[GHC] #13384: Windows build thinks sqrt (-1) == -1

[GHC]

#13384: Windows build thinks sqrt (-1) == -1
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        Reporter:  bgamari           |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.2.1
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect result  |  Unknown/Multiple
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by bgamari):

 Ummmm....
 {{{
 ben at schildmann MINGW64 ~/ghc$ hi.c
 #include <math.h>
 #include <stdio.h>

 void main() { printf("%f\n", sqrt(-1)); }

 ben at schildmann MINGW64 ~/ghc$ gcc hi.c -O0

 ben at schildmann MINGW64 ~/ghc$ ./a.exe
 -1.000000
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13384#comment:1>
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