[PATCH] D100486: [COST]Improve cost model for shuffles in SLP.

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added a comment.

Sorry for the slow response on this one - please can you split the DAG legalization change out as the first patch and the TTI change as a followup?



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Comment at: llvm/include/llvm/Analysis/VectorUtils.h:401
 
+SmallVector<SmallVector<SmallVector<int>>>
+computeShuffleMasks(ArrayRef<int> Mask, unsigned NumOfSrcRegs,
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Description comment?


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Comment at: llvm/include/llvm/Analysis/VectorUtils.h:402
+SmallVector<SmallVector<SmallVector<int>>>
+computeShuffleMasks(ArrayRef<int> Mask, unsigned NumOfSrcRegs,
+                    unsigned NumOfDestRegs);
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Should this be splitShuffleMasks?


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Comment at: llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp:2140
+      }
+      Output = Op0;
     }
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I'm rather surprised this didn't reduce further (same for the TTI) - maybe there's more functionality that can be moved into the computeShuffleMasks helper? 


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  https://reviews.llvm.org/D100486/new/

https://reviews.llvm.org/D100486