Re: [RTL, ColdFire 24/63] Add support for a MODE_INDEX_REG_CLASS macro

[Jeffrey Law <law at redhat dot com>]

On Wed, 2007-02-28 at 16:34 +0000, Richard Sandiford wrote:
> Jeffrey Law <law@redhat.com> writes:
> >> My concern about efficiency still stands though.  Concretely,
> >> your patch is going to mean that the MIPS port does (29 modes x
> >> 188 regs =) 5452 legitimate address checks at startup, all of
> >> which will be false.  The figure for PowerPC is (38 modes x 114 regs =)
> >> 4332 checks and the figure for ia64 is (40 modes * 334 regs =) 13360 checks.
> >> (I realise that ia64 is one of those targets where you expect the compiler
> >> to be slower, but still. ;))  As the patch stands, it will also create
> >> new garbage addresses for each check.  I think at the very least you
> >> should:
> >> 
> >>   - create one address and use it for all checks, changing parts of
> >>     it as appropriate
> > Definitely.  Please go ahead and do this.
> 
> Sorry, but I still strongly believe you're leading us in the
> wrong direction here.  I suggest we leave it for someone else
> with less strong feelings.  And...
I have strong feelings because I'm more than familiar with the code
in question.  I'm going to object if someone tries to install your 
patch.  It's unnecessary and papering over the bogus code which computes
double_reg_address_ok.

You have a path by which you can get the coldfire problems resolved
cleanly, would you please take it rather than continuing to argue for
the  original patch.

jeff