Re: [GHC] #10518: unregisterised GHC generates incorrect 0xUL literals for certain onstants

13 Jun 2015

      #10518: unregisterised GHC generates incorrect 0xUL literals for certain onstants
-------------------------------------+-------------------------------------
        Reporter:  slyfox            |                   Owner:  slyfox
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  Compiler          |                 Version:  7.10.1
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  None/Unknown      |  Unknown/Multiple
      Blocked By:                    |               Test Case:
 Related Tickets:                    |                Blocking:
                                     |  Differential Revisions:
-------------------------------------+-------------------------------------
Description changed by int-e:

Old description:
...
jakzale reports:
21:47:27 < int-e> Oh, nice. Yes, indeed pprHexVal (2^32) W32 (function
from cmm/PprC.hs) would result in 0xU.
21:50:29 < jakzale> int-e: yes, truncInt takes module 2^32, then go
returns empty string (I guess)
Here comes the test:
{{{
$ cat a.cmm
foo() {
    bits64 a;
    a = 0x10000000000000000; // overflows 64 bits
    return (a);
}
$ inplace/bin/ghc-stage2 -c a.cmm
/tmp/ghc8580_0/ghc_2.hc: In function 'foo':
/tmp/ghc8580_0/ghc_2.hc:8:7: error:
     error: invalid suffix "xUL" on integer constant
     _c0 = 0xUL;
           ^
}}}
I've broke it with commit:43f1b2ecd1960fa7377cf55a2b97c66059a701ef
when introduced truncation that can generate more zeroes.
New description:

 jakzale reports:
 21:47:27 < int-e> Oh, nice. Yes, indeed pprHexVal (2^32^) W32 (function
 from cmm/PprC.hs) would result in 0xU.
 21:50:29 < jakzale> int-e: yes, truncInt takes module 2^32^, then go
 returns empty string (I guess)

 Here comes the test:
 {{{
 $ cat a.cmm

 foo() {
     bits64 a;
     a = 0x10000000000000000; // overflows 64 bits
     return (a);
 }

 $ inplace/bin/ghc-stage2 -c a.cmm
 /tmp/ghc8580_0/ghc_2.hc: In function 'foo':

 /tmp/ghc8580_0/ghc_2.hc:8:7: error:
      error: invalid suffix "xUL" on integer constant
      _c0 = 0xUL;
            ^
 }}}
 I've broke it with commit:43f1b2ecd1960fa7377cf55a2b97c66059a701ef
 when introduced truncation that can generate more zeroes.

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Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10518#comment:2
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