[llvm] e0efedd - [SLP][NFC]Fix non-determinism in reordering, NFC.

[Alexey Bataev via llvm-commits]

Author: Alexey Bataev
Date: 2021-12-30T13:10:25-08:00
New Revision: e0efedd2c33bf2bef232f255f1449a18d2b61d77

URL: https://github.com/llvm/llvm-project/commit/e0efedd2c33bf2bef232f255f1449a18d2b61d77
DIFF: https://github.com/llvm/llvm-project/commit/e0efedd2c33bf2bef232f255f1449a18d2b61d77.diff

LOG: [SLP][NFC]Fix non-determinism in reordering, NFC.

Need to clear CurrentOrder order mask if it is determined that
extractelements form identity order and need to use a vector-like
construct when iterating over ordered entries in the reorderTopToBottom
function.

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 37ae13666f7a..1dd31dcae253 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -3040,7 +3040,7 @@ Optional<BoUpSLP::OrdersType> BoUpSLP::getReorderingData(const TreeEntry &TE,
 
 void BoUpSLP::reorderTopToBottom() {
   // Maps VF to the graph nodes.
-  DenseMap<unsigned, SmallPtrSet<TreeEntry *, 4>> VFToOrderedEntries;
+  DenseMap<unsigned, SetVector<TreeEntry *>> VFToOrderedEntries;
   // ExtractElement gather nodes which can be vectorized and need to handle
   // their ordering.
   DenseMap<const TreeEntry *, OrdersType> GathersToOrders;
@@ -3066,7 +3066,7 @@ void BoUpSLP::reorderTopToBottom() {
     // Try to find the most profitable order. We just are looking for the most
     // used order and reorder scalar elements in the nodes according to this
     // mostly used order.
-    const SmallPtrSetImpl<TreeEntry *> &OrderedEntries = It->getSecond();
+    ArrayRef<TreeEntry *> OrderedEntries = It->second.getArrayRef();
     // All operands are reordered and used only in this node - propagate the
     // most used order to the user node.
     MapVector<OrdersType, unsigned,
@@ -4459,6 +4459,8 @@ bool BoUpSLP::canReuseExtract(ArrayRef<Value *> VL, Value *OpValue,
     CurrentOrder.clear();
     return false;
   }
+  if (ShouldKeepOrder)
+    CurrentOrder.clear();
 
   return ShouldKeepOrder;
 }