[GHC] #16037: memcpy test inexplicably failing

[GHC]

#16037: memcpy test inexplicably failing
-------------------------------------+-------------------------------------
           Reporter:  bgamari        |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  high           |         Milestone:  8.8.1
          Component:  Compiler       |           Version:  8.7
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 I have started seeing failures in the `memcpy` test:
 {{{#!diff
 diff -uw "codeGen/should_gen_asm/memcpy.run/memcpy.asm.normalised"
 "codeGen/should_gen_asm/memcpy.run/memcpy.s.normalised"
 --- codeGen/should_gen_asm/memcpy.run/memcpy.asm.normalised     2018-12-11
 23:13:18.763730758 -0500
 +++ codeGen/should_gen_asm/memcpy.run/memcpy.s.normalised       2018-12-11
 23:13:18.763730758 -0500
 @@ -1,9 +1,9 @@
  callMemcpy:
 +subq
  movq
  movq
  movl
 -subq
 -movl
 +xorl
  call memcpy
  addq
  jmp
 }}}
 The failures aren't themselves concerning; the new assembler is perfectly
 valid:
 {{{#!asm

 .section .text
 .align 8
 .globl callMemcpy
 .type callMemcpy, @function
 callMemcpy:
 .Lc6:
         movl $1024,%eax
         subq $8,%rsp
         movq %rax,%rdx
         movq %rbx,%rdi
         movq %r14,%rsi
         xorl %eax,%eax
         call memcpy
         addq $8,%rsp
         jmp *(%rbp)
         .size callMemcpy, .-callMemcpy
 .section .note.GNU-stack,"", at progbits
 .ident "GHC 8.7.20181211"
 }}}

 However, I have no explanation for why this suddenly started happening.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16037>
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