"I cant use the C compiler as it is generating very huge code"

This may not be the compiler per se - it could be down to the way you're writing your 'C' source.

Big Hint: don't use printf!
printf is huuuuuuuuuuuuge; eg, you can use up almost the entire 2K limit of the Keil evaluation just with

printf( "Hello, world!n" );

and it's all down to the printf.