DAG: Use poison when legalizing scalar_to_vector results

[arsenm]

No description provided.

[arsenm]

• DAG: Use poison for some load/store offsets in legalizer #167756
• DAG: Use poison in SplitVecRes_VP_LOAD_FF #167753
• DAG: Use poison when legalizing scalar_to_vector results #167751 👈 (View in Graphite)
• DAG: Use poison when widening build_vector #167631
• main

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[llvmbot]

@llvm/pr-subscribers-backend-risc-v
@llvm/pr-subscribers-llvm-selectiondag

@llvm/pr-subscribers-backend-aarch64

Author: Matt Arsenault (arsenm)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/167751.diff

1 Files Affected:

• (modified) llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp (+1-1)

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
index 6284ded3be922..461cea2e80748 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
@@ -2186,7 +2186,7 @@ void DAGTypeLegalizer::SplitVecRes_ScalarOp(SDNode *N, SDValue &Lo,
   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));
   Lo = DAG.getNode(N->getOpcode(), dl, LoVT, N->getOperand(0));
   if (N->getOpcode() == ISD::SCALAR_TO_VECTOR) {
-    Hi = DAG.getUNDEF(HiVT);
+    Hi = DAG.getPOISON(HiVT);
   } else {
     assert(N->getOpcode() == ISD::SPLAT_VECTOR && "Unexpected opcode");
     Hi = Lo;

[llvmbot]

@llvm/pr-subscribers-backend-x86

Author: Matt Arsenault (arsenm)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/167751.diff

1 Files Affected:

• (modified) llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp (+1-1)

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
index 6284ded3be922..461cea2e80748 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
@@ -2186,7 +2186,7 @@ void DAGTypeLegalizer::SplitVecRes_ScalarOp(SDNode *N, SDValue &Lo,
   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));
   Lo = DAG.getNode(N->getOpcode(), dl, LoVT, N->getOperand(0));
   if (N->getOpcode() == ISD::SCALAR_TO_VECTOR) {
-    Hi = DAG.getUNDEF(HiVT);
+    Hi = DAG.getPOISON(HiVT);
   } else {
     assert(N->getOpcode() == ISD::SPLAT_VECTOR && "Unexpected opcode");
     Hi = Lo;

[llvmbot]

@llvm/pr-subscribers-backend-arm

Author: Matt Arsenault (arsenm)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/167751.diff

1 Files Affected:

• (modified) llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp (+1-1)

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
index 6284ded3be922..461cea2e80748 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
@@ -2186,7 +2186,7 @@ void DAGTypeLegalizer::SplitVecRes_ScalarOp(SDNode *N, SDValue &Lo,
   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));
   Lo = DAG.getNode(N->getOpcode(), dl, LoVT, N->getOperand(0));
   if (N->getOpcode() == ISD::SCALAR_TO_VECTOR) {
-    Hi = DAG.getUNDEF(HiVT);
+    Hi = DAG.getPOISON(HiVT);
   } else {
     assert(N->getOpcode() == ISD::SPLAT_VECTOR && "Unexpected opcode");
     Hi = Lo;

[RKSimon]

Should we update the description in ISDOpcodes.h ?

[arsenm]

ping