SLPVectorizer: Add support for trees with external users.

For example:
bar() {
  int a = A[i];
  int b = A[i+1];
  B[i] = a;
  B[i+1] = b;
  foo(a);  <--- a is used outside the vectorized expression.
}

llvm-svn: 181648

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Vectorize/VecUtils.h b/llvm/lib/Transforms/Vectorize/VecUtils.h
index 5456c6c7795..abb35840e93 100644
--- a/llvm/lib/Transforms/Vectorize/VecUtils.h
+++ b/llvm/lib/Transforms/Vectorize/VecUtils.h
@@ -127,6 +127,11 @@ private:
   /// NOTICE: The vectorization methods also use this set.
   ValueSet MustScalarize;
 
+  /// Contains values that have users outside of the vectorized graph.
+  /// We need to generate extract instructions for these values.
+  /// NOTICE: The vectorization methods also use this set.
+  ValueSet MustExtract;
+
   /// Contains a list of values that are used outside the current tree. This
   /// set must be reset between runs.
   ValueSet MultiUserVals;