[GHC] #10433: Fix load/store barriers in pre-ARMv7 builds

[GHC]

#10433: Fix load/store barriers in pre-ARMv7 builds
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        Reporter:  thoughtpolice     |                Owner:
            Type:  bug               |               Status:  merge
        Priority:  high              |            Milestone:  8.0.1
       Component:  Runtime System    |              Version:
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:  arm
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #10244            |  Differential Rev(s):  Phab:D1704
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"9fe7d20e2e5c60325ce04f476bc89fae06e43208/ghc"
 9fe7d20e/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="9fe7d20e2e5c60325ce04f476bc89fae06e43208"
 Ensure that we don't produce code for pre-ARMv7 without barriers

 We are unable to produce load/store barriers for pre-ARMv7 targets.
 Phab:D894 added dummy cases to SMP.h for these barriers to prevent the
 build from failing under the assumption that there are no SMP-capable
 devices of this vintage. However, #10433 points out that it is more
 correct to simply set NOSMP for such targets.

 Tested By: rwbarton

 Test Plan: Validate

 Reviewers: erikd, rwbarton, austin

 Reviewed By: rwbarton

 Subscribers: thomie

 Differential Revision: https://phabricator.haskell.org/D1704

 GHC Trac Issues: #10433
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10433#comment:10>
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