Strange bug in optimizator

    .file   "kirienko.cpp"
    .text
    .def    ___tcf_0;   .scl    3;  .type   32; .endef
___tcf_0:
LFB990:
    .cfi_startproc
    subl    $28, %esp
    .cfi_def_cfa_offset 32
    movl    $__ZStL8__ioinit, (%esp)
    call    __ZNSt8ios_base4InitD1Ev
    addl    $28, %esp
    .cfi_def_cfa_offset 4
    ret
    .cfi_endproc
LFE990:
    .def    ___main;    .scl    2;  .type   32; .endef
    .section .rdata,"dr"
LC0:
    .ascii " \0"
    .text
    .globl  _main
    .def    _main;  .scl    2;  .type   32; .endef
_main:
LFB983:
    .cfi_startproc
    pushl   %ebp
    .cfi_def_cfa_offset 8
    .cfi_offset 5, -8
    movl    %esp, %ebp
    .cfi_def_cfa_register 5
    pushl   %esi
    pushl   %ebx
    andl    $-16, %esp
    subl    $32, %esp
    .cfi_offset 3, -16
    .cfi_offset 6, -12
    call    ___main
    leal    28(%esp), %eax
    movl    %eax, 4(%esp)
    movl    $__ZSt3cin, (%esp)
    call    __ZNSirsERi
    movl    28(%esp), %esi
    testl   %esi, %esi
    jle L6
    movl    $0, %ebx
L4:
    leal    _A(,%ebx,8), %eax
    movl    %eax, 4(%esp)
    movl    $__ZSt3cin, (%esp)
    call    __ZNSi10_M_extractIxEERSiRT_
    incl    %ebx
    movl    28(%esp), %esi
    cmpl    %ebx, %esi
    jg  L4
    movl    %esi, %edx
    testl   %esi, %esi
    jle L7
    movl    $0, %eax
    movl    $0, %ecx
    movl    $0, %ebx
L5:
    addl    _A(,%eax,8), %ecx
    adcl    _A+4(,%eax,8), %ebx
    incl    %eax
    cmpl    %edx, %eax
    jne L5
    jmp L3
L6:
    movl    $0, %ecx
    movl    $0, %ebx
    jmp L3
L7:
    movl    $0, %ecx
    movl    $0, %ebx
L3:
    movl    %ecx, 4(%esp)
    movl    %ebx, 8(%esp)
    movl    $__ZSt4cout, (%esp)
    call    __ZNSo9_M_insertIxEERSoT_
    movl    $LC0, 4(%esp)
    movl    %eax, (%esp)
    call    __ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc
    movl    %esi, 4(%esp)
    movl    %eax, (%esp)
    call    __ZNSolsEi
    movl    $0, %eax
    leal    -8(%ebp), %esp
    popl    %ebx
    .cfi_restore 3
    popl    %esi
    .cfi_restore 6
    popl    %ebp
    .cfi_def_cfa 4, 4
    .cfi_restore 5
    ret
    .cfi_endproc
LFE983:
    .def    __GLOBAL__sub_I_A;  .scl    3;  .type   32; .endef
__GLOBAL__sub_I_A:
LFB991:
    .cfi_startproc
    subl    $28, %esp
    .cfi_def_cfa_offset 32
    movl    $__ZStL8__ioinit, (%esp)
    call    __ZNSt8ios_base4InitC1Ev
    movl    $___tcf_0, (%esp)
    call    _atexit
    addl    $28, %esp
    .cfi_def_cfa_offset 4
    ret
    .cfi_endproc
LFE991:
    .section    .ctors,"w"
    .align 4
    .long   __GLOBAL__sub_I_A
    .globl  _A
    .bss
    .align 32
_A:
    .space 80
.lcomm __ZStL8__ioinit,1,1
    .def    __ZNSt8ios_base4InitD1Ev;   .scl    2;  .type   32; .endef
    .def    __ZNSirsERi;    .scl    2;  .type   32; .endef
    .def    __ZNSi10_M_extractIxEERSiRT_;   .scl    2;  .type   32; .endef
    .def    __ZNSo9_M_insertIxEERSoT_;  .scl    2;  .type   32; .endef
    .def    __ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc;   .scl    2;  .type   32; .endef
    .def    __ZNSolsEi; .scl    2;  .type   32; .endef
    .def    __ZNSt8ios_base4InitC1Ev;   .scl    2;  .type   32; .endef
    .def    _atexit;    .scl    2;  .type   32; .endef