[llvm] [SLP][NFC] Make calculateTreeCostAndTrimNonProfitable compatible (PR #191905)

[Alexey Bataev via llvm-commits]

https://github.com/alexey-bataev created https://github.com/llvm/llvm-project/pull/191905

with processBuildVector, NFC

processBuildVector adjusts the scalars to match the entry vector factor,
while calculateTreeCostAndTrimNonProfitable does not. Sync the behovior
  to avoid potential issues. Currently it does not affect the cost
  estimations, so it is NFC.


>From eb42df343349903a78997620f7fd378659bcf912 Mon Sep 17 00:00:00 2001
From: Alexey Bataev <a.bataev at outlook.com>
Date: Mon, 13 Apr 2026 15:51:29 -0700
Subject: [PATCH] =?UTF-8?q?[=F0=9D=98=80=F0=9D=97=BD=F0=9D=97=BF]=20initia?=
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Created using spr 1.3.7
---
 llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 0e647fa235916..803507f110007 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -18075,20 +18075,18 @@ InstructionCost BoUpSLP::calculateTreeCostAndTrimNonProfitable(
       Worklist.pop();
       continue;
     }
-    const unsigned Sz = TE->Scalars.size();
-    APInt DemandedElts = APInt::getAllOnes(Sz);
+    const unsigned EntryVF = TE->getVectorFactor();
+    APInt DemandedElts = APInt::getZero(EntryVF);
     for (auto [Idx, V] : enumerate(TE->Scalars)) {
-      if (isConstant(V))
-        DemandedElts.clearBit(Idx);
+      if (!isConstant(V))
+        DemandedElts.setBit(Idx);
     }
 
     Type *ScalarTy = getValueType(TE->Scalars.front());
     auto It = MinBWs.find(TE);
     if (It != MinBWs.end())
       ScalarTy = IntegerType::get(ScalarTy->getContext(), It->second.first);
-    auto *VecTy = getWidenedType(ScalarTy, Sz);
-    const unsigned EntryVF = TE->getVectorFactor();
-    auto *FinalVecTy = getWidenedType(ScalarTy, EntryVF);
+    auto *VecTy = getWidenedType(ScalarTy, EntryVF);
     InstructionCost GatherCost = ::getScalarizationOverhead(
         *TTI, ScalarTy, VecTy, DemandedElts,
         /*Insert=*/true, /*Extract=*/false, CostKind);
@@ -18111,7 +18109,7 @@ InstructionCost BoUpSLP::calculateTreeCostAndTrimNonProfitable(
       ::addMask(Mask, TE->ReuseShuffleIndices);
     if (!Mask.empty() && !ShuffleVectorInst::isIdentityMask(Mask, EntryVF))
       GatherCost +=
-          ::getShuffleCost(*TTI, TTI::SK_PermuteSingleSrc, FinalVecTy, Mask);
+          ::getShuffleCost(*TTI, TTI::SK_PermuteSingleSrc, VecTy, Mask);
     // If all scalars are reused in gather node(s) or other vector nodes, there
     // might be extra cost for inserting them.
     if ((!TE->hasState() || !TE->isAltShuffle()) &&