sync_fetch_and_add creating unrecognizable insn

[Razya Ladelsky <RAZYA at il dot ibm dot com>]

Hi,

When passing an address of a local variable as the first argument of 
'sync_fetch_and_add' 
I get an error of unrecognizable insn.
For example, the test below (extracted from 
gcc.c-torture/compile/sync-1.c) fails on powerpc.
If however, 'uc' was a global variable, the compilation passed perfectly.
This scenario does not happen for ints, only for chars.

void test_op_ignore (void)
{
  unsigned char uc;
  (void) __sync_fetch_and_add (&uc, 1);
}

Here's the failure message:

error: unrecognizable insn:
(insn 16 15 17 3 (parallel [
            (set (reg:SI 123)
                (ior:SI (and:SI (plus:SI (mem/v:QI (reg/f:SI 115 
virtual-stack-vars) [-1 S1 A64])
                            (reg:SI 119))
                        (reg:SI 121))
                    (and:SI (not:SI (reg:SI 121))
                        (mem/v:QI (reg/f:SI 115 virtual-stack-vars) [-1 S1 
A64]))))
            (set (reg:SI 122)
                (mem/v:QI (reg/f:SI 115 virtual-stack-vars) [-1 S1 A64]))
            (set (mem/v:QI (reg/f:SI 115 virtual-stack-vars) [-1 S1 A64])
                (unspec:SI [
                        (ior:SI (and:SI (plus:SI (mem/v:QI (reg/f:SI 115 
virtual-stack-vars) [-1 S1 A64])
                                    (reg:SI 119))
                                (reg:SI 121))
                            (and:SI (not:SI (reg:SI 121))
                                (mem/v:QI (reg/f:SI 115 
virtual-stack-vars) [-1 S1 A64])))
                    ] 40))
            (clobber (scratch:CC))
            (clobber (scratch:SI))
        ]) -1 (nil)
    (nil))

Does anyone know why that happens?
Thanks,
Razya