This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: RTL definition
"Fran Baena" <franbaena@gmail.com> writes:
> 2008/3/10, Jim Wilson <wilson@tuliptree.org>:
>> Fran Baena wrote:
>> > RTL represents a low-level language, machine-independent. But I didn't
>> > find any especification of such language represented. This is, I found
>> > no document where the language represented were described or defined
>> > in a grammar way.
>>
>>
>> RTL isn't a programming language, and hence has no grammar. It is
>> merely one of the internal representations that gcc uses for optimizing
>> and generating code. We do have gcc internals documentation that you
>> have already been pointed at.
>
> i agree with you, RTL is not a programming language, is a language
> that is represented internally. But it could match a grammar
> definition. And this is my question, what is the process to define a
> RTL.
RTL is a set of data structures. It's defined by rtl.def and rtl.h.
The closest thing to a grammar for RTL is rtl.def, which defines how
each of the fields are represented given the RTL code.
By the way, RTL is not really machine-independent. The data
structures are machine independent. But the contents are not. You
can not, even in principle, take the RTL generated for one processor
and compile it on another processor.
Ian