[GHC] #14085: powModInteger sometimes ignores sign of argument

[GHC]

#14085: powModInteger sometimes ignores sign of argument
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        Reporter:  ocheron           |                Owner:  ocheron
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Core Libraries    |              Version:  8.2.1
      Resolution:                    |             Keywords:  integer-gmp
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect result  |  Unknown/Multiple
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3826
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"c5605ae00e9bff90db7a5f24ff3b8de2aba3b55b/ghc"
 c5605ae0/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="c5605ae00e9bff90db7a5f24ff3b8de2aba3b55b"
 Make function intToSBigNat# preserve sign (fixes #14085)

 Impacts only functions gcdExtInteger, powModInteger and
 recipModInteger which gave invalid results on negative S# inputs.

 Also fixes gcdExtInteger assertion when first argument is negative.

 Test Plan: Updated test case integerGmpInternals

 Reviewers: austin, hvr, goldfire, bgamari

 Reviewed By: bgamari

 Subscribers: rwbarton, thomie

 GHC Trac Issues: #14085

 Differential Revision: https://phabricator.haskell.org/D3826
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14085#comment:4>
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