gnupic: Re: [gnupic] Linker Optimizations
Subject:
Re: [gnupic] Linker Optimizations
From:
"Scott Dattalo" ####@####.####
Date:
2 Mar 2007 21:14:40 +0000
Message-Id: <61451.71.139.37.215.1172870052.squirrel@ruckus.brouhaha.com>
On Fri, 2007-03-02 at 12:47 -0600, David Barnett wrote:
> I've always been frustrated about some big optimizations that can only
> be made manually; the linker doesn't seem to have enough information
> to optimize them. HI-TECH will avoid these issues by using
> "omnicode", meaning all source files are compiled at the same time,
> and SourceBoost seems to skirt the problem with a custom object file
> format. The two that stand out to me are:
> a) code-flow-related optimizations on page and bank selections
> b) removal of unused functions and global variables
>
<snip>
David,
I agree with you fully (for whatever that's worth). In my opinion, the
linker should be capable of Bank selection, Simulator assertions for
banks, tail optimization, dead code elimination, peephole optimization,
etc. and much more.
I suggested at one point that the pCode optimizer I started in SDCC should
be ported into gputils. In it's first implementation, it did much of the
stuff we'd want. The pCode optimizer was written before the linker was
used too much. So consequently, it dealt with single C-files at a time.
When linker support became more prevalent, the pCode optimizer had to be
changed quite a bit.
The only issue I have is time...
Scott
