Why does printf generate an extra function when using MinGW-w64?

Question

Looking at the assembly output by GCC with -O2 I see that if I use printf GCC will create a function named, for example, _Z6printfPKcz, which then calls __mingw_vprintf. What is the purpose for this indirection? Why doesn't printf translate directly to a call to __mingw_printf? This is the same for the other related functions, such as sprintf.

Edit:

For the record, I know what name mangling is and how it works. My question is why is the compiler generating the function in the first place, a function which does nothing but forward the arguments to __mingw_vprintf, when it could simply call __mingw_printf directly and save the unnecessary indirection.

In other words, why should this:

printf("%d\n", var);

compile to this:

_Z6printfPKcz:
    sub rsp, 56
    mov QWORD PTR 72[rsp], rdx
    lea rdx, 72[rsp]
    mov QWORD PTR 80[rsp], r8
    mov QWORD PTR 88[rsp], r9
    mov QWORD PTR 40[rsp], rdx
    call    __mingw_vprintf
    add rsp, 56
    ret

main:
    ...
    call    _Z6printfPKcz
    ...

when this would suffice

main:
    ...
    call    __mingw_printf
    ...

Answer 1

_Z6printfPKcz is just the mangled name of printf - search "name mangling" for more information on that. It's the actual printf function.

__mingw_vprintf is an internal function which printf calls - there's no requirement that printf doesn't call another function to do its work. Maybe __mingw_vprintf handles all the formatting and printing, and printf is written like this:

int printf(const char *fmt, ...)
{
    va_list va;
    va_start(va, fmt);
    int result = __mingw_vprintf(fmt, va);
    va_end(va);
    return result;
}