Combined top-down and bottom-up instruction scheduler

[Segher Boessenkool]

On Tue, Sep 08, 2015 at 06:39:19PM +0000, Aditya K wrote:
> IIUC, in the haifa-sched.c, the default scheduling algorithm seems to be top-down (before reload).
> Is there a way to schedule the other way (bottom up), or both ways?
> 
> As a use case for bottom-up or some other heuristic:
> Currently, the first priority in the selection is given to the longest path, in some cases this may produce code with stalls at the end of the basic block. Whereas in the case of combined top-down + bottom-up scheduling we would end up having stalls in the middle of the basic block.

Why would that be better?


Segher