profiling question

[Senti]

Hello
I'm building a gcc cross-comiler for an 
processor.
What i wanted was to add some code for 
profiling.
I have written the two macros related to basic 
block profiling :

#define BLOCK_PROFILER(FILE, BLOCKNO)
#define FUNCTION_BLOCK_PROFILER(FILE, 
BLOCK_OR_LABEL)
but when i try compiling a program using -ax 
option gcc is saying :
cc1: warning: '-ax' option (jump profiling) not 
supported
What should i do for enabling -ax option. 
Should i write something else too into gcc ?
Thanks in advance, Adrian.