Porting GCC help/doubts

[Nithya Babu]

Hi,
Im currently studying the method of porting GCC to other targets for which I have been using the "Porting GCC' document available at the GNU site.

A few questions for which I need answers
a) I generate an RTL file output from the compiler, is the RTL file output target specific, I mean - will the output change according to various targets or will it remain the same ?

b) If the answer to my previous question is no, then it means that RTL patterns are different for different targets. I hope not this is the case. But if it is, then how do we tell the compiler to use a specific combination of RTL instructions for a particular instruction. The .md file doesnt seem to make anything about this.....

c) Any other reading material apart from the 'Using and Porting GNU GCC' ?

Thanks,
Nithya R. Babu