[llvm] [AArch64][CostModel] Consider the cost of const vector (PR #117539)

[Alexey Bataev via llvm-commits]

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@@ -11019,8 +11039,6 @@ BoUpSLP::getEntryCost(const TreeEntry *E, ArrayRef<Value *> VectorizedVals,
 
   bool NeedToShuffleReuses = !E->ReuseShuffleIndices.empty();
   if (E->isGather()) {
-    if (allConstant(VL))
-      return 0;
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alexey-bataev wrote:

Check RISCVTargetTransformInfo.cpp, RISCVTTIImpl::getArithmeticInstrCost function. It has lambda `getConstantMatCost` which is called if Op1Info.isConstant() is true or Op2Info.isConstant() is true to add the constants materialization costs, if operands are constants

https://github.com/llvm/llvm-project/pull/117539