[Bug middle-end/55478] New: [devirt] trunk fails inline-devirt test #4

[matt at use dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55478



             Bug #: 55478

           Summary: [devirt] trunk fails inline-devirt test #4

    Classification: Unclassified

           Product: gcc

           Version: 4.8.0

            Status: UNCONFIRMED

          Severity: normal

          Priority: P3

         Component: middle-end

        AssignedTo: unassig...@gcc.gnu.org

        ReportedBy: m...@use.net





Created attachment 28783

  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28783

test case that fails in trunk but passed with Maxim's devirt patches



trunk currently fails test #4 here (also attached):

http://gcc.gnu.org/ml/gcc-patches/2011-10/msg02589.html



$ g++-4.8 -O2 inline-devirt-4.C && objdump -d -Mintel a.out | less -p main\>



0000000000400630 <main>:

  400630:       48 83 ec 18             sub    rsp,0x18

  400634:       48 89 e7                mov    rdi,rsp

  400637:       48 c7 04 24 d0 09 40    mov    QWORD PTR [rsp],0x4009d0

  40063e:       00 

  40063f:       c6 44 24 0a 00          mov    BYTE PTR [rsp+0xa],0x0

  400644:       c6 44 24 08 61          mov    BYTE PTR [rsp+0x8],0x61

  400649:       c6 44 24 09 62          mov    BYTE PTR [rsp+0x9],0x62

  40064e:       e8 2d 01 00 00          call   400780

<_Z12print_lengthRK6String>

  400653:       31 c0                   xor    eax,eax

  400655:       48 83 c4 18             add    rsp,0x18

  400659:       c3                      ret    

  40065a:       66 0f 1f 44 00 00       nop    WORD PTR [rax+rax*1+0x0]



It does inline the FixedString ctor, but not print_length(const String&), nor

does it even inline FixedString::length() into print_length(const String&). I

tried -O3 and -Ofast along with various inline --params, but to no avail.