[avr-gcc-list] Asm Operator for Address Negation

[Ram Kumar Rengaswamy]

Hi,
     I have a large C application in which I would like to write one  
of the routines in assembly to improve performance.


uint8_t permsTable[128]; // This is a global variable.

# The following is the assembly routine.
# The offset into permsTable is present in the register pair r30:r31
# I am trying to subtract the negative value of the permsTable from  
the offset.
permsCheck:
        SUBI r30, lo8(-permsTable)
        SBCI r31, hi8(-permsTable)

However, I am getting a syntax error with the above operation.
I would appreciate if anyone could tell me how to perform the above  
operation.
I have seen the C compiler generate such code.

Thanks,
-Ram