[LLVMdev] [LLVMDev] [Question] How do I get the number of machine registers.

Jakob Stoklund Olesen stoklund at 2pi.dk
Wed Sep 29 09:17:16 PDT 2010


On Sep 29, 2010, at 8:11 AM, Jeff Kunkel wrote:

> Jacob, have you completed the topological sorting or the registers? It
> seems I iterate through sub/alias-registers quite often, and I think a
> performance gain might occur if the sub-registers were grouped better.

I abandoned the experiment because it didn't give a significant performance gain.

Another problem is that aliases don't always form a nice tree, so sometimes topological sorting is not possible.

The fast register allocator now avoids iterating over aliases by using a working-set strategy instead.

/jakob





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