[parisc-linux] Inline Assembly Help request

[jsoe0708@tiscali.be]

Hi all,

Continuing to figure out how to translate this C in assembly:
static inline int __put_user_u64(unsigned long long val, unsigned long long
*  ptr)
{
    int  err;
    err = (int) put_user((unsigned int)(val>>32) ,(unsigned int *)ptr);
    err |= (int) put_user((unsigned int)val,(unsigned int *)ptr+1);
    return err;
}

(needed for > evms-1.1.0)

With many luck, I found interresting references about online assembly in
gcc.

But I do not yet find explanation about details of the following asm code:
#define __put_user_asm(stx,x,ptr)                           \
        __asm__ __volatile__ (                              \
                "\n1:\t" stx "\t%2,0(%%sr3,%1)\n"           \
                "2:\n"                                      \
                "\t.section __ex_table,\"a\"\n"             \
                 "\t.word\t1b\n"                            \
                 "\t.word\t(2b-1b)+1\n"                     \
                 "\t.previous"                              \
                : "=r"(__pu_err)                            \
                : "r"(ptr), "r"(x), "0"(__pu_err))

which is more clear with gcc -S:

1:      stw     %r21,0(%sr3,%r19)
2:
        .section __ex_table,"a"
        .word   1b
        .word   (2b-1b)+1
        .previous

My questions are:
what are the actual means "1:", "2:" (seems like label?)

and what means the rest
".section __ex_table,...
 ...
 .previous"

I do not yet found reference on this part (even in Assembly-HOWTO).
Where could I found doc on this details?

Thanks in advance for attention,
    Joel
                          


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