Patch to fix unintentional(?) pessimisation in dbr_schedule

[Richard Henderson]

On Mon, Apr 05, 2004 at 11:52:17PM +0100, Richard Sandiford wrote:
>   (a) dbr_schedule starts off with S, the registers live at D.  It will
>       correctly detect that S includes "x" because it scans from the
>       previous barrier and notices the assignment in B.

Look at one of the other three alternatives you showed: ABCD.
The set of registers live at D will be assumed to be the set of
registers live at the barrier before C.  The scan forward from
there will not see a set of x, so it'll never be considered live.


r~