[gnu.gcc] putting architectural info outside gcc ?

eho@clarity.Princeton.EDU (Eric Ho) (09/10/89)

I was just thinking that since gcc is a retargetable optimizing compiler,
wouldn't it be nice to put all kinds of architectural info outside the
compiler -- i.e. in a seperate file or data/rule base of some sort and gcc
reads this file according to what architecture the user is compiling his/her
program on.  This way, you save a lot of time by avoiding to rebuild gcc
everytime you've need recompile your code for different architectures.
For instance, if I want to remake my application for a new architecture
then all I need to do is supply that architectural info/database to gcc and
it'll generate the correct binary for that new architecture (without
recompiling gcc at all) and I can do all this on my Sun-4 or do it on the new
machine.

What do others think ?  It shouldn't be too difficult to reorgainize gcc this
way, right ?


--

Eric Ho
Cognitive Science Lab.,		Princeton University
voice = 609-258-2987		email = eho@confidence.princeton.edu
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regards.

-eric-

ham@Neon.Stanford.EDU (Peter R. Ham) (09/11/89)

Persoally, I like the generality of your approach.
Unfortunately, compilations would probably run much slower
using such an architectual database. Speed, is one of
the primary advantages of using macros that way gcc does.
Turning all of those machine dependent macros into
items in a database seems like a huge chore to me.
I wouldn't recommend this trying to implement this change
to anyone, although I agree the results would be "clean",
but probably much slower. If you are going to rewrite gcc
from scatch and are not concerned about compilation speed,
the go for it. The use of macros is a major design decision
in gcc. (At least it looks like it from reading the code).
Maybe further discussiong of gcc's design should go 
ong gnu.gcc.bug.
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Peter Ham			PO Box 3430	(h)(415) 324-9645
MS Computer Science Student	Stanford, CA	ham@polya.stanford.edu
Stanford University 		94309		(o)(415) 723-2067

eho@clarity.Princeton.EDU (Eric Ho) (09/11/89)

> In article <HAM.89Sep10115811@Neon.Stanford.EDU> ham@Neon.Stanford.EDU (Peter
> R. Ham) writes: 
> 
>    Persoally, I like the generality of your approach.
>    Unfortunately, compilations would probably run much slower
>    using such an architectual database. Speed, is one of
>    the primary advantages of using macros that way gcc does.
>    Turning all of those machine dependent macros into
>    items in a database seems like a huge chore to me.

Hm... so there is no easy way to read in those macros dynamically huh ?
How about keeping everything as what it is now (I don't fancy doing major
changes to gcc -- I can spend my time on better things than rewriting gcc) but
say to extend it to be able to read in those macros dynamically on user's
demand ?
--

Eric Ho
Cognitive Science Lab.,		Princeton University
voice = 609-258-2987		email = eho@confidence.princeton.edu
	609-258-2819 (messages)		eho@bogey.princeton.edu

regards.

-eric-