diff --git a/clang/test/CodeGen/aarch64-bf16-getset-intrinsics.c b/clang/test/CodeGen/aarch64-bf16-getset-intrinsics.c
--- a/clang/test/CodeGen/aarch64-bf16-getset-intrinsics.c
+++ b/clang/test/CodeGen/aarch64-bf16-getset-intrinsics.c
@@ -98,8 +98,8 @@
 
 // CHECK-LABEL: @test_vget_lane_bf16(
 // CHECK-NEXT:  entry:
-// CHECK-NEXT:    [[DOTCAST1:%.*]] = extractelement <4 x bfloat> [[V:%.*]], i32 1
-// CHECK-NEXT:    ret bfloat [[DOTCAST1]]
+// CHECK-NEXT:    [[VGET_LANE:%.*]] = extractelement <4 x bfloat> [[V:%.*]], i32 1
+// CHECK-NEXT:    ret bfloat [[VGET_LANE]]
 //
 bfloat16_t test_vget_lane_bf16(bfloat16x4_t v) {
   return vget_lane_bf16(v, 1);
@@ -107,8 +107,8 @@
 
 // CHECK-LABEL: @test_vgetq_lane_bf16(
 // CHECK-NEXT:  entry:
-// CHECK-NEXT:    [[DOTCAST1:%.*]] = extractelement <8 x bfloat> [[V:%.*]], i32 7
-// CHECK-NEXT:    ret bfloat [[DOTCAST1]]
+// CHECK-NEXT:    [[VGETQ_LANE:%.*]] = extractelement <8 x bfloat> [[V:%.*]], i32 7
+// CHECK-NEXT:    ret bfloat [[VGETQ_LANE]]
 //
 bfloat16_t test_vgetq_lane_bf16(bfloat16x8_t v) {
   return vgetq_lane_bf16(v, 7);
@@ -116,8 +116,8 @@
 
 // CHECK-LABEL: @test_vset_lane_bf16(
 // CHECK-NEXT:  entry:
-// CHECK-NEXT:    [[TMP0:%.*]] = insertelement <4 x bfloat> [[V:%.*]], bfloat [[A:%.*]], i32 1
-// CHECK-NEXT:    ret <4 x bfloat> [[TMP0]]
+// CHECK-NEXT:    [[VSET_LANE:%.*]] = insertelement <4 x bfloat> [[V:%.*]], bfloat [[A:%.*]], i32 1
+// CHECK-NEXT:    ret <4 x bfloat> [[VSET_LANE]]
 //
 bfloat16x4_t test_vset_lane_bf16(bfloat16_t a, bfloat16x4_t v) {
   return vset_lane_bf16(a, v, 1);
@@ -125,8 +125,8 @@
 
 // CHECK-LABEL: @test_vsetq_lane_bf16(
 // CHECK-NEXT:  entry:
-// CHECK-NEXT:    [[TMP0:%.*]] = insertelement <8 x bfloat> [[V:%.*]], bfloat [[A:%.*]], i32 7
-// CHECK-NEXT:    ret <8 x bfloat> [[TMP0]]
+// CHECK-NEXT:    [[VSET_LANE:%.*]] = insertelement <8 x bfloat> [[V:%.*]], bfloat [[A:%.*]], i32 7
+// CHECK-NEXT:    ret <8 x bfloat> [[VSET_LANE]]
 //
 bfloat16x8_t test_vsetq_lane_bf16(bfloat16_t a, bfloat16x8_t v) {
   return vsetq_lane_bf16(a, v, 7);
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -1740,8 +1740,7 @@
       for (unsigned i = 0; i != DstNumElts; ++i)
         Mask.push_back(IdxN + i);
 
-      Value *Shuffle =
-          Builder.CreateShuffleVector(Vec, UndefValue::get(VecTy), Mask);
+      Value *Shuffle = Builder.CreateShuffleVector(Vec, Mask);
       replaceInstUsesWith(CI, Shuffle);
       return eraseInstFromFunction(CI);
     }
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -679,7 +679,10 @@
       is_splat(Shuf->getShuffleMask()) &&
       Shuf->getType() == Shuf->getOperand(0)->getType()) {
     // trunc (shuf X, Undef, SplatMask) --> shuf (trunc X), Undef, SplatMask
-    Constant *NarrowUndef = UndefValue::get(Trunc.getType());
+    // trunc (shuf X, Poison, SplatMask) --> shuf (trunc X), Poison, SplatMask
+    Constant *NarrowUndef = isa<PoisonValue>(Shuf->getOperand(1))
+                                ? PoisonValue::get(Trunc.getType())
+                                : UndefValue::get(Trunc.getType());
     Value *NarrowOp = Builder.CreateTrunc(Shuf->getOperand(0), Trunc.getType());
     return new ShuffleVectorInst(NarrowOp, NarrowUndef, Shuf->getShuffleMask());
   }
@@ -711,7 +714,8 @@
   if (isa<UndefValue>(VecOp)) {
     // trunc   (inselt undef, X, Index) --> inselt undef,   (trunc X), Index
     // fptrunc (inselt undef, X, Index) --> inselt undef, (fptrunc X), Index
-    UndefValue *NarrowUndef = UndefValue::get(DestTy);
+    Value *NarrowUndef = isa<PoisonValue>(VecOp) ? PoisonValue::get(DestTy)
+                                                 : UndefValue::get(DestTy);
     Value *NarrowOp = Builder.CreateCast(Opcode, ScalarOp, DestScalarTy);
     return InsertElementInst::Create(NarrowUndef, NarrowOp, Index);
   }
@@ -2609,8 +2613,9 @@
     // Beware: messing with this target-specific oddity may cause trouble.
     if (DestVTy->getNumElements() == 1 && SrcTy->isX86_MMXTy()) {
       Value *Elem = Builder.CreateBitCast(Src, DestVTy->getElementType());
-      return InsertElementInst::Create(UndefValue::get(DestTy), Elem,
-                     Constant::getNullValue(Type::getInt32Ty(CI.getContext())));
+      return InsertElementInst::Create(
+          PoisonValue::get(DestTy), Elem,
+          Constant::getNullValue(Type::getInt32Ty(CI.getContext())));
     }
 
     if (isa<IntegerType>(SrcTy)) {
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -5469,6 +5469,7 @@
   ArrayRef<int> M;
   if (!match(LHS, m_Shuffle(m_Value(V1), m_Undef(), m_Mask(M))))
     return nullptr;
+  ShuffleVectorInst *LHSSV = cast<ShuffleVectorInst>(LHS);
 
   // If both arguments of the cmp are shuffles that use the same mask and
   // shuffle within a single vector, move the shuffle after the cmp:
@@ -5476,8 +5477,15 @@
   Type *V1Ty = V1->getType();
   if (match(RHS, m_Shuffle(m_Value(V2), m_Undef(), m_SpecificMask(M))) &&
       V1Ty == V2->getType() && (LHS->hasOneUse() || RHS->hasOneUse())) {
+    ShuffleVectorInst *RHSSV = cast<ShuffleVectorInst>(RHS);
     Value *NewCmp = Builder.CreateCmp(Pred, V1, V2);
-    return new ShuffleVectorInst(NewCmp, UndefValue::get(NewCmp->getType()), M);
+    // RHS of the new shuffle is poison if either of the original RHS is poison
+    // (cmps propagate poison)
+    Value *NewRHS = isa<PoisonValue>(LHSSV->getOperand(1)) ||
+                            isa<PoisonValue>(RHSSV->getOperand(1))
+                        ? PoisonValue::get(NewCmp->getType())
+                        : UndefValue::get(NewCmp->getType());
+    return new ShuffleVectorInst(NewCmp, NewRHS, M);
   }
 
   // Try to canonicalize compare with splatted operand and splat constant.
@@ -5498,8 +5506,11 @@
                                  ScalarC);
     SmallVector<int, 8> NewM(M.size(), MaskSplatIndex);
     Value *NewCmp = Builder.CreateCmp(Pred, V1, C);
-    return new ShuffleVectorInst(NewCmp, UndefValue::get(NewCmp->getType()),
-                                 NewM);
+    // Cmps propagate poison.
+    Value *NewRHS = isa<PoisonValue>(LHSSV->getOperand(1))
+                        ? PoisonValue::get(NewCmp->getType())
+                        : UndefValue::get(NewCmp->getType());
+    return new ShuffleVectorInst(NewCmp, NewRHS, NewM);
   }
 
   return nullptr;
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1554,11 +1554,22 @@
   if (!isSafeToSpeculativelyExecute(&Inst))
     return nullptr;
 
-  auto createBinOpShuffle = [&](Value *X, Value *Y, ArrayRef<int> M) {
+  auto createBinOpShuffle = [&](Value *X, Value *Y, ArrayRef<int> M,
+                                bool RHSPoison) {
     Value *XY = Builder.CreateBinOp(Opcode, X, Y);
     if (auto *BO = dyn_cast<BinaryOperator>(XY))
       BO->copyIRFlags(&Inst);
-    return new ShuffleVectorInst(XY, UndefValue::get(XY->getType()), M);
+    ElementCount ElemCount = cast<VectorType>(X->getType())->getElementCount();
+    Value *RHS;
+    bool MaskTouchesXYOnly =
+        !ElemCount.isScalable() && all_of(M, [&ElemCount](int Mask) {
+          return Mask < (int)ElemCount.getKnownMinValue();
+        });
+    if (RHSPoison || MaskTouchesXYOnly)
+      RHS = PoisonValue::get(XY->getType());
+    else
+      RHS = UndefValue::get(XY->getType());
+    return new ShuffleVectorInst(XY, RHS, M);
   };
 
   // If both arguments of the binary operation are shuffles that use the same
@@ -1569,7 +1580,10 @@
       V1->getType() == V2->getType() &&
       (LHS->hasOneUse() || RHS->hasOneUse() || LHS == RHS)) {
     // Op(shuffle(V1, Mask), shuffle(V2, Mask)) -> shuffle(Op(V1, V2), Mask)
-    return createBinOpShuffle(V1, V2, Mask);
+    bool RHSPoison =
+        isa<PoisonValue>(cast<ShuffleVectorInst>(LHS)->getOperand(1)) ||
+        isa<PoisonValue>(cast<ShuffleVectorInst>(RHS)->getOperand(1));
+    return createBinOpShuffle(V1, V2, Mask, RHSPoison);
   }
 
   // If both arguments of a commutative binop are select-shuffles that use the
@@ -1676,7 +1690,7 @@
       // Op(C, shuffle(V1, Mask)) -> shuffle(Op(NewC, V1), Mask)
       Value *NewLHS = ConstOp1 ? V1 : NewC;
       Value *NewRHS = ConstOp1 ? NewC : V1;
-      return createBinOpShuffle(NewLHS, NewRHS, Mask);
+      return createBinOpShuffle(NewLHS, NewRHS, Mask, false);
     }
   }
 
diff --git a/llvm/test/Transforms/CodeGenPrepare/ARM/sink-add-mul-shufflevector-inseltpoison.ll b/llvm/test/Transforms/CodeGenPrepare/ARM/sink-add-mul-shufflevector-inseltpoison.ll
--- a/llvm/test/Transforms/CodeGenPrepare/ARM/sink-add-mul-shufflevector-inseltpoison.ll
+++ b/llvm/test/Transforms/CodeGenPrepare/ARM/sink-add-mul-shufflevector-inseltpoison.ll
@@ -3,7 +3,7 @@
 define void @sink_add_mul(i32* %s1, i32 %x, i32* %d, i32 %n) {
 ; CHECK-LABEL: @sink_add_mul(
 ; CHECK:    vector.ph:
-; CHECK-NOT:  [[BROADCAST_SPLATINSERT8:%.*]] = insertelement <4 x i32> undef, i32 [[X:%.*]], i32 0
+; CHECK-NOT:  [[BROADCAST_SPLATINSERT8:%.*]] = insertelement <4 x i32> poison, i32 [[X:%.*]], i32 0
 ; CHECK-NOT:  [[BROADCAST_SPLAT9:%.*]] = shufflevector <4 x i32> [[BROADCAST_SPLATINSERT8]], <4 x i32> poison, <4 x i32> zeroinitializer
 ; CHECK:    vector.body:
 ; CHECK:      [[TMP2:%.*]] = insertelement <4 x i32> poison, i32 [[X:%.*]], i32 0
@@ -42,7 +42,7 @@
 define void @sink_add_mul_multiple(i32* %s1, i32* %s2, i32 %x, i32* %d, i32* %d2, i32 %n) {
 ; CHECK-LABEL: @sink_add_mul_multiple(
 ; CHECK:    vector.ph:
-; CHECK-NOT:  [[BROADCAST_SPLATINSERT8:%.*]] = insertelement <4 x i32> undef, i32 [[X:%.*]], i32 0
+; CHECK-NOT:  [[BROADCAST_SPLATINSERT8:%.*]] = insertelement <4 x i32> poison, i32 [[X:%.*]], i32 0
 ; CHECK-NOT:  [[BROADCAST_SPLAT9:%.*]] = shufflevector <4 x i32> [[BROADCAST_SPLATINSERT8]], <4 x i32> poison, <4 x i32> zeroinitializer
 ; CHECK:    vector.body:
 ; CHECK:      [[TMP2:%.*]] = insertelement <4 x i32> poison, i32 %x, i32 0
diff --git a/llvm/test/Transforms/InstCombine/bitcast-vec-canon-inseltpoison.ll b/llvm/test/Transforms/InstCombine/bitcast-vec-canon-inseltpoison.ll
--- a/llvm/test/Transforms/InstCombine/bitcast-vec-canon-inseltpoison.ll
+++ b/llvm/test/Transforms/InstCombine/bitcast-vec-canon-inseltpoison.ll
@@ -51,7 +51,7 @@
 define <1 x i64> @f(x86_mmx %y) {
 ; CHECK-LABEL: @f(
 ; CHECK-NEXT:    [[TMP1:%.*]] = bitcast x86_mmx [[Y:%.*]] to i64
-; CHECK-NEXT:    [[C:%.*]] = insertelement <1 x i64> undef, i64 [[TMP1]], i32 0
+; CHECK-NEXT:    [[C:%.*]] = insertelement <1 x i64> poison, i64 [[TMP1]], i32 0
 ; CHECK-NEXT:    ret <1 x i64> [[C]]
 ;
   %c = bitcast x86_mmx %y to <1 x i64>
diff --git a/llvm/test/Transforms/InstCombine/bitcast-vec-canon.ll b/llvm/test/Transforms/InstCombine/bitcast-vec-canon.ll
--- a/llvm/test/Transforms/InstCombine/bitcast-vec-canon.ll
+++ b/llvm/test/Transforms/InstCombine/bitcast-vec-canon.ll
@@ -51,7 +51,7 @@
 define <1 x i64> @f(x86_mmx %y) {
 ; CHECK-LABEL: @f(
 ; CHECK-NEXT:    [[TMP1:%.*]] = bitcast x86_mmx [[Y:%.*]] to i64
-; CHECK-NEXT:    [[C:%.*]] = insertelement <1 x i64> undef, i64 [[TMP1]], i32 0
+; CHECK-NEXT:    [[C:%.*]] = insertelement <1 x i64> poison, i64 [[TMP1]], i32 0
 ; CHECK-NEXT:    ret <1 x i64> [[C]]
 ;
   %c = bitcast x86_mmx %y to <1 x i64>
diff --git a/llvm/test/Transforms/InstCombine/broadcast-inseltpoison.ll b/llvm/test/Transforms/InstCombine/broadcast-inseltpoison.ll
--- a/llvm/test/Transforms/InstCombine/broadcast-inseltpoison.ll
+++ b/llvm/test/Transforms/InstCombine/broadcast-inseltpoison.ll
@@ -44,7 +44,7 @@
 ; CHECK-LABEL: @good4(
 ; CHECK-NEXT:    [[T:%.*]] = insertelement <4 x float> poison, float [[ARG:%.*]], i32 0
 ; CHECK-NEXT:    [[TMP1:%.*]] = fadd <4 x float> [[T]], [[T]]
-; CHECK-NEXT:    [[T7:%.*]] = shufflevector <4 x float> [[TMP1]], <4 x float> undef, <4 x i32> zeroinitializer
+; CHECK-NEXT:    [[T7:%.*]] = shufflevector <4 x float> [[TMP1]], <4 x float> poison, <4 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <4 x float> [[T7]]
 ;
   %t = insertelement <4 x float> zeroinitializer, float %arg, i32 0
diff --git a/llvm/test/Transforms/InstCombine/broadcast.ll b/llvm/test/Transforms/InstCombine/broadcast.ll
--- a/llvm/test/Transforms/InstCombine/broadcast.ll
+++ b/llvm/test/Transforms/InstCombine/broadcast.ll
@@ -44,7 +44,7 @@
 ; CHECK-LABEL: @good4(
 ; CHECK-NEXT:    [[T:%.*]] = insertelement <4 x float> poison, float [[ARG:%.*]], i32 0
 ; CHECK-NEXT:    [[TMP1:%.*]] = fadd <4 x float> [[T]], [[T]]
-; CHECK-NEXT:    [[T7:%.*]] = shufflevector <4 x float> [[TMP1]], <4 x float> undef, <4 x i32> zeroinitializer
+; CHECK-NEXT:    [[T7:%.*]] = shufflevector <4 x float> [[TMP1]], <4 x float> poison, <4 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <4 x float> [[T7]]
 ;
   %t = insertelement <4 x float> zeroinitializer, float %arg, i32 0
diff --git a/llvm/test/Transforms/InstCombine/canonicalize-vector-extract.ll b/llvm/test/Transforms/InstCombine/canonicalize-vector-extract.ll
--- a/llvm/test/Transforms/InstCombine/canonicalize-vector-extract.ll
+++ b/llvm/test/Transforms/InstCombine/canonicalize-vector-extract.ll
@@ -30,7 +30,7 @@
 
 define <2 x i32> @valid_extraction_a(<8 x i32> %vec) {
 ; CHECK-LABEL: @valid_extraction_a(
-; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> undef, <2 x i32> <i32 0, i32 1>
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> poison, <2 x i32> <i32 0, i32 1>
 ; CHECK-NEXT:    ret <2 x i32> [[TMP1]]
 ;
   %1 = call <2 x i32> @llvm.experimental.vector.extract.v2i32.v4i32(<8 x i32> %vec, i64 0)
@@ -39,7 +39,7 @@
 
 define <2 x i32> @valid_extraction_b(<8 x i32> %vec) {
 ; CHECK-LABEL: @valid_extraction_b(
-; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> undef, <2 x i32> <i32 2, i32 3>
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> poison, <2 x i32> <i32 2, i32 3>
 ; CHECK-NEXT:    ret <2 x i32> [[TMP1]]
 ;
   %1 = call <2 x i32> @llvm.experimental.vector.extract.v2i32.v4i32(<8 x i32> %vec, i64 2)
@@ -48,7 +48,7 @@
 
 define <2 x i32> @valid_extraction_c(<8 x i32> %vec) {
 ; CHECK-LABEL: @valid_extraction_c(
-; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> undef, <2 x i32> <i32 4, i32 5>
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> poison, <2 x i32> <i32 4, i32 5>
 ; CHECK-NEXT:    ret <2 x i32> [[TMP1]]
 ;
   %1 = call <2 x i32> @llvm.experimental.vector.extract.v2i32.v4i32(<8 x i32> %vec, i64 4)
@@ -57,7 +57,7 @@
 
 define <2 x i32> @valid_extraction_d(<8 x i32> %vec) {
 ; CHECK-LABEL: @valid_extraction_d(
-; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> undef, <2 x i32> <i32 6, i32 7>
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> poison, <2 x i32> <i32 6, i32 7>
 ; CHECK-NEXT:    ret <2 x i32> [[TMP1]]
 ;
   %1 = call <2 x i32> @llvm.experimental.vector.extract.v2i32.v4i32(<8 x i32> %vec, i64 6)
@@ -66,7 +66,7 @@
 
 define <4 x i32> @valid_extraction_e(<8 x i32> %vec) {
 ; CHECK-LABEL: @valid_extraction_e(
-; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> undef, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> poison, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
 ; CHECK-NEXT:    ret <4 x i32> [[TMP1]]
 ;
   %1 = call <4 x i32> @llvm.experimental.vector.extract.v4i32.v8i32(<8 x i32> %vec, i64 0)
@@ -75,7 +75,7 @@
 
 define <4 x i32> @valid_extraction_f(<8 x i32> %vec) {
 ; CHECK-LABEL: @valid_extraction_f(
-; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> undef, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> poison, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
 ; CHECK-NEXT:    ret <4 x i32> [[TMP1]]
 ;
   %1 = call <4 x i32> @llvm.experimental.vector.extract.v4i32.v8i32(<8 x i32> %vec, i64 4)
@@ -84,7 +84,7 @@
 
 define <3 x i32> @valid_extraction_g(<8 x i32> %vec) {
 ; CHECK-LABEL: @valid_extraction_g(
-; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> undef, <3 x i32> <i32 0, i32 1, i32 2>
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> poison, <3 x i32> <i32 0, i32 1, i32 2>
 ; CHECK-NEXT:    ret <3 x i32> [[TMP1]]
 ;
   %1 = call <3 x i32> @llvm.experimental.vector.extract.v3i32.v8i32(<8 x i32> %vec, i64 0)
@@ -93,7 +93,7 @@
 
 define <3 x i32> @valid_extraction_h(<8 x i32> %vec) {
 ; CHECK-LABEL: @valid_extraction_h(
-; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> undef, <3 x i32> <i32 3, i32 4, i32 5>
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[VEC:%.*]], <8 x i32> poison, <3 x i32> <i32 3, i32 4, i32 5>
 ; CHECK-NEXT:    ret <3 x i32> [[TMP1]]
 ;
   %1 = call <3 x i32> @llvm.experimental.vector.extract.v3i32.v8i32(<8 x i32> %vec, i64 3)
diff --git a/llvm/test/Transforms/InstCombine/gep-inbounds-null.ll b/llvm/test/Transforms/InstCombine/gep-inbounds-null.ll
--- a/llvm/test/Transforms/InstCombine/gep-inbounds-null.ll
+++ b/llvm/test/Transforms/InstCombine/gep-inbounds-null.ll
@@ -92,7 +92,7 @@
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[DOTSPLATINSERT:%.*]] = insertelement <2 x i8*> poison, i8* [[BASE:%.*]], i32 0
 ; CHECK-NEXT:    [[TMP0:%.*]] = icmp eq <2 x i8*> [[DOTSPLATINSERT]], zeroinitializer
-; CHECK-NEXT:    [[CND:%.*]] = shufflevector <2 x i1> [[TMP0]], <2 x i1> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[CND:%.*]] = shufflevector <2 x i1> [[TMP0]], <2 x i1> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i1> [[CND]]
 ;
 entry:
diff --git a/llvm/test/Transforms/InstCombine/getelementptr.ll b/llvm/test/Transforms/InstCombine/getelementptr.ll
--- a/llvm/test/Transforms/InstCombine/getelementptr.ll
+++ b/llvm/test/Transforms/InstCombine/getelementptr.ll
@@ -218,7 +218,7 @@
 ; CHECK-NEXT:    [[DOTSPLATINSERT:%.*]] = insertelement <2 x i64> poison, i64 [[X:%.*]], i32 0
 ; CHECK-NEXT:    [[TMP1:%.*]] = shl <2 x i64> [[DOTSPLATINSERT]], <i64 2, i64 0>
 ; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq <2 x i64> [[TMP1]], <i64 -4, i64 poison>
-; CHECK-NEXT:    [[C:%.*]] = shufflevector <2 x i1> [[TMP2]], <2 x i1> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[C:%.*]] = shufflevector <2 x i1> [[TMP2]], <2 x i1> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i1> [[C]]
 ;
   %A = getelementptr inbounds %S, <2 x %S*> %P, <2 x i64> zeroinitializer, <2 x i32> <i32 1, i32 1>, i64 %X
@@ -233,7 +233,7 @@
 ; CHECK-NEXT:    [[DOTSPLATINSERT:%.*]] = insertelement <2 x i64> poison, i64 [[X:%.*]], i32 0
 ; CHECK-NEXT:    [[TMP1:%.*]] = shl <2 x i64> [[DOTSPLATINSERT]], <i64 2, i64 0>
 ; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq <2 x i64> [[TMP1]], <i64 4, i64 poison>
-; CHECK-NEXT:    [[C:%.*]] = shufflevector <2 x i1> [[TMP2]], <2 x i1> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[C:%.*]] = shufflevector <2 x i1> [[TMP2]], <2 x i1> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i1> [[C]]
 ;
   %A = getelementptr inbounds %S, <2 x %S*> %P, <2 x i64> zeroinitializer, <2 x i32> <i32 1, i32 1>, i64 %X
diff --git a/llvm/test/Transforms/InstCombine/icmp-vec-inseltpoison.ll b/llvm/test/Transforms/InstCombine/icmp-vec-inseltpoison.ll
--- a/llvm/test/Transforms/InstCombine/icmp-vec-inseltpoison.ll
+++ b/llvm/test/Transforms/InstCombine/icmp-vec-inseltpoison.ll
@@ -213,7 +213,7 @@
 define <4 x i1> @same_shuffle_inputs_icmp(<4 x i8> %x, <4 x i8> %y) {
 ; CHECK-LABEL: @same_shuffle_inputs_icmp(
 ; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt <4 x i8> [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> undef, <4 x i32> <i32 3, i32 3, i32 2, i32 0>
+; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> poison, <4 x i32> <i32 3, i32 3, i32 2, i32 0>
 ; CHECK-NEXT:    ret <4 x i1> [[CMP]]
 ;
   %shufx = shufflevector <4 x i8> %x, <4 x i8> poison, <4 x i32> < i32 3, i32 3, i32 2, i32 0 >
@@ -227,7 +227,7 @@
 define <5 x i1> @same_shuffle_inputs_fcmp(<4 x float> %x, <4 x float> %y) {
 ; CHECK-LABEL: @same_shuffle_inputs_fcmp(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fcmp oeq <4 x float> [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> undef, <5 x i32> <i32 0, i32 1, i32 3, i32 2, i32 0>
+; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> poison, <5 x i32> <i32 0, i32 1, i32 3, i32 2, i32 0>
 ; CHECK-NEXT:    ret <5 x i1> [[CMP]]
 ;
   %shufx = shufflevector <4 x float> %x, <4 x float> poison, <5 x i32> < i32 0, i32 1, i32 3, i32 2, i32 0 >
@@ -242,7 +242,7 @@
 ; CHECK-LABEL: @same_shuffle_inputs_icmp_extra_use1(
 ; CHECK-NEXT:    [[SHUFX:%.*]] = shufflevector <4 x i8> [[X:%.*]], <4 x i8> poison, <4 x i32> <i32 3, i32 3, i32 3, i32 3>
 ; CHECK-NEXT:    [[TMP1:%.*]] = icmp ugt <4 x i8> [[X]], [[Y:%.*]]
-; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> undef, <4 x i32> <i32 3, i32 3, i32 3, i32 3>
+; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> poison, <4 x i32> <i32 3, i32 3, i32 3, i32 3>
 ; CHECK-NEXT:    call void @use_v4i8(<4 x i8> [[SHUFX]])
 ; CHECK-NEXT:    ret <4 x i1> [[CMP]]
 ;
@@ -259,7 +259,7 @@
 ; CHECK-LABEL: @same_shuffle_inputs_icmp_extra_use2(
 ; CHECK-NEXT:    [[SHUFY:%.*]] = shufflevector <4 x i8> [[Y:%.*]], <4 x i8> poison, <2 x i32> <i32 3, i32 2>
 ; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq <4 x i8> [[X:%.*]], [[Y]]
-; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> undef, <2 x i32> <i32 3, i32 2>
+; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> poison, <2 x i32> <i32 3, i32 2>
 ; CHECK-NEXT:    call void @use_v2i8(<2 x i8> [[SHUFY]])
 ; CHECK-NEXT:    ret <2 x i1> [[CMP]]
 ;
@@ -292,7 +292,7 @@
 define <4 x i1> @splat_icmp(<4 x i8> %x) {
 ; CHECK-LABEL: @splat_icmp(
 ; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt <4 x i8> [[X:%.*]], <i8 42, i8 42, i8 42, i8 42>
-; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> undef, <4 x i32> <i32 3, i32 3, i32 3, i32 3>
+; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> poison, <4 x i32> <i32 3, i32 3, i32 3, i32 3>
 ; CHECK-NEXT:    ret <4 x i1> [[CMP]]
 ;
   %splatx = shufflevector <4 x i8> %x, <4 x i8> poison, <4 x i32> <i32 3, i32 3, i32 3, i32 3>
@@ -303,7 +303,7 @@
 define <4 x i1> @splat_icmp_undef(<4 x i8> %x) {
 ; CHECK-LABEL: @splat_icmp_undef(
 ; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult <4 x i8> [[X:%.*]], <i8 42, i8 42, i8 42, i8 42>
-; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> undef, <4 x i32> <i32 2, i32 2, i32 2, i32 2>
+; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> poison, <4 x i32> <i32 2, i32 2, i32 2, i32 2>
 ; CHECK-NEXT:    ret <4 x i1> [[CMP]]
 ;
   %splatx = shufflevector <4 x i8> %x, <4 x i8> poison, <4 x i32> <i32 2, i32 undef, i32 undef, i32 2>
@@ -314,7 +314,7 @@
 define <4 x i1> @splat_icmp_larger_size(<2 x i8> %x) {
 ; CHECK-LABEL: @splat_icmp_larger_size(
 ; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq <2 x i8> [[X:%.*]], <i8 42, i8 42>
-; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <2 x i1> [[TMP1]], <2 x i1> undef, <4 x i32> <i32 1, i32 1, i32 1, i32 1>
+; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <2 x i1> [[TMP1]], <2 x i1> poison, <4 x i32> <i32 1, i32 1, i32 1, i32 1>
 ; CHECK-NEXT:    ret <4 x i1> [[CMP]]
 ;
   %splatx = shufflevector <2 x i8> %x, <2 x i8> poison, <4 x i32> <i32 1, i32 undef, i32 1, i32 undef>
@@ -325,7 +325,7 @@
 define <4 x i1> @splat_fcmp_smaller_size(<5 x float> %x) {
 ; CHECK-LABEL: @splat_fcmp_smaller_size(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fcmp oeq <5 x float> [[X:%.*]], <float 4.200000e+01, float 4.200000e+01, float 4.200000e+01, float 4.200000e+01, float 4.200000e+01>
-; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <5 x i1> [[TMP1]], <5 x i1> undef, <4 x i32> <i32 1, i32 1, i32 1, i32 1>
+; CHECK-NEXT:    [[CMP:%.*]] = shufflevector <5 x i1> [[TMP1]], <5 x i1> poison, <4 x i32> <i32 1, i32 1, i32 1, i32 1>
 ; CHECK-NEXT:    ret <4 x i1> [[CMP]]
 ;
   %splatx = shufflevector <5 x float> %x, <5 x float> poison, <4 x i32> <i32 1, i32 undef, i32 1, i32 undef>
diff --git a/llvm/test/Transforms/InstCombine/select-extractelement.ll b/llvm/test/Transforms/InstCombine/select-extractelement.ll
--- a/llvm/test/Transforms/InstCombine/select-extractelement.ll
+++ b/llvm/test/Transforms/InstCombine/select-extractelement.ll
@@ -5,8 +5,8 @@
 
 define float @extract_one_select(<4 x float> %a, <4 x float> %b, i32 %c) #0 {
 ; CHECK-LABEL: @extract_one_select(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[C:%.*]], 0
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[CMP]], <4 x float> [[B:%.*]], <4 x float> [[A:%.*]]
+; CHECK-NEXT:    [[CMP_NOT:%.*]] = icmp eq i32 [[C:%.*]], 0
+; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[CMP_NOT]], <4 x float> [[B:%.*]], <4 x float> [[A:%.*]]
 ; CHECK-NEXT:    [[EXTRACT:%.*]] = extractelement <4 x float> [[SEL]], i32 2
 ; CHECK-NEXT:    ret float [[EXTRACT]]
 ;
@@ -19,8 +19,8 @@
 ; Multiple extractelements
 define <2 x float> @extract_two_select(<4 x float> %a, <4 x float> %b, i32 %c) #0 {
 ; CHECK-LABEL: @extract_two_select(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[C:%.*]], 0
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[CMP]], <4 x float> [[B:%.*]], <4 x float> [[A:%.*]]
+; CHECK-NEXT:    [[CMP_NOT:%.*]] = icmp eq i32 [[C:%.*]], 0
+; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[CMP_NOT]], <4 x float> [[B:%.*]], <4 x float> [[A:%.*]]
 ; CHECK-NEXT:    [[BUILD2:%.*]] = shufflevector <4 x float> [[SEL]], <4 x float> undef, <2 x i32> <i32 1, i32 2>
 ; CHECK-NEXT:    ret <2 x float> [[BUILD2]]
 ;
@@ -36,8 +36,8 @@
 ; Select has an extra non-extractelement user, don't change it
 define float @extract_one_select_user(<4 x float> %a, <4 x float> %b, i32 %c) #0 {
 ; CHECK-LABEL: @extract_one_select_user(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[C:%.*]], 0
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[CMP]], <4 x float> [[B:%.*]], <4 x float> [[A:%.*]]
+; CHECK-NEXT:    [[CMP_NOT:%.*]] = icmp eq i32 [[C:%.*]], 0
+; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[CMP_NOT]], <4 x float> [[B:%.*]], <4 x float> [[A:%.*]]
 ; CHECK-NEXT:    [[EXTRACT:%.*]] = extractelement <4 x float> [[SEL]], i32 2
 ; CHECK-NEXT:    call void @v4float_user(<4 x float> [[SEL]])
 ; CHECK-NEXT:    ret float [[EXTRACT]]
@@ -51,8 +51,8 @@
 
 define float @extract_one_vselect_user(<4 x float> %a, <4 x float> %b, <4 x i32> %c) #0 {
 ; CHECK-LABEL: @extract_one_vselect_user(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <4 x i32> [[C:%.*]], zeroinitializer
-; CHECK-NEXT:    [[SEL:%.*]] = select <4 x i1> [[CMP]], <4 x float> [[B:%.*]], <4 x float> [[A:%.*]]
+; CHECK-NEXT:    [[CMP_NOT:%.*]] = icmp eq <4 x i32> [[C:%.*]], zeroinitializer
+; CHECK-NEXT:    [[SEL:%.*]] = select <4 x i1> [[CMP_NOT]], <4 x float> [[B:%.*]], <4 x float> [[A:%.*]]
 ; CHECK-NEXT:    [[EXTRACT:%.*]] = extractelement <4 x float> [[SEL]], i32 2
 ; CHECK-NEXT:    call void @v4float_user(<4 x float> [[SEL]])
 ; CHECK-NEXT:    ret float [[EXTRACT]]
@@ -69,8 +69,8 @@
 
 define float @extract_one_vselect(<4 x float> %a, <4 x float> %b, <4 x i32> %c) #0 {
 ; CHECK-LABEL: @extract_one_vselect(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <4 x i32> [[C:%.*]], zeroinitializer
-; CHECK-NEXT:    [[SELECT:%.*]] = select <4 x i1> [[CMP]], <4 x float> [[B:%.*]], <4 x float> [[A:%.*]]
+; CHECK-NEXT:    [[CMP_NOT:%.*]] = icmp eq <4 x i32> [[C:%.*]], zeroinitializer
+; CHECK-NEXT:    [[SELECT:%.*]] = select <4 x i1> [[CMP_NOT]], <4 x float> [[B:%.*]], <4 x float> [[A:%.*]]
 ; CHECK-NEXT:    [[EXTRACT:%.*]] = extractelement <4 x float> [[SELECT]], i32 0
 ; CHECK-NEXT:    ret float [[EXTRACT]]
 ;
@@ -83,8 +83,8 @@
 ; Multiple extractelements from a vector select
 define <2 x float> @extract_two_vselect(<4 x float> %a, <4 x float> %b, <4 x i32> %c) #0 {
 ; CHECK-LABEL: @extract_two_vselect(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <4 x i32> [[C:%.*]], zeroinitializer
-; CHECK-NEXT:    [[SEL:%.*]] = select <4 x i1> [[CMP]], <4 x float> [[B:%.*]], <4 x float> [[A:%.*]]
+; CHECK-NEXT:    [[CMP_NOT:%.*]] = icmp eq <4 x i32> [[C:%.*]], zeroinitializer
+; CHECK-NEXT:    [[SEL:%.*]] = select <4 x i1> [[CMP_NOT]], <4 x float> [[B:%.*]], <4 x float> [[A:%.*]]
 ; CHECK-NEXT:    [[BUILD2:%.*]] = shufflevector <4 x float> [[SEL]], <4 x float> undef, <2 x i32> <i32 1, i32 2>
 ; CHECK-NEXT:    ret <2 x float> [[BUILD2]]
 ;
@@ -104,19 +104,19 @@
 ; CHECK-LABEL: @simple_vector_select(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <4 x i32> [[C:%.*]], i32 0
-; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq i32 [[TMP0]], 0
-; CHECK-NEXT:    [[A_SINK:%.*]] = select i1 [[TOBOOL]], <4 x float> [[B:%.*]], <4 x float> [[A:%.*]]
+; CHECK-NEXT:    [[TOBOOL_NOT:%.*]] = icmp eq i32 [[TMP0]], 0
+; CHECK-NEXT:    [[A_SINK:%.*]] = select i1 [[TOBOOL_NOT]], <4 x float> [[B:%.*]], <4 x float> [[A:%.*]]
 ; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <4 x i32> [[C]], i32 1
-; CHECK-NEXT:    [[TOBOOL1:%.*]] = icmp eq i32 [[TMP1]], 0
-; CHECK-NEXT:    [[A_SINK1:%.*]] = select i1 [[TOBOOL1]], <4 x float> [[B]], <4 x float> [[A]]
+; CHECK-NEXT:    [[TOBOOL1_NOT:%.*]] = icmp eq i32 [[TMP1]], 0
+; CHECK-NEXT:    [[A_SINK1:%.*]] = select i1 [[TOBOOL1_NOT]], <4 x float> [[B]], <4 x float> [[A]]
 ; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <4 x float> [[A_SINK]], <4 x float> [[A_SINK1]], <4 x i32> <i32 0, i32 5, i32 undef, i32 undef>
 ; CHECK-NEXT:    [[TMP3:%.*]] = extractelement <4 x i32> [[C]], i32 2
-; CHECK-NEXT:    [[TOBOOL6:%.*]] = icmp eq i32 [[TMP3]], 0
-; CHECK-NEXT:    [[A_SINK2:%.*]] = select i1 [[TOBOOL6]], <4 x float> [[B]], <4 x float> [[A]]
+; CHECK-NEXT:    [[TOBOOL6_NOT:%.*]] = icmp eq i32 [[TMP3]], 0
+; CHECK-NEXT:    [[A_SINK2:%.*]] = select i1 [[TOBOOL6_NOT]], <4 x float> [[B]], <4 x float> [[A]]
 ; CHECK-NEXT:    [[TMP4:%.*]] = shufflevector <4 x float> [[TMP2]], <4 x float> [[A_SINK2]], <4 x i32> <i32 0, i32 1, i32 6, i32 undef>
 ; CHECK-NEXT:    [[TMP5:%.*]] = extractelement <4 x i32> [[C]], i32 3
-; CHECK-NEXT:    [[TOBOOL11:%.*]] = icmp eq i32 [[TMP5]], 0
-; CHECK-NEXT:    [[A_SINK3:%.*]] = select i1 [[TOBOOL11]], <4 x float> [[B]], <4 x float> [[A]]
+; CHECK-NEXT:    [[TOBOOL11_NOT:%.*]] = icmp eq i32 [[TMP5]], 0
+; CHECK-NEXT:    [[A_SINK3:%.*]] = select i1 [[TOBOOL11_NOT]], <4 x float> [[B]], <4 x float> [[A]]
 ; CHECK-NEXT:    [[TMP6:%.*]] = shufflevector <4 x float> [[TMP4]], <4 x float> [[A_SINK3]], <4 x i32> <i32 0, i32 1, i32 2, i32 7>
 ; CHECK-NEXT:    ret <4 x float> [[TMP6]]
 ;
diff --git a/llvm/test/Transforms/InstCombine/shufflevector-div-rem-inseltpoison.ll b/llvm/test/Transforms/InstCombine/shufflevector-div-rem-inseltpoison.ll
--- a/llvm/test/Transforms/InstCombine/shufflevector-div-rem-inseltpoison.ll
+++ b/llvm/test/Transforms/InstCombine/shufflevector-div-rem-inseltpoison.ll
@@ -10,7 +10,7 @@
 ; CHECK-LABEL: @test_srem_orig(
 ; CHECK-NEXT:    [[SPLATINSERT:%.*]] = insertelement <2 x i16> poison, i16 [[A:%.*]], i32 0
 ; CHECK-NEXT:    [[TMP1:%.*]] = srem <2 x i16> [[SPLATINSERT]], <i16 2, i16 1>
-; CHECK-NEXT:    [[SPLAT_OP:%.*]] = shufflevector <2 x i16> [[TMP1]], <2 x i16> undef, <2 x i32> <i32 undef, i32 0>
+; CHECK-NEXT:    [[SPLAT_OP:%.*]] = shufflevector <2 x i16> [[TMP1]], <2 x i16> poison, <2 x i32> <i32 undef, i32 0>
 ; CHECK-NEXT:    [[T2:%.*]] = select i1 [[CMP:%.*]], <2 x i16> <i16 poison, i16 1>, <2 x i16> [[SPLAT_OP]]
 ; CHECK-NEXT:    [[T3:%.*]] = extractelement <2 x i16> [[T2]], i32 1
 ; CHECK-NEXT:    ret i16 [[T3]]
@@ -97,7 +97,7 @@
 ; CHECK-NEXT:    ret <2 x float> [[T2]]
 ;
   %splatinsert = insertelement <2 x float> poison, float %a, i32 0
-  %denom = insertelement <2 x float> <float 3.0, float undef>, float 1.0, i32 1
+  %denom = insertelement <2 x float> <float 3.0, float poison>, float 1.0, i32 1
   %t1 = fdiv <2 x float> %splatinsert, %denom
   %splat.op = shufflevector <2 x float> %t1, <2 x float> poison, <2 x i32> <i32 undef, i32 0>
   %t2 = select i1 %cmp, <2 x float> <float 77.0, float 99.0>, <2 x float> %splat.op
diff --git a/llvm/test/Transforms/InstCombine/shufflevector-div-rem.ll b/llvm/test/Transforms/InstCombine/shufflevector-div-rem.ll
--- a/llvm/test/Transforms/InstCombine/shufflevector-div-rem.ll
+++ b/llvm/test/Transforms/InstCombine/shufflevector-div-rem.ll
@@ -10,7 +10,7 @@
 ; CHECK-LABEL: @test_srem_orig(
 ; CHECK-NEXT:    [[SPLATINSERT:%.*]] = insertelement <2 x i16> undef, i16 [[A:%.*]], i32 0
 ; CHECK-NEXT:    [[TMP1:%.*]] = srem <2 x i16> [[SPLATINSERT]], <i16 2, i16 1>
-; CHECK-NEXT:    [[SPLAT_OP:%.*]] = shufflevector <2 x i16> [[TMP1]], <2 x i16> undef, <2 x i32> <i32 undef, i32 0>
+; CHECK-NEXT:    [[SPLAT_OP:%.*]] = shufflevector <2 x i16> [[TMP1]], <2 x i16> poison, <2 x i32> <i32 undef, i32 0>
 ; CHECK-NEXT:    [[T2:%.*]] = select i1 [[CMP:%.*]], <2 x i16> <i16 poison, i16 1>, <2 x i16> [[SPLAT_OP]]
 ; CHECK-NEXT:    [[T3:%.*]] = extractelement <2 x i16> [[T2]], i32 1
 ; CHECK-NEXT:    ret i16 [[T3]]
diff --git a/llvm/test/Transforms/InstCombine/trunc-inseltpoison.ll b/llvm/test/Transforms/InstCombine/trunc-inseltpoison.ll
--- a/llvm/test/Transforms/InstCombine/trunc-inseltpoison.ll
+++ b/llvm/test/Transforms/InstCombine/trunc-inseltpoison.ll
@@ -922,7 +922,7 @@
 define <4 x i8> @wide_splat1(<4 x i32> %x) {
 ; CHECK-LABEL: @wide_splat1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = trunc <4 x i32> [[X:%.*]] to <4 x i8>
-; CHECK-NEXT:    [[TRUNC:%.*]] = shufflevector <4 x i8> [[TMP1]], <4 x i8> undef, <4 x i32> <i32 2, i32 2, i32 2, i32 2>
+; CHECK-NEXT:    [[TRUNC:%.*]] = shufflevector <4 x i8> [[TMP1]], <4 x i8> poison, <4 x i32> <i32 2, i32 2, i32 2, i32 2>
 ; CHECK-NEXT:    ret <4 x i8> [[TRUNC]]
 ;
   %shuf = shufflevector <4 x i32> %x, <4 x i32> poison, <4 x i32> <i32 2, i32 2, i32 2, i32 2>
@@ -936,7 +936,7 @@
 define <3 x i31> @wide_splat2(<3 x i33> %x) {
 ; CHECK-LABEL: @wide_splat2(
 ; CHECK-NEXT:    [[TMP1:%.*]] = trunc <3 x i33> [[X:%.*]] to <3 x i31>
-; CHECK-NEXT:    [[TRUNC:%.*]] = shufflevector <3 x i31> [[TMP1]], <3 x i31> undef, <3 x i32> <i32 1, i32 1, i32 1>
+; CHECK-NEXT:    [[TRUNC:%.*]] = shufflevector <3 x i31> [[TMP1]], <3 x i31> poison, <3 x i32> <i32 1, i32 1, i32 1>
 ; CHECK-NEXT:    ret <3 x i31> [[TRUNC]]
 ;
   %shuf = shufflevector <3 x i33> %x, <3 x i33> poison, <3 x i32> <i32 1, i32 1, i32 1>
diff --git a/llvm/test/Transforms/InstCombine/vec-binop-select-inseltpoison.ll b/llvm/test/Transforms/InstCombine/vec-binop-select-inseltpoison.ll
--- a/llvm/test/Transforms/InstCombine/vec-binop-select-inseltpoison.ll
+++ b/llvm/test/Transforms/InstCombine/vec-binop-select-inseltpoison.ll
@@ -17,7 +17,7 @@
 define <vscale x 4 x i32> @vscaleand(<vscale x 4 x i32> %x, <vscale x 4 x i32> %y) {
 ; CHECK-LABEL: @vscaleand(
 ; CHECK-NEXT:    [[TMP1:%.*]] = and <vscale x 4 x i32> [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <vscale x 4 x i32> [[TMP1]], <vscale x 4 x i32> undef, <vscale x 4 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <vscale x 4 x i32> [[TMP1]], <vscale x 4 x i32> poison, <vscale x 4 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <vscale x 4 x i32> [[R]]
 ;
   %sel1 = shufflevector <vscale x 4 x i32> %x, <vscale x 4 x i32> poison, <vscale x 4 x i32> zeroinitializer
diff --git a/llvm/test/Transforms/InstCombine/vec-binop-select.ll b/llvm/test/Transforms/InstCombine/vec-binop-select.ll
--- a/llvm/test/Transforms/InstCombine/vec-binop-select.ll
+++ b/llvm/test/Transforms/InstCombine/vec-binop-select.ll
@@ -16,9 +16,9 @@
 
 define <vscale x 4 x i32> @vscaleand(<vscale x 4 x i32> %x, <vscale x 4 x i32> %y) {
 ; CHECK-LABEL: @vscaleand(
-; CHECK-NEXT:    [[R:%.*]] = and <vscale x 4 x i32> [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[S:%.*]] = shufflevector <vscale x 4 x i32> [[R]], <vscale x 4 x i32> undef, <vscale x 4 x i32> zeroinitializer
-; CHECK-NEXT:    ret <vscale x 4 x i32> [[S]]
+; CHECK-NEXT:    [[TMP1:%.*]] = and <vscale x 4 x i32> [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <vscale x 4 x i32> [[TMP1]], <vscale x 4 x i32> undef, <vscale x 4 x i32> zeroinitializer
+; CHECK-NEXT:    ret <vscale x 4 x i32> [[R]]
 ;
   %sel1 = shufflevector <vscale x 4 x i32> %x, <vscale x 4 x i32> undef, <vscale x 4 x i32> zeroinitializer
   %sel2 = shufflevector <vscale x 4 x i32> %y, <vscale x 4 x i32> undef, <vscale x 4 x i32> zeroinitializer
diff --git a/llvm/test/Transforms/InstCombine/vec_shuffle-inseltpoison.ll b/llvm/test/Transforms/InstCombine/vec_shuffle-inseltpoison.ll
--- a/llvm/test/Transforms/InstCombine/vec_shuffle-inseltpoison.ll
+++ b/llvm/test/Transforms/InstCombine/vec_shuffle-inseltpoison.ll
@@ -394,7 +394,7 @@
 define <4 x i32> @shuffle_17and(<4 x i32> %v1, <4 x i32> %v2) {
 ; CHECK-LABEL: @shuffle_17and(
 ; CHECK-NEXT:    [[TMP1:%.*]] = and <4 x i32> [[V1:%.*]], [[V2:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v1, <4 x i32> zeroinitializer, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
@@ -411,7 +411,7 @@
 ; CHECK-LABEL: @shuffle_fadd_multiuse(
 ; CHECK-NEXT:    [[T1:%.*]] = shufflevector <2 x float> [[V1:%.*]], <2 x float> poison, <2 x i32> <i32 1, i32 0>
 ; CHECK-NEXT:    [[TMP1:%.*]] = fadd <2 x float> [[V1]], [[V2:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> <i32 1, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> <i32 1, i32 0>
 ; CHECK-NEXT:    call void @use(<2 x float> [[T1]])
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
@@ -426,7 +426,7 @@
 ; CHECK-LABEL: @shuffle_fdiv_multiuse(
 ; CHECK-NEXT:    [[T2:%.*]] = shufflevector <2 x float> [[V2:%.*]], <2 x float> poison, <2 x i32> <i32 1, i32 0>
 ; CHECK-NEXT:    [[TMP1:%.*]] = fdiv <2 x float> [[V1:%.*]], [[V2]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> <i32 1, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> <i32 1, i32 0>
 ; CHECK-NEXT:    call void @use(<2 x float> [[T2]])
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
@@ -459,7 +459,7 @@
 define <4 x i32> @shuffle_17add(<4 x i32> %v1, <4 x i32> %v2) {
 ; CHECK-LABEL: @shuffle_17add(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add <4 x i32> [[V1:%.*]], [[V2:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v1, <4 x i32> zeroinitializer, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
@@ -471,7 +471,7 @@
 define <4 x i32> @shuffle_17addnsw(<4 x i32> %v1, <4 x i32> %v2) {
 ; CHECK-LABEL: @shuffle_17addnsw(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add nsw <4 x i32> [[V1:%.*]], [[V2:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v1, <4 x i32> zeroinitializer, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
@@ -483,7 +483,7 @@
 define <4 x i32> @shuffle_17addnuw(<4 x i32> %v1, <4 x i32> %v2) {
 ; CHECK-LABEL: @shuffle_17addnuw(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add nuw <4 x i32> [[V1:%.*]], [[V2:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v1, <4 x i32> zeroinitializer, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
@@ -495,7 +495,7 @@
 define <4 x float> @shuffle_17fsub_fast(<4 x float> %v1, <4 x float> %v2) {
 ; CHECK-LABEL: @shuffle_17fsub_fast(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fsub fast <4 x float> [[V1:%.*]], [[V2:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x float> [[TMP1]], <4 x float> undef, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x float> [[TMP1]], <4 x float> poison, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
 ; CHECK-NEXT:    ret <4 x float> [[R]]
 ;
   %t1 = shufflevector <4 x float> %v1, <4 x float> zeroinitializer, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
@@ -507,7 +507,7 @@
 define <4 x i32> @add_const(<4 x i32> %v) {
 ; CHECK-LABEL: @add_const(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add <4 x i32> [[V:%.*]], <i32 44, i32 41, i32 42, i32 43>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v, <4 x i32> poison, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
@@ -518,7 +518,7 @@
 define <4 x i32> @sub_const(<4 x i32> %v) {
 ; CHECK-LABEL: @sub_const(
 ; CHECK-NEXT:    [[TMP1:%.*]] = sub <4 x i32> <i32 44, i32 43, i32 42, i32 41>, [[V:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v, <4 x i32> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
@@ -546,7 +546,7 @@
 define <4 x i32> @mul_const_splat(<4 x i32> %v) {
 ; CHECK-LABEL: @mul_const_splat(
 ; CHECK-NEXT:    [[TMP1:%.*]] = mul <4 x i32> [[V:%.*]], <i32 poison, i32 42, i32 poison, i32 poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 1, i32 1, i32 1, i32 1>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 1, i32 1, i32 1, i32 1>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v, <4 x i32> poison, <4 x i32> <i32 1, i32 1, i32 1, i32 1>
@@ -559,7 +559,7 @@
 define <4 x i32> @lshr_const_half_splat(<4 x i32> %v) {
 ; CHECK-LABEL: @lshr_const_half_splat(
 ; CHECK-NEXT:    [[TMP1:%.*]] = lshr <4 x i32> <i32 undef, i32 8, i32 9, i32 undef>, [[V:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 1, i32 1, i32 2, i32 2>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 1, i32 1, i32 2, i32 2>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v, <4 x i32> poison, <4 x i32> <i32 1, i32 1, i32 2, i32 2>
@@ -585,7 +585,7 @@
 define <4 x i8> @widening_shuffle_add_1(<2 x i8> %x) {
 ; CHECK-LABEL: @widening_shuffle_add_1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add <2 x i8> [[X:%.*]], <i8 42, i8 43>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i8> [[TMP1]], <2 x i8> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i8> [[TMP1]], <2 x i8> poison, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
 ; CHECK-NEXT:    ret <4 x i8> [[R]]
 ;
   %widex = shufflevector <2 x i8> %x, <2 x i8> poison, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
@@ -598,7 +598,7 @@
 define <4 x i8> @widening_shuffle_add_2(<2 x i8> %x) {
 ; CHECK-LABEL: @widening_shuffle_add_2(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add <2 x i8> [[X:%.*]], <i8 43, i8 42>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i8> [[TMP1]], <2 x i8> undef, <4 x i32> <i32 1, i32 0, i32 undef, i32 undef>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i8> [[TMP1]], <2 x i8> poison, <4 x i32> <i32 1, i32 0, i32 undef, i32 undef>
 ; CHECK-NEXT:    ret <4 x i8> [[R]]
 ;
   %widex = shufflevector <2 x i8> %x, <2 x i8> poison, <4 x i32> <i32 1, i32 0, i32 undef, i32 undef>
@@ -638,7 +638,7 @@
 define <4 x i16> @widening_shuffle_shl_constant_op0(<2 x i16> %v) {
 ; CHECK-LABEL: @widening_shuffle_shl_constant_op0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = shl <2 x i16> <i16 42, i16 -42>, [[V:%.*]]
-; CHECK-NEXT:    [[BO:%.*]] = shufflevector <2 x i16> [[TMP1]], <2 x i16> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
+; CHECK-NEXT:    [[BO:%.*]] = shufflevector <2 x i16> [[TMP1]], <2 x i16> poison, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
 ; CHECK-NEXT:    ret <4 x i16> [[BO]]
 ;
   %shuf = shufflevector <2 x i16> %v, <2 x i16> poison, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
@@ -652,7 +652,7 @@
 define <4 x i16> @widening_shuffle_shl_constant_op1(<2 x i16> %v) {
 ; CHECK-LABEL: @widening_shuffle_shl_constant_op1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = shl <2 x i16> [[V:%.*]], <i16 2, i16 4>
-; CHECK-NEXT:    [[BO:%.*]] = shufflevector <2 x i16> [[TMP1]], <2 x i16> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
+; CHECK-NEXT:    [[BO:%.*]] = shufflevector <2 x i16> [[TMP1]], <2 x i16> poison, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
 ; CHECK-NEXT:    ret <4 x i16> [[BO]]
 ;
   %shuf = shufflevector <2 x i16> %v, <2 x i16> poison, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
@@ -702,7 +702,7 @@
 define <4 x i32> @shuffle_17mulsplat(<4 x i32> %v) {
 ; CHECK-LABEL: @shuffle_17mulsplat(
 ; CHECK-NEXT:    [[TMP1:%.*]] = mul <4 x i32> [[V:%.*]], [[V]]
-; CHECK-NEXT:    [[M1:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> zeroinitializer
+; CHECK-NEXT:    [[M1:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <4 x i32> [[M1]]
 ;
   %s1 = shufflevector <4 x i32> %v, <4 x i32> zeroinitializer, <4 x i32> zeroinitializer
@@ -728,7 +728,7 @@
 define <4 x i16> @pr19717a(<8 x i16> %in0, <8 x i16> %in1) {
 ; CHECK-LABEL: @pr19717a(
 ; CHECK-NEXT:    [[TMP1:%.*]] = mul <8 x i16> [[IN0:%.*]], [[IN1:%.*]]
-; CHECK-NEXT:    [[MUL:%.*]] = shufflevector <8 x i16> [[TMP1]], <8 x i16> undef, <4 x i32> <i32 5, i32 5, i32 5, i32 5>
+; CHECK-NEXT:    [[MUL:%.*]] = shufflevector <8 x i16> [[TMP1]], <8 x i16> poison, <4 x i32> <i32 5, i32 5, i32 5, i32 5>
 ; CHECK-NEXT:    ret <4 x i16> [[MUL]]
 ;
   %shuffle = shufflevector <8 x i16> %in0, <8 x i16> %in0, <4 x i32> <i32 5, i32 5, i32 5, i32 5>
@@ -814,7 +814,7 @@
 define <2 x i32> @add_splat_constant(<2 x i32> %x) {
 ; CHECK-LABEL: @add_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add <2 x i32> [[X:%.*]], <i32 42, i32 poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -825,7 +825,7 @@
 define <2 x i32> @sub_splat_constant0(<2 x i32> %x) {
 ; CHECK-LABEL: @sub_splat_constant0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = sub <2 x i32> <i32 42, i32 poison>, [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -836,7 +836,7 @@
 define <2 x i32> @sub_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @sub_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add <2 x i32> [[X:%.*]], <i32 -42, i32 poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -847,7 +847,7 @@
 define <2 x i32> @mul_splat_constant(<2 x i32> %x) {
 ; CHECK-LABEL: @mul_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = mul <2 x i32> [[X:%.*]], <i32 42, i32 poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -858,7 +858,7 @@
 define <2 x i32> @shl_splat_constant0(<2 x i32> %x) {
 ; CHECK-LABEL: @shl_splat_constant0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = shl <2 x i32> <i32 5, i32 undef>, [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -869,7 +869,7 @@
 define <2 x i32> @shl_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @shl_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = shl <2 x i32> [[X:%.*]], <i32 5, i32 0>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -880,7 +880,7 @@
 define <2 x i32> @ashr_splat_constant0(<2 x i32> %x) {
 ; CHECK-LABEL: @ashr_splat_constant0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = ashr <2 x i32> <i32 5, i32 undef>, [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -891,7 +891,7 @@
 define <2 x i32> @ashr_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @ashr_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = ashr <2 x i32> [[X:%.*]], <i32 5, i32 0>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -902,7 +902,7 @@
 define <2 x i32> @lshr_splat_constant0(<2 x i32> %x) {
 ; CHECK-LABEL: @lshr_splat_constant0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = lshr <2 x i32> <i32 5, i32 undef>, [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -913,7 +913,7 @@
 define <2 x i32> @lshr_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @lshr_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = lshr <2 x i32> [[X:%.*]], <i32 5, i32 0>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -935,7 +935,7 @@
 define <2 x i32> @urem_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @urem_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = urem <2 x i32> [[X:%.*]], <i32 42, i32 1>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -957,7 +957,7 @@
 define <2 x i32> @srem_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @srem_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = srem <2 x i32> [[X:%.*]], <i32 42, i32 1>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -979,7 +979,7 @@
 define <2 x i32> @udiv_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @udiv_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = udiv <2 x i32> [[X:%.*]], <i32 42, i32 1>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -1001,7 +1001,7 @@
 define <2 x i32> @sdiv_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @sdiv_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = sdiv <2 x i32> [[X:%.*]], <i32 42, i32 1>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -1012,7 +1012,7 @@
 define <2 x i32> @and_splat_constant(<2 x i32> %x) {
 ; CHECK-LABEL: @and_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = and <2 x i32> [[X:%.*]], <i32 42, i32 poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -1067,7 +1067,7 @@
 ; CHECK-LABEL: @and_constant_mask_undef_4(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = and <4 x i16> [[ADD:%.*]], <i16 9, i16 20, i16 poison, i16 poison>
-; CHECK-NEXT:    [[AND:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> undef, <4 x i32> <i32 0, i32 1, i32 1, i32 undef>
+; CHECK-NEXT:    [[AND:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> poison, <4 x i32> <i32 0, i32 1, i32 1, i32 undef>
 ; CHECK-NEXT:    ret <4 x i16> [[AND]]
 ;
 entry:
@@ -1080,7 +1080,7 @@
 ; CHECK-LABEL: @and_constant_mask_not_undef(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = and <4 x i16> [[ADD:%.*]], <i16 poison, i16 -1, i16 0, i16 0>
-; CHECK-NEXT:    [[AND:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> undef, <4 x i32> <i32 2, i32 3, i32 1, i32 1>
+; CHECK-NEXT:    [[AND:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> poison, <4 x i32> <i32 2, i32 3, i32 1, i32 1>
 ; CHECK-NEXT:    ret <4 x i16> [[AND]]
 ;
 entry:
@@ -1136,7 +1136,7 @@
 ; CHECK-LABEL: @or_constant_mask_undef_4(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = or <4 x i16> [[IN:%.*]], <i16 poison, i16 99, i16 poison, i16 poison>
-; CHECK-NEXT:    [[OR:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> undef, <4 x i32> <i32 undef, i32 1, i32 1, i32 undef>
+; CHECK-NEXT:    [[OR:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> poison, <4 x i32> <i32 undef, i32 1, i32 1, i32 undef>
 ; CHECK-NEXT:    ret <4 x i16> [[OR]]
 ;
 entry:
@@ -1149,7 +1149,7 @@
 ; CHECK-LABEL: @or_constant_mask_not_undef(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = or <4 x i16> [[IN:%.*]], <i16 poison, i16 -1, i16 0, i16 0>
-; CHECK-NEXT:    [[AND:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> undef, <4 x i32> <i32 2, i32 3, i32 1, i32 1>
+; CHECK-NEXT:    [[AND:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> poison, <4 x i32> <i32 2, i32 3, i32 1, i32 1>
 ; CHECK-NEXT:    ret <4 x i16> [[AND]]
 ;
 entry:
@@ -1174,7 +1174,7 @@
 define <4 x i16> @add_constant_mask_undef(<4 x i16> %in) {
 ; CHECK-LABEL: @add_constant_mask_undef(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i16> [[IN:%.*]], <4 x i16> undef, <4 x i32> <i32 undef, i32 undef, i32 1, i32 1>
+; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i16> [[IN:%.*]], <4 x i16> poison, <4 x i32> <i32 undef, i32 undef, i32 1, i32 1>
 ; CHECK-NEXT:    ret <4 x i16> [[ADD]]
 ;
 entry:
@@ -1187,7 +1187,7 @@
 ; CHECK-LABEL: @add_constant_mask_undef_2(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add <4 x i16> [[IN:%.*]], <i16 poison, i16 0, i16 3, i16 poison>
-; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> undef, <4 x i32> <i32 undef, i32 2, i32 1, i32 1>
+; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> poison, <4 x i32> <i32 undef, i32 2, i32 1, i32 1>
 ; CHECK-NEXT:    ret <4 x i16> [[ADD]]
 ;
 entry:
@@ -1199,7 +1199,7 @@
 define <4 x i16> @sub_constant_mask_undef(<4 x i16> %in) {
 ; CHECK-LABEL: @sub_constant_mask_undef(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[SUB:%.*]] = shufflevector <4 x i16> [[IN:%.*]], <4 x i16> undef, <4 x i32> <i32 undef, i32 undef, i32 1, i32 1>
+; CHECK-NEXT:    [[SUB:%.*]] = shufflevector <4 x i16> [[IN:%.*]], <4 x i16> poison, <4 x i32> <i32 undef, i32 undef, i32 1, i32 1>
 ; CHECK-NEXT:    ret <4 x i16> [[SUB]]
 ;
 entry:
@@ -1212,7 +1212,7 @@
 ; CHECK-LABEL: @sub_constant_mask_undef_2(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add <4 x i16> [[IN:%.*]], <i16 poison, i16 0, i16 -10, i16 poison>
-; CHECK-NEXT:    [[SUB:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> undef, <4 x i32> <i32 1, i32 1, i32 2, i32 undef>
+; CHECK-NEXT:    [[SUB:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> poison, <4 x i32> <i32 1, i32 1, i32 2, i32 undef>
 ; CHECK-NEXT:    ret <4 x i16> [[SUB]]
 ;
 entry:
@@ -1224,7 +1224,7 @@
 define <2 x i32> @or_splat_constant(<2 x i32> %x) {
 ; CHECK-LABEL: @or_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = or <2 x i32> [[X:%.*]], <i32 42, i32 poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -1235,7 +1235,7 @@
 define <2 x i32> @xor_splat_constant(<2 x i32> %x) {
 ; CHECK-LABEL: @xor_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = xor <2 x i32> [[X:%.*]], <i32 42, i32 poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> poison, <2 x i32> zeroinitializer
@@ -1246,7 +1246,7 @@
 define <2 x float> @fadd_splat_constant(<2 x float> %x) {
 ; CHECK-LABEL: @fadd_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fadd <2 x float> [[X:%.*]], <float 4.200000e+01, float poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> poison, <2 x i32> zeroinitializer
@@ -1257,7 +1257,7 @@
 define <2 x float> @fsub_splat_constant0(<2 x float> %x) {
 ; CHECK-LABEL: @fsub_splat_constant0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fsub <2 x float> <float 4.200000e+01, float poison>, [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> poison, <2 x i32> zeroinitializer
@@ -1268,7 +1268,7 @@
 define <2 x float> @fsub_splat_constant1(<2 x float> %x) {
 ; CHECK-LABEL: @fsub_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fadd <2 x float> [[X:%.*]], <float -4.200000e+01, float poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> poison, <2 x i32> zeroinitializer
@@ -1279,7 +1279,7 @@
 define <2 x float> @fneg(<2 x float> %x) {
 ; CHECK-LABEL: @fneg(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fneg <2 x float> [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> poison, <2 x i32> zeroinitializer
@@ -1290,7 +1290,7 @@
 define <2 x float> @fmul_splat_constant(<2 x float> %x) {
 ; CHECK-LABEL: @fmul_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fmul <2 x float> [[X:%.*]], <float 4.200000e+01, float poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> poison, <2 x i32> zeroinitializer
@@ -1301,7 +1301,7 @@
 define <2 x float> @fdiv_splat_constant0(<2 x float> %x) {
 ; CHECK-LABEL: @fdiv_splat_constant0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fdiv <2 x float> <float 4.200000e+01, float poison>, [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> poison, <2 x i32> zeroinitializer
@@ -1312,7 +1312,7 @@
 define <2 x float> @fdiv_splat_constant1(<2 x float> %x) {
 ; CHECK-LABEL: @fdiv_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fdiv <2 x float> [[X:%.*]], <float 4.200000e+01, float poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> poison, <2 x i32> zeroinitializer
@@ -1323,7 +1323,7 @@
 define <2 x float> @frem_splat_constant0(<2 x float> %x) {
 ; CHECK-LABEL: @frem_splat_constant0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = frem <2 x float> <float 4.200000e+01, float poison>, [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> poison, <2 x i32> zeroinitializer
@@ -1334,7 +1334,7 @@
 define <2 x float> @frem_splat_constant1(<2 x float> %x) {
 ; CHECK-LABEL: @frem_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = frem <2 x float> [[X:%.*]], <float 4.200000e+01, float poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> poison, <2 x i32> zeroinitializer
diff --git a/llvm/test/Transforms/InstCombine/vec_shuffle.ll b/llvm/test/Transforms/InstCombine/vec_shuffle.ll
--- a/llvm/test/Transforms/InstCombine/vec_shuffle.ll
+++ b/llvm/test/Transforms/InstCombine/vec_shuffle.ll
@@ -393,7 +393,7 @@
 define <4 x i32> @shuffle_17and(<4 x i32> %v1, <4 x i32> %v2) {
 ; CHECK-LABEL: @shuffle_17and(
 ; CHECK-NEXT:    [[TMP1:%.*]] = and <4 x i32> [[V1:%.*]], [[V2:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v1, <4 x i32> zeroinitializer, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
@@ -410,7 +410,7 @@
 ; CHECK-LABEL: @shuffle_fadd_multiuse(
 ; CHECK-NEXT:    [[T1:%.*]] = shufflevector <2 x float> [[V1:%.*]], <2 x float> undef, <2 x i32> <i32 1, i32 0>
 ; CHECK-NEXT:    [[TMP1:%.*]] = fadd <2 x float> [[V1]], [[V2:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> <i32 1, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> <i32 1, i32 0>
 ; CHECK-NEXT:    call void @use(<2 x float> [[T1]])
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
@@ -425,7 +425,7 @@
 ; CHECK-LABEL: @shuffle_fdiv_multiuse(
 ; CHECK-NEXT:    [[T2:%.*]] = shufflevector <2 x float> [[V2:%.*]], <2 x float> undef, <2 x i32> <i32 1, i32 0>
 ; CHECK-NEXT:    [[TMP1:%.*]] = fdiv <2 x float> [[V1:%.*]], [[V2]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> <i32 1, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> <i32 1, i32 0>
 ; CHECK-NEXT:    call void @use(<2 x float> [[T2]])
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
@@ -458,7 +458,7 @@
 define <4 x i32> @shuffle_17add(<4 x i32> %v1, <4 x i32> %v2) {
 ; CHECK-LABEL: @shuffle_17add(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add <4 x i32> [[V1:%.*]], [[V2:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v1, <4 x i32> zeroinitializer, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
@@ -470,7 +470,7 @@
 define <4 x i32> @shuffle_17addnsw(<4 x i32> %v1, <4 x i32> %v2) {
 ; CHECK-LABEL: @shuffle_17addnsw(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add nsw <4 x i32> [[V1:%.*]], [[V2:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v1, <4 x i32> zeroinitializer, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
@@ -482,7 +482,7 @@
 define <4 x i32> @shuffle_17addnuw(<4 x i32> %v1, <4 x i32> %v2) {
 ; CHECK-LABEL: @shuffle_17addnuw(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add nuw <4 x i32> [[V1:%.*]], [[V2:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v1, <4 x i32> zeroinitializer, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
@@ -494,7 +494,7 @@
 define <4 x float> @shuffle_17fsub_fast(<4 x float> %v1, <4 x float> %v2) {
 ; CHECK-LABEL: @shuffle_17fsub_fast(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fsub fast <4 x float> [[V1:%.*]], [[V2:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x float> [[TMP1]], <4 x float> undef, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x float> [[TMP1]], <4 x float> poison, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
 ; CHECK-NEXT:    ret <4 x float> [[R]]
 ;
   %t1 = shufflevector <4 x float> %v1, <4 x float> zeroinitializer, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
@@ -506,7 +506,7 @@
 define <4 x i32> @add_const(<4 x i32> %v) {
 ; CHECK-LABEL: @add_const(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add <4 x i32> [[V:%.*]], <i32 44, i32 41, i32 42, i32 43>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v, <4 x i32> undef, <4 x i32> <i32 1, i32 2, i32 3, i32 0>
@@ -517,7 +517,7 @@
 define <4 x i32> @sub_const(<4 x i32> %v) {
 ; CHECK-LABEL: @sub_const(
 ; CHECK-NEXT:    [[TMP1:%.*]] = sub <4 x i32> <i32 44, i32 43, i32 42, i32 41>, [[V:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v, <4 x i32> undef, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
@@ -545,7 +545,7 @@
 define <4 x i32> @mul_const_splat(<4 x i32> %v) {
 ; CHECK-LABEL: @mul_const_splat(
 ; CHECK-NEXT:    [[TMP1:%.*]] = mul <4 x i32> [[V:%.*]], <i32 poison, i32 42, i32 poison, i32 poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 1, i32 1, i32 1, i32 1>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 1, i32 1, i32 1, i32 1>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v, <4 x i32> undef, <4 x i32> <i32 1, i32 1, i32 1, i32 1>
@@ -558,7 +558,7 @@
 define <4 x i32> @lshr_const_half_splat(<4 x i32> %v) {
 ; CHECK-LABEL: @lshr_const_half_splat(
 ; CHECK-NEXT:    [[TMP1:%.*]] = lshr <4 x i32> <i32 undef, i32 8, i32 9, i32 undef>, [[V:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> <i32 1, i32 1, i32 2, i32 2>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> <i32 1, i32 1, i32 2, i32 2>
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
 ;
   %t1 = shufflevector <4 x i32> %v, <4 x i32> undef, <4 x i32> <i32 1, i32 1, i32 2, i32 2>
@@ -584,7 +584,7 @@
 define <4 x i8> @widening_shuffle_add_1(<2 x i8> %x) {
 ; CHECK-LABEL: @widening_shuffle_add_1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add <2 x i8> [[X:%.*]], <i8 42, i8 43>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i8> [[TMP1]], <2 x i8> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i8> [[TMP1]], <2 x i8> poison, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
 ; CHECK-NEXT:    ret <4 x i8> [[R]]
 ;
   %widex = shufflevector <2 x i8> %x, <2 x i8> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
@@ -597,7 +597,7 @@
 define <4 x i8> @widening_shuffle_add_2(<2 x i8> %x) {
 ; CHECK-LABEL: @widening_shuffle_add_2(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add <2 x i8> [[X:%.*]], <i8 43, i8 42>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i8> [[TMP1]], <2 x i8> undef, <4 x i32> <i32 1, i32 0, i32 undef, i32 undef>
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i8> [[TMP1]], <2 x i8> poison, <4 x i32> <i32 1, i32 0, i32 undef, i32 undef>
 ; CHECK-NEXT:    ret <4 x i8> [[R]]
 ;
   %widex = shufflevector <2 x i8> %x, <2 x i8> undef, <4 x i32> <i32 1, i32 0, i32 undef, i32 undef>
@@ -637,7 +637,7 @@
 define <4 x i16> @widening_shuffle_shl_constant_op0(<2 x i16> %v) {
 ; CHECK-LABEL: @widening_shuffle_shl_constant_op0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = shl <2 x i16> <i16 42, i16 -42>, [[V:%.*]]
-; CHECK-NEXT:    [[BO:%.*]] = shufflevector <2 x i16> [[TMP1]], <2 x i16> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
+; CHECK-NEXT:    [[BO:%.*]] = shufflevector <2 x i16> [[TMP1]], <2 x i16> poison, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
 ; CHECK-NEXT:    ret <4 x i16> [[BO]]
 ;
   %shuf = shufflevector <2 x i16> %v, <2 x i16> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
@@ -651,7 +651,7 @@
 define <4 x i16> @widening_shuffle_shl_constant_op1(<2 x i16> %v) {
 ; CHECK-LABEL: @widening_shuffle_shl_constant_op1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = shl <2 x i16> [[V:%.*]], <i16 2, i16 4>
-; CHECK-NEXT:    [[BO:%.*]] = shufflevector <2 x i16> [[TMP1]], <2 x i16> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
+; CHECK-NEXT:    [[BO:%.*]] = shufflevector <2 x i16> [[TMP1]], <2 x i16> poison, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
 ; CHECK-NEXT:    ret <4 x i16> [[BO]]
 ;
   %shuf = shufflevector <2 x i16> %v, <2 x i16> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
@@ -701,7 +701,7 @@
 define <4 x i32> @shuffle_17mulsplat(<4 x i32> %v) {
 ; CHECK-LABEL: @shuffle_17mulsplat(
 ; CHECK-NEXT:    [[TMP1:%.*]] = mul <4 x i32> [[V:%.*]], [[V]]
-; CHECK-NEXT:    [[M1:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> zeroinitializer
+; CHECK-NEXT:    [[M1:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <4 x i32> [[M1]]
 ;
   %s1 = shufflevector <4 x i32> %v, <4 x i32> zeroinitializer, <4 x i32> zeroinitializer
@@ -727,7 +727,7 @@
 define <4 x i16> @pr19717a(<8 x i16> %in0, <8 x i16> %in1) {
 ; CHECK-LABEL: @pr19717a(
 ; CHECK-NEXT:    [[TMP1:%.*]] = mul <8 x i16> [[IN0:%.*]], [[IN1:%.*]]
-; CHECK-NEXT:    [[MUL:%.*]] = shufflevector <8 x i16> [[TMP1]], <8 x i16> undef, <4 x i32> <i32 5, i32 5, i32 5, i32 5>
+; CHECK-NEXT:    [[MUL:%.*]] = shufflevector <8 x i16> [[TMP1]], <8 x i16> poison, <4 x i32> <i32 5, i32 5, i32 5, i32 5>
 ; CHECK-NEXT:    ret <4 x i16> [[MUL]]
 ;
   %shuffle = shufflevector <8 x i16> %in0, <8 x i16> %in0, <4 x i32> <i32 5, i32 5, i32 5, i32 5>
@@ -813,7 +813,7 @@
 define <2 x i32> @add_splat_constant(<2 x i32> %x) {
 ; CHECK-LABEL: @add_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add <2 x i32> [[X:%.*]], <i32 42, i32 poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -824,7 +824,7 @@
 define <2 x i32> @sub_splat_constant0(<2 x i32> %x) {
 ; CHECK-LABEL: @sub_splat_constant0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = sub <2 x i32> <i32 42, i32 poison>, [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -835,7 +835,7 @@
 define <2 x i32> @sub_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @sub_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = add <2 x i32> [[X:%.*]], <i32 -42, i32 poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -846,7 +846,7 @@
 define <2 x i32> @mul_splat_constant(<2 x i32> %x) {
 ; CHECK-LABEL: @mul_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = mul <2 x i32> [[X:%.*]], <i32 42, i32 poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -857,7 +857,7 @@
 define <2 x i32> @shl_splat_constant0(<2 x i32> %x) {
 ; CHECK-LABEL: @shl_splat_constant0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = shl <2 x i32> <i32 5, i32 undef>, [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -868,7 +868,7 @@
 define <2 x i32> @shl_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @shl_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = shl <2 x i32> [[X:%.*]], <i32 5, i32 0>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -879,7 +879,7 @@
 define <2 x i32> @ashr_splat_constant0(<2 x i32> %x) {
 ; CHECK-LABEL: @ashr_splat_constant0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = ashr <2 x i32> <i32 5, i32 undef>, [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -890,7 +890,7 @@
 define <2 x i32> @ashr_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @ashr_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = ashr <2 x i32> [[X:%.*]], <i32 5, i32 0>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -901,7 +901,7 @@
 define <2 x i32> @lshr_splat_constant0(<2 x i32> %x) {
 ; CHECK-LABEL: @lshr_splat_constant0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = lshr <2 x i32> <i32 5, i32 undef>, [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -912,7 +912,7 @@
 define <2 x i32> @lshr_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @lshr_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = lshr <2 x i32> [[X:%.*]], <i32 5, i32 0>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -934,7 +934,7 @@
 define <2 x i32> @urem_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @urem_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = urem <2 x i32> [[X:%.*]], <i32 42, i32 1>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -956,7 +956,7 @@
 define <2 x i32> @srem_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @srem_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = srem <2 x i32> [[X:%.*]], <i32 42, i32 1>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -978,7 +978,7 @@
 define <2 x i32> @udiv_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @udiv_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = udiv <2 x i32> [[X:%.*]], <i32 42, i32 1>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -1000,7 +1000,7 @@
 define <2 x i32> @sdiv_splat_constant1(<2 x i32> %x) {
 ; CHECK-LABEL: @sdiv_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = sdiv <2 x i32> [[X:%.*]], <i32 42, i32 1>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -1011,7 +1011,7 @@
 define <2 x i32> @and_splat_constant(<2 x i32> %x) {
 ; CHECK-LABEL: @and_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = and <2 x i32> [[X:%.*]], <i32 42, i32 poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -1066,7 +1066,7 @@
 ; CHECK-LABEL: @and_constant_mask_undef_4(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = and <4 x i16> [[ADD:%.*]], <i16 9, i16 20, i16 poison, i16 poison>
-; CHECK-NEXT:    [[AND:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> undef, <4 x i32> <i32 0, i32 1, i32 1, i32 undef>
+; CHECK-NEXT:    [[AND:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> poison, <4 x i32> <i32 0, i32 1, i32 1, i32 undef>
 ; CHECK-NEXT:    ret <4 x i16> [[AND]]
 ;
 entry:
@@ -1079,7 +1079,7 @@
 ; CHECK-LABEL: @and_constant_mask_not_undef(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = and <4 x i16> [[ADD:%.*]], <i16 poison, i16 -1, i16 0, i16 0>
-; CHECK-NEXT:    [[AND:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> undef, <4 x i32> <i32 2, i32 3, i32 1, i32 1>
+; CHECK-NEXT:    [[AND:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> poison, <4 x i32> <i32 2, i32 3, i32 1, i32 1>
 ; CHECK-NEXT:    ret <4 x i16> [[AND]]
 ;
 entry:
@@ -1135,7 +1135,7 @@
 ; CHECK-LABEL: @or_constant_mask_undef_4(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = or <4 x i16> [[IN:%.*]], <i16 poison, i16 99, i16 poison, i16 poison>
-; CHECK-NEXT:    [[OR:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> undef, <4 x i32> <i32 undef, i32 1, i32 1, i32 undef>
+; CHECK-NEXT:    [[OR:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> poison, <4 x i32> <i32 undef, i32 1, i32 1, i32 undef>
 ; CHECK-NEXT:    ret <4 x i16> [[OR]]
 ;
 entry:
@@ -1148,7 +1148,7 @@
 ; CHECK-LABEL: @or_constant_mask_not_undef(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = or <4 x i16> [[IN:%.*]], <i16 poison, i16 -1, i16 0, i16 0>
-; CHECK-NEXT:    [[AND:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> undef, <4 x i32> <i32 2, i32 3, i32 1, i32 1>
+; CHECK-NEXT:    [[AND:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> poison, <4 x i32> <i32 2, i32 3, i32 1, i32 1>
 ; CHECK-NEXT:    ret <4 x i16> [[AND]]
 ;
 entry:
@@ -1173,7 +1173,7 @@
 define <4 x i16> @add_constant_mask_undef(<4 x i16> %in) {
 ; CHECK-LABEL: @add_constant_mask_undef(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i16> [[IN:%.*]], <4 x i16> undef, <4 x i32> <i32 undef, i32 undef, i32 1, i32 1>
+; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i16> [[IN:%.*]], <4 x i16> poison, <4 x i32> <i32 undef, i32 undef, i32 1, i32 1>
 ; CHECK-NEXT:    ret <4 x i16> [[ADD]]
 ;
 entry:
@@ -1186,7 +1186,7 @@
 ; CHECK-LABEL: @add_constant_mask_undef_2(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add <4 x i16> [[IN:%.*]], <i16 poison, i16 0, i16 3, i16 poison>
-; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> undef, <4 x i32> <i32 undef, i32 2, i32 1, i32 1>
+; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> poison, <4 x i32> <i32 undef, i32 2, i32 1, i32 1>
 ; CHECK-NEXT:    ret <4 x i16> [[ADD]]
 ;
 entry:
@@ -1198,7 +1198,7 @@
 define <4 x i16> @sub_constant_mask_undef(<4 x i16> %in) {
 ; CHECK-LABEL: @sub_constant_mask_undef(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[SUB:%.*]] = shufflevector <4 x i16> [[IN:%.*]], <4 x i16> undef, <4 x i32> <i32 undef, i32 undef, i32 1, i32 1>
+; CHECK-NEXT:    [[SUB:%.*]] = shufflevector <4 x i16> [[IN:%.*]], <4 x i16> poison, <4 x i32> <i32 undef, i32 undef, i32 1, i32 1>
 ; CHECK-NEXT:    ret <4 x i16> [[SUB]]
 ;
 entry:
@@ -1211,7 +1211,7 @@
 ; CHECK-LABEL: @sub_constant_mask_undef_2(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add <4 x i16> [[IN:%.*]], <i16 poison, i16 0, i16 -10, i16 poison>
-; CHECK-NEXT:    [[SUB:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> undef, <4 x i32> <i32 1, i32 1, i32 2, i32 undef>
+; CHECK-NEXT:    [[SUB:%.*]] = shufflevector <4 x i16> [[TMP0]], <4 x i16> poison, <4 x i32> <i32 1, i32 1, i32 2, i32 undef>
 ; CHECK-NEXT:    ret <4 x i16> [[SUB]]
 ;
 entry:
@@ -1223,7 +1223,7 @@
 define <2 x i32> @or_splat_constant(<2 x i32> %x) {
 ; CHECK-LABEL: @or_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = or <2 x i32> [[X:%.*]], <i32 42, i32 poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -1234,7 +1234,7 @@
 define <2 x i32> @xor_splat_constant(<2 x i32> %x) {
 ; CHECK-LABEL: @xor_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = xor <2 x i32> [[X:%.*]], <i32 42, i32 poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %splat = shufflevector <2 x i32> %x, <2 x i32> undef, <2 x i32> zeroinitializer
@@ -1245,7 +1245,7 @@
 define <2 x float> @fadd_splat_constant(<2 x float> %x) {
 ; CHECK-LABEL: @fadd_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fadd <2 x float> [[X:%.*]], <float 4.200000e+01, float poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> undef, <2 x i32> zeroinitializer
@@ -1256,7 +1256,7 @@
 define <2 x float> @fsub_splat_constant0(<2 x float> %x) {
 ; CHECK-LABEL: @fsub_splat_constant0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fsub <2 x float> <float 4.200000e+01, float poison>, [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> undef, <2 x i32> zeroinitializer
@@ -1267,7 +1267,7 @@
 define <2 x float> @fsub_splat_constant1(<2 x float> %x) {
 ; CHECK-LABEL: @fsub_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fadd <2 x float> [[X:%.*]], <float -4.200000e+01, float poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> undef, <2 x i32> zeroinitializer
@@ -1278,7 +1278,7 @@
 define <2 x float> @fneg(<2 x float> %x) {
 ; CHECK-LABEL: @fneg(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fneg <2 x float> [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> undef, <2 x i32> zeroinitializer
@@ -1289,7 +1289,7 @@
 define <2 x float> @fmul_splat_constant(<2 x float> %x) {
 ; CHECK-LABEL: @fmul_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fmul <2 x float> [[X:%.*]], <float 4.200000e+01, float poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> undef, <2 x i32> zeroinitializer
@@ -1300,7 +1300,7 @@
 define <2 x float> @fdiv_splat_constant0(<2 x float> %x) {
 ; CHECK-LABEL: @fdiv_splat_constant0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fdiv <2 x float> <float 4.200000e+01, float poison>, [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> undef, <2 x i32> zeroinitializer
@@ -1311,7 +1311,7 @@
 define <2 x float> @fdiv_splat_constant1(<2 x float> %x) {
 ; CHECK-LABEL: @fdiv_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fdiv <2 x float> [[X:%.*]], <float 4.200000e+01, float poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> undef, <2 x i32> zeroinitializer
@@ -1322,7 +1322,7 @@
 define <2 x float> @frem_splat_constant0(<2 x float> %x) {
 ; CHECK-LABEL: @frem_splat_constant0(
 ; CHECK-NEXT:    [[TMP1:%.*]] = frem <2 x float> <float 4.200000e+01, float poison>, [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> undef, <2 x i32> zeroinitializer
@@ -1333,7 +1333,7 @@
 define <2 x float> @frem_splat_constant1(<2 x float> %x) {
 ; CHECK-LABEL: @frem_splat_constant1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = frem <2 x float> [[X:%.*]], <float 4.200000e+01, float poison>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <2 x float> [[R]]
 ;
   %splat = shufflevector <2 x float> %x, <2 x float> undef, <2 x i32> zeroinitializer
diff --git a/llvm/test/Transforms/InstCombine/vector-casts-inseltpoison.ll b/llvm/test/Transforms/InstCombine/vector-casts-inseltpoison.ll
--- a/llvm/test/Transforms/InstCombine/vector-casts-inseltpoison.ll
+++ b/llvm/test/Transforms/InstCombine/vector-casts-inseltpoison.ll
@@ -294,7 +294,7 @@
 define <3 x i16> @trunc_inselt_undef(i32 %x) {
 ; CHECK-LABEL: @trunc_inselt_undef(
 ; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 [[X:%.*]] to i16
-; CHECK-NEXT:    [[TRUNC:%.*]] = insertelement <3 x i16> undef, i16 [[TMP1]], i32 1
+; CHECK-NEXT:    [[TRUNC:%.*]] = insertelement <3 x i16> poison, i16 [[TMP1]], i32 1
 ; CHECK-NEXT:    ret <3 x i16> [[TRUNC]]
 ;
   %vec = insertelement <3 x i32> poison, i32 %x, i32 1
@@ -308,10 +308,10 @@
 define <2 x float> @fptrunc_inselt_undef(double %x, i32 %index) {
 ; CHECK-LABEL: @fptrunc_inselt_undef(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fptrunc double [[X:%.*]] to float
-; CHECK-NEXT:    [[TRUNC:%.*]] = insertelement <2 x float> undef, float [[TMP1]], i32 [[INDEX:%.*]]
+; CHECK-NEXT:    [[TRUNC:%.*]] = insertelement <2 x float> poison, float [[TMP1]], i32 [[INDEX:%.*]]
 ; CHECK-NEXT:    ret <2 x float> [[TRUNC]]
 ;
-  %vec = insertelement <2 x double> <double undef, double undef>, double %x, i32 %index
+  %vec = insertelement <2 x double> poison, double %x, i32 %index
   %trunc = fptrunc <2 x double> %vec to <2 x float>
   ret <2 x float> %trunc
 }
diff --git a/llvm/test/Transforms/InstCombine/vscale_cmp.ll b/llvm/test/Transforms/InstCombine/vscale_cmp.ll
--- a/llvm/test/Transforms/InstCombine/vscale_cmp.ll
+++ b/llvm/test/Transforms/InstCombine/vscale_cmp.ll
@@ -14,7 +14,7 @@
 ; CHECK-LABEL: @gep_scalevector1(
 ; CHECK-NEXT:    [[DOTSPLATINSERT:%.*]] = insertelement <vscale x 2 x i32*> poison, i32* [[X:%.*]], i32 0
 ; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq <vscale x 2 x i32*> [[DOTSPLATINSERT]], zeroinitializer
-; CHECK-NEXT:    [[C:%.*]] = shufflevector <vscale x 2 x i1> [[TMP1]], <vscale x 2 x i1> undef, <vscale x 2 x i32> zeroinitializer
+; CHECK-NEXT:    [[C:%.*]] = shufflevector <vscale x 2 x i1> [[TMP1]], <vscale x 2 x i1> poison, <vscale x 2 x i32> zeroinitializer
 ; CHECK-NEXT:    ret <vscale x 2 x i1> [[C]]
 ;
   %A = getelementptr inbounds i32, i32* %X, <vscale x 2 x i64> zeroinitializer
diff --git a/llvm/test/Transforms/InstSimplify/shufflevector-inseltpoison.ll b/llvm/test/Transforms/InstSimplify/shufflevector-inseltpoison.ll
--- a/llvm/test/Transforms/InstSimplify/shufflevector-inseltpoison.ll
+++ b/llvm/test/Transforms/InstSimplify/shufflevector-inseltpoison.ll
@@ -124,7 +124,7 @@
 ; CHECK-LABEL: @undef_mask(
 ; CHECK-NEXT:    ret <4 x i32> undef
 ;
-  %shuf = shufflevector <4 x i32> %x, <4 x i32> undef, <4 x i32> poison
+  %shuf = shufflevector <4 x i32> %x, <4 x i32> poison, <4 x i32> poison
   ret <4 x i32> %shuf
 }
 
diff --git a/llvm/test/Transforms/PhaseOrdering/X86/shuffle-inseltpoison.ll b/llvm/test/Transforms/PhaseOrdering/X86/shuffle-inseltpoison.ll
--- a/llvm/test/Transforms/PhaseOrdering/X86/shuffle-inseltpoison.ll
+++ b/llvm/test/Transforms/PhaseOrdering/X86/shuffle-inseltpoison.ll
@@ -75,7 +75,7 @@
 ; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <4 x i32> [[V1:%.*]] to <8 x i16>
 ; CHECK-NEXT:    [[TMP2:%.*]] = bitcast <4 x i32> [[V2:%.*]] to <8 x i16>
 ; CHECK-NEXT:    [[TMP3:%.*]] = add <8 x i16> [[TMP2]], [[TMP1]]
-; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <8 x i16> [[TMP3]], <8 x i16> undef, <8 x i32> <i32 4, i32 5, i32 6, i32 7, i32 2, i32 3, i32 0, i32 1>
+; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <8 x i16> [[TMP3]], <8 x i16> poison, <8 x i32> <i32 4, i32 5, i32 6, i32 7, i32 2, i32 3, i32 0, i32 1>
 ; CHECK-NEXT:    ret <8 x i16> [[ADD]]
 ;
   %shuffle1 = shufflevector <4 x i32> %v1, <4 x i32> poison, <4 x i32> <i32 2, i32 3, i32 1, i32 0>
@@ -93,7 +93,7 @@
 ; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <4 x i32> [[V1:%.*]] to <16 x i8>
 ; CHECK-NEXT:    [[TMP2:%.*]] = bitcast <4 x i32> [[V2:%.*]] to <16 x i8>
 ; CHECK-NEXT:    [[TMP3:%.*]] = add <16 x i8> [[TMP2]], [[TMP1]]
-; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <16 x i8> [[TMP3]], <16 x i8> undef, <16 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3>
+; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <16 x i8> [[TMP3]], <16 x i8> poison, <16 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3>
 ; CHECK-NEXT:    ret <16 x i8> [[ADD]]
 ;
   %shuffle1 = shufflevector <4 x i32> %v1, <4 x i32> poison, <4 x i32> <i32 2, i32 3, i32 1, i32 0>
@@ -111,7 +111,7 @@
 ; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <8 x i16> [[V1:%.*]] to <16 x i8>
 ; CHECK-NEXT:    [[TMP2:%.*]] = bitcast <8 x i16> [[V2:%.*]] to <16 x i8>
 ; CHECK-NEXT:    [[TMP3:%.*]] = add <16 x i8> [[TMP2]], [[TMP1]]
-; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <16 x i8> [[TMP3]], <16 x i8> undef, <16 x i32> <i32 4, i32 5, i32 6, i32 7, i32 2, i32 3, i32 0, i32 1, i32 8, i32 9, i32 10, i32 11, i32 14, i32 15, i32 12, i32 13>
+; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <16 x i8> [[TMP3]], <16 x i8> poison, <16 x i32> <i32 4, i32 5, i32 6, i32 7, i32 2, i32 3, i32 0, i32 1, i32 8, i32 9, i32 10, i32 11, i32 14, i32 15, i32 12, i32 13>
 ; CHECK-NEXT:    ret <16 x i8> [[ADD]]
 ;
   %shuffle1 = shufflevector <8 x i16> %v1, <8 x i16> poison, <8 x i32> <i32 2, i32 3, i32 1, i32 0, i32 4, i32 5, i32 7, i32 6>
@@ -129,7 +129,7 @@
 ; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <8 x i16> [[V1:%.*]] to <4 x i32>
 ; CHECK-NEXT:    [[TMP2:%.*]] = bitcast <8 x i16> [[V2:%.*]] to <4 x i32>
 ; CHECK-NEXT:    [[TMP3:%.*]] = add <4 x i32> [[TMP2]], [[TMP1]]
-; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i32> [[TMP3]], <4 x i32> undef, <4 x i32> <i32 2, i32 3, i32 0, i32 1>
+; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i32> [[TMP3]], <4 x i32> poison, <4 x i32> <i32 2, i32 3, i32 0, i32 1>
 ; CHECK-NEXT:    ret <4 x i32> [[ADD]]
 ;
   %shuffle1 = shufflevector <8 x i16> %v1, <8 x i16> poison, <8 x i32> <i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3>
@@ -147,7 +147,7 @@
 ; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <16 x i8> [[V1:%.*]] to <4 x i32>
 ; CHECK-NEXT:    [[TMP2:%.*]] = bitcast <16 x i8> [[V2:%.*]] to <4 x i32>
 ; CHECK-NEXT:    [[TMP3:%.*]] = add <4 x i32> [[TMP2]], [[TMP1]]
-; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i32> [[TMP3]], <4 x i32> undef, <4 x i32> <i32 1, i32 0, i32 2, i32 3>
+; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i32> [[TMP3]], <4 x i32> poison, <4 x i32> <i32 1, i32 0, i32 2, i32 3>
 ; CHECK-NEXT:    ret <4 x i32> [[ADD]]
 ;
   %shuffle1 = shufflevector <16 x i8> %v1, <16 x i8> poison, <16 x i32> <i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
diff --git a/llvm/test/Transforms/PhaseOrdering/X86/shuffle.ll b/llvm/test/Transforms/PhaseOrdering/X86/shuffle.ll
--- a/llvm/test/Transforms/PhaseOrdering/X86/shuffle.ll
+++ b/llvm/test/Transforms/PhaseOrdering/X86/shuffle.ll
@@ -75,7 +75,7 @@
 ; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <4 x i32> [[V1:%.*]] to <8 x i16>
 ; CHECK-NEXT:    [[TMP2:%.*]] = bitcast <4 x i32> [[V2:%.*]] to <8 x i16>
 ; CHECK-NEXT:    [[TMP3:%.*]] = add <8 x i16> [[TMP2]], [[TMP1]]
-; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <8 x i16> [[TMP3]], <8 x i16> undef, <8 x i32> <i32 4, i32 5, i32 6, i32 7, i32 2, i32 3, i32 0, i32 1>
+; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <8 x i16> [[TMP3]], <8 x i16> poison, <8 x i32> <i32 4, i32 5, i32 6, i32 7, i32 2, i32 3, i32 0, i32 1>
 ; CHECK-NEXT:    ret <8 x i16> [[ADD]]
 ;
   %shuffle1 = shufflevector <4 x i32> %v1, <4 x i32> undef, <4 x i32> <i32 2, i32 3, i32 1, i32 0>
@@ -93,7 +93,7 @@
 ; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <4 x i32> [[V1:%.*]] to <16 x i8>
 ; CHECK-NEXT:    [[TMP2:%.*]] = bitcast <4 x i32> [[V2:%.*]] to <16 x i8>
 ; CHECK-NEXT:    [[TMP3:%.*]] = add <16 x i8> [[TMP2]], [[TMP1]]
-; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <16 x i8> [[TMP3]], <16 x i8> undef, <16 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3>
+; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <16 x i8> [[TMP3]], <16 x i8> poison, <16 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3>
 ; CHECK-NEXT:    ret <16 x i8> [[ADD]]
 ;
   %shuffle1 = shufflevector <4 x i32> %v1, <4 x i32> undef, <4 x i32> <i32 2, i32 3, i32 1, i32 0>
@@ -111,7 +111,7 @@
 ; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <8 x i16> [[V1:%.*]] to <16 x i8>
 ; CHECK-NEXT:    [[TMP2:%.*]] = bitcast <8 x i16> [[V2:%.*]] to <16 x i8>
 ; CHECK-NEXT:    [[TMP3:%.*]] = add <16 x i8> [[TMP2]], [[TMP1]]
-; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <16 x i8> [[TMP3]], <16 x i8> undef, <16 x i32> <i32 4, i32 5, i32 6, i32 7, i32 2, i32 3, i32 0, i32 1, i32 8, i32 9, i32 10, i32 11, i32 14, i32 15, i32 12, i32 13>
+; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <16 x i8> [[TMP3]], <16 x i8> poison, <16 x i32> <i32 4, i32 5, i32 6, i32 7, i32 2, i32 3, i32 0, i32 1, i32 8, i32 9, i32 10, i32 11, i32 14, i32 15, i32 12, i32 13>
 ; CHECK-NEXT:    ret <16 x i8> [[ADD]]
 ;
   %shuffle1 = shufflevector <8 x i16> %v1, <8 x i16> undef, <8 x i32> <i32 2, i32 3, i32 1, i32 0, i32 4, i32 5, i32 7, i32 6>
@@ -129,7 +129,7 @@
 ; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <8 x i16> [[V1:%.*]] to <4 x i32>
 ; CHECK-NEXT:    [[TMP2:%.*]] = bitcast <8 x i16> [[V2:%.*]] to <4 x i32>
 ; CHECK-NEXT:    [[TMP3:%.*]] = add <4 x i32> [[TMP2]], [[TMP1]]
-; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i32> [[TMP3]], <4 x i32> undef, <4 x i32> <i32 2, i32 3, i32 0, i32 1>
+; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i32> [[TMP3]], <4 x i32> poison, <4 x i32> <i32 2, i32 3, i32 0, i32 1>
 ; CHECK-NEXT:    ret <4 x i32> [[ADD]]
 ;
   %shuffle1 = shufflevector <8 x i16> %v1, <8 x i16> undef, <8 x i32> <i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3>
@@ -147,7 +147,7 @@
 ; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <16 x i8> [[V1:%.*]] to <4 x i32>
 ; CHECK-NEXT:    [[TMP2:%.*]] = bitcast <16 x i8> [[V2:%.*]] to <4 x i32>
 ; CHECK-NEXT:    [[TMP3:%.*]] = add <4 x i32> [[TMP2]], [[TMP1]]
-; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i32> [[TMP3]], <4 x i32> undef, <4 x i32> <i32 1, i32 0, i32 2, i32 3>
+; CHECK-NEXT:    [[ADD:%.*]] = shufflevector <4 x i32> [[TMP3]], <4 x i32> poison, <4 x i32> <i32 1, i32 0, i32 2, i32 3>
 ; CHECK-NEXT:    ret <4 x i32> [[ADD]]
 ;
   %shuffle1 = shufflevector <16 x i8> %v1, <16 x i8> undef, <16 x i32> <i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
diff --git a/llvm/test/Transforms/SLPVectorizer/AArch64/transpose-inseltpoison.ll b/llvm/test/Transforms/SLPVectorizer/AArch64/transpose-inseltpoison.ll
--- a/llvm/test/Transforms/SLPVectorizer/AArch64/transpose-inseltpoison.ll
+++ b/llvm/test/Transforms/SLPVectorizer/AArch64/transpose-inseltpoison.ll
@@ -193,9 +193,9 @@
 ; CHECK-NEXT:    [[TMP1_0:%.*]] = mul i32 [[V0_0]], [[V1_0]]
 ; CHECK-NEXT:    [[TMP1_1:%.*]] = mul i32 [[V0_1]], [[V1_1]]
 ; CHECK-NEXT:    [[TMP1:%.*]] = xor <2 x i32> [[V0]], [[V1]]
-; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    [[TMP3:%.*]] = xor <2 x i32> [[V0]], [[V1]]
-; CHECK-NEXT:    [[TMP4:%.*]] = shufflevector <2 x i32> [[TMP3]], <2 x i32> undef, <2 x i32> <i32 1, i32 1>
+; CHECK-NEXT:    [[TMP4:%.*]] = shufflevector <2 x i32> [[TMP3]], <2 x i32> poison, <2 x i32> <i32 1, i32 1>
 ; CHECK-NEXT:    [[TMP2_0:%.*]] = add i32 [[TMP0_0]], [[TMP0_1]]
 ; CHECK-NEXT:    [[TMP2_1:%.*]] = add i32 [[TMP1_0]], [[TMP1_1]]
 ; CHECK-NEXT:    [[TMP5:%.*]] = add <2 x i32> [[TMP2]], [[TMP4]]
diff --git a/llvm/test/Transforms/SLPVectorizer/AArch64/transpose.ll b/llvm/test/Transforms/SLPVectorizer/AArch64/transpose.ll
--- a/llvm/test/Transforms/SLPVectorizer/AArch64/transpose.ll
+++ b/llvm/test/Transforms/SLPVectorizer/AArch64/transpose.ll
@@ -193,9 +193,9 @@
 ; CHECK-NEXT:    [[TMP1_0:%.*]] = mul i32 [[V0_0]], [[V1_0]]
 ; CHECK-NEXT:    [[TMP1_1:%.*]] = mul i32 [[V0_1]], [[V1_1]]
 ; CHECK-NEXT:    [[TMP1:%.*]] = xor <2 x i32> [[V0]], [[V1]]
-; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <2 x i32> [[TMP1]], <2 x i32> poison, <2 x i32> zeroinitializer
 ; CHECK-NEXT:    [[TMP3:%.*]] = xor <2 x i32> [[V0]], [[V1]]
-; CHECK-NEXT:    [[TMP4:%.*]] = shufflevector <2 x i32> [[TMP3]], <2 x i32> undef, <2 x i32> <i32 1, i32 1>
+; CHECK-NEXT:    [[TMP4:%.*]] = shufflevector <2 x i32> [[TMP3]], <2 x i32> poison, <2 x i32> <i32 1, i32 1>
 ; CHECK-NEXT:    [[TMP2_0:%.*]] = add i32 [[TMP0_0]], [[TMP0_1]]
 ; CHECK-NEXT:    [[TMP2_1:%.*]] = add i32 [[TMP1_0]], [[TMP1_1]]
 ; CHECK-NEXT:    [[TMP5:%.*]] = add <2 x i32> [[TMP2]], [[TMP4]]
diff --git a/llvm/test/Transforms/SLPVectorizer/X86/alternate-int-inseltpoison.ll b/llvm/test/Transforms/SLPVectorizer/X86/alternate-int-inseltpoison.ll
--- a/llvm/test/Transforms/SLPVectorizer/X86/alternate-int-inseltpoison.ll
+++ b/llvm/test/Transforms/SLPVectorizer/X86/alternate-int-inseltpoison.ll
@@ -425,10 +425,10 @@
 ; CHECK-NEXT:    [[AB5:%.*]] = sdiv i32 [[A5]], 4
 ; CHECK-NEXT:    [[AB6:%.*]] = sdiv i32 [[A6]], 8
 ; CHECK-NEXT:    [[AB7:%.*]] = sdiv i32 [[A7]], 16
-; CHECK-NEXT:    [[TMP1:%.*]] = insertelement <8 x i32> poison, i32 [[AB1]], i32 1
-; CHECK-NEXT:    [[TMP2:%.*]] = insertelement <8 x i32> [[TMP1]], i32 [[AB2]], i32 2
-; CHECK-NEXT:    [[R4:%.*]] = insertelement <8 x i32> [[TMP2]], i32 [[AB3]], i32 3
-; CHECK-NEXT:    [[R5:%.*]] = insertelement <8 x i32> [[R4]], i32 [[AB5]], i32 5
+; CHECK-NEXT:    [[R1:%.*]] = insertelement <8 x i32> poison, i32 [[AB1]], i32 1
+; CHECK-NEXT:    [[R2:%.*]] = insertelement <8 x i32> [[R1]], i32 [[AB2]], i32 2
+; CHECK-NEXT:    [[R3:%.*]] = insertelement <8 x i32> [[R2]], i32 [[AB3]], i32 3
+; CHECK-NEXT:    [[R5:%.*]] = insertelement <8 x i32> [[R3]], i32 [[AB5]], i32 5
 ; CHECK-NEXT:    [[R6:%.*]] = insertelement <8 x i32> [[R5]], i32 [[AB6]], i32 6
 ; CHECK-NEXT:    [[R7:%.*]] = insertelement <8 x i32> [[R6]], i32 [[AB7]], i32 7
 ; CHECK-NEXT:    ret <8 x i32> [[R7]]
diff --git a/llvm/test/Transforms/Scalarizer/variable-extractelement.ll b/llvm/test/Transforms/Scalarizer/variable-extractelement.ll
--- a/llvm/test/Transforms/Scalarizer/variable-extractelement.ll
+++ b/llvm/test/Transforms/Scalarizer/variable-extractelement.ll
@@ -19,8 +19,8 @@
 ; DEFAULT-NEXT:    [[RES_UPTO2:%.*]] = select i1 [[INDEX_IS_2]], i32 [[SRC_I2]], i32 [[RES_UPTO1]]
 ; DEFAULT-NEXT:    [[INDEX_IS_3:%.*]] = icmp eq i32 [[INDEX]], 3
 ; DEFAULT-NEXT:    [[SRC_I3:%.*]] = extractelement <4 x i32> [[SRC]], i32 3
-; DEFAULT-NEXT:    [[RES:%.*]] = select i1 [[INDEX_IS_3]], i32 [[SRC_I3]], i32 [[RES_UPTO2]]
-; DEFAULT-NEXT:    ret i32 [[RES]]
+; DEFAULT-NEXT:    [[RES_UPTO3:%.*]] = select i1 [[INDEX_IS_3]], i32 [[SRC_I3]], i32 [[RES_UPTO2]]
+; DEFAULT-NEXT:    ret i32 [[RES_UPTO3]]
 ;
 ; OFF-LABEL: @f1(
 ; OFF-NEXT:    [[RES:%.*]] = extractelement <4 x i32> [[SRC:%.*]], i32 [[INDEX:%.*]]
@@ -48,8 +48,8 @@
 ; DEFAULT-NEXT:    [[INDEX_IS_2:%.*]] = icmp eq i32 [[INDEX]], 2
 ; DEFAULT-NEXT:    [[VAL2_UPTO2:%.*]] = select i1 [[INDEX_IS_2]], i32 [[VAL1_I2]], i32 [[VAL2_UPTO1]]
 ; DEFAULT-NEXT:    [[INDEX_IS_3:%.*]] = icmp eq i32 [[INDEX]], 3
-; DEFAULT-NEXT:    [[VAL2:%.*]] = select i1 [[INDEX_IS_3]], i32 [[VAL1_I3]], i32 [[VAL2_UPTO2]]
-; DEFAULT-NEXT:    ret i32 [[VAL2]]
+; DEFAULT-NEXT:    [[VAL2_UPTO3:%.*]] = select i1 [[INDEX_IS_3]], i32 [[VAL1_I3]], i32 [[VAL2_UPTO2]]
+; DEFAULT-NEXT:    ret i32 [[VAL2_UPTO3]]
 ;
 ; OFF-LABEL: @f2(
 ; OFF-NEXT:    [[VAL0:%.*]] = load <4 x i32>, <4 x i32>* [[SRC:%.*]], align 16