Question : about difference with bdnz and bdnz+

HongWoo Lee hongwoo7 at
Thu Aug 27 15:04:35 EST 2009

Hi ~

I found the code in the linux kernel.

static __inline__ void clear_page(void *addr)
    unsigned long lines, line_size;
    line_size = cpu_caches.dline_size;
    lines = cpu_caches.dlines_per_page;

    __asm__ __volatile__(
            "mtctr  %1      # clear_page\n\
            1:  dcbz    0,%0\n\
            add     %0,%0,%3\n\
            bdnz+   1b"
            : "=r" (addr)
            : "r" (lines), "0" (addr), "r" (line_size)
            : "ctr", "memory");

And I have a question about bdnz+ instruction.
Through googling, I learned that bdnz does decrement count register and 
branch if it is still nonzero.
But I couldn't find what "bdnz+" is.
Can anybody explain to me what it is ??

Thanks in advance.


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