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Re: Should -fcross-jumping be part of -O1?
- From: Scott Robert Ladd <coyote at coyotegulch dot com>
- To: gcc mailing list <gcc at gcc dot gnu dot org>
- Date: Wed, 03 Dec 2003 10:00:07 -0500
- Subject: Re: Should -fcross-jumping be part of -O1?
- References: <10312031406.AA12282@vlsi1.ultra.nyu.edu>
Richard Kenner wrote:
I don't see why it would be any worse than all the -f options we
currently have.
I agree.
A thought experiment: Allow a complexity of switches for those of us
that want to fine-tune code, while implementing "general purpose"
switches (e.g., -Os/-Ospeed) for people who are less complexity in their
use of GCC.
Based on personal experience and the conversation herein, optimization
appears to be a five-dimensional space with these axis:
* compilation speed (-Ospeed)
* debugability (-Odebug)
* code size (-Osize)
* execution speed (-Ofast)
* FP accuracy (-Oaccuracy)
The switches would be weighted; for example, specifying -Osize=0
-Ospeed=2 -Oaccuracy=3 would request the highest-accuracy, with speed as
a secondary consideration, and no concern for code size.
Hmmm... I'm still not certain if that's too complicated. for right now,
I'm just tossing out ideas; working out the interactions of the axes
would be the next step, if the model makes sense.
--
Scott Robert Ladd
Coyote Gulch Productions (http://www.coyotegulch.com)
Software Invention for High-Performance Computing