[Bug libgcc/56300] New: Add __sync_fetch_and_add_8 and other 8-byte atomic functions to 32-bit MIPS targets

[chaoyingfu at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56300



             Bug #: 56300

           Summary: Add __sync_fetch_and_add_8 and other 8-byte atomic

                    functions to 32-bit MIPS targets

    Classification: Unclassified

           Product: gcc

           Version: unknown

            Status: UNCONFIRMED

          Severity: normal

          Priority: P3

         Component: libgcc

        AssignedTo: unassig...@gcc.gnu.org

        ReportedBy: chaoyin...@gcc.gnu.org





There is no hardware support for 8 bytes atomic operations on 32-bit MIPS

targets.  Unfortunately, programmers still want to use them.  Ex: please check

this webkit bug: https://bugs.webkit.org/show_bug.cgi?id=106739 and the

following example.



Ex:

fu@debian6:~/dev/test$ cat sync.c

long long K;

void main()

{

   __sync_fetch_and_add(&K, 1);

}



fu@debian6:~/dev/test$ gcc -o sync sync.c

/tmp/ccUoSg9M.o: In function `main':

sync.c:(.text+0x28): undefined reference to `__sync_fetch_and_add_8'

collect2: ld returned 1 exit status



That will be great, if we can add missing atomic functions (via pthread

implementation or other methods) to libgcc for 32-bit MIPS targets.



Thanks a lot!