[llvm] 4dcc0d1 - [CodeGen][SVE] Avoid scalarizing zero splat stores on scalable vectors.

[Danilo C. Grael via llvm-commits]

Author: Henry Kao
Date: 2020-06-09T12:52:39-04:00
New Revision: 4dcc0d1958f8eab1a05ca545ff3935d5b487cbbe

URL: https://github.com/llvm/llvm-project/commit/4dcc0d1958f8eab1a05ca545ff3935d5b487cbbe
DIFF: https://github.com/llvm/llvm-project/commit/4dcc0d1958f8eab1a05ca545ff3935d5b487cbbe.diff

LOG: [CodeGen][SVE] Avoid scalarizing zero splat stores on scalable vectors.

Summary: Implemented in replaceZeroVectorStore(). Fixes several warnings in AArch64 SVE unit tests.

Reviewers: sdesmalen, kmclaughlin, dancgr, efriedma, each, andwar, rengolin

Reviewed By: sdesmalen

Subscribers: tschuett, kristof.beyls, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80824

Added: 
    

Modified: 
    llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

Removed: 
    


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diff  --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index a3fec1da68b9..86712098f910 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -12069,6 +12069,10 @@ static SDValue replaceZeroVectorStore(SelectionDAG &DAG, StoreSDNode &St) {
   SDValue StVal = St.getValue();
   EVT VT = StVal.getValueType();
 
+  // Avoid scalarizing zero splat stores for scalable vectors.
+  if (VT.isScalableVector())
+    return SDValue();
+
   // It is beneficial to scalarize a zero splat store for 2 or 3 i64 elements or
   // 2, 3 or 4 i32 elements.
   int NumVecElts = VT.getVectorNumElements();