[SLP]Fix vector factor for repeated node for bv

When adding a node vector, when it is used already in the shuffle for
buildvector, need to calculate vector factor from all vector, not only
this single vector, to avoid incorrect result. Also, need to increase
stability of the reused entries detection to avoid mismatch in cost
estimation/codegen.

Fixes #123639

Author: alexey-bataev

llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

@@ -13205,9 +13205,12 @@ BoUpSLP::isGatherShuffledSingleRegisterEntry(
           VTE = *MIt;
         }
       }
-      Instruction &LastBundleInst = getLastInstructionInBundle(VTE);
-      if (&LastBundleInst == TEInsertPt || !CheckOrdering(&LastBundleInst))
-        continue;
+      if (none_of(TE->CombinedEntriesWithIndices,
+                  [&](const auto &P) { return P.first == VTE->Idx; })) {
+        Instruction &LastBundleInst = getLastInstructionInBundle(VTE);
+        if (&LastBundleInst == TEInsertPt || !CheckOrdering(&LastBundleInst))
+          continue;
+      }
       VToTEs.insert(VTE);
     }
     if (VToTEs.empty())
@@ -14497,7 +14500,9 @@ class BoUpSLP::ShuffleInstructionBuilder final : public BaseShuffleAnalysis {
           break;
         }
     }
-    int VF = getVF(V1);
+    unsigned VF = 0;
+    for (Value *V : InVectors)
+      VF = std::max(VF, getVF(V));
     for (unsigned Idx = 0, Sz = CommonMask.size(); Idx < Sz; ++Idx)
       if (Mask[Idx] != PoisonMaskElem && CommonMask[Idx] == PoisonMaskElem)
         CommonMask[Idx] = Mask[Idx] + (It == InVectors.begin() ? 0 : VF);

llvm/test/Transforms/SLPVectorizer/X86/multi-node-reuse-in-bv.ll

@@ -8,7 +8,7 @@
 ; YAML-NEXT: Function:        test
 ; YAML-NEXT: Args:
 ; YAML-NEXT:   - String:          'Vectorized horizontal reduction with cost '
-; YAML-NEXT:   - Cost:            '-38'
+; YAML-NEXT:   - Cost:            '-41'
 ; YAML-NEXT:   - String:          ' and with tree size '
 ; YAML-NEXT:   - TreeSize:        '7'
 ; YAML-NEXT: ...
@@ -17,7 +17,7 @@ define i64 @test() {
 ; CHECK-LABEL: define i64 @test(
 ; CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
 ; CHECK-NEXT:  [[ENTRY:.*:]]
-; CHECK-NEXT:    [[TMP0:%.*]] = insertelement <32 x i32> <i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 undef, i32 0, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 undef, i32 undef, i32 undef, i32 undef, i32 0, i32 0, i32 0, i32 0>, i32 0, i32 6
+; CHECK-NEXT:    [[TMP0:%.*]] = insertelement <32 x i32> <i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 undef, i32 0, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 undef, i32 undef, i32 undef, i32 undef, i32 0, i32 0, i32 1, i32 0>, i32 0, i32 6
 ; CHECK-NEXT:    [[TMP1:%.*]] = call <32 x i32> @llvm.vector.insert.v32i32.v8i32(<32 x i32> [[TMP0]], <8 x i32> zeroinitializer, i64 8)
 ; CHECK-NEXT:    [[TMP2:%.*]] = call <32 x i32> @llvm.vector.insert.v32i32.v4i32(<32 x i32> [[TMP1]], <4 x i32> <i32 0, i32 0, i32 0, i32 1>, i64 24)
 ; CHECK-NEXT:    [[TMP3:%.*]] = sub <32 x i32> zeroinitializer, [[TMP2]]