H8/300H code size issues (RTX_COSTS)

[Kazu Hirata]

Hi Toshi,

> > > BTW, I've been looking at code size issues on the H8/300H, and I've
> > > found some interesting things lately.
> > 
> > For at least several months, I've kept a patch for shift insn portion
> > of RTX_COSTS.  I just tried the patch again, and saw that about 800
> > lines of assembly code were cut down in newlib.
> > 
> > This may not reduce your code by 50% but may be a good starting point.
> > 
> > Would you mind sending me a preprocessed copy of your code?
> 
> Will send in private mail to avoid torturing POTS modem users.

Thanks.

I added lots of insn patterns for the combiner to exploit and cut down
411 lines, excluding labels, which amounts to more than 10% of the
original.

Although making the combiner happy isn't the only thing to do, I do
think that we have to teach h8300.md how to take advantage of the
how registers are configured.

Kazu Hirata