[llvm] a2e9c68 - [SLP] Extract a helper for buildvector [nfc]

[Philip Reames via llvm-commits]

Author: Philip Reames
Date: 2022-03-07T19:11:40-08:00
New Revision: a2e9c68fcd4425fbce7380746e916966f00a39a0

URL: https://github.com/llvm/llvm-project/commit/a2e9c68fcd4425fbce7380746e916966f00a39a0
DIFF: https://github.com/llvm/llvm-project/commit/a2e9c68fcd4425fbce7380746e916966f00a39a0.diff

LOG: [SLP] Extract a helper for buildvector [nfc]

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 9e81326bb39c3..0efe62a19b629 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -1965,6 +1965,11 @@ class BoUpSLP {
   /// Vectorize a single entry in the tree, starting in \p VL.
   Value *vectorizeTree(ArrayRef<Value *> VL);
 
+  /// Create a new vector from a list of scalar values.  Produces a sequence
+  /// which exploits values reused across lanes, and arranges the inserts
+  /// for ease of later optimization.
+  Value *createBuildVector(ArrayRef<Value *> VL);
+
   /// \returns the scalarization cost for this type. Scalarization in this
   /// context means the creation of vectors from a group of scalars. If \p
   /// NeedToShuffle is true, need to add a cost of reshuffling some of the
@@ -6557,7 +6562,7 @@ class ShuffleInstructionBuilder {
 } // namespace
 
 Value *BoUpSLP::vectorizeTree(ArrayRef<Value *> VL) {
-  unsigned VF = VL.size();
+  const unsigned VF = VL.size();
   InstructionsState S = getSameOpcode(VL);
   if (S.getOpcode()) {
     if (TreeEntry *E = getTreeEntry(S.OpValue))
@@ -6613,7 +6618,13 @@ Value *BoUpSLP::vectorizeTree(ArrayRef<Value *> VL) {
       }
   }
 
-  // Check that every instruction appears once in this bundle.
+  // Can't vectorize this, so simply build a new vector with each lane
+  // corresponding to the requested value.
+  return createBuildVector(VL);
+}
+Value *BoUpSLP::createBuildVector(ArrayRef<Value *> VL) {
+  unsigned VF = VL.size();
+  // Exploit possible reuse of values across lanes.
   SmallVector<int> ReuseShuffleIndicies;
   SmallVector<Value *> UniqueValues;
   if (VL.size() > 2) {