[Bug rtl-optimization/21617] [4.4/4.5/4.6/4.7 Regression] CRC64 algorithm optimization problem on Intel 32-bit

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21617

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> 2011-12-08 
03:34:57 UTC ---
-O1:
.L2:
    movl    %eax, %edx
    sarl    $31, %edx
    shrl    $24, %edx
    leal    (%eax,%edx), %ecx
    andl    $255, %ecx
    subl    %edx, %ecx
    movb    %cl, (%ebx,%eax)
    addl    $1, %eax
    cmpl    $8192, %eax
    jne    .L2

-O2:
.L4:
    movl    76(%esp), %ecx
    movl    %edi, %ebx
    shrl    $24, %ebx
    movzbl    (%ecx), %edx
    addl    $1, %ecx
    movl    %ecx, 76(%esp)
    movl    %esi, %ecx
    sall    $8, %ecx
    xorl    %ebx, %edx
    movl    %edi, %ebx
    shldl    $8, %esi, %ebx
    movl    crc_table+4(,%edx,8), %edi
    movl    crc_table(,%edx,8), %esi
    xorl    %ebx, %edi
    xorl    %ecx, %esi
    cmpl    %eax, 76(%esp)
    jne    .L4