diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -12683,7 +12683,8 @@
 /// blends. For vXi8/vXi16 shuffles we may use unpack instead of blend.
 static SDValue lowerShuffleAsDecomposedShuffleMerge(
     const SDLoc &DL, MVT VT, SDValue V1, SDValue V2, ArrayRef<int> Mask,
-    const X86Subtarget &Subtarget, SelectionDAG &DAG) {
+    const X86Subtarget &Subtarget, SelectionDAG &DAG,
+    bool BlendOfIdentitiesOnly = false) {
   int NumElts = Mask.size();
   int NumLanes = VT.getSizeInBits() / 128;
   int NumEltsPerLane = NumElts / NumLanes;
@@ -12739,6 +12740,10 @@
     canonicalizeBroadcastableInput(V2, V2Mask);
   }
 
+  if (BlendOfIdentitiesOnly &&
+      !(isNoopShuffleMask(V1Mask) && isNoopShuffleMask(V2Mask)))
+    return SDValue();
+
   // Try to lower with the simpler initial blend/unpack/rotate strategies unless
   // one of the input shuffles would be a no-op. We prefer to shuffle inputs as
   // the shuffle may be able to fold with a load or other benefit. However, when
@@ -12787,6 +12792,14 @@
   return DAG.getVectorShuffle(VT, DL, V1, V2, FinalMask);
 }
 
+static SDValue lowerShuffleAsBlendOfIdentities(
+    const SDLoc &DL, ArrayRef<int> Mask, const APInt &Zeroable, MVT VT,
+    SDValue V1, SDValue V2, const X86Subtarget &Subtarget, SelectionDAG &DAG) {
+  return lowerShuffleAsDecomposedShuffleMerge(DL, VT, V1, V2, Mask, Subtarget,
+                                              DAG,
+                                              /*BlendOfIdentitiesOnly=*/true);
+}
+
 /// Try to lower a vector shuffle as a bit rotation.
 ///
 /// Look for a repeated rotation pattern in each sub group.
@@ -17222,6 +17235,8 @@
             DL, MVT::v4f64, V1, V2, Mask, Subtarget, DAG))
       return V;
 
+    // FIXME: we should run `lowerShuffleAsBlendOfIdentities()` here.
+
     // Try to permute the lanes and then use a per-lane permute.
     if (SDValue V = lowerShuffleAsLanePermuteAndPermute(DL, MVT::v4f64, V1, V2,
                                                         Mask, DAG, Subtarget))
@@ -17245,6 +17260,12 @@
                                           Zeroable, Subtarget, DAG))
     return Op;
 
+  // See if this shuffle can be represented as a broadcast of 0'th element
+  // of some input, and a blend between said broadcast and an input.
+  if (SDValue Blend = lowerShuffleAsBlendOfIdentities(
+          DL, Mask, Zeroable, MVT::v4f64, V1, V2, Subtarget, DAG))
+    return Blend;
+
   // If we have lane crossing shuffles AND they don't all come from the lower
   // lane elements, lower to SHUFPD(VPERM2F128(V1, V2), VPERM2F128(V1, V2)).
   // TODO: Handle BUILD_VECTOR sources which getVectorShuffle currently
@@ -17367,6 +17388,12 @@
   if (SDValue V = lowerShuffleWithUNPCK(DL, MVT::v4i64, Mask, V1, V2, DAG))
     return V;
 
+  // See if this shuffle can be represented as a broadcast of 0'th element
+  // of some input, and a blend between said broadcast and an input.
+  if (SDValue Blend = lowerShuffleAsBlendOfIdentities(
+          DL, Mask, Zeroable, MVT::v4i64, V1, V2, Subtarget, DAG))
+    return Blend;
+
   // If we have one input in place, then we can permute the other input and
   // blend the result.
   if (isShuffleMaskInputInPlace(0, Mask) || isShuffleMaskInputInPlace(1, Mask))
diff --git a/llvm/test/CodeGen/X86/copy-low-subvec-elt-to-high-subvec-elt.ll b/llvm/test/CodeGen/X86/copy-low-subvec-elt-to-high-subvec-elt.ll
--- a/llvm/test/CodeGen/X86/copy-low-subvec-elt-to-high-subvec-elt.ll
+++ b/llvm/test/CodeGen/X86/copy-low-subvec-elt-to-high-subvec-elt.ll
@@ -151,8 +151,8 @@
 define <4 x double> @vec256_eltty_double_source_subvec_0_target_subvec_mask_2_binary(<4 x double> %x, <4 x double> %y) nounwind {
 ; CHECK-LABEL: vec256_eltty_double_source_subvec_0_target_subvec_mask_2_binary:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    vinsertf128 $1, %xmm1, %ymm0, %ymm1
-; CHECK-NEXT:    vshufpd {{.*#+}} ymm0 = ymm0[0],ymm1[1],ymm0[2],ymm1[2]
+; CHECK-NEXT:    vbroadcastsd %xmm1, %ymm1
+; CHECK-NEXT:    vblendps {{.*#+}} ymm0 = ymm0[0,1,2,3,4,5],ymm1[6,7]
 ; CHECK-NEXT:    retq
   %r = shufflevector <4 x double> %x, <4 x double> %y, <4 x i32> <i32 0, i32 1, i32 2, i32 4>
   ret <4 x double> %r
diff --git a/llvm/test/CodeGen/X86/horizontal-sum.ll b/llvm/test/CodeGen/X86/horizontal-sum.ll
--- a/llvm/test/CodeGen/X86/horizontal-sum.ll
+++ b/llvm/test/CodeGen/X86/horizontal-sum.ll
@@ -273,13 +273,13 @@
 ; AVX2-SLOW-NEXT:    vshufps {{.*#+}} xmm1 = xmm2[1,3],xmm1[1,3]
 ; AVX2-SLOW-NEXT:    vblendps {{.*#+}} xmm1 = xmm1[0,1,2],xmm4[3]
 ; AVX2-SLOW-NEXT:    vaddps %xmm1, %xmm3, %xmm1
-; AVX2-SLOW-NEXT:    vpermilpd {{.*#+}} xmm2 = xmm1[1,0]
-; AVX2-SLOW-NEXT:    vinsertf128 $1, %xmm2, %ymm0, %ymm0
-; AVX2-SLOW-NEXT:    vmovddup {{.*#+}} xmm1 = xmm1[0,0]
-; AVX2-SLOW-NEXT:    vhaddps %xmm7, %xmm6, %xmm2
-; AVX2-SLOW-NEXT:    vhaddps %xmm2, %xmm2, %xmm2
-; AVX2-SLOW-NEXT:    vinsertf128 $1, %xmm2, %ymm1, %ymm1
-; AVX2-SLOW-NEXT:    vshufpd {{.*#+}} ymm0 = ymm0[0],ymm1[1],ymm0[2],ymm1[2]
+; AVX2-SLOW-NEXT:    vmovlhps {{.*#+}} xmm0 = xmm0[0],xmm1[0]
+; AVX2-SLOW-NEXT:    vpermilpd {{.*#+}} xmm1 = xmm1[1,0]
+; AVX2-SLOW-NEXT:    vinsertf128 $1, %xmm1, %ymm0, %ymm0
+; AVX2-SLOW-NEXT:    vhaddps %xmm7, %xmm6, %xmm1
+; AVX2-SLOW-NEXT:    vhaddps %xmm1, %xmm1, %xmm1
+; AVX2-SLOW-NEXT:    vbroadcastsd %xmm1, %ymm1
+; AVX2-SLOW-NEXT:    vblendps {{.*#+}} ymm0 = ymm0[0,1,2,3,4,5],ymm1[6,7]
 ; AVX2-SLOW-NEXT:    retq
 ;
 ; AVX2-FAST-LABEL: pair_sum_v8f32_v4f32:
@@ -294,13 +294,13 @@
 ; AVX2-FAST-NEXT:    vshufps {{.*#+}} xmm1 = xmm2[1,3],xmm1[1,3]
 ; AVX2-FAST-NEXT:    vblendps {{.*#+}} xmm1 = xmm1[0,1,2],xmm4[3]
 ; AVX2-FAST-NEXT:    vaddps %xmm1, %xmm3, %xmm1
-; AVX2-FAST-NEXT:    vpermilpd {{.*#+}} xmm2 = xmm1[1,0]
-; AVX2-FAST-NEXT:    vinsertf128 $1, %xmm2, %ymm0, %ymm0
-; AVX2-FAST-NEXT:    vmovddup {{.*#+}} xmm1 = xmm1[0,0]
-; AVX2-FAST-NEXT:    vhaddps %xmm7, %xmm6, %xmm2
-; AVX2-FAST-NEXT:    vhaddps %xmm0, %xmm2, %xmm2
-; AVX2-FAST-NEXT:    vinsertf128 $1, %xmm2, %ymm1, %ymm1
-; AVX2-FAST-NEXT:    vshufpd {{.*#+}} ymm0 = ymm0[0],ymm1[1],ymm0[2],ymm1[2]
+; AVX2-FAST-NEXT:    vmovlhps {{.*#+}} xmm0 = xmm0[0],xmm1[0]
+; AVX2-FAST-NEXT:    vpermilpd {{.*#+}} xmm1 = xmm1[1,0]
+; AVX2-FAST-NEXT:    vinsertf128 $1, %xmm1, %ymm0, %ymm0
+; AVX2-FAST-NEXT:    vhaddps %xmm7, %xmm6, %xmm1
+; AVX2-FAST-NEXT:    vhaddps %xmm0, %xmm1, %xmm1
+; AVX2-FAST-NEXT:    vbroadcastsd %xmm1, %ymm1
+; AVX2-FAST-NEXT:    vblendps {{.*#+}} ymm0 = ymm0[0,1,2,3,4,5],ymm1[6,7]
 ; AVX2-FAST-NEXT:    retq
   %9 = shufflevector <4 x float> %0, <4 x float> poison, <2 x i32> <i32 0, i32 2>
   %10 = shufflevector <4 x float> %0, <4 x float> poison, <2 x i32> <i32 1, i32 3>
diff --git a/llvm/test/CodeGen/X86/subvector-broadcast.ll b/llvm/test/CodeGen/X86/subvector-broadcast.ll
--- a/llvm/test/CodeGen/X86/subvector-broadcast.ll
+++ b/llvm/test/CodeGen/X86/subvector-broadcast.ll
@@ -1677,18 +1677,44 @@
 }
 
 define <8 x float> @broadcast_v8f32_v2f32_u1uu0uEu(<2 x float>* %vp, <8 x float> %default) {
-; X86-LABEL: broadcast_v8f32_v2f32_u1uu0uEu:
-; X86:       # %bb.0:
-; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT:    vbroadcastsd (%eax), %ymm1
-; X86-NEXT:    vshufpd {{.*#+}} ymm0 = ymm1[0],ymm0[0],ymm1[2],ymm0[3]
-; X86-NEXT:    retl
+; X86-AVX1-LABEL: broadcast_v8f32_v2f32_u1uu0uEu:
+; X86-AVX1:       # %bb.0:
+; X86-AVX1-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-AVX1-NEXT:    vbroadcastsd (%eax), %ymm1
+; X86-AVX1-NEXT:    vshufpd {{.*#+}} ymm0 = ymm1[0],ymm0[0],ymm1[2],ymm0[3]
+; X86-AVX1-NEXT:    retl
 ;
-; X64-LABEL: broadcast_v8f32_v2f32_u1uu0uEu:
-; X64:       # %bb.0:
-; X64-NEXT:    vbroadcastsd (%rdi), %ymm1
-; X64-NEXT:    vshufpd {{.*#+}} ymm0 = ymm1[0],ymm0[0],ymm1[2],ymm0[3]
-; X64-NEXT:    retq
+; X86-AVX2-LABEL: broadcast_v8f32_v2f32_u1uu0uEu:
+; X86-AVX2:       # %bb.0:
+; X86-AVX2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-AVX2-NEXT:    vbroadcastsd (%eax), %ymm1
+; X86-AVX2-NEXT:    vunpckhpd {{.*#+}} ymm0 = ymm1[1],ymm0[1],ymm1[3],ymm0[3]
+; X86-AVX2-NEXT:    retl
+;
+; X86-AVX512-LABEL: broadcast_v8f32_v2f32_u1uu0uEu:
+; X86-AVX512:       # %bb.0:
+; X86-AVX512-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-AVX512-NEXT:    vbroadcastsd (%eax), %ymm1
+; X86-AVX512-NEXT:    vunpckhpd {{.*#+}} ymm0 = ymm1[1],ymm0[1],ymm1[3],ymm0[3]
+; X86-AVX512-NEXT:    retl
+;
+; X64-AVX1-LABEL: broadcast_v8f32_v2f32_u1uu0uEu:
+; X64-AVX1:       # %bb.0:
+; X64-AVX1-NEXT:    vbroadcastsd (%rdi), %ymm1
+; X64-AVX1-NEXT:    vshufpd {{.*#+}} ymm0 = ymm1[0],ymm0[0],ymm1[2],ymm0[3]
+; X64-AVX1-NEXT:    retq
+;
+; X64-AVX2-LABEL: broadcast_v8f32_v2f32_u1uu0uEu:
+; X64-AVX2:       # %bb.0:
+; X64-AVX2-NEXT:    vbroadcastsd (%rdi), %ymm1
+; X64-AVX2-NEXT:    vunpckhpd {{.*#+}} ymm0 = ymm1[1],ymm0[1],ymm1[3],ymm0[3]
+; X64-AVX2-NEXT:    retq
+;
+; X64-AVX512-LABEL: broadcast_v8f32_v2f32_u1uu0uEu:
+; X64-AVX512:       # %bb.0:
+; X64-AVX512-NEXT:    vbroadcastsd (%rdi), %ymm1
+; X64-AVX512-NEXT:    vunpckhpd {{.*#+}} ymm0 = ymm1[1],ymm0[1],ymm1[3],ymm0[3]
+; X64-AVX512-NEXT:    retq
   %vec = load <2 x float>, <2 x float>* %vp
   %shuf = shufflevector <2 x float> %vec, <2 x float> undef, <8 x i32> <i32 undef, i32 1, i32 undef, i32 undef, i32 0, i32 2, i32 3, i32 undef>
   %res = select <8 x i1> <i1 1, i1 1, i1 1, i1 1, i1 1, i1 1, i1 0, i1 1>, <8 x float> %shuf, <8 x float> %default
diff --git a/llvm/test/CodeGen/X86/vector-shuffle-256-v4.ll b/llvm/test/CodeGen/X86/vector-shuffle-256-v4.ll
--- a/llvm/test/CodeGen/X86/vector-shuffle-256-v4.ll
+++ b/llvm/test/CodeGen/X86/vector-shuffle-256-v4.ll
@@ -701,27 +701,16 @@
 ;
 ; AVX2-LABEL: shuffle_v4f64_0044:
 ; AVX2:       # %bb.0:
-; AVX2-NEXT:    vmovlhps {{.*#+}} xmm0 = xmm0[0],xmm1[0]
-; AVX2-NEXT:    vpermpd {{.*#+}} ymm0 = ymm0[0,0,1,1]
+; AVX2-NEXT:    vmovddup {{.*#+}} xmm0 = xmm0[0,0]
+; AVX2-NEXT:    vbroadcastsd %xmm1, %ymm1
+; AVX2-NEXT:    vblendps {{.*#+}} ymm0 = ymm0[0,1,2,3],ymm1[4,5,6,7]
 ; AVX2-NEXT:    retq
 ;
-; AVX512VL-SLOW-LABEL: shuffle_v4f64_0044:
-; AVX512VL-SLOW:       # %bb.0:
-; AVX512VL-SLOW-NEXT:    vmovlhps {{.*#+}} xmm0 = xmm0[0],xmm1[0]
-; AVX512VL-SLOW-NEXT:    vpermpd {{.*#+}} ymm0 = ymm0[0,0,1,1]
-; AVX512VL-SLOW-NEXT:    retq
-;
-; AVX512VL-FAST-ALL-LABEL: shuffle_v4f64_0044:
-; AVX512VL-FAST-ALL:       # %bb.0:
-; AVX512VL-FAST-ALL-NEXT:    vmovapd {{.*#+}} ymm2 = [0,0,4,4]
-; AVX512VL-FAST-ALL-NEXT:    vpermt2pd %ymm1, %ymm2, %ymm0
-; AVX512VL-FAST-ALL-NEXT:    retq
-;
-; AVX512VL-FAST-PERLANE-LABEL: shuffle_v4f64_0044:
-; AVX512VL-FAST-PERLANE:       # %bb.0:
-; AVX512VL-FAST-PERLANE-NEXT:    vmovlhps {{.*#+}} xmm0 = xmm0[0],xmm1[0]
-; AVX512VL-FAST-PERLANE-NEXT:    vpermpd {{.*#+}} ymm0 = ymm0[0,0,1,1]
-; AVX512VL-FAST-PERLANE-NEXT:    retq
+; AVX512VL-LABEL: shuffle_v4f64_0044:
+; AVX512VL:       # %bb.0:
+; AVX512VL-NEXT:    vmovapd {{.*#+}} ymm2 = [0,0,4,4]
+; AVX512VL-NEXT:    vpermt2pd %ymm1, %ymm2, %ymm0
+; AVX512VL-NEXT:    retq
   %1 = shufflevector <4 x double> %a, <4 x double> %b, <4 x i32> <i32 0, i32 0, i32 4, i32 4>
   ret <4 x double> %1
 }
diff --git a/llvm/test/CodeGen/X86/vector-shuffle-combining-avx.ll b/llvm/test/CodeGen/X86/vector-shuffle-combining-avx.ll
--- a/llvm/test/CodeGen/X86/vector-shuffle-combining-avx.ll
+++ b/llvm/test/CodeGen/X86/vector-shuffle-combining-avx.ll
@@ -468,11 +468,11 @@
 ; X86-AVX2-NEXT:    movl {{[0-9]+}}(%esp), %eax
 ; X86-AVX2-NEXT:    movl {{[0-9]+}}(%esp), %ecx
 ; X86-AVX2-NEXT:    movl {{[0-9]+}}(%esp), %edx
-; X86-AVX2-NEXT:    vinsertf128 $1, %xmm1, %ymm0, %ymm3
+; X86-AVX2-NEXT:    vbroadcastsd %xmm1, %ymm3
 ; X86-AVX2-NEXT:    vperm2f128 {{.*#+}} ymm4 = ymm1[2,3],ymm2[0,1]
 ; X86-AVX2-NEXT:    vpermilpd {{.*#+}} xmm5 = xmm1[1,0]
 ; X86-AVX2-NEXT:    vperm2f128 {{.*#+}} ymm6 = ymm0[0,1],ymm2[0,1]
-; X86-AVX2-NEXT:    vpermpd {{.*#+}} ymm3 = ymm3[0,2,2,1]
+; X86-AVX2-NEXT:    vperm2f128 {{.*#+}} ymm3 = ymm3[2,3],ymm0[0,1]
 ; X86-AVX2-NEXT:    vblendpd {{.*#+}} ymm3 = ymm6[0],ymm3[1],ymm6[2],ymm3[3]
 ; X86-AVX2-NEXT:    vmovapd %ymm3, (%edx)
 ; X86-AVX2-NEXT:    vblendpd {{.*#+}} ymm3 = ymm5[0,1],ymm0[2],ymm5[3]
@@ -495,8 +495,8 @@
 ; X86-AVX512-NEXT:    movl {{[0-9]+}}(%esp), %eax
 ; X86-AVX512-NEXT:    movl {{[0-9]+}}(%esp), %ecx
 ; X86-AVX512-NEXT:    movl {{[0-9]+}}(%esp), %edx
-; X86-AVX512-NEXT:    vinsertf128 $1, %xmm1, %ymm0, %ymm3
-; X86-AVX512-NEXT:    vshufpd {{.*#+}} ymm3 = ymm0[0],ymm3[1],ymm0[2],ymm3[2]
+; X86-AVX512-NEXT:    vbroadcastsd %xmm1, %ymm3
+; X86-AVX512-NEXT:    vblendpd {{.*#+}} ymm3 = ymm0[0,1,2],ymm3[3]
 ; X86-AVX512-NEXT:    vperm2f128 {{.*#+}} ymm4 = ymm1[2,3],ymm2[0,1]
 ; X86-AVX512-NEXT:    vshufpd {{.*#+}} ymm4 = ymm1[1],ymm4[0],ymm1[2],ymm4[3]
 ; X86-AVX512-NEXT:    vmovapd {{.*#+}} ymm5 = [0,0,3,0,8,0,1,0]
@@ -538,11 +538,11 @@
 ;
 ; X64-AVX2-LABEL: PR48908:
 ; X64-AVX2:       # %bb.0:
-; X64-AVX2-NEXT:    vinsertf128 $1, %xmm1, %ymm0, %ymm3
+; X64-AVX2-NEXT:    vbroadcastsd %xmm1, %ymm3
 ; X64-AVX2-NEXT:    vperm2f128 {{.*#+}} ymm4 = ymm1[2,3],ymm2[0,1]
 ; X64-AVX2-NEXT:    vpermilpd {{.*#+}} xmm5 = xmm1[1,0]
 ; X64-AVX2-NEXT:    vperm2f128 {{.*#+}} ymm6 = ymm0[0,1],ymm2[0,1]
-; X64-AVX2-NEXT:    vpermpd {{.*#+}} ymm3 = ymm3[0,2,2,1]
+; X64-AVX2-NEXT:    vperm2f128 {{.*#+}} ymm3 = ymm3[2,3],ymm0[0,1]
 ; X64-AVX2-NEXT:    vblendpd {{.*#+}} ymm3 = ymm6[0],ymm3[1],ymm6[2],ymm3[3]
 ; X64-AVX2-NEXT:    vmovapd %ymm3, (%rdi)
 ; X64-AVX2-NEXT:    vblendpd {{.*#+}} ymm3 = ymm5[0,1],ymm0[2],ymm5[3]
@@ -562,8 +562,8 @@
 ; X64-AVX512-NEXT:    # kill: def $ymm2 killed $ymm2 def $zmm2
 ; X64-AVX512-NEXT:    # kill: def $ymm1 killed $ymm1 def $zmm1
 ; X64-AVX512-NEXT:    # kill: def $ymm0 killed $ymm0 def $zmm0
-; X64-AVX512-NEXT:    vinsertf128 $1, %xmm1, %ymm0, %ymm3
-; X64-AVX512-NEXT:    vshufpd {{.*#+}} ymm3 = ymm0[0],ymm3[1],ymm0[2],ymm3[2]
+; X64-AVX512-NEXT:    vbroadcastsd %xmm1, %ymm3
+; X64-AVX512-NEXT:    vblendpd {{.*#+}} ymm3 = ymm0[0,1,2],ymm3[3]
 ; X64-AVX512-NEXT:    vperm2f128 {{.*#+}} ymm4 = ymm1[2,3],ymm2[0,1]
 ; X64-AVX512-NEXT:    vshufpd {{.*#+}} ymm4 = ymm1[1],ymm4[0],ymm1[2],ymm4[3]
 ; X64-AVX512-NEXT:    vmovapd {{.*#+}} ymm5 = [0,3,8,1]