diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 6aa42fba4eb0..155df1577f45 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -7462,16 +7462,18 @@ static bool getFauxShuffleMask(SDValue N, const APInt &DemandedElts,
     }
 
     // Peek through trunc/aext/zext.
-    // TODO: handle elements smaller than VT.
     // TODO: aext shouldn't require SM_SentinelZero padding.
     // TODO: handle shift of scalars.
+    unsigned MinBitsPerElt = Scl.getScalarValueSizeInBits();
     while (Scl.getOpcode() == ISD::TRUNCATE ||
            Scl.getOpcode() == ISD::ANY_EXTEND ||
            Scl.getOpcode() == ISD::ZERO_EXTEND) {
       Scl = Scl.getOperand(0);
-      if (Scl.getScalarValueSizeInBits() < NumBitsPerElt)
-        return false;
+      if (MinBitsPerElt > Scl.getScalarValueSizeInBits())
+        MinBitsPerElt = Scl.getScalarValueSizeInBits();
     }
+    if ((MinBitsPerElt % 8) != 0)
+      return false;
 
     // Attempt to find the source vector the scalar was extracted from.
     SDValue SrcExtract;
@@ -7486,31 +7488,29 @@ static bool getFauxShuffleMask(SDValue N, const APInt &DemandedElts,
 
     SDValue SrcVec = SrcExtract.getOperand(0);
     EVT SrcVT = SrcVec.getValueType();
-    unsigned NumSrcElts = SrcVT.getVectorNumElements();
-    unsigned NumZeros =
-        std::max<int>((NumBitsPerElt / SrcVT.getScalarSizeInBits()) - 1, 0);
-
-    if ((NumSrcElts % NumElts) != 0)
+    if (!SrcVT.getScalarType().isByteSized())
       return false;
-
     unsigned SrcIdx = SrcExtract.getConstantOperandVal(1);
-    if (NumSrcElts <= SrcIdx)
-      return false;
+    unsigned SrcByte = SrcIdx * (SrcVT.getScalarSizeInBits() / 8);
+    unsigned DstByte = DstIdx * NumBytesPerElt;
 
+    // Create 'identity' byte level shuffle mask and then add inserted bytes.
     if (Opcode == ISD::SCALAR_TO_VECTOR) {
       Ops.push_back(SrcVec);
-      Mask.append(NumSrcElts, SM_SentinelUndef);
+      Mask.append(NumSizeInBytes, SM_SentinelUndef);
     } else {
       Ops.push_back(SrcVec);
       Ops.push_back(N.getOperand(0));
-      for (int i = 0; i != (int)NumSrcElts; ++i)
-        Mask.push_back(NumSrcElts + i);
+      for (int i = 0; i != (int)NumSizeInBytes; ++i)
+        Mask.push_back(NumSizeInBytes + i);
     }
 
-    int Scale = NumSrcElts / NumElts;
-    Mask[Scale * DstIdx] = SrcIdx;
-    for (int i = 0; i != (int)NumZeros; ++i)
-      Mask[(Scale * DstIdx) + i + 1] = SM_SentinelZero;
+    unsigned MinBytesPerElts = MinBitsPerElt / 8;
+    MinBytesPerElts = std::min(MinBytesPerElts, NumBytesPerElt);
+    for (unsigned i = 0; i != MinBytesPerElts; ++i)
+      Mask[DstByte + i] = SrcByte + i;
+    for (unsigned i = MinBytesPerElts; i < NumBytesPerElt; ++i)
+      Mask[DstByte + i] = SM_SentinelZero;
     return true;
   }
   case X86ISD::PACKSS:
diff --git a/llvm/test/CodeGen/X86/buildvec-extract.ll b/llvm/test/CodeGen/X86/buildvec-extract.ll
index 218701250e43..863ab4dee123 100644
--- a/llvm/test/CodeGen/X86/buildvec-extract.ll
+++ b/llvm/test/CodeGen/X86/buildvec-extract.ll
@@ -293,24 +293,19 @@ define <2 x i64> @extract2_i32_zext_insert1_i64_undef(<4 x i32> %x) {
 define <2 x i64> @extract2_i32_zext_insert1_i64_zero(<4 x i32> %x) {
 ; SSE2-LABEL: extract2_i32_zext_insert1_i64_zero:
 ; SSE2:       # %bb.0:
-; SSE2-NEXT:    pshufd {{.*#+}} xmm0 = xmm0[2,3,0,1]
-; SSE2-NEXT:    movd %xmm0, %eax
-; SSE2-NEXT:    movq %rax, %xmm0
-; SSE2-NEXT:    pslldq {{.*#+}} xmm0 = zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1,2,3,4,5,6,7]
+; SSE2-NEXT:    andps {{.*}}(%rip), %xmm0
 ; SSE2-NEXT:    retq
 ;
 ; SSE41-LABEL: extract2_i32_zext_insert1_i64_zero:
 ; SSE41:       # %bb.0:
-; SSE41-NEXT:    extractps $2, %xmm0, %eax
-; SSE41-NEXT:    movq %rax, %xmm0
-; SSE41-NEXT:    pslldq {{.*#+}} xmm0 = zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1,2,3,4,5,6,7]
+; SSE41-NEXT:    xorps %xmm1, %xmm1
+; SSE41-NEXT:    blendps {{.*#+}} xmm0 = xmm1[0,1],xmm0[2],xmm1[3]
 ; SSE41-NEXT:    retq
 ;
 ; AVX-LABEL: extract2_i32_zext_insert1_i64_zero:
 ; AVX:       # %bb.0:
-; AVX-NEXT:    vextractps $2, %xmm0, %eax
-; AVX-NEXT:    vmovq %rax, %xmm0
-; AVX-NEXT:    vpslldq {{.*#+}} xmm0 = zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1,2,3,4,5,6,7]
+; AVX-NEXT:    vxorps %xmm1, %xmm1, %xmm1
+; AVX-NEXT:    vblendps {{.*#+}} xmm0 = xmm1[0,1],xmm0[2],xmm1[3]
 ; AVX-NEXT:    retq
   %e = extractelement <4 x i32> %x, i32 2
   %z = zext i32 %e to i64
@@ -386,16 +381,22 @@ define <2 x i64> @extract0_i16_zext_insert0_i64_undef(<8 x i16> %x) {
 }
 
 define <2 x i64> @extract0_i16_zext_insert0_i64_zero(<8 x i16> %x) {
-; SSE-LABEL: extract0_i16_zext_insert0_i64_zero:
-; SSE:       # %bb.0:
-; SSE-NEXT:    pextrw $0, %xmm0, %eax
-; SSE-NEXT:    movd %eax, %xmm0
-; SSE-NEXT:    retq
+; SSE2-LABEL: extract0_i16_zext_insert0_i64_zero:
+; SSE2:       # %bb.0:
+; SSE2-NEXT:    pextrw $0, %xmm0, %eax
+; SSE2-NEXT:    movd %eax, %xmm0
+; SSE2-NEXT:    retq
+;
+; SSE41-LABEL: extract0_i16_zext_insert0_i64_zero:
+; SSE41:       # %bb.0:
+; SSE41-NEXT:    pxor %xmm1, %xmm1
+; SSE41-NEXT:    pblendw {{.*#+}} xmm0 = xmm0[0],xmm1[1,2,3,4,5,6,7]
+; SSE41-NEXT:    retq
 ;
 ; AVX-LABEL: extract0_i16_zext_insert0_i64_zero:
 ; AVX:       # %bb.0:
-; AVX-NEXT:    vpextrw $0, %xmm0, %eax
-; AVX-NEXT:    vmovd %eax, %xmm0
+; AVX-NEXT:    vpxor %xmm1, %xmm1, %xmm1
+; AVX-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0],xmm1[1,2,3,4,5,6,7]
 ; AVX-NEXT:    retq
   %e = extractelement <8 x i16> %x, i32 0
   %z = zext i16 %e to i64
diff --git a/llvm/test/CodeGen/X86/buildvec-insertvec.ll b/llvm/test/CodeGen/X86/buildvec-insertvec.ll
index 3add65914b58..9fb78491b608 100644
--- a/llvm/test/CodeGen/X86/buildvec-insertvec.ll
+++ b/llvm/test/CodeGen/X86/buildvec-insertvec.ll
@@ -21,10 +21,7 @@ define void @foo(<3 x float> %in, <4 x i8>* nocapture %out) nounwind {
 ; SSE41-LABEL: foo:
 ; SSE41:       # %bb.0:
 ; SSE41-NEXT:    cvttps2dq %xmm0, %xmm0
-; SSE41-NEXT:    pextrb $8, %xmm0, %eax
-; SSE41-NEXT:    pextrb $4, %xmm0, %ecx
-; SSE41-NEXT:    pinsrb $1, %ecx, %xmm0
-; SSE41-NEXT:    pinsrb $2, %eax, %xmm0
+; SSE41-NEXT:    pshufb {{.*#+}} xmm0 = xmm0[0,4,8],zero,xmm0[u,u,u,u,u,u,u,u,u,u,u,u]
 ; SSE41-NEXT:    movl $255, %eax
 ; SSE41-NEXT:    pinsrb $3, %eax, %xmm0
 ; SSE41-NEXT:    movd %xmm0, (%rdi)
diff --git a/llvm/test/CodeGen/X86/extract-concat.ll b/llvm/test/CodeGen/X86/extract-concat.ll
index 085560c1a504..26e07d86bfc3 100644
--- a/llvm/test/CodeGen/X86/extract-concat.ll
+++ b/llvm/test/CodeGen/X86/extract-concat.ll
@@ -24,10 +24,7 @@ define void @foo(<4 x float> %in, <4 x i8>* %out) {
 ; SSE42-LABEL: foo:
 ; SSE42:       # %bb.0:
 ; SSE42-NEXT:    cvttps2dq %xmm0, %xmm0
-; SSE42-NEXT:    pextrb $8, %xmm0, %eax
-; SSE42-NEXT:    pextrb $4, %xmm0, %ecx
-; SSE42-NEXT:    pinsrb $1, %ecx, %xmm0
-; SSE42-NEXT:    pinsrb $2, %eax, %xmm0
+; SSE42-NEXT:    pshufb {{.*#+}} xmm0 = xmm0[0,4,8],zero,xmm0[u,u,u,u,u,u,u,u,u,u,u,u]
 ; SSE42-NEXT:    movl $255, %eax
 ; SSE42-NEXT:    pinsrb $3, %eax, %xmm0
 ; SSE42-NEXT:    movd %xmm0, (%rdi)
@@ -36,10 +33,7 @@ define void @foo(<4 x float> %in, <4 x i8>* %out) {
 ; AVX-LABEL: foo:
 ; AVX:       # %bb.0:
 ; AVX-NEXT:    vcvttps2dq %xmm0, %xmm0
-; AVX-NEXT:    vpextrb $8, %xmm0, %eax
-; AVX-NEXT:    vpextrb $4, %xmm0, %ecx
-; AVX-NEXT:    vpinsrb $1, %ecx, %xmm0, %xmm0
-; AVX-NEXT:    vpinsrb $2, %eax, %xmm0, %xmm0
+; AVX-NEXT:    vpshufb {{.*#+}} xmm0 = xmm0[0,4,8],zero,xmm0[u,u,u,u,u,u,u,u,u,u,u,u]
 ; AVX-NEXT:    movl $255, %eax
 ; AVX-NEXT:    vpinsrb $3, %eax, %xmm0, %xmm0
 ; AVX-NEXT:    vmovd %xmm0, (%rdi)
diff --git a/llvm/test/CodeGen/X86/vector-shuffle-combining.ll b/llvm/test/CodeGen/X86/vector-shuffle-combining.ll
index c80ff1e8ee33..6b42178c6719 100644
--- a/llvm/test/CodeGen/X86/vector-shuffle-combining.ll
+++ b/llvm/test/CodeGen/X86/vector-shuffle-combining.ll
@@ -3028,40 +3028,109 @@ define void @PR43024() {
 }
 
 define void @PR45604(<32 x i16>* %dst, <8 x i16>* %src) {
-; SSE-LABEL: PR45604:
-; SSE:       # %bb.0:
-; SSE-NEXT:    movdqa (%rsi), %xmm1
-; SSE-NEXT:    movd %xmm1, %eax
-; SSE-NEXT:    movzwl %ax, %eax
-; SSE-NEXT:    movd %eax, %xmm0
-; SSE-NEXT:    movl $11, %eax
-; SSE-NEXT:    pinsrw $2, %eax, %xmm0
-; SSE-NEXT:    pextrw $1, %xmm1, %ecx
-; SSE-NEXT:    pinsrw $4, %ecx, %xmm0
-; SSE-NEXT:    pinsrw $6, %eax, %xmm0
-; SSE-NEXT:    pextrw $2, %xmm1, %ecx
-; SSE-NEXT:    movd %ecx, %xmm2
-; SSE-NEXT:    pinsrw $2, %eax, %xmm2
-; SSE-NEXT:    pextrw $3, %xmm1, %ecx
-; SSE-NEXT:    pinsrw $4, %ecx, %xmm2
-; SSE-NEXT:    pinsrw $6, %eax, %xmm2
-; SSE-NEXT:    pextrw $4, %xmm1, %ecx
-; SSE-NEXT:    movd %ecx, %xmm3
-; SSE-NEXT:    pinsrw $2, %eax, %xmm3
-; SSE-NEXT:    pextrw $5, %xmm1, %ecx
-; SSE-NEXT:    pinsrw $4, %ecx, %xmm3
-; SSE-NEXT:    pinsrw $6, %eax, %xmm3
-; SSE-NEXT:    pextrw $6, %xmm1, %ecx
-; SSE-NEXT:    movd %ecx, %xmm4
-; SSE-NEXT:    pinsrw $2, %eax, %xmm4
-; SSE-NEXT:    pextrw $7, %xmm1, %ecx
-; SSE-NEXT:    pinsrw $4, %ecx, %xmm4
-; SSE-NEXT:    pinsrw $6, %eax, %xmm4
-; SSE-NEXT:    movdqa %xmm4, 48(%rdi)
-; SSE-NEXT:    movdqa %xmm3, 32(%rdi)
-; SSE-NEXT:    movdqa %xmm2, 16(%rdi)
-; SSE-NEXT:    movdqa %xmm0, (%rdi)
-; SSE-NEXT:    retq
+; SSE2-LABEL: PR45604:
+; SSE2:       # %bb.0:
+; SSE2-NEXT:    movdqa (%rsi), %xmm1
+; SSE2-NEXT:    movd %xmm1, %eax
+; SSE2-NEXT:    movzwl %ax, %eax
+; SSE2-NEXT:    movd %eax, %xmm0
+; SSE2-NEXT:    movl $11, %eax
+; SSE2-NEXT:    pinsrw $2, %eax, %xmm0
+; SSE2-NEXT:    pextrw $1, %xmm1, %ecx
+; SSE2-NEXT:    pinsrw $4, %ecx, %xmm0
+; SSE2-NEXT:    pinsrw $6, %eax, %xmm0
+; SSE2-NEXT:    pextrw $2, %xmm1, %ecx
+; SSE2-NEXT:    movd %ecx, %xmm2
+; SSE2-NEXT:    pinsrw $2, %eax, %xmm2
+; SSE2-NEXT:    pextrw $3, %xmm1, %ecx
+; SSE2-NEXT:    pinsrw $4, %ecx, %xmm2
+; SSE2-NEXT:    pinsrw $6, %eax, %xmm2
+; SSE2-NEXT:    pextrw $4, %xmm1, %ecx
+; SSE2-NEXT:    movd %ecx, %xmm3
+; SSE2-NEXT:    pinsrw $2, %eax, %xmm3
+; SSE2-NEXT:    pextrw $5, %xmm1, %ecx
+; SSE2-NEXT:    pinsrw $4, %ecx, %xmm3
+; SSE2-NEXT:    pinsrw $6, %eax, %xmm3
+; SSE2-NEXT:    pextrw $6, %xmm1, %ecx
+; SSE2-NEXT:    movd %ecx, %xmm4
+; SSE2-NEXT:    pinsrw $2, %eax, %xmm4
+; SSE2-NEXT:    pextrw $7, %xmm1, %ecx
+; SSE2-NEXT:    pinsrw $4, %ecx, %xmm4
+; SSE2-NEXT:    pinsrw $6, %eax, %xmm4
+; SSE2-NEXT:    movdqa %xmm4, 48(%rdi)
+; SSE2-NEXT:    movdqa %xmm3, 32(%rdi)
+; SSE2-NEXT:    movdqa %xmm2, 16(%rdi)
+; SSE2-NEXT:    movdqa %xmm0, (%rdi)
+; SSE2-NEXT:    retq
+;
+; SSSE3-LABEL: PR45604:
+; SSSE3:       # %bb.0:
+; SSSE3-NEXT:    movdqa (%rsi), %xmm1
+; SSSE3-NEXT:    movd %xmm1, %eax
+; SSSE3-NEXT:    movzwl %ax, %eax
+; SSSE3-NEXT:    movd %eax, %xmm0
+; SSSE3-NEXT:    movl $11, %eax
+; SSSE3-NEXT:    pinsrw $2, %eax, %xmm0
+; SSSE3-NEXT:    pextrw $1, %xmm1, %ecx
+; SSSE3-NEXT:    pinsrw $4, %ecx, %xmm0
+; SSSE3-NEXT:    pinsrw $6, %eax, %xmm0
+; SSSE3-NEXT:    pextrw $2, %xmm1, %ecx
+; SSSE3-NEXT:    movd %ecx, %xmm2
+; SSSE3-NEXT:    pinsrw $2, %eax, %xmm2
+; SSSE3-NEXT:    pextrw $3, %xmm1, %ecx
+; SSSE3-NEXT:    pinsrw $4, %ecx, %xmm2
+; SSSE3-NEXT:    pinsrw $6, %eax, %xmm2
+; SSSE3-NEXT:    pextrw $4, %xmm1, %ecx
+; SSSE3-NEXT:    movd %ecx, %xmm3
+; SSSE3-NEXT:    pinsrw $2, %eax, %xmm3
+; SSSE3-NEXT:    pextrw $5, %xmm1, %ecx
+; SSSE3-NEXT:    pinsrw $4, %ecx, %xmm3
+; SSSE3-NEXT:    pinsrw $6, %eax, %xmm3
+; SSSE3-NEXT:    pextrw $6, %xmm1, %ecx
+; SSSE3-NEXT:    movd %ecx, %xmm4
+; SSSE3-NEXT:    pinsrw $2, %eax, %xmm4
+; SSSE3-NEXT:    pextrw $7, %xmm1, %ecx
+; SSSE3-NEXT:    pinsrw $4, %ecx, %xmm4
+; SSSE3-NEXT:    pinsrw $6, %eax, %xmm4
+; SSSE3-NEXT:    movdqa %xmm4, 48(%rdi)
+; SSSE3-NEXT:    movdqa %xmm3, 32(%rdi)
+; SSSE3-NEXT:    movdqa %xmm2, 16(%rdi)
+; SSSE3-NEXT:    movdqa %xmm0, (%rdi)
+; SSSE3-NEXT:    retq
+;
+; SSE41-LABEL: PR45604:
+; SSE41:       # %bb.0:
+; SSE41-NEXT:    movdqa (%rsi), %xmm1
+; SSE41-NEXT:    pextrw $2, %xmm1, %eax
+; SSE41-NEXT:    movd %eax, %xmm0
+; SSE41-NEXT:    movl $11, %eax
+; SSE41-NEXT:    pinsrw $2, %eax, %xmm0
+; SSE41-NEXT:    pextrw $3, %xmm1, %ecx
+; SSE41-NEXT:    pinsrw $4, %ecx, %xmm0
+; SSE41-NEXT:    pinsrw $6, %eax, %xmm0
+; SSE41-NEXT:    pextrw $4, %xmm1, %ecx
+; SSE41-NEXT:    movd %ecx, %xmm2
+; SSE41-NEXT:    pinsrw $2, %eax, %xmm2
+; SSE41-NEXT:    pextrw $5, %xmm1, %ecx
+; SSE41-NEXT:    pinsrw $4, %ecx, %xmm2
+; SSE41-NEXT:    pinsrw $6, %eax, %xmm2
+; SSE41-NEXT:    pextrw $6, %xmm1, %ecx
+; SSE41-NEXT:    movd %ecx, %xmm3
+; SSE41-NEXT:    pinsrw $2, %eax, %xmm3
+; SSE41-NEXT:    pextrw $7, %xmm1, %ecx
+; SSE41-NEXT:    pinsrw $4, %ecx, %xmm3
+; SSE41-NEXT:    pinsrw $6, %eax, %xmm3
+; SSE41-NEXT:    pxor %xmm4, %xmm4
+; SSE41-NEXT:    pblendw {{.*#+}} xmm4 = xmm1[0],xmm4[1,2,3,4,5,6,7]
+; SSE41-NEXT:    pinsrw $2, %eax, %xmm4
+; SSE41-NEXT:    pextrw $1, %xmm1, %ecx
+; SSE41-NEXT:    pinsrw $4, %ecx, %xmm4
+; SSE41-NEXT:    pinsrw $6, %eax, %xmm4
+; SSE41-NEXT:    movdqa %xmm4, (%rdi)
+; SSE41-NEXT:    movdqa %xmm3, 48(%rdi)
+; SSE41-NEXT:    movdqa %xmm2, 32(%rdi)
+; SSE41-NEXT:    movdqa %xmm0, 16(%rdi)
+; SSE41-NEXT:    retq
 ;
 ; AVX1-LABEL: PR45604:
 ; AVX1:       # %bb.0: