diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -3520,10 +3520,11 @@
   // vectors, or at the start and middle of the first vector if it's an unary
   // interleave.
   // In both cases, HalfNumElts will be extracted.
-  // So make sure that EvenSrc/OddSrc are within range.
+  // We need to ensure that the extract indices are 0 or HalfNumElts otherwise
+  // we'll create an illegal extract_subvector.
+  // FIXME: We could support other values using a slidedown first.
   int HalfNumElts = NumElts / 2;
-  return (((EvenSrc % NumElts) + HalfNumElts) <= NumElts) &&
-         (((OddSrc % NumElts) + HalfNumElts) <= NumElts);
+  return ((EvenSrc % HalfNumElts) == 0) && ((OddSrc % HalfNumElts) == 0);
 }
 
 /// Match shuffles that concatenate two vectors, rotate the concatenation,
diff --git a/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-interleave.ll b/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-interleave.ll
--- a/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-interleave.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-interleave.ll
@@ -202,23 +202,28 @@
 define <4 x i32> @interleave_v4i32_offset_1(<4 x i32> %x, <4 x i32> %y) {
 ; V128-LABEL: interleave_v4i32_offset_1:
 ; V128:       # %bb.0:
-; V128-NEXT:    vsetivli zero, 2, e32, m1, ta, ma
-; V128-NEXT:    vslidedown.vi v10, v9, 1
-; V128-NEXT:    vsetivli zero, 2, e32, mf2, ta, ma
-; V128-NEXT:    vwaddu.vv v9, v8, v10
-; V128-NEXT:    li a0, -1
-; V128-NEXT:    vwmaccu.vx v9, a0, v10
-; V128-NEXT:    vmv1r.v v8, v9
+; V128-NEXT:    vsetivli zero, 4, e32, m1, ta, mu
+; V128-NEXT:    vid.v v10
+; V128-NEXT:    vsrl.vi v11, v10, 1
+; V128-NEXT:    vrgather.vv v10, v8, v11
+; V128-NEXT:    li a0, 10
+; V128-NEXT:    vmv.s.x v0, a0
+; V128-NEXT:    vadd.vi v8, v11, 1
+; V128-NEXT:    vrgather.vv v10, v9, v8, v0.t
+; V128-NEXT:    vmv.v.v v8, v10
 ; V128-NEXT:    ret
 ;
 ; V512-LABEL: interleave_v4i32_offset_1:
 ; V512:       # %bb.0:
-; V512-NEXT:    vsetivli zero, 2, e32, mf2, ta, ma
-; V512-NEXT:    vslidedown.vi v10, v9, 1
-; V512-NEXT:    vwaddu.vv v9, v8, v10
-; V512-NEXT:    li a0, -1
-; V512-NEXT:    vwmaccu.vx v9, a0, v10
-; V512-NEXT:    vmv1r.v v8, v9
+; V512-NEXT:    vsetivli zero, 4, e32, mf2, ta, mu
+; V512-NEXT:    vid.v v10
+; V512-NEXT:    vsrl.vi v11, v10, 1
+; V512-NEXT:    vrgather.vv v10, v8, v11
+; V512-NEXT:    li a0, 10
+; V512-NEXT:    vmv.s.x v0, a0
+; V512-NEXT:    vadd.vi v8, v11, 1
+; V512-NEXT:    vrgather.vv v10, v9, v8, v0.t
+; V512-NEXT:    vmv1r.v v8, v10
 ; V512-NEXT:    ret
   %a = shufflevector <4 x i32> %x, <4 x i32> %y, <4 x i32> <i32 0, i32 5, i32 1, i32 6>
   ret <4 x i32> %a
@@ -762,22 +767,19 @@
 define <4 x i8> @unary_interleave_10uu_v4i8(<4 x i8> %x) {
 ; V128-LABEL: unary_interleave_10uu_v4i8:
 ; V128:       # %bb.0:
-; V128-NEXT:    vsetivli zero, 2, e8, mf4, ta, ma
-; V128-NEXT:    vslidedown.vi v10, v8, 1
-; V128-NEXT:    vsetivli zero, 2, e8, mf8, ta, ma
-; V128-NEXT:    vwaddu.vv v9, v10, v8
-; V128-NEXT:    li a0, -1
-; V128-NEXT:    vwmaccu.vx v9, a0, v8
+; V128-NEXT:    vsetivli zero, 4, e8, mf4, ta, ma
+; V128-NEXT:    vid.v v9
+; V128-NEXT:    vrsub.vi v10, v9, 1
+; V128-NEXT:    vrgather.vv v9, v8, v10
 ; V128-NEXT:    vmv1r.v v8, v9
 ; V128-NEXT:    ret
 ;
 ; V512-LABEL: unary_interleave_10uu_v4i8:
 ; V512:       # %bb.0:
-; V512-NEXT:    vsetivli zero, 2, e8, mf8, ta, ma
-; V512-NEXT:    vslidedown.vi v10, v8, 1
-; V512-NEXT:    vwaddu.vv v9, v10, v8
-; V512-NEXT:    li a0, -1
-; V512-NEXT:    vwmaccu.vx v9, a0, v8
+; V512-NEXT:    vsetivli zero, 4, e8, mf8, ta, ma
+; V512-NEXT:    vid.v v9
+; V512-NEXT:    vrsub.vi v10, v9, 1
+; V512-NEXT:    vrgather.vv v9, v8, v10
 ; V512-NEXT:    vmv1r.v v8, v9
 ; V512-NEXT:    ret
   %a = shufflevector <4 x i8> %x, <4 x i8> poison, <4 x i32> <i32 1, i32 0, i32 undef, i32 undef>