[PATCH] D55301: RegAlloc: Allow targets to split register allocation

[Quentin Colombet via Phabricator via llvm-commits]

qcolombet added a comment.

Hi Matt,

Have you tried to use combined V+S register classes?
By describing such classes, when a S or V register would be split, they would eventually have constraints in that "super" class. Thus, inside of spilling, the splitting mechanism would naturally insert copies of the form `[V|S] = copy V+S` or `V+S = copy [V|S]`, which seem to be what you are trying to achieve. The advantage of such approach is that we would not have to effectively split the allocation.

Cheers,
-Quentin


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