[PATCH] D98206: [TTI] Add a Mask to getShuffleCost

[Alexey Bataev via Phabricator via llvm-commits]

ABataev added inline comments.


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Comment at: llvm/include/llvm/Analysis/TargetTransformInfo.h:1047
   /// NOTE: For subvector extractions Tp represents the source type.
-  int getShuffleCost(ShuffleKind Kind, VectorType *Tp, int Index = 0,
-                     VectorType *SubTp = nullptr) const;
+  int getShuffleCost(ShuffleKind Kind, VectorType *Tp, ArrayRef<int> Mask,
+                     int Index = 0, VectorType *SubTp = nullptr) const;
----------------
`ArrayRef<int> Mask = llvm::None`? How about make it a param with the default value?


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Comment at: llvm/include/llvm/CodeGen/BasicTTIImpl.h:1260
+          TTI::SK_ExtractSubvector, cast<VectorType>(Args[0]->getType()),
+          ArrayRef<int>(), Index, cast<VectorType>(RetTy));
     }
----------------
Better to use `llvm::None` here and in the other places


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Comment at: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:294
 static Optional<TargetTransformInfo::ShuffleKind>
-isShuffle(ArrayRef<Value *> VL) {
+isShuffle(ArrayRef<Value *> VL, SmallVector<int> &Mask) {
   auto *EI0 = cast<ExtractElementInst>(VL[0]);
----------------
`SmalVectorImpl<int> &`?


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Comment at: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:313
+    if (Idx->getValue().uge(Size)) {
+      Mask.push_back(-1);
       continue;
----------------
`UndefMaskElem`


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Comment at: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:3474
+    ReuseShuffleCost = TTI->getShuffleCost(
+        TargetTransformInfo::SK_PermuteSingleSrc, VecTy, ArrayRef<int>());
   }
----------------
dmgreen wrote:
> I don't know the SLP vectorizer very well. Could these use E->ReuseShuffleIndices?
I think yes.


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Comment at: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:3556
         CommonCost = TTI->getShuffleCost(
-            TargetTransformInfo::SK_PermuteSingleSrc, VecTy);
+            TargetTransformInfo::SK_PermuteSingleSrc, VecTy, ArrayRef<int>());
       }
----------------
You can call `inversePermutation` to get a mask out of `E->ReorderIndices`


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Comment at: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:3782
         VecLdCost += TTI->getShuffleCost(
-            TargetTransformInfo::SK_PermuteSingleSrc, VecTy);
+            TargetTransformInfo::SK_PermuteSingleSrc, VecTy, ArrayRef<int>());
       LLVM_DEBUG(dumpTreeCosts(E, ReuseShuffleCost, VecLdCost, ScalarLdCost));
----------------
Same, call `inversePermutation` to get a mask out of `E->ReorderIndices`


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Comment at: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:3799
         VecStCost += TTI->getShuffleCost(
-            TargetTransformInfo::SK_PermuteSingleSrc, VecTy);
+            TargetTransformInfo::SK_PermuteSingleSrc, VecTy, ArrayRef<int>());
       LLVM_DEBUG(dumpTreeCosts(E, ReuseShuffleCost, VecStCost, ScalarStCost));
----------------
Same, call `inversePermutation` to get a mask out of `E->ReorderIndices`


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Comment at: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:3867
+      VecCost += TTI->getShuffleCost(TargetTransformInfo::SK_Select, VecTy,
+                                     ArrayRef<int>(), 0);
       LLVM_DEBUG(dumpTreeCosts(E, ReuseShuffleCost, VecCost, ScalarCost));
----------------
The mask here is something like `1010101...`, just in case


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  https://reviews.llvm.org/D98206/new/

https://reviews.llvm.org/D98206