[SLP]Fix PR90211: vectorized node must match completely to be reused.

If the gather node matches the vectorized node, it must also match with
the scalars completely. Otherwise, need to revectorize the gather node
to generate correct code.

Author: alexey-bataev

llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

@@ -13166,7 +13166,8 @@ Value *BoUpSLP::vectorizeTree(
     auto *TE = const_cast<TreeEntry *>(E);
     if (auto *VecTE = getTreeEntry(TE->Scalars.front()))
       if (VecTE->isSame(TE->UserTreeIndices.front().UserTE->getOperand(
-              TE->UserTreeIndices.front().EdgeIdx)))
+              TE->UserTreeIndices.front().EdgeIdx)) &&
+          VecTE->isSame(TE->Scalars))
         // Found gather node which is absolutely the same as one of the
         // vectorized nodes. It may happen after reordering.
         continue;

llvm/test/Transforms/SLPVectorizer/X86/gather-node-same-as-vect-but-order.ll

@@ -21,8 +21,7 @@ define void @foo(ptr %i7, i32 %0, i1 %tobool62.not) {
 ; CHECK-NEXT:    [[TMP10:%.*]] = shufflevector <4 x float> [[TMP8]], <4 x float> [[TMP9]], <4 x i32> <i32 0, i32 4, i32 5, i32 poison>
 ; CHECK-NEXT:    [[TMP11:%.*]] = insertelement <4 x float> [[TMP10]], float [[TMP7]], i32 3
 ; CHECK-NEXT:    [[TMP12:%.*]] = fcmp olt <4 x float> [[TMP11]], zeroinitializer
-; CHECK-NEXT:    [[TMP13:%.*]] = load <4 x float>, ptr poison, align 16
-; CHECK-NEXT:    [[TMP14:%.*]] = fcmp olt <4 x float> [[TMP13]], zeroinitializer
+; CHECK-NEXT:    [[TMP14:%.*]] = fcmp olt <4 x float> [[TMP5]], zeroinitializer
 ; CHECK-NEXT:    [[TMP15:%.*]] = select <4 x i1> [[TMP14]], <4 x float> [[TMP5]], <4 x float> zeroinitializer
 ; CHECK-NEXT:    [[TMP16:%.*]] = select <4 x i1> [[TMP12]], <4 x float> zeroinitializer, <4 x float> [[TMP15]]
 ; CHECK-NEXT:    store <4 x float> [[TMP16]], ptr [[RC21]], align 4