[parisc-linux] Compiler switches

[John David Anglin]

> > I think they definitely should be implied by configuring for hppa-linux.
> > I don't see any enthusiasm for allowing use of additional space registers
> > for special purposes.
> 
> Ok, I will do some testing with fast indirect and no space registers.

I have installed a GCC patch on 3.3 and trunk that changes the
hppa-unknown-linux-gnu target (no change to hppa64-unknown-linux-gnu) to
include MASK_NO_SPACE_REGISTERS in the target default.  The patch also
improves the code generated in a few situations where we unnecessarily
loaded the destination space register when doing an external branch.
As these were in rather uncommon situations, I doubt anyone will see
much difference in performance.  This really only affects PA 1.x as
PA 2.0 has the "bve" insn which sets the space register automatically.

It's not a good idea to make fast indirect the default.  Fast indirect
calls only work when a program has static linkage (i.e., the're not
compatible with shared libraries because the PIC register is not set
when you do a fast indirect call).

Dave
-- 
J. David Anglin                                  dave.anglin@nrc-cnrc.gc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6605)