diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2638,10 +2638,19 @@
 
 SDValue SelectionDAG::getSplatValue(SDValue V) {
   int SplatIdx;
-  if (SDValue SrcVector = getSplatSourceVector(V, SplatIdx))
-    return getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(V),
-                   SrcVector.getValueType().getScalarType(), SrcVector,
+  if (SDValue SrcVector = getSplatSourceVector(V, SplatIdx)) {
+    EVT SVT = SrcVector.getValueType().getScalarType();
+    EVT LegalSVT = SVT;
+    if (NewNodesMustHaveLegalTypes && !TLI->isTypeLegal(SVT)) {
+      if (!SVT.isInteger())
+        return SDValue();
+      LegalSVT = TLI->getTypeToTransformTo(*getContext(), LegalSVT);
+      if (LegalSVT.bitsLT(SVT))
+        return SDValue();
+    }
+    return getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(V), LegalSVT, SrcVector,
                    getVectorIdxConstant(SplatIdx, SDLoc(V)));
+  }
   return SDValue();
 }
 
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
@@ -28090,6 +28090,17 @@
   return SDValue();
 }
 
+// A version of SelectionDAG::getSplatValue which may return illegal types,
+// even after type legalization.
+static SDValue getSplatValue(SDValue V, SelectionDAG &DAG) {
+  int SplatIdx;
+  if (SDValue SrcVector = DAG.getSplatSourceVector(V, SplatIdx))
+    return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(V),
+                       SrcVector.getValueType().getScalarType(), SrcVector,
+                       DAG.getVectorIdxConstant(SplatIdx, SDLoc(V)));
+  return SDValue();
+}
+
 static SDValue LowerScalarVariableShift(SDValue Op, SelectionDAG &DAG,
                                         const X86Subtarget &Subtarget) {
   MVT VT = Op.getSimpleValueType();
@@ -28100,7 +28111,7 @@
   unsigned X86OpcI = getTargetVShiftUniformOpcode(Opcode, false);
   unsigned X86OpcV = getTargetVShiftUniformOpcode(Opcode, true);
 
-  if (SDValue BaseShAmt = DAG.getSplatValue(Amt)) {
+  if (SDValue BaseShAmt = getSplatValue(Amt, DAG)) {
     if (SupportedVectorShiftWithBaseAmnt(VT, Subtarget, Opcode)) {
       MVT EltVT = VT.getVectorElementType();
       assert(EltVT.bitsLE(MVT::i64) && "Unexpected element type!");
diff --git a/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-shuffles.ll b/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-shuffles.ll
--- a/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-shuffles.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-shuffles.ll
@@ -347,3 +347,29 @@
   %s = shufflevector <8 x i64> %x, <8 x i64> <i64 5, i64 5, i64 5, i64 5, i64 5, i64 5, i64 5, i64 5>, <8 x i32> <i32 0, i32 3, i32 10, i32 9, i32 4, i32 1, i32 7, i32 14>
   ret <8 x i64> %s
 }
+
+define <4 x i8> @interleave_shuffles(<4 x i8> %x) {
+; CHECK-LABEL: interleave_shuffles:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    vsetvli zero, zero, e8,mf4,ta,mu
+; CHECK-NEXT:    vmv.x.s a0, v8
+; CHECK-NEXT:    vsetivli a1, 4, e8,mf4,ta,mu
+; CHECK-NEXT:    vrgather.vi v25, v8, 1
+; CHECK-NEXT:    addi a1, zero, 1
+; CHECK-NEXT:    vmv.s.x v26, a1
+; CHECK-NEXT:    vmv.v.i v27, 0
+; CHECK-NEXT:    vsetivli a1, 4, e8,mf4,tu,mu
+; CHECK-NEXT:    vslideup.vi v27, v26, 3
+; CHECK-NEXT:    addi a1, zero, 10
+; CHECK-NEXT:    vsetivli a2, 1, e8,mf8,ta,mu
+; CHECK-NEXT:    vmv.s.x v0, a1
+; CHECK-NEXT:    vsetivli a1, 4, e8,mf4,ta,mu
+; CHECK-NEXT:    vmv.v.x v8, a0
+; CHECK-NEXT:    vsetivli a0, 4, e8,mf4,tu,mu
+; CHECK-NEXT:    vrgather.vv v8, v25, v27, v0.t
+; CHECK-NEXT:    ret
+  %y = shufflevector <4 x i8> %x, <4 x i8> undef, <4 x i32> <i32 0, i32 0, i32 0, i32 0>
+  %z = shufflevector <4 x i8> %x, <4 x i8> undef, <4 x i32> <i32 1, i32 1, i32 1, i32 1>
+  %w = shufflevector <4 x i8> %y, <4 x i8> %z, <4 x i32> <i32 0, i32 4, i32 1, i32 5>
+  ret <4 x i8> %w
+}