[Bug c++/60747] the tree-vrp compilation flag produce wrong assembly

[techsgin at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60747

--- Comment #2 from tech <techsgin at gmail dot com> ---
Created attachment 32533
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32533&action=edit
Assembly of O2 no tree-vrp

Assembly of O2 no tree-vrp

    .file    "main.cpp"
    .text
    .p2align 4,,15
.globl _Z7hash_itPKci
    .type    _Z7hash_itPKci, @function
_Z7hash_itPKci:
.LFB26:
    .cfi_startproc
    .cfi_personality 0x3,__gxx_personality_v0
    pushq    %rbp
    .cfi_def_cfa_offset 16
    .cfi_offset 6, -16
    movl    %esi, %ebp
    pushq    %rbx
    .cfi_def_cfa_offset 24
    .cfi_offset 3, -24
    movq    %rdi, %rbx
    subq    $8, %rsp
    .cfi_def_cfa_offset 32
    call    strlen
    testl    %eax, %eax
    movl    %eax, %edx
    jle    .L3
    leaq    1(%rbx), %rcx
    leal    -1(%rax), %esi
    leaq    (%rcx,%rsi), %rsi
    jmp    .L4
    .p2align 4,,10
    .p2align 3
.L11:
    addq    $1, %rcx
.L4:
    movsbl    (%rbx), %ebx
    imull    $777, %edx, %edx
    addl    %ebx, %edx
    cmpq    %rsi, %rcx
    movq    %rcx, %rbx
    jne    .L11
.L3:
    testl    %edx, %edx
    jns    .L9
    negl    %edx
.L9:
    movl    %edx, %eax
    sarl    $31, %edx
    addq    $8, %rsp
    .cfi_def_cfa_offset 24
    idivl    %ebp
    popq    %rbx
    .cfi_def_cfa_offset 16
    popq    %rbp
    .cfi_def_cfa_offset 8
    movl    %edx, %eax
    ret