[SLPVectorizer] Moving Entry->NeedToGather check out of inner loop,

since it is invariant there. NFCI.

llvm-svn: 306749

llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

@@ -1062,14 +1062,14 @@ void BoUpSLP::buildTree(ArrayRef<Value *> Roots,
   for (TreeEntry &EIdx : VectorizableTree) {
     TreeEntry *Entry = &EIdx;
 
+    // No need to handle users of gathered values.
+    if (Entry->NeedToGather)
+      continue;
+
     // For each lane:
     for (int Lane = 0, LE = Entry->Scalars.size(); Lane != LE; ++Lane) {
       Value *Scalar = Entry->Scalars[Lane];
 
-      // No need to handle users of gathered values.
-      if (Entry->NeedToGather)
-        continue;
-
       // Check if the scalar is externally used as an extra arg.
       auto ExtI = ExternallyUsedValues.find(Scalar);
       if (ExtI != ExternallyUsedValues.end()) {