[llvm] 7f36981 - [LV] Adjust trip count based on IsOrdered in widenPHIInstruction (NFC).

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2021-06-26T13:13:25+01:00
New Revision: 7f369819774d376f043200220f1a2d36d53487a2

URL: https://github.com/llvm/llvm-project/commit/7f369819774d376f043200220f1a2d36d53487a2
DIFF: https://github.com/llvm/llvm-project/commit/7f369819774d376f043200220f1a2d36d53487a2.diff

LOG: [LV] Adjust trip count based on IsOrdered in widenPHIInstruction (NFC).

Suggested in D104197, avoids the early exit.

Added: 
    

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

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index f28dbaac2d45..b53c14424a70 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -4801,11 +4801,8 @@ void InnerLoopVectorizer::widenPHIInstruction(Instruction *PN,
     bool IsOrdered = State.VF.isVector() &&
                      Cost->isInLoopReduction(cast<PHINode>(PN)) &&
                      Cost->useOrderedReductions(*RdxDesc);
-
-    for (unsigned Part = 0; Part < State.UF; ++Part) {
-      // This is phase one of vectorizing PHIs.
-      if (Part > 0 && IsOrdered)
-        return;
+    unsigned LastPartForNewPhi = IsOrdered ? 1 : State.UF;
+    for (unsigned Part = 0; Part < LastPartForNewPhi; ++Part) {
       Value *EntryPart = PHINode::Create(
           VecTy, 2, "vec.phi", &*LoopVectorBody->getFirstInsertionPt());
       State.set(PhiR, EntryPart, Part);