Re: porting gcc (Bonz)
17 Sep 2000 23:01:58 -0400

          From comp.compilers

Related articles
porting gcc (2000-09-15)
Re: porting gcc (Jeff Sturm) (2000-09-17)
Re: porting gcc (Michael A. Sewell) (2000-09-17)
Re: porting gcc (2000-09-17)
Re: porting gcc (2000-09-28)
Re: porting gcc (Tom Payne) (2000-10-08)
| List of all articles for this month |

From: (Bonz)
Newsgroups: comp.compilers
Date: 17 Sep 2000 23:01:58 -0400
Organization: Mailgate.ORG Server - http://www.Mailgate.ORG
References: 00-09-104
Keywords: GCC

> I hope I will be presented int n=*p++; in some abstract
> "pointer-plusplus"-token/struct, not in a "risc"
> MOVB R0,[R1]; ADD R1,4 ?

No, you are presented with elementary instructions. Then as far as I
remember the machine description can:
- use bottom-up (yacc like) algorithms to combine instructions and
obtain macro-patterns
- expand instructions (or sequences like above) to simpler, even more
RISCy sequences (e.g. x = ~x --> x = x ^ 0xFFFFFFFF)
- do peephole optimizations on the generated instructions.

> I guess what I am trying to ask is whether the backend programmer got
> full abstract C type information.

I don't know exactly, but there must be something because the compiler
does do alias analysis.

> - actually I want g++. assuming a g++ port, is the result any use for
> porting gcc? are they "RTL-compatible" ?

Yes, RTL is universal.

> and the "how to port gcc"

Search "Porting GCC for dummies" (not joking). A much more complicated
(and complete) guide can be found on any linux machine (`info gcc').

> please advice URLs.

Download gcc-core-2.95.2 (or something like that) from any GNU mirror.
Not really lean -- about 8 Megs. The 68000 machine description is
actually complex, better start with something like the PDP.

Post a followup to this message

Return to the comp.compilers page.
Search the comp.compilers archives again.