Should -fcross-jumping be part of -O1?

[Scott Robert Ladd]

I'm working out a plan of action in terms of finding better option sets 
for the various -O levels. The comments in this thread have been most 
useful.

1) I can analyze for executable code size, compile speed, and execution 
time; I'm adding such options to Acovea.

2) Testing only on Intel chips is a severe limitation; I'm updating 
Acovea for my UltraSparc IIi system, and I have a G4 Mac coming 
available in the next week or so. In the next few days, I'll publish an 
update to Acovea, so people with Alphas and such can test on their 
boxes, if they want to.

3) In addition to the other categories, I'm also going to look at a 
-Oaccuracy option. As it stands now, options that may cause inaccuracies 
are bundled inside -ffast-math; I've seen some evidence of accuracy 
problems with other options as well, but want to confirm my anecdotal 
evidence with some real tests.

4) Is it reasonable to perform different optimizations on different 
architectures? It seems to me that a PowerPC or Opteron has very 
different characteristics from a P4, but maybe I'm splitting hairs.


-- 
Scott Robert Ladd
Coyote Gulch Productions (http://www.coyotegulch.com)
Software Invention for High-Performance Computing