Should -fcross-jumping be part of -O1?

[Scott Robert Ladd]

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