impressive clang optimization

foo.c

int is_json_space(char c) {
    return c == ' ' || c == '\t' || c == '\n' || c == '\r';
}

foo.s

is_json_space:
        cmpb    $32, %dil
        ja      .LBB0_2
        movzbl  %dil, %ecx
        movl    $1, %eax
        movabsq $4294977024, %rdx
        btq     %rcx, %rdx
        jb      .LBB0_3
.LBB0_2:
        xorl    %eax, %eax
.LBB0_3:
        ret