On May 13, 2007, at 3:32 AM, Rask Ingemann Lambertsen wrote:
On Fri, Jan 06, 2006 at 02:48:30PM -0800, Richard Henderson wrote:
What they're looking for is, for functions that don't use
the pic register, to not reserve the pic register so that
it's available for computation. This is harder. In theory,
ppc has some scheme for this, where they eliminate the pic
register to itself. I've never really understood how that's
supposed to work.
Suppose you tell reload that %rpic can be eliminated as %rpic + 0.
Reload
will start out by assuming that the elimination is possible and
%rpic will
be available for reloads. If no insns mention %rpic at all, it
should just
work, and you will have recovered a register.
Hum... Could this work on the i386 port (32-bit) to get another
register? If so, we'd love to have the extra register when
possible. :-)
