gcc power optimization

[AJ]

Hi,

I am trying to optimize gcc for power consumption. Technique I am
using is rescheduling instruction based on hamming distance between
two consecutive instructions. Now I want to create a new pass after
register allocation and final jump optimization. I am new to gcc
development and am having trouble finding out how to create a new
pass. Also I understand my scheduler will have to operate on RTL code.
what would be the data structures I would need to create or which ones
could be reused.

How much code from schedule_insns() could be reused. I only need to
change the cost model in it.

Any kind of suggestion from you experts would be very beneficial for
me.

Alex

 

[Keith Thompson]

I am trying to optimize gcc for power consumption. Technique I am
using is rescheduling instruction based on hamming distance between
two consecutive instructions. Now I want to create a new pass after
register allocation and final jump optimization. I am new to gcc
development and am having trouble finding out how to create a new
pass. Also I understand my scheduler will have to operate on RTL code.
what would be the data structures I would need to create or which ones
could be reused.

How much code from schedule_insns() could be reused. I only need to
change the cost model in it.

Any kind of suggestion from you experts would be very beneficial for
me.

I'll have to take your word for it that this will optimize power
consumption, but in any case your question isn't about the C
programming language. comp.compilers is probably a better place to
ask.

 

[Flash Gordon]

Keith Thompson wrote, On 07/11/08 05:44:

I'll have to take your word for it that this will optimize power
consumption, but in any case your question isn't about the C
programming language. comp.compilers is probably a better place to
ask.

I would suggest the gcc development mailing list might be better as some
of the question is highly specific to gcc.

Also from personal experience I would suggest that the OP start be
looking at the design of the SW that will be built with gcc first. On
one project by judicious changes I was able to end up with the processor
spending a lot of time in its idle state not executing *any*
instructions (just waiting for an interrupt) and this can save a lot of
power. Such discussions, however, belong on comp.arch.embedded not here.