diff --git a/llvm/lib/Target/DirectX/DXILIntrinsicExpansion.cpp b/llvm/lib/Target/DirectX/DXILIntrinsicExpansion.cpp
index d2bfca1fada55..78fb094c9e5d0 100644
--- a/llvm/lib/Target/DirectX/DXILIntrinsicExpansion.cpp
+++ b/llvm/lib/Target/DirectX/DXILIntrinsicExpansion.cpp
@@ -67,10 +67,43 @@ static bool isIntrinsicExpansion(Function &F) {
   case Intrinsic::dx_sign:
   case Intrinsic::dx_step:
   case Intrinsic::dx_radians:
+  case Intrinsic::vector_reduce_add:
+  case Intrinsic::vector_reduce_fadd:
     return true;
   }
   return false;
 }
+static Value *expandVecReduceAdd(CallInst *Orig, Intrinsic::ID IntrinsicId) {
+  assert(IntrinsicId == Intrinsic::vector_reduce_add ||
+         IntrinsicId == Intrinsic::vector_reduce_fadd);
+
+  IRBuilder<> Builder(Orig);
+  bool IsFAdd = (IntrinsicId == Intrinsic::vector_reduce_fadd);
+
+  Value *X = Orig->getOperand(IsFAdd ? 1 : 0);
+  Type *Ty = X->getType();
+  auto *XVec = dyn_cast<FixedVectorType>(Ty);
+  unsigned XVecSize = XVec->getNumElements();
+  Value *Sum = Builder.CreateExtractElement(X, static_cast<uint64_t>(0));
+
+  // Handle the initial start value for floating-point addition.
+  if (IsFAdd) {
+    Constant *StartValue = dyn_cast<Constant>(Orig->getOperand(0));
+    if (StartValue && !StartValue->isZeroValue())
+      Sum = Builder.CreateFAdd(Sum, StartValue);
+  }
+
+  // Accumulate the remaining vector elements.
+  for (unsigned I = 1; I < XVecSize; I++) {
+    Value *Elt = Builder.CreateExtractElement(X, I);
+    if (IsFAdd)
+      Sum = Builder.CreateFAdd(Sum, Elt);
+    else
+      Sum = Builder.CreateAdd(Sum, Elt);
+  }
+
+  return Sum;
+}
 
 static Value *expandAbs(CallInst *Orig) {
   Value *X = Orig->getOperand(0);
@@ -580,6 +613,10 @@ static bool expandIntrinsic(Function &F, CallInst *Orig) {
   case Intrinsic::dx_radians:
     Result = expandRadiansIntrinsic(Orig);
     break;
+  case Intrinsic::vector_reduce_add:
+  case Intrinsic::vector_reduce_fadd:
+    Result = expandVecReduceAdd(Orig, IntrinsicId);
+    break;
   }
   if (Result) {
     Orig->replaceAllUsesWith(Result);
diff --git a/llvm/test/CodeGen/DirectX/vector_reduce_add.ll b/llvm/test/CodeGen/DirectX/vector_reduce_add.ll
new file mode 100644
index 0000000000000..d4ee16a24cb45
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/vector_reduce_add.ll
@@ -0,0 +1,343 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -S  -dxil-intrinsic-expansion  < %s | FileCheck %s
+
+; Make sure dxil operation function calls for lvm.vector.reduce.fadd and lvm.vector.reduce.add are generate.
+
+define noundef half @test_length_half2(<2 x half> noundef %p0) {
+; CHECK-LABEL: define noundef half @test_length_half2(
+; CHECK-SAME: <2 x half> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <2 x half> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <2 x half> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = fadd half [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret half [[TMP2]]
+;
+entry:
+  %rdx.fadd = call half @llvm.vector.reduce.fadd.v2f16(half 0xH0000, <2 x half> %p0)
+  ret half %rdx.fadd
+}
+
+define noundef half @test_length_half2_start1(<2 x half> noundef %p0) {
+; CHECK-LABEL: define noundef half @test_length_half2_start1(
+; CHECK-SAME: <2 x half> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <2 x half> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = fadd half [[TMP0]], 0xH0001
+; CHECK-NEXT:    [[TMP2:%.*]] = extractelement <2 x half> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP3:%.*]] = fadd half [[TMP1]], [[TMP2]]
+; CHECK-NEXT:    ret half [[TMP3]]
+;
+entry:
+  %rdx.fadd = call half @llvm.vector.reduce.fadd.v2f16(half 0xH0001, <2 x half> %p0)
+  ret half %rdx.fadd
+}
+
+define noundef half @test_length_half3(<3 x half> noundef %p0) {
+; CHECK-LABEL: define noundef half @test_length_half3(
+; CHECK-SAME: <3 x half> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <3 x half> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <3 x half> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = fadd half [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[TMP3:%.*]] = extractelement <3 x half> [[P0]], i64 2
+; CHECK-NEXT:    [[TMP4:%.*]] = fadd half [[TMP2]], [[TMP3]]
+; CHECK-NEXT:    ret half [[TMP4]]
+;
+entry:
+  %rdx.fadd = call half @llvm.vector.reduce.fadd.v3f16(half 0xH0000, <3 x half> %p0)
+  ret half %rdx.fadd
+}
+
+define noundef half @test_length_half4(<4 x half> noundef %p0) {
+; CHECK-LABEL: define noundef half @test_length_half4(
+; CHECK-SAME: <4 x half> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <4 x half> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <4 x half> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = fadd half [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[TMP3:%.*]] = extractelement <4 x half> [[P0]], i64 2
+; CHECK-NEXT:    [[TMP4:%.*]] = fadd half [[TMP2]], [[TMP3]]
+; CHECK-NEXT:    [[TMP5:%.*]] = extractelement <4 x half> [[P0]], i64 3
+; CHECK-NEXT:    [[TMP6:%.*]] = fadd half [[TMP4]], [[TMP5]]
+; CHECK-NEXT:    ret half [[TMP6]]
+;
+entry:
+  %rdx.fadd = call half @llvm.vector.reduce.fadd.v4f16(half 0xH0000, <4 x half> %p0)
+  ret half %rdx.fadd
+}
+
+define noundef float @test_length_float2(<2 x float> noundef %p0) {
+; CHECK-LABEL: define noundef float @test_length_float2(
+; CHECK-SAME: <2 x float> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <2 x float> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <2 x float> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = fadd float [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret float [[TMP2]]
+;
+entry:
+  %rdx.fadd = call float @llvm.vector.reduce.fadd.v2f32(float 0.000000e+00, <2 x float> %p0)
+  ret float %rdx.fadd
+}
+
+define noundef float @test_length_float3(<3 x float> noundef %p0) {
+; CHECK-LABEL: define noundef float @test_length_float3(
+; CHECK-SAME: <3 x float> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <3 x float> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <3 x float> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = fadd float [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[TMP3:%.*]] = extractelement <3 x float> [[P0]], i64 2
+; CHECK-NEXT:    [[TMP4:%.*]] = fadd float [[TMP2]], [[TMP3]]
+; CHECK-NEXT:    ret float [[TMP4]]
+;
+entry:
+  %rdx.fadd = call float @llvm.vector.reduce.fadd.v3f32(float 0.000000e+00, <3 x float> %p0)
+  ret float %rdx.fadd
+}
+
+define noundef float @test_length_float3_start1(<3 x float> noundef %p0) {
+; CHECK-LABEL: define noundef float @test_length_float3_start1(
+; CHECK-SAME: <3 x float> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <3 x float> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = fadd float [[TMP0]], 1.000000e+00
+; CHECK-NEXT:    [[TMP2:%.*]] = extractelement <3 x float> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP3:%.*]] = fadd float [[TMP1]], [[TMP2]]
+; CHECK-NEXT:    [[TMP4:%.*]] = extractelement <3 x float> [[P0]], i64 2
+; CHECK-NEXT:    [[TMP5:%.*]] = fadd float [[TMP3]], [[TMP4]]
+; CHECK-NEXT:    ret float [[TMP5]]
+;
+entry:
+  %rdx.fadd = call float @llvm.vector.reduce.fadd.v3f32(float 1.000000e+00, <3 x float> %p0)
+  ret float %rdx.fadd
+}
+
+define noundef float @test_length_float4(<4 x float> noundef %p0) {
+; CHECK-LABEL: define noundef float @test_length_float4(
+; CHECK-SAME: <4 x float> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <4 x float> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <4 x float> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = fadd float [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[TMP3:%.*]] = extractelement <4 x float> [[P0]], i64 2
+; CHECK-NEXT:    [[TMP4:%.*]] = fadd float [[TMP2]], [[TMP3]]
+; CHECK-NEXT:    [[TMP5:%.*]] = extractelement <4 x float> [[P0]], i64 3
+; CHECK-NEXT:    [[TMP6:%.*]] = fadd float [[TMP4]], [[TMP5]]
+; CHECK-NEXT:    ret float [[TMP6]]
+;
+entry:
+  %rdx.fadd = call float @llvm.vector.reduce.fadd.v4f32(float 0.000000e+00, <4 x float> %p0)
+  ret float %rdx.fadd
+}
+
+define noundef double @test_length_double2(<2 x double> noundef %p0) {
+; CHECK-LABEL: define noundef double @test_length_double2(
+; CHECK-SAME: <2 x double> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <2 x double> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <2 x double> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = fadd double [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+entry:
+  %rdx.fadd = call double @llvm.vector.reduce.fadd.v2f64(double 0.000000e+00, <2 x double> %p0)
+  ret double %rdx.fadd
+}
+
+define noundef double @test_length_double3(<3 x double> noundef %p0) {
+; CHECK-LABEL: define noundef double @test_length_double3(
+; CHECK-SAME: <3 x double> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <3 x double> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <3 x double> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = fadd double [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[TMP3:%.*]] = extractelement <3 x double> [[P0]], i64 2
+; CHECK-NEXT:    [[TMP4:%.*]] = fadd double [[TMP2]], [[TMP3]]
+; CHECK-NEXT:    ret double [[TMP4]]
+;
+entry:
+  %rdx.fadd = call double @llvm.vector.reduce.fadd.v3f64(double 0.000000e+00, <3 x double> %p0)
+  ret double %rdx.fadd
+}
+
+define noundef double @test_length_double4(<4 x double> noundef %p0) {
+; CHECK-LABEL: define noundef double @test_length_double4(
+; CHECK-SAME: <4 x double> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <4 x double> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <4 x double> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = fadd double [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[TMP3:%.*]] = extractelement <4 x double> [[P0]], i64 2
+; CHECK-NEXT:    [[TMP4:%.*]] = fadd double [[TMP2]], [[TMP3]]
+; CHECK-NEXT:    [[TMP5:%.*]] = extractelement <4 x double> [[P0]], i64 3
+; CHECK-NEXT:    [[TMP6:%.*]] = fadd double [[TMP4]], [[TMP5]]
+; CHECK-NEXT:    ret double [[TMP6]]
+;
+entry:
+  %rdx.fadd = call double @llvm.vector.reduce.fadd.v4f64(double 0.000000e+00, <4 x double> %p0)
+  ret double %rdx.fadd
+}
+
+define noundef double @test_length_double4_start1(<4 x double> noundef %p0) {
+; CHECK-LABEL: define noundef double @test_length_double4_start1(
+; CHECK-SAME: <4 x double> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <4 x double> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = fadd double [[TMP0]], 1.000000e+00
+; CHECK-NEXT:    [[TMP2:%.*]] = extractelement <4 x double> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP3:%.*]] = fadd double [[TMP1]], [[TMP2]]
+; CHECK-NEXT:    [[TMP4:%.*]] = extractelement <4 x double> [[P0]], i64 2
+; CHECK-NEXT:    [[TMP5:%.*]] = fadd double [[TMP3]], [[TMP4]]
+; CHECK-NEXT:    [[TMP6:%.*]] = extractelement <4 x double> [[P0]], i64 3
+; CHECK-NEXT:    [[TMP7:%.*]] = fadd double [[TMP5]], [[TMP6]]
+; CHECK-NEXT:    ret double [[TMP7]]
+;
+entry:
+  %rdx.fadd = call double @llvm.vector.reduce.fadd.v4f64(double 1.000000e+00, <4 x double> %p0)
+  ret double %rdx.fadd
+}
+
+define noundef i16 @test_length_short2(<2 x i16> noundef %p0) {
+; CHECK-LABEL: define noundef i16 @test_length_short2(
+; CHECK-SAME: <2 x i16> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <2 x i16> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <2 x i16> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = add i16 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret i16 [[TMP2]]
+;
+entry:
+  %rdx.add = call i16 @llvm.vector.reduce.add.v2i16(<2 x i16> %p0)
+  ret i16 %rdx.add
+}
+
+define noundef i16 @test_length_short3(<3 x i16> noundef %p0) {
+; CHECK-LABEL: define noundef i16 @test_length_short3(
+; CHECK-SAME: <3 x i16> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <3 x i16> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <3 x i16> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = add i16 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[TMP3:%.*]] = extractelement <3 x i16> [[P0]], i64 2
+; CHECK-NEXT:    [[TMP4:%.*]] = add i16 [[TMP2]], [[TMP3]]
+; CHECK-NEXT:    ret i16 [[TMP4]]
+;
+entry:
+  %rdx.fadd = call i16 @llvm.vector.reduce.add.v3i16(<3 x i16> %p0)
+  ret i16 %rdx.fadd
+}
+
+define noundef i16 @test_length_short4(<4 x i16> noundef %p0) {
+; CHECK-LABEL: define noundef i16 @test_length_short4(
+; CHECK-SAME: <4 x i16> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <4 x i16> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <4 x i16> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = add i16 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[TMP3:%.*]] = extractelement <4 x i16> [[P0]], i64 2
+; CHECK-NEXT:    [[TMP4:%.*]] = add i16 [[TMP2]], [[TMP3]]
+; CHECK-NEXT:    [[TMP5:%.*]] = extractelement <4 x i16> [[P0]], i64 3
+; CHECK-NEXT:    [[TMP6:%.*]] = add i16 [[TMP4]], [[TMP5]]
+; CHECK-NEXT:    ret i16 [[TMP6]]
+;
+entry:
+  %rdx.fadd = call i16 @llvm.vector.reduce.add.v4i16(<4 x i16> %p0)
+  ret i16 %rdx.fadd
+}
+
+define noundef i32 @test_length_int2(<2 x i32> noundef %p0) {
+; CHECK-LABEL: define noundef i32 @test_length_int2(
+; CHECK-SAME: <2 x i32> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <2 x i32> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <2 x i32> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = add i32 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret i32 [[TMP2]]
+;
+entry:
+  %rdx.add = call i32 @llvm.vector.reduce.add.v2i32(<2 x i32> %p0)
+  ret i32 %rdx.add
+}
+
+define noundef i32 @test_length_int3(<3 x i32> noundef %p0) {
+; CHECK-LABEL: define noundef i32 @test_length_int3(
+; CHECK-SAME: <3 x i32> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <3 x i32> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <3 x i32> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = add i32 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[TMP3:%.*]] = extractelement <3 x i32> [[P0]], i64 2
+; CHECK-NEXT:    [[TMP4:%.*]] = add i32 [[TMP2]], [[TMP3]]
+; CHECK-NEXT:    ret i32 [[TMP4]]
+;
+entry:
+  %rdx.fadd = call i32 @llvm.vector.reduce.add.v3i32(<3 x i32> %p0)
+  ret i32 %rdx.fadd
+}
+
+define noundef i32 @test_length_int4(<4 x i32> noundef %p0) {
+; CHECK-LABEL: define noundef i32 @test_length_int4(
+; CHECK-SAME: <4 x i32> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <4 x i32> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <4 x i32> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = add i32 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[TMP3:%.*]] = extractelement <4 x i32> [[P0]], i64 2
+; CHECK-NEXT:    [[TMP4:%.*]] = add i32 [[TMP2]], [[TMP3]]
+; CHECK-NEXT:    [[TMP5:%.*]] = extractelement <4 x i32> [[P0]], i64 3
+; CHECK-NEXT:    [[TMP6:%.*]] = add i32 [[TMP4]], [[TMP5]]
+; CHECK-NEXT:    ret i32 [[TMP6]]
+;
+entry:
+  %rdx.fadd = call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %p0)
+  ret i32 %rdx.fadd
+}
+
+define noundef i64 @test_length_int64_2(<2 x i64> noundef %p0) {
+; CHECK-LABEL: define noundef i64 @test_length_int64_2(
+; CHECK-SAME: <2 x i64> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <2 x i64> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <2 x i64> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = add i64 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret i64 [[TMP2]]
+;
+entry:
+  %rdx.add = call i64 @llvm.vector.reduce.add.v2i64(<2 x i64> %p0)
+  ret i64 %rdx.add
+}
+
+define noundef i64 @test_length_int64_3(<3 x i64> noundef %p0) {
+; CHECK-LABEL: define noundef i64 @test_length_int64_3(
+; CHECK-SAME: <3 x i64> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <3 x i64> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <3 x i64> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = add i64 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[TMP3:%.*]] = extractelement <3 x i64> [[P0]], i64 2
+; CHECK-NEXT:    [[TMP4:%.*]] = add i64 [[TMP2]], [[TMP3]]
+; CHECK-NEXT:    ret i64 [[TMP4]]
+;
+entry:
+  %rdx.fadd = call i64 @llvm.vector.reduce.add.v3i64(<3 x i64> %p0)
+  ret i64 %rdx.fadd
+}
+
+define noundef i64 @test_length_int64_4(<4 x i64> noundef %p0) {
+; CHECK-LABEL: define noundef i64 @test_length_int64_4(
+; CHECK-SAME: <4 x i64> noundef [[P0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <4 x i64> [[P0]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <4 x i64> [[P0]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = add i64 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[TMP3:%.*]] = extractelement <4 x i64> [[P0]], i64 2
+; CHECK-NEXT:    [[TMP4:%.*]] = add i64 [[TMP2]], [[TMP3]]
+; CHECK-NEXT:    [[TMP5:%.*]] = extractelement <4 x i64> [[P0]], i64 3
+; CHECK-NEXT:    [[TMP6:%.*]] = add i64 [[TMP4]], [[TMP5]]
+; CHECK-NEXT:    ret i64 [[TMP6]]
+;
+entry:
+  %rdx.fadd = call i64 @llvm.vector.reduce.add.v4i64(<4 x i64> %p0)
+  ret i64 %rdx.fadd
+}