187aa4b31c382d5a5094b6fa5
 # good: [2324b40f65b5cb7e427c5ec0185d635422b4a265] removeWay should also
 unset the wayGeneralFlags
 git bisect good 2324b40f65b5cb7e427c5ec0185d635422b4a265
 # good: [a7e0d4484189d08125083638582a6f8e4ae44801] a small -fPIC
 optimisation
 git bisect good a7e0d4484189d08125083638582a6f8e4ae44801
 }}}

 It seems that the first bad commit is,
 {{{
 commit 88a6f863d9f127fc1b03a1e2f068fd20ecbe096c
 Author: Simon Marlow <marlowsd at gmail.com>
 Date:   Tue Oct 23 13:06:17 2012 +0100

     Small optimisation: always sink/inline reg1 = reg2 assignments

 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7366#comment:3>
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