[GHC] #7684: cgrun071 segfaults

[GHC]

#7684: cgrun071 segfaults
----------------------------------+----------------------------------
        Reporter:  tibbe          |            Owner:  leroux
            Type:  bug            |           Status:  new
        Priority:  normal         |        Milestone:  7.8.1
       Component:  Compiler       |          Version:  7.7
      Resolution:                 |         Keywords:
Operating System:  MacOS X        |     Architecture:  x86_64 (amd64)
 Type of failure:  Runtime crash  |       Difficulty:  Unknown
       Test Case:  cgrun071       |       Blocked By:
        Blocking:                 |  Related Tickets:
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Comment (by leroux):

 Alright, ran the gcc42 version in gdb and got a useful message. =)
 {{{
 Program received signal EXC_BAD_ACCESS, Could not access memory.
 Reason: 13 at address: 0x0000000000000000
 0x000000010027f74b in hs_popcnt8 ()
 (gdb) display/i $pc
 1: x/i $pc  0x10027f74b <hs_popcnt8+11>:        movzbl (%rdi,%rax,1),%eax
 }}}

 {{{
 _hs_popcnt8:
 000000010027f740        pushq   %rbp
 000000010027f741        movq    %rsp, %rbp
 000000010027f744        leaq    _popcount_tab(%rip), %rax
 000000010027f74b        movzbl  (%rdi,%rax), %eax         <-------
 0x10027f74b
 000000010027f74f        popq    %rbp
 000000010027f750        ret
 000000010027f751        nopl    (%rax)
 000000010027f758        nopl    (%rax,%rax)
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7684#comment:26>
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