[Bug target/59968] Unused BT patterns

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59968

--- Comment #5 from H.J. Lu <hjl.tools at gmail dot com> ---
For

int
__attribute__((noinline))
foo1 (int x, int y)
{
  x &= (1 << y);
  return x != 0;
}

we generate

    movl    %esi, %ecx
    movl    $1, %eax
    sall    %cl, %eax
    testl    %edi, %eax
    setne    %al
    movzbl    %al, %eax
    ret

I am expecting:

    bt      %esi, %edi
    setc    %al
        movzbl    %al, %eax
        ret