[LLVMdev] Recalculating live intervals

[Anton Vayvod]

On 8/7/06, Chris Lattner <sabre at nondot.org> wrote:
>
> On Sun, 6 Aug 2006, Anton Vayvod wrote:
> > I'm developing a register allocator that works iteratively. It spills
> some
> > virtual registers on each iteration until all the rest have physical
> ones
> > assigned.
>
> Take a look at the linear scan allocator.  It is also iterative: it uses
> the spiller interface to insert spill code, which creates (unspillable)
> intervals for the spill code it inserts.
>
> > How can I spill some live intervals at the end of each iteration with
> new
> > live intervals having correct weights?
>
> The linscan allocator inserts spill code with infinite weight, take a look
> at how it works.


So, as far as I understood live intervals with weight equal to HUGE_VAL are
spilled and I don't need to allocate physical registers for them, right?
Shoud hasStackSlot method of VirtRegMap return true for these intervals' reg
members?
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