[GHC] #15482: the_gc_thread variable from GC.c is not aligned to 64

[GHC]

#15482: the_gc_thread variable from GC.c is not aligned to 64
-------------------------------------+-------------------------------------
        Reporter:  arrowd            |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.4.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:  x86_64
                                     |  (amd64)
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D5052
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"68a1fc29b4bb3eae54e4d96c9aec20e700040f34/ghc"
 68a1fc29/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="68a1fc29b4bb3eae54e4d96c9aec20e700040f34"
 rts: Align the_gc_thread to 64 bytes

 In a previous attempt (c6cc93bca69abc258513af8cf2370b14e70fd8fb) I had
 tried aligning to 8 bytes under the assumption that the problem was that
 the_gc_thread, a StgWord8[], wasn't being aligned to 8-bytes as the
 gc_thread struct would expect. However, we actually need even stronger
 alignment due to the alignment attribute attached to gen_workspace,
 which claims it should be aligned to a 64-byte boundary.

 This fixes #15482.

 Reviewers: erikd, simonmar

 Reviewed By: simonmar

 Subscribers: rwbarton, carter

 GHC Trac Issues: #15482

 Differential Revision: https://phabricator.haskell.org/D5052
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15482#comment:11>
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