[GHC] #10332: AArch64 : divbyzero test fails

[GHC]

#10332: AArch64 : divbyzero test fails
-------------------------------------+-------------------------------------
              Reporter:  erikd       |             Owner:
                  Type:  bug         |            Status:  new
              Priority:  normal      |         Milestone:  7.12.1
             Component:  Compiler    |           Version:  7.11
              Keywords:              |  Operating System:  Unknown/Multiple
          Architecture:  aarch64     |   Type of failure:  Incorrect result
             Test Case:              |  at runtime
  testsuite/tests/rts/divbyzero.hs   |        Blocked By:
              Blocking:              |   Related Tickets:
Differential Revisions:              |
-------------------------------------+-------------------------------------
 On AArch64/Linux the test in `testsuite/tests/rts/divbyzero.hs` which is:

 {{{
 main :: IO ()
 main = print (5 `divInt` 0)
 }}}

 just prints "0" and exits with a zero status code.

 From the "ARMv8 Instriction Set Overview" document I found (wasn't able to
 find anything more recent):

 https://www.element14.com/community/servlet/JiveServlet/downloadBody/41836-102-1-229511/ARM.Reference_Manual.pdf

 Section 3.6 says "There is no hardware check for “divide by zero”, but
 this check can be performed in the shadow of a long latency division. A
 divide by zero writes zero to the destination register."

 Looks like we need extra code to check for this, but not sure how to
 report it. Should probably look at what GCC and Clang do.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10332>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler