[GHC] #8695: Arithmetic overflow from (minBound :: Int) `quot` (-1)

[GHC]

#8695: Arithmetic overflow from (minBound :: Int) `quot` (-1)
------------------------------------------------+--------------------------
        Reporter:  rleslie                      |            Owner:
            Type:  bug                          |           Status:  new
        Priority:  normal                       |        Milestone:
       Component:  libraries/haskell2010        |          Version:  7.6.3
      Resolution:                               |         Keywords:
Operating System:  Unknown/Multiple             |     Architecture:
 Type of failure:  Incorrect result at runtime  |  Unknown/Multiple
       Test Case:                               |       Difficulty:
        Blocking:                               |  Unknown
                                                |       Blocked By:
                                                |  Related Tickets:
------------------------------------------------+--------------------------

Comment (by hvr):

 Fwiw as a precedent, the following C99 program when compiled with gcc or
 clang, and executed on Linux results in a runtime exception as well:

 {{{#!c
 #include <stdio.h>
 #include <inttypes.h>

 int main(int argc, char *argv[])
 {
   volatile int32_t a = INT32_MIN;
   volatile int32_t b = -1;
   volatile int32_t c = a / b;
   printf("%" PRId32 "\n", c);
   return 0;
 }
 }}}


 Given that `quot`/`div` is already a partial function due to div-by-zero,
 and {{{minBound `quot` -1}}} being the only special case (beside div-by-
 zero) for (`quot`/`div`) which leads to a result outside the
 `[minBound..maxBound]` range, so I'd rather have this exception thrown
 than to have a program which didn't take into account this non-obvious
 overflow silently misbehaving due to a flipped sign (as you pointed out
 yourself if I understood you correctly, but then dismissed it as not being
 worth an exception).

 PS: I believe one may as well argue (as an academic exercise) in a
 parallel way, that `quotRem` by 0 could be assigned a value that satisfies
 the laws from § 6.4.2 as well, thus making it a total function.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8695#comment:6>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler