Index: llvm/trunk/lib/Target/AArch64/AArch64SVEInstrInfo.td
===================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64SVEInstrInfo.td
+++ llvm/trunk/lib/Target/AArch64/AArch64SVEInstrInfo.td
@@ -1348,6 +1348,9 @@
   defm LDNT1W_ZZR_D  : sve2_mem_cldnt_vs<0b11010, "ldnt1w",  Z_d, ZPR64>;
   defm LDNT1D_ZZR_D  : sve2_mem_cldnt_vs<0b11110, "ldnt1d",  Z_d, ZPR64>;
 
+  // SVE2 vector splice (constructive)
+  defm SPLICE_ZPZZ : sve2_int_perm_splice_cons<"splice">;
+
   // Predicated shifts
   defm SQSHL_ZPmI  : sve_int_bin_pred_shift_imm_left< 0b0110, "sqshl">;
   defm UQSHL_ZPmI  : sve_int_bin_pred_shift_imm_left< 0b0111, "uqshl">;
Index: llvm/trunk/lib/Target/AArch64/SVEInstrFormats.td
===================================================================
--- llvm/trunk/lib/Target/AArch64/SVEInstrFormats.td
+++ llvm/trunk/lib/Target/AArch64/SVEInstrFormats.td
@@ -4275,6 +4275,30 @@
   def _D : sve_int_perm_splice<0b11, asm, ZPR64>;
 }
 
+class sve2_int_perm_splice_cons<bits<2> sz8_64, string asm,
+                               ZPRRegOp zprty, RegisterOperand VecList>
+: I<(outs zprty:$Zd), (ins PPR3bAny:$Pg, VecList:$Zn),
+  asm, "\t$Zd, $Pg, $Zn",
+  "",
+  []>, Sched<[]> {
+  bits<3> Pg;
+  bits<5> Zn;
+  bits<5> Zd;
+  let Inst{31-24} = 0b00000101;
+  let Inst{23-22} = sz8_64;
+  let Inst{21-13} = 0b101101100;
+  let Inst{12-10} = Pg;
+  let Inst{9-5}   = Zn;
+  let Inst{4-0}   = Zd;
+}
+
+multiclass sve2_int_perm_splice_cons<string asm> {
+  def _B : sve2_int_perm_splice_cons<0b00, asm, ZPR8,  ZZ_b>;
+  def _H : sve2_int_perm_splice_cons<0b01, asm, ZPR16, ZZ_h>;
+  def _S : sve2_int_perm_splice_cons<0b10, asm, ZPR32, ZZ_s>;
+  def _D : sve2_int_perm_splice_cons<0b11, asm, ZPR64, ZZ_d>;
+}
+
 class sve_int_perm_rev<bits<2> sz8_64, bits<2> opc, string asm,
                        ZPRRegOp zprty>
 : I<(outs zprty:$Zd), (ins zprty:$_Zd, PPR3bAny:$Pg, zprty:$Zn),
Index: llvm/trunk/test/MC/AArch64/SVE2/splice-diagnostics.s
===================================================================
--- llvm/trunk/test/MC/AArch64/SVE2/splice-diagnostics.s
+++ llvm/trunk/test/MC/AArch64/SVE2/splice-diagnostics.s
@@ -0,0 +1,83 @@
+// RUN: not llvm-mc -triple=aarch64 -show-encoding -mattr=+sve2  2>&1 < %s| FileCheck %s
+
+
+// ------------------------------------------------------------------------- //
+// Invalid element widths.
+
+splice z0.b, p0, { z1.h, z2.h }
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid operand for instruction
+// CHECK-NEXT: splice z0.b, p0, { z1.h, z2.h }
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+
+// --------------------------------------------------------------------------//
+// Invalid vector list.
+
+splice z0.b, p0, { }
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: vector register expected
+// CHECK-NEXT: splice z0.b, p0, { }
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+splice z0.b, p0, { z1.b }
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid operand for instruction
+// CHECK-NEXT: splice z0.b, p0, { z1.b }
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+splice z0.b, p0, { z1.b, z2.b, z3.b }
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid operand for instruction
+// CHECK-NEXT: splice z0.b, p0, { z1.b, z2.b, z3.b }
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+splice z0.b, p0, { z1.b, z2.h }
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: mismatched register size suffix
+// CHECK-NEXT: splice z0.b, p0, { z1.b, z2.h }
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+splice z0.b, p0, { z1.b, z31.b }
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: registers must be sequential
+// CHECK-NEXT: splice z0.b, p0, { z1.b, z31.b }
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+splice z0.b, p0, { v0.4b, v1.4b }
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid operand for instruction
+// CHECK-NEXT: splice z0.b, p0, { v0.4b, v1.4b }
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+
+// --------------------------------------------------------------------------//
+// Invalid predicate operation
+
+splice z0.b, p0/z, { z1.b, z2.b }
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: vector register expected
+// CHECK-NEXT: splice z0.b, p0/z, { z1.b, z2.b }
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+splice z0.b, p0/m, { z1.b, z2.b }
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: vector register expected
+// CHECK-NEXT: splice z0.b, p0/m, { z1.b, z2.b }
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+
+// --------------------------------------------------------------------------//
+// Predicate not in restricted predicate range
+
+splice z0.b, p8, { z1.b, z2.b }
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: restricted predicate has range [0, 7]
+// CHECK-NEXT: splice z0.b, p8, { z1.b, z2.b }
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+
+// --------------------------------------------------------------------------//
+// Negative tests for instructions that are incompatible with movprfx
+
+movprfx z31, z6
+splice z31.b, p0, { z30.b, z31.b }
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: instruction is unpredictable when following a movprfx, suggest replacing movprfx with mov
+// CHECK-NEXT: splice z31.b, p0, { z30.b, z31.b }
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+movprfx z31.b, p0/z, z6.b
+splice z31.b, p0, { z30.b, z31.b }
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: instruction is unpredictable when following a movprfx, suggest replacing movprfx with mov
+// CHECK-NEXT: splice z31.b, p0, { z30.b, z31.b }
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
Index: llvm/trunk/test/MC/AArch64/SVE2/splice.s
===================================================================
--- llvm/trunk/test/MC/AArch64/SVE2/splice.s
+++ llvm/trunk/test/MC/AArch64/SVE2/splice.s
@@ -0,0 +1,32 @@
+// RUN: llvm-mc -triple=aarch64 -show-encoding -mattr=+sve2 < %s \
+// RUN:        | FileCheck %s --check-prefixes=CHECK-ENCODING,CHECK-INST
+// RUN: not llvm-mc -triple=aarch64 -show-encoding < %s 2>&1 \
+// RUN:        | FileCheck %s --check-prefix=CHECK-ERROR
+// RUN: llvm-mc -triple=aarch64 -filetype=obj -mattr=+sve2 < %s \
+// RUN:        | llvm-objdump -d -mattr=+sve2 - | FileCheck %s --check-prefix=CHECK-INST
+// RUN: llvm-mc -triple=aarch64 -filetype=obj -mattr=+sve2 < %s \
+// RUN:        | llvm-objdump -d - | FileCheck %s --check-prefix=CHECK-UNKNOWN
+
+splice  z29.b, p7, { z30.b, z31.b }
+// CHECK-INST: splice  z29.b, p7, { z30.b, z31.b }
+// CHECK-ENCODING: [0xdd,0x9f,0x2d,0x05]
+// CHECK-ERROR: instruction requires: sve2
+// CHECK-UNKNOWN: dd 9f 2d 05 <unknown>
+
+splice  z29.h, p7, { z30.h, z31.h }
+// CHECK-INST: splice  z29.h, p7, { z30.h, z31.h }
+// CHECK-ENCODING: [0xdd,0x9f,0x6d,0x05]
+// CHECK-ERROR: instruction requires: sve2
+// CHECK-UNKNOWN: dd 9f 6d 05 <unknown>
+
+splice  z29.s, p7, { z30.s, z31.s }
+// CHECK-INST: splice  z29.s, p7, { z30.s, z31.s }
+// CHECK-ENCODING: [0xdd,0x9f,0xad,0x05]
+// CHECK-ERROR: instruction requires: sve2
+// CHECK-UNKNOWN: dd 9f ad 05 <unknown>
+
+splice  z29.d, p7, { z30.d, z31.d }
+// CHECK-INST: splice  z29.d, p7, { z30.d, z31.d }
+// CHECK-ENCODING: [0xdd,0x9f,0xed,0x05]
+// CHECK-ERROR: instruction requires: sve2
+// CHECK-UNKNOWN: dd 9f ed 05 <unknown>