[X86] Don't reuse an unrelated variable, create a new one. NFC.

Using Op makes it look like we're doing something with it.
We're really not.

llvm-svn: 260315

1 files changed, 28 insertions, 26 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index fb39d1d829d..bd6d9388ddc 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -23380,6 +23380,8 @@ static bool combineX86ShuffleChain(SDValue Op, SDValue Root, ArrayRef<int> Mask,
   MVT RootVT = Root.getSimpleValueType();
   SDLoc DL(Root);
 
+  SDValue Res;
+
   if (Mask.size() == 1) {
     int Index = Mask[0];
     assert((Index >= 0 || Index == SM_SentinelUndef ||
@@ -23430,14 +23432,14 @@ static bool combineX86ShuffleChain(SDValue Op, SDValue Root, ArrayRef<int> Mask,
       }
       if (Depth == 1 && Root->getOpcode() == Shuffle)
         return false; // Nothing to do!
-      Op = DAG.getBitcast(ShuffleVT, Input);
-      DCI.AddToWorklist(Op.getNode());
+      Res = DAG.getBitcast(ShuffleVT, Input);
+      DCI.AddToWorklist(Res.getNode());
       if (Shuffle == X86ISD::MOVDDUP)
-        Op = DAG.getNode(Shuffle, DL, ShuffleVT, Op);
+        Res = DAG.getNode(Shuffle, DL, ShuffleVT, Res);
       else
-        Op = DAG.getNode(Shuffle, DL, ShuffleVT, Op, Op);
-      DCI.AddToWorklist(Op.getNode());
-      DCI.CombineTo(Root.getNode(), DAG.getBitcast(RootVT, Op),
+        Res = DAG.getNode(Shuffle, DL, ShuffleVT, Res, Res);
+      DCI.AddToWorklist(Res.getNode());
+      DCI.CombineTo(Root.getNode(), DAG.getBitcast(RootVT, Res),
                     /*AddTo*/ true);
       return true;
     }
@@ -23448,11 +23450,11 @@ static bool combineX86ShuffleChain(SDValue Op, SDValue Root, ArrayRef<int> Mask,
       MVT ShuffleVT = MVT::v4f32;
       if (Depth == 1 && Root->getOpcode() == Shuffle)
         return false; // Nothing to do!
-      Op = DAG.getBitcast(ShuffleVT, Input);
-      DCI.AddToWorklist(Op.getNode());
-      Op = DAG.getNode(Shuffle, DL, ShuffleVT, Op);
-      DCI.AddToWorklist(Op.getNode());
-      DCI.CombineTo(Root.getNode(), DAG.getBitcast(RootVT, Op),
+      Res = DAG.getBitcast(ShuffleVT, Input);
+      DCI.AddToWorklist(Res.getNode());
+      Res = DAG.getNode(Shuffle, DL, ShuffleVT, Res);
+      DCI.AddToWorklist(Res.getNode());
+      DCI.CombineTo(Root.getNode(), DAG.getBitcast(RootVT, Res),
                     /*AddTo*/ true);
       return true;
     }
@@ -23462,11 +23464,11 @@ static bool combineX86ShuffleChain(SDValue Op, SDValue Root, ArrayRef<int> Mask,
       MVT ShuffleVT = MVT::v4f32;
       if (Depth == 1 && Root->getOpcode() == Shuffle)
         return false; // Nothing to do!
-      Op = DAG.getBitcast(ShuffleVT, Input);
-      DCI.AddToWorklist(Op.getNode());
-      Op = DAG.getNode(Shuffle, DL, ShuffleVT, Op, Op);
-      DCI.AddToWorklist(Op.getNode());
-      DCI.CombineTo(Root.getNode(), DAG.getBitcast(RootVT, Op),
+      Res = DAG.getBitcast(ShuffleVT, Input);
+      DCI.AddToWorklist(Res.getNode());
+      Res = DAG.getNode(Shuffle, DL, ShuffleVT, Res, Res);
+      DCI.AddToWorklist(Res.getNode());
+      DCI.CombineTo(Root.getNode(), DAG.getBitcast(RootVT, Res),
                     /*AddTo*/ true);
       return true;
     }
@@ -23496,11 +23498,11 @@ static bool combineX86ShuffleChain(SDValue Op, SDValue Root, ArrayRef<int> Mask,
     default:
       llvm_unreachable("Impossible mask size!");
     };
-    Op = DAG.getBitcast(ShuffleVT, Input);
-    DCI.AddToWorklist(Op.getNode());
-    Op = DAG.getNode(Shuffle, DL, ShuffleVT, Op, Op);
-    DCI.AddToWorklist(Op.getNode());
-    DCI.CombineTo(Root.getNode(), DAG.getBitcast(RootVT, Op),
+    Res = DAG.getBitcast(ShuffleVT, Input);
+    DCI.AddToWorklist(Res.getNode());
+    Res = DAG.getNode(Shuffle, DL, ShuffleVT, Res, Res);
+    DCI.AddToWorklist(Res.getNode());
+    DCI.CombineTo(Root.getNode(), DAG.getBitcast(RootVT, Res),
                   /*AddTo*/ true);
     return true;
   }
@@ -23535,14 +23537,14 @@ static bool combineX86ShuffleChain(SDValue Op, SDValue Root, ArrayRef<int> Mask,
       PSHUFBMask.push_back(DAG.getConstant(M, DL, MVT::i8));
     }
     MVT ByteVT = MVT::getVectorVT(MVT::i8, NumBytes);
-    Op = DAG.getBitcast(ByteVT, Input);
-    DCI.AddToWorklist(Op.getNode());
+    Res = DAG.getBitcast(ByteVT, Input);
+    DCI.AddToWorklist(Res.getNode());
     SDValue PSHUFBMaskOp =
         DAG.getNode(ISD::BUILD_VECTOR, DL, ByteVT, PSHUFBMask);
     DCI.AddToWorklist(PSHUFBMaskOp.getNode());
-    Op = DAG.getNode(X86ISD::PSHUFB, DL, ByteVT, Op, PSHUFBMaskOp);
-    DCI.AddToWorklist(Op.getNode());
-    DCI.CombineTo(Root.getNode(), DAG.getBitcast(RootVT, Op),
+    Res = DAG.getNode(X86ISD::PSHUFB, DL, ByteVT, Res, PSHUFBMaskOp);
+    DCI.AddToWorklist(Res.getNode());
+    DCI.CombineTo(Root.getNode(), DAG.getBitcast(RootVT, Res),
                   /*AddTo*/ true);
     return true;
   }