cross module optimization

hello

i am using different platform to build keil environment project and i want to enable cross module optimization.
i am using following keywords to enable linker options.

add option {

// some other options enabled

"--feedback=cross-module optimization" // : cross module optimization
}

after building the code i am getting following errors:

Fatal error: L6002U: Could not open file optimization: No such file or directory
Not enough information to produce a FEEDBACK file.
Finished: 1 information, 0 warning, 0 error and 1 fatal error messages.

Please suggest me correct keyword to enable it.

Thanks..