[llvm-commits] [PATCH] add get(Extract/Insert)SubvectorCost to VTTI

[Hal Finkel]

Nadav, et al.,

Most of the shuffles that the BB vectorizer forms are subvector extractions and insertions. On some targets, some of these extractions and insertions are cheaper than general shuffles, and I'd like to add a cost interface to capture that.

I've attached a small patch to add these interfaces. What do you think? Will it matter to the costs whether either of the vectors being used will be used again? (meaning will there be cheaper 'destructive' extracts than otherwise?). The default implementation does not contain any logic to detected trivial insertions and extractions (between a type and a type to which the first is promoted). If we like this interface, I'll add that logic as well.

Thanks again,
Hal

-- 
Hal Finkel
Postdoctoral Appointee
Leadership Computing Facility
Argonne National Laboratory
-------------- next part --------------
A non-text attachment was scrubbed...
Name: llvm_eisvc.patch
Type: text/x-patch
Size: 2834 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20121106/e294cd06/attachment.bin>