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
@@ -791,6 +791,7 @@
         setOperationAction(ISD::EXTRACT_SUBVECTOR, VT, Custom);
 
         setOperationAction(ISD::BUILD_VECTOR, VT, Custom);
+        setOperationAction(ISD::CONCAT_VECTORS, VT, Custom);
         setOperationAction(ISD::VECTOR_SHUFFLE, VT, Custom);
         setOperationAction(ISD::INSERT_VECTOR_ELT, VT, Custom);
         setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT, Custom);
diff --git a/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-fp-conv.ll b/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-fp-conv.ll
--- a/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-fp-conv.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-fp-conv.ll
@@ -157,24 +157,22 @@
 ;
 ; LMULMAX1-LABEL: fpround_v8f32_v8f16:
 ; LMULMAX1:       # %bb.0:
-; LMULMAX1-NEXT:    addi sp, sp, -32
-; LMULMAX1-NEXT:    .cfi_def_cfa_offset 32
 ; LMULMAX1-NEXT:    vsetivli zero, 4, e32, m1, ta, mu
-; LMULMAX1-NEXT:    addi a2, a0, 16
-; LMULMAX1-NEXT:    vle32.v v25, (a2)
+; LMULMAX1-NEXT:    vle32.v v25, (a0)
+; LMULMAX1-NEXT:    addi a0, a0, 16
 ; LMULMAX1-NEXT:    vle32.v v26, (a0)
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e16, mf2, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.f.w v27, v25
-; LMULMAX1-NEXT:    addi a0, sp, 24
-; LMULMAX1-NEXT:    vse16.v v27, (a0)
-; LMULMAX1-NEXT:    vfncvt.f.f.w v25, v26
-; LMULMAX1-NEXT:    addi a0, sp, 16
-; LMULMAX1-NEXT:    vse16.v v25, (a0)
 ; LMULMAX1-NEXT:    vsetivli zero, 8, e16, m1, ta, mu
-; LMULMAX1-NEXT:    addi a0, sp, 16
-; LMULMAX1-NEXT:    vle16.v v25, (a0)
+; LMULMAX1-NEXT:    vmv.v.i v25, 0
+; LMULMAX1-NEXT:    vsetivli zero, 4, e16, m1, tu, mu
+; LMULMAX1-NEXT:    vslideup.vi v25, v27, 0
+; LMULMAX1-NEXT:    vsetivli zero, 4, e16, mf2, ta, mu
+; LMULMAX1-NEXT:    vfncvt.f.f.w v27, v26
+; LMULMAX1-NEXT:    vsetivli zero, 8, e16, m1, tu, mu
+; LMULMAX1-NEXT:    vslideup.vi v25, v27, 4
+; LMULMAX1-NEXT:    vsetvli zero, zero, e16, m1, ta, mu
 ; LMULMAX1-NEXT:    vse16.v v25, (a1)
-; LMULMAX1-NEXT:    addi sp, sp, 32
 ; LMULMAX1-NEXT:    ret
   %a = load <8 x float>, <8 x float>* %x
   %d = fptrunc <8 x float> %a to <8 x half>
@@ -196,45 +194,42 @@
 ;
 ; LMULMAX1-LABEL: fpround_v8f64_v8f16:
 ; LMULMAX1:       # %bb.0:
-; LMULMAX1-NEXT:    addi sp, sp, -32
-; LMULMAX1-NEXT:    .cfi_def_cfa_offset 32
+; LMULMAX1-NEXT:    addi a2, a0, 48
 ; LMULMAX1-NEXT:    vsetivli zero, 2, e64, m1, ta, mu
-; LMULMAX1-NEXT:    vle64.v v25, (a0)
-; LMULMAX1-NEXT:    addi a2, a0, 16
+; LMULMAX1-NEXT:    vle64.v v25, (a2)
+; LMULMAX1-NEXT:    addi a2, a0, 32
 ; LMULMAX1-NEXT:    vle64.v v26, (a2)
-; LMULMAX1-NEXT:    addi a2, a0, 48
-; LMULMAX1-NEXT:    vle64.v v27, (a2)
-; LMULMAX1-NEXT:    addi a0, a0, 32
+; LMULMAX1-NEXT:    vle64.v v27, (a0)
+; LMULMAX1-NEXT:    addi a0, a0, 16
 ; LMULMAX1-NEXT:    vle64.v v28, (a0)
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e32, mf2, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.rod.f.f.w v29, v27
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e16, mf4, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.f.w v27, v29
-; LMULMAX1-NEXT:    addi a0, sp, 28
-; LMULMAX1-NEXT:    vse16.v v27, (a0)
-; LMULMAX1-NEXT:    vsetvli zero, zero, e32, mf2, ta, mu
+; LMULMAX1-NEXT:    vsetivli zero, 8, e16, m1, ta, mu
+; LMULMAX1-NEXT:    vmv.v.i v29, 0
+; LMULMAX1-NEXT:    vsetivli zero, 2, e16, m1, tu, mu
+; LMULMAX1-NEXT:    vslideup.vi v29, v27, 0
+; LMULMAX1-NEXT:    vsetivli zero, 2, e32, mf2, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.rod.f.f.w v27, v28
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e16, mf4, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.f.w v28, v27
-; LMULMAX1-NEXT:    addi a0, sp, 24
-; LMULMAX1-NEXT:    vse16.v v28, (a0)
-; LMULMAX1-NEXT:    vsetvli zero, zero, e32, mf2, ta, mu
+; LMULMAX1-NEXT:    vsetivli zero, 4, e16, m1, tu, mu
+; LMULMAX1-NEXT:    vslideup.vi v29, v28, 2
+; LMULMAX1-NEXT:    vsetivli zero, 2, e32, mf2, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.rod.f.f.w v27, v26
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e16, mf4, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.f.w v26, v27
-; LMULMAX1-NEXT:    addi a0, sp, 20
-; LMULMAX1-NEXT:    vse16.v v26, (a0)
-; LMULMAX1-NEXT:    vsetvli zero, zero, e32, mf2, ta, mu
+; LMULMAX1-NEXT:    vsetivli zero, 6, e16, m1, tu, mu
+; LMULMAX1-NEXT:    vslideup.vi v29, v26, 4
+; LMULMAX1-NEXT:    vsetivli zero, 2, e32, mf2, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.rod.f.f.w v26, v25
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e16, mf4, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.f.w v25, v26
-; LMULMAX1-NEXT:    addi a0, sp, 16
-; LMULMAX1-NEXT:    vse16.v v25, (a0)
-; LMULMAX1-NEXT:    vsetivli zero, 8, e16, m1, ta, mu
-; LMULMAX1-NEXT:    addi a0, sp, 16
-; LMULMAX1-NEXT:    vle16.v v25, (a0)
-; LMULMAX1-NEXT:    vse16.v v25, (a1)
-; LMULMAX1-NEXT:    addi sp, sp, 32
+; LMULMAX1-NEXT:    vsetivli zero, 8, e16, m1, tu, mu
+; LMULMAX1-NEXT:    vslideup.vi v29, v25, 6
+; LMULMAX1-NEXT:    vsetvli zero, zero, e16, m1, ta, mu
+; LMULMAX1-NEXT:    vse16.v v29, (a1)
 ; LMULMAX1-NEXT:    ret
   %a = load <8 x double>, <8 x double>* %x
   %d = fptrunc <8 x double> %a to <8 x half>
diff --git a/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-i2fp.ll b/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-i2fp.ll
--- a/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-i2fp.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-i2fp.ll
@@ -466,45 +466,42 @@
 ;
 ; LMULMAX1-LABEL: si2fp_v8i64_v8f16:
 ; LMULMAX1:       # %bb.0:
-; LMULMAX1-NEXT:    addi sp, sp, -32
-; LMULMAX1-NEXT:    .cfi_def_cfa_offset 32
+; LMULMAX1-NEXT:    addi a2, a0, 48
 ; LMULMAX1-NEXT:    vsetivli zero, 2, e64, m1, ta, mu
-; LMULMAX1-NEXT:    vle64.v v25, (a0)
-; LMULMAX1-NEXT:    addi a2, a0, 16
+; LMULMAX1-NEXT:    vle64.v v25, (a2)
+; LMULMAX1-NEXT:    addi a2, a0, 32
 ; LMULMAX1-NEXT:    vle64.v v26, (a2)
-; LMULMAX1-NEXT:    addi a2, a0, 48
-; LMULMAX1-NEXT:    vle64.v v27, (a2)
-; LMULMAX1-NEXT:    addi a0, a0, 32
+; LMULMAX1-NEXT:    vle64.v v27, (a0)
+; LMULMAX1-NEXT:    addi a0, a0, 16
 ; LMULMAX1-NEXT:    vle64.v v28, (a0)
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e32, mf2, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.x.w v29, v27
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e16, mf4, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.f.w v27, v29
-; LMULMAX1-NEXT:    addi a0, sp, 28
-; LMULMAX1-NEXT:    vse16.v v27, (a0)
-; LMULMAX1-NEXT:    vsetvli zero, zero, e32, mf2, ta, mu
+; LMULMAX1-NEXT:    vsetivli zero, 8, e16, m1, ta, mu
+; LMULMAX1-NEXT:    vmv.v.i v29, 0
+; LMULMAX1-NEXT:    vsetivli zero, 2, e16, m1, tu, mu
+; LMULMAX1-NEXT:    vslideup.vi v29, v27, 0
+; LMULMAX1-NEXT:    vsetivli zero, 2, e32, mf2, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.x.w v27, v28
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e16, mf4, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.f.w v28, v27
-; LMULMAX1-NEXT:    addi a0, sp, 24
-; LMULMAX1-NEXT:    vse16.v v28, (a0)
-; LMULMAX1-NEXT:    vsetvli zero, zero, e32, mf2, ta, mu
+; LMULMAX1-NEXT:    vsetivli zero, 4, e16, m1, tu, mu
+; LMULMAX1-NEXT:    vslideup.vi v29, v28, 2
+; LMULMAX1-NEXT:    vsetivli zero, 2, e32, mf2, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.x.w v27, v26
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e16, mf4, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.f.w v26, v27
-; LMULMAX1-NEXT:    addi a0, sp, 20
-; LMULMAX1-NEXT:    vse16.v v26, (a0)
-; LMULMAX1-NEXT:    vsetvli zero, zero, e32, mf2, ta, mu
+; LMULMAX1-NEXT:    vsetivli zero, 6, e16, m1, tu, mu
+; LMULMAX1-NEXT:    vslideup.vi v29, v26, 4
+; LMULMAX1-NEXT:    vsetivli zero, 2, e32, mf2, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.x.w v26, v25
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e16, mf4, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.f.w v25, v26
-; LMULMAX1-NEXT:    addi a0, sp, 16
-; LMULMAX1-NEXT:    vse16.v v25, (a0)
-; LMULMAX1-NEXT:    vsetivli zero, 8, e16, m1, ta, mu
-; LMULMAX1-NEXT:    addi a0, sp, 16
-; LMULMAX1-NEXT:    vle16.v v25, (a0)
-; LMULMAX1-NEXT:    vse16.v v25, (a1)
-; LMULMAX1-NEXT:    addi sp, sp, 32
+; LMULMAX1-NEXT:    vsetivli zero, 8, e16, m1, tu, mu
+; LMULMAX1-NEXT:    vslideup.vi v29, v25, 6
+; LMULMAX1-NEXT:    vsetvli zero, zero, e16, m1, ta, mu
+; LMULMAX1-NEXT:    vse16.v v29, (a1)
 ; LMULMAX1-NEXT:    ret
   %a = load <8 x i64>, <8 x i64>* %x
   %d = sitofp <8 x i64> %a to <8 x half>
@@ -526,45 +523,42 @@
 ;
 ; LMULMAX1-LABEL: ui2fp_v8i64_v8f16:
 ; LMULMAX1:       # %bb.0:
-; LMULMAX1-NEXT:    addi sp, sp, -32
-; LMULMAX1-NEXT:    .cfi_def_cfa_offset 32
+; LMULMAX1-NEXT:    addi a2, a0, 48
 ; LMULMAX1-NEXT:    vsetivli zero, 2, e64, m1, ta, mu
-; LMULMAX1-NEXT:    vle64.v v25, (a0)
-; LMULMAX1-NEXT:    addi a2, a0, 16
+; LMULMAX1-NEXT:    vle64.v v25, (a2)
+; LMULMAX1-NEXT:    addi a2, a0, 32
 ; LMULMAX1-NEXT:    vle64.v v26, (a2)
-; LMULMAX1-NEXT:    addi a2, a0, 48
-; LMULMAX1-NEXT:    vle64.v v27, (a2)
-; LMULMAX1-NEXT:    addi a0, a0, 32
+; LMULMAX1-NEXT:    vle64.v v27, (a0)
+; LMULMAX1-NEXT:    addi a0, a0, 16
 ; LMULMAX1-NEXT:    vle64.v v28, (a0)
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e32, mf2, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.xu.w v29, v27
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e16, mf4, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.f.w v27, v29
-; LMULMAX1-NEXT:    addi a0, sp, 28
-; LMULMAX1-NEXT:    vse16.v v27, (a0)
-; LMULMAX1-NEXT:    vsetvli zero, zero, e32, mf2, ta, mu
+; LMULMAX1-NEXT:    vsetivli zero, 8, e16, m1, ta, mu
+; LMULMAX1-NEXT:    vmv.v.i v29, 0
+; LMULMAX1-NEXT:    vsetivli zero, 2, e16, m1, tu, mu
+; LMULMAX1-NEXT:    vslideup.vi v29, v27, 0
+; LMULMAX1-NEXT:    vsetivli zero, 2, e32, mf2, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.xu.w v27, v28
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e16, mf4, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.f.w v28, v27
-; LMULMAX1-NEXT:    addi a0, sp, 24
-; LMULMAX1-NEXT:    vse16.v v28, (a0)
-; LMULMAX1-NEXT:    vsetvli zero, zero, e32, mf2, ta, mu
+; LMULMAX1-NEXT:    vsetivli zero, 4, e16, m1, tu, mu
+; LMULMAX1-NEXT:    vslideup.vi v29, v28, 2
+; LMULMAX1-NEXT:    vsetivli zero, 2, e32, mf2, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.xu.w v27, v26
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e16, mf4, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.f.w v26, v27
-; LMULMAX1-NEXT:    addi a0, sp, 20
-; LMULMAX1-NEXT:    vse16.v v26, (a0)
-; LMULMAX1-NEXT:    vsetvli zero, zero, e32, mf2, ta, mu
+; LMULMAX1-NEXT:    vsetivli zero, 6, e16, m1, tu, mu
+; LMULMAX1-NEXT:    vslideup.vi v29, v26, 4
+; LMULMAX1-NEXT:    vsetivli zero, 2, e32, mf2, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.xu.w v26, v25
 ; LMULMAX1-NEXT:    vsetvli zero, zero, e16, mf4, ta, mu
 ; LMULMAX1-NEXT:    vfncvt.f.f.w v25, v26
-; LMULMAX1-NEXT:    addi a0, sp, 16
-; LMULMAX1-NEXT:    vse16.v v25, (a0)
-; LMULMAX1-NEXT:    vsetivli zero, 8, e16, m1, ta, mu
-; LMULMAX1-NEXT:    addi a0, sp, 16
-; LMULMAX1-NEXT:    vle16.v v25, (a0)
-; LMULMAX1-NEXT:    vse16.v v25, (a1)
-; LMULMAX1-NEXT:    addi sp, sp, 32
+; LMULMAX1-NEXT:    vsetivli zero, 8, e16, m1, tu, mu
+; LMULMAX1-NEXT:    vslideup.vi v29, v25, 6
+; LMULMAX1-NEXT:    vsetvli zero, zero, e16, m1, ta, mu
+; LMULMAX1-NEXT:    vse16.v v29, (a1)
 ; LMULMAX1-NEXT:    ret
   %a = load <8 x i64>, <8 x i64>* %x
   %d = uitofp <8 x i64> %a to <8 x half>