Index: llvm/trunk/lib/Target/AArch64/AArch64SVEInstrInfo.td
===================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64SVEInstrInfo.td
+++ llvm/trunk/lib/Target/AArch64/AArch64SVEInstrInfo.td
@@ -386,6 +386,40 @@
   def PRFS_PRR : sve_mem_prfm_ss<0b101, "prfw", GPR64NoXZRshifted32>;
   def PRFD_PRR : sve_mem_prfm_ss<0b111, "prfd", GPR64NoXZRshifted64>;
 
+  // Gather prefetch using scaled 32-bit offsets, e.g.
+  //    prfh pldl1keep, p0, [x0, z0.s, uxtw #1]
+  defm PRFB_S : sve_mem_32b_prfm_sv_scaled<0b00, "prfb", ZPR32ExtSXTW8Only,  ZPR32ExtUXTW8Only>;
+  defm PRFH_S : sve_mem_32b_prfm_sv_scaled<0b01, "prfh", ZPR32ExtSXTW16, ZPR32ExtUXTW16>;
+  defm PRFW_S : sve_mem_32b_prfm_sv_scaled<0b10, "prfw", ZPR32ExtSXTW32, ZPR32ExtUXTW32>;
+  defm PRFD_S : sve_mem_32b_prfm_sv_scaled<0b11, "prfd", ZPR32ExtSXTW64, ZPR32ExtUXTW64>;
+
+  // Gather prefetch using unpacked, scaled 32-bit offsets, e.g.
+  //    prfh pldl1keep, p0, [x0, z0.d, uxtw #1]
+  defm PRFB_D : sve_mem_64b_prfm_sv_ext_scaled<0b00, "prfb", ZPR64ExtSXTW8Only, ZPR64ExtUXTW8Only>;
+  defm PRFH_D : sve_mem_64b_prfm_sv_ext_scaled<0b01, "prfh", ZPR64ExtSXTW16, ZPR64ExtUXTW16>;
+  defm PRFW_D : sve_mem_64b_prfm_sv_ext_scaled<0b10, "prfw", ZPR64ExtSXTW32, ZPR64ExtUXTW32>;
+  defm PRFD_D : sve_mem_64b_prfm_sv_ext_scaled<0b11, "prfd", ZPR64ExtSXTW64, ZPR64ExtUXTW64>;
+
+  // Gather prefetch using scaled 64-bit offsets, e.g.
+  //    prfh pldl1keep, p0, [x0, z0.d, lsl #1]
+  defm PRFB_D_SCALED : sve_mem_64b_prfm_sv_lsl_scaled<0b00, "prfb", ZPR64ExtLSL8>;
+  defm PRFH_D_SCALED : sve_mem_64b_prfm_sv_lsl_scaled<0b01, "prfh", ZPR64ExtLSL16>;
+  defm PRFW_D_SCALED : sve_mem_64b_prfm_sv_lsl_scaled<0b10, "prfw", ZPR64ExtLSL32>;
+  defm PRFD_D_SCALED : sve_mem_64b_prfm_sv_lsl_scaled<0b11, "prfd", ZPR64ExtLSL64>;
+
+  // Gather prefetch using 32/64-bit pointers with offset, e.g.
+  //    prfh pldl1keep, p0, [z0.s, #16]
+  //    prfh pldl1keep, p0, [z0.d, #16]
+  defm PRFB_S_PZI : sve_mem_32b_prfm_vi<0b00, "prfb", imm0_31>;
+  defm PRFH_S_PZI : sve_mem_32b_prfm_vi<0b01, "prfh", uimm5s2>;
+  defm PRFW_S_PZI : sve_mem_32b_prfm_vi<0b10, "prfw", uimm5s4>;
+  defm PRFD_S_PZI : sve_mem_32b_prfm_vi<0b11, "prfd", uimm5s8>;
+
+  defm PRFB_D_PZI : sve_mem_64b_prfm_vi<0b00, "prfb", imm0_31>;
+  defm PRFH_D_PZI : sve_mem_64b_prfm_vi<0b01, "prfh", uimm5s2>;
+  defm PRFW_D_PZI : sve_mem_64b_prfm_vi<0b10, "prfw", uimm5s4>;
+  defm PRFD_D_PZI : sve_mem_64b_prfm_vi<0b11, "prfd", uimm5s8>;
+
   defm ZIP1_ZZZ : sve_int_perm_bin_perm_zz<0b000, "zip1">;
   defm ZIP2_ZZZ : sve_int_perm_bin_perm_zz<0b001, "zip2">;
 
Index: llvm/trunk/lib/Target/AArch64/SVEInstrFormats.td
===================================================================
--- llvm/trunk/lib/Target/AArch64/SVEInstrFormats.td
+++ llvm/trunk/lib/Target/AArch64/SVEInstrFormats.td
@@ -1325,6 +1325,64 @@
   let hasSideEffects = 1;
 }
 
+class sve_mem_32b_prfm_sv<bits<2> msz, bit xs, string asm,
+                          RegisterOperand zprext>
+: I<(outs), (ins sve_prfop:$prfop, PPR3bAny:$Pg, GPR64sp:$Rn, zprext:$Zm),
+  asm, "\t$prfop, $Pg, [$Rn, $Zm]",
+  "",
+  []>, Sched<[]> {
+  bits<3> Pg;
+  bits<5> Rn;
+  bits<5> Zm;
+  bits<4> prfop;
+  let Inst{31-23} = 0b100001000;
+  let Inst{22}    = xs;
+  let Inst{21}    = 0b1;
+  let Inst{20-16} = Zm;
+  let Inst{15}    = 0b0;
+  let Inst{14-13} = msz;
+  let Inst{12-10} = Pg;
+  let Inst{9-5}   = Rn;
+  let Inst{4}     = 0b0;
+  let Inst{3-0}   = prfop;
+
+  let hasSideEffects = 1;
+}
+
+multiclass sve_mem_32b_prfm_sv_scaled<bits<2> msz, string asm,
+                                      RegisterOperand sxtw_opnd,
+                                      RegisterOperand uxtw_opnd> {
+  def _UXTW_SCALED : sve_mem_32b_prfm_sv<msz, 0, asm, uxtw_opnd>;
+  def _SXTW_SCALED : sve_mem_32b_prfm_sv<msz, 1, asm, sxtw_opnd>;
+}
+
+class sve_mem_32b_prfm_vi<bits<2> msz, string asm, Operand imm_ty>
+: I<(outs), (ins sve_prfop:$prfop, PPR3bAny:$Pg, ZPR32:$Zn, imm_ty:$imm5),
+  asm, "\t$prfop, $Pg, [$Zn, $imm5]",
+  "",
+  []>, Sched<[]> {
+  bits<3> Pg;
+  bits<5> Zn;
+  bits<5> imm5;
+  bits<4> prfop;
+  let Inst{31-25} = 0b1000010;
+  let Inst{24-23} = msz;
+  let Inst{22-21} = 0b00;
+  let Inst{20-16} = imm5;
+  let Inst{15-13} = 0b111;
+  let Inst{12-10} = Pg;
+  let Inst{9-5}   = Zn;
+  let Inst{4}     = 0b0;
+  let Inst{3-0}   = prfop;
+}
+
+multiclass sve_mem_32b_prfm_vi<bits<2> msz, string asm, Operand imm_ty> {
+  def NAME : sve_mem_32b_prfm_vi<msz, asm, imm_ty>;
+
+  def : InstAlias<asm # "\t$prfop, $Pg, [$Zn]",
+                  (!cast<Instruction>(NAME) sve_prfop:$prfop, PPR3bAny:$Pg, ZPR32:$Zn, 0), 1>;
+}
+
 class sve_mem_z_fill<string asm>
 : I<(outs ZPRAny:$Zt), (ins GPR64sp:$Rn, simm9:$imm9),
   asm, "\t$Zt, [$Rn, $imm9, mul vl]",
@@ -1482,3 +1540,70 @@
   def : InstAlias<asm # "\t$Zt, $Pg/z, [$Zn]",
                   (!cast<Instruction>(NAME # _IMM_REAL) Z_d:$Zt, PPR3bAny:$Pg, ZPR64:$Zn, 0), 1>;
 }
+
+// bit lsl is '0' if the offsets are extended (uxtw/sxtw), '1' if shifted (lsl)
+class sve_mem_64b_prfm_sv<bits<2> msz, bit xs, bit lsl, string asm,
+                          RegisterOperand zprext>
+: I<(outs), (ins sve_prfop:$prfop, PPR3bAny:$Pg, GPR64sp:$Rn, zprext:$Zm),
+  asm, "\t$prfop, $Pg, [$Rn, $Zm]",
+  "",
+  []>, Sched<[]> {
+  bits<3> Pg;
+  bits<5> Rn;
+  bits<5> Zm;
+  bits<4> prfop;
+  let Inst{31-23} = 0b110001000;
+  let Inst{22}    = xs;
+  let Inst{21}    = 0b1;
+  let Inst{20-16} = Zm;
+  let Inst{15}    = lsl;
+  let Inst{14-13} = msz;
+  let Inst{12-10} = Pg;
+  let Inst{9-5}   = Rn;
+  let Inst{4}     = 0b0;
+  let Inst{3-0}   = prfop;
+
+  let hasSideEffects = 1;
+}
+
+multiclass sve_mem_64b_prfm_sv_ext_scaled<bits<2> msz, string asm,
+                                          RegisterOperand sxtw_opnd,
+                                          RegisterOperand uxtw_opnd> {
+  def _UXTW_SCALED : sve_mem_64b_prfm_sv<msz, 0, 0, asm, uxtw_opnd>;
+  def _SXTW_SCALED : sve_mem_64b_prfm_sv<msz, 1, 0, asm, sxtw_opnd>;
+}
+
+multiclass sve_mem_64b_prfm_sv_lsl_scaled<bits<2> msz, string asm,
+                                          RegisterOperand zprext> {
+  def NAME : sve_mem_64b_prfm_sv<msz, 1, 1, asm, zprext>;
+}
+
+
+class sve_mem_64b_prfm_vi<bits<2> msz, string asm, Operand imm_ty>
+: I<(outs), (ins sve_prfop:$prfop, PPR3bAny:$Pg, ZPR64:$Zn, imm_ty:$imm5),
+  asm, "\t$prfop, $Pg, [$Zn, $imm5]",
+  "",
+  []>, Sched<[]> {
+  bits<3> Pg;
+  bits<5> Zn;
+  bits<5> imm5;
+  bits<4> prfop;
+  let Inst{31-25} = 0b1100010;
+  let Inst{24-23} = msz;
+  let Inst{22-21} = 0b00;
+  let Inst{20-16} = imm5;
+  let Inst{15-13} = 0b111;
+  let Inst{12-10} = Pg;
+  let Inst{9-5}   = Zn;
+  let Inst{4}     = 0b0;
+  let Inst{3-0}   = prfop;
+
+  let hasSideEffects = 1;
+}
+
+multiclass sve_mem_64b_prfm_vi<bits<2> msz, string asm, Operand imm_ty> {
+  def NAME : sve_mem_64b_prfm_vi<msz, asm, imm_ty>;
+
+  def : InstAlias<asm # "\t$prfop, $Pg, [$Zn]",
+                  (!cast<Instruction>(NAME) sve_prfop:$prfop, PPR3bAny:$Pg, ZPR64:$Zn, 0), 1>;
+}
Index: llvm/trunk/test/MC/AArch64/SVE/prfb-diagnostics.s
===================================================================
--- llvm/trunk/test/MC/AArch64/SVE/prfb-diagnostics.s
+++ llvm/trunk/test/MC/AArch64/SVE/prfb-diagnostics.s
@@ -26,7 +26,7 @@
 
 
 // --------------------------------------------------------------------------//
-// invalid addressing modes
+// invalid scalar + scalar addressing modes
 
 prfb #0, p0, [x0, #-33, mul vl]
 // CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be an integer in range [-32, 31].
@@ -55,6 +55,73 @@
 
 
 // --------------------------------------------------------------------------//
+// Invalid scalar + vector addressing modes
+
+prfb #0, p0, [x0, z0.b]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (uxtw|sxtw)'
+// CHECK-NEXT: prfb #0, p0, [x0, z0.b]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfb #0, p0, [x0, z0.h]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (uxtw|sxtw)'
+// CHECK-NEXT: prfb #0, p0, [x0, z0.h]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfb #0, p0, [x0, z0.s]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (uxtw|sxtw)'
+// CHECK-NEXT: prfb #0, p0, [x0, z0.s]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfb #0, p0, [x0, z0.s]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (uxtw|sxtw)'
+// CHECK-NEXT: prfb #0, p0, [x0, z0.s]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfb #0, p0, [x0, z0.s, uxtw #1]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (uxtw|sxtw)'
+// CHECK-NEXT: prfb #0, p0, [x0, z0.s, uxtw #1]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfb #0, p0, [x0, z0.s, lsl #0]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (uxtw|sxtw)'
+// CHECK-NEXT: prfb #0, p0, [x0, z0.s, lsl #0]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfb #0, p0, [x0, z0.d, lsl #1]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (uxtw|sxtw)'
+// CHECK-NEXT: prfb #0, p0, [x0, z0.d, lsl #1]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfb #0, p0, [x0, z0.d, sxtw #1]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (uxtw|sxtw)'
+// CHECK-NEXT: prfb #0, p0, [x0, z0.d, sxtw #1]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+// --------------------------------------------------------------------------//
+// Invalid vector + immediate addressing modes
+
+prfb #0, p0, [z0.s, #-1]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: immediate must be an integer in range [0, 31].
+// CHECK-NEXT: prfb #0, p0, [z0.s, #-1]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfb #0, p0, [z0.s, #32]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: immediate must be an integer in range [0, 31].
+// CHECK-NEXT: prfb #0, p0, [z0.s, #32]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfb #0, p0, [z0.d, #-1]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: immediate must be an integer in range [0, 31].
+// CHECK-NEXT: prfb #0, p0, [z0.d, #-1]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfb #0, p0, [z0.d, #32]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: immediate must be an integer in range [0, 31].
+// CHECK-NEXT: prfb #0, p0, [z0.d, #32]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+
+// --------------------------------------------------------------------------//
 // invalid predicate
 
 prfb #0, p8, [x0]
Index: llvm/trunk/test/MC/AArch64/SVE/prfb.s
===================================================================
--- llvm/trunk/test/MC/AArch64/SVE/prfb.s
+++ llvm/trunk/test/MC/AArch64/SVE/prfb.s
@@ -192,3 +192,57 @@
 // CHECK-ENCODING: [0x01,0x00,0xdf,0x85]
 // CHECK-ERROR: instruction requires: sve
 // CHECK-UNKNOWN: 01 00 df 85 <unknown>
+
+prfb    pldl1keep, p0, [x0, z0.s, uxtw]
+// CHECK-INST: prfb    pldl1keep, p0, [x0, z0.s, uxtw]
+// CHECK-ENCODING: [0x00,0x00,0x20,0x84]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 00 00 20 84 <unknown>
+
+prfb    pldl3strm, p5, [x10, z21.s, uxtw]
+// CHECK-INST: prfb    pldl3strm, p5, [x10, z21.s, uxtw]
+// CHECK-ENCODING: [0x45,0x15,0x35,0x84]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 45 15 35 84 <unknown>
+
+prfb    pldl1keep, p0, [x0, z0.d, uxtw]
+// CHECK-INST: prfb    pldl1keep, p0, [x0, z0.d, uxtw]
+// CHECK-ENCODING: [0x00,0x00,0x20,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 00 00 20 c4 <unknown>
+
+prfb    pldl3strm, p5, [x10, z21.d, sxtw]
+// CHECK-INST: prfb    pldl3strm, p5, [x10, z21.d, sxtw]
+// CHECK-ENCODING: [0x45,0x15,0x75,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 45 15 75 c4 <unknown>
+
+prfb    pldl1keep, p0, [x0, z0.d]
+// CHECK-INST: prfb    pldl1keep, p0, [x0, z0.d]
+// CHECK-ENCODING: [0x00,0x80,0x60,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 00 80 60 c4 <unknown>
+
+prfb    #7, p3, [z13.s, #0]
+// CHECK-INST: prfb    #7, p3, [z13.s]
+// CHECK-ENCODING: [0xa7,0xed,0x00,0x84]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: a7 ed 00 84 <unknown>
+
+prfb    #7, p3, [z13.s, #31]
+// CHECK-INST: prfb    #7, p3, [z13.s, #31]
+// CHECK-ENCODING: [0xa7,0xed,0x1f,0x84]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: a7 ed 1f 84 <unknown>
+
+prfb    pldl3strm, p5, [z10.d, #0]
+// CHECK-INST: prfb    pldl3strm, p5, [z10.d]
+// CHECK-ENCODING: [0x45,0xf5,0x00,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 45 f5 00 c4 <unknown>
+
+prfb    pldl3strm, p5, [z10.d, #31]
+// CHECK-INST: prfb    pldl3strm, p5, [z10.d, #31]
+// CHECK-ENCODING: [0x45,0xf5,0x1f,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 45 f5 1f c4 <unknown>
Index: llvm/trunk/test/MC/AArch64/SVE/prfd-diagnostics.s
===================================================================
--- llvm/trunk/test/MC/AArch64/SVE/prfd-diagnostics.s
+++ llvm/trunk/test/MC/AArch64/SVE/prfd-diagnostics.s
@@ -26,7 +26,7 @@
 
 
 // --------------------------------------------------------------------------//
-// invalid addressing modes
+// invalid scalar + scalar addressing modes
 
 prfd #0, p0, [x0, #-33, mul vl]
 // CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be an integer in range [-32, 31].
@@ -55,6 +55,59 @@
 
 
 // --------------------------------------------------------------------------//
+// Invalid scalar + vector addressing modes
+
+prfd #0, p0, [x0, z0.s]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #3'
+// CHECK-NEXT: prfd #0, p0, [x0, z0.s]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfd #0, p0, [x0, z0.d, uxtw #2]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #3'
+// CHECK-NEXT: prfd #0, p0, [x0, z0.d, uxtw #2]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfd #0, p0, [x0, z0.d, lsl #2]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #3'
+// CHECK-NEXT: prfd #0, p0, [x0, z0.d, lsl #2]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfd #0, p0, [x0, z0.d, lsl]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: expected #imm after shift specifier
+// CHECK-NEXT: prfd #0, p0, [x0, z0.d, lsl]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+
+// --------------------------------------------------------------------------//
+// Invalid vector + immediate addressing modes
+
+prfd #0, p0, [z0.d, #-8]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 8 in range [0, 248].
+// CHECK-NEXT: prfd #0, p0, [z0.d, #-8]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfd #0, p0, [z0.d, #-1]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 8 in range [0, 248].
+// CHECK-NEXT: prfd #0, p0, [z0.d, #-1]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfd #0, p0, [z0.d, #249]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 8 in range [0, 248].
+// CHECK-NEXT: prfd #0, p0, [z0.d, #249]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfd #0, p0, [z0.d, #256]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 8 in range [0, 248].
+// CHECK-NEXT: prfd #0, p0, [z0.d, #256]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfd #0, p0, [z0.d, #3]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 8 in range [0, 248].
+// CHECK-NEXT: prfd #0, p0, [z0.d, #3]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+
+// --------------------------------------------------------------------------//
 // invalid predicate
 
 prfd #0, p8, [x0]
Index: llvm/trunk/test/MC/AArch64/SVE/prfd.s
===================================================================
--- llvm/trunk/test/MC/AArch64/SVE/prfd.s
+++ llvm/trunk/test/MC/AArch64/SVE/prfd.s
@@ -192,3 +192,57 @@
 // CHECK-ENCODING: [0x01,0x60,0xdf,0x85]
 // CHECK-ERROR: instruction requires: sve
 // CHECK-UNKNOWN: 01 60 df 85
+
+prfd    pldl1keep, p0, [x0, z0.s, uxtw #3]
+// CHECK-INST: prfd    pldl1keep, p0, [x0, z0.s, uxtw #3]
+// CHECK-ENCODING: [0x00,0x60,0x20,0x84]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 00 60 20 84 <unknown>
+
+prfd    pldl1keep, p0, [x0, z0.s, sxtw #3]
+// CHECK-INST: prfd    pldl1keep, p0, [x0, z0.s, sxtw #3]
+// CHECK-ENCODING: [0x00,0x60,0x60,0x84]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 00 60 60 84 <unknown>
+
+prfd    pldl1keep, p0, [x0, z0.d, uxtw #3]
+// CHECK-INST: prfd    pldl1keep, p0, [x0, z0.d, uxtw #3]
+// CHECK-ENCODING: [0x00,0x60,0x20,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 00 60 20 c4 <unknown>
+
+prfd    pldl1keep, p0, [x0, z0.d, sxtw #3]
+// CHECK-INST: prfd    pldl1keep, p0, [x0, z0.d, sxtw #3]
+// CHECK-ENCODING: [0x00,0x60,0x60,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 00 60 60 c4 <unknown>
+
+prfd    pldl1keep, p0, [x0, z0.d, lsl #3]
+// CHECK-INST: prfd    pldl1keep, p0, [x0, z0.d, lsl #3]
+// CHECK-ENCODING: [0x00,0xe0,0x60,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 00 e0 60 c4 <unknown>
+
+prfd    #15, p7, [z31.s, #0]
+// CHECK-INST: prfd    #15, p7, [z31.s]
+// CHECK-ENCODING: [0xef,0xff,0x80,0x85]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: ef ff 80 85 <unknown>
+
+prfd    #15, p7, [z31.s, #248]
+// CHECK-INST: prfd    #15, p7, [z31.s, #248]
+// CHECK-ENCODING: [0xef,0xff,0x9f,0x85]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: ef ff 9f 85 <unknown>
+
+prfd    #15, p7, [z31.d, #0]
+// CHECK-INST: prfd    #15, p7, [z31.d]
+// CHECK-ENCODING: [0xef,0xff,0x80,0xc5]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: ef ff 80 c5 <unknown>
+
+prfd    #15, p7, [z31.d, #248]
+// CHECK-INST: prfd    #15, p7, [z31.d, #248]
+// CHECK-ENCODING: [0xef,0xff,0x9f,0xc5]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: ef ff 9f c5 <unknown>
Index: llvm/trunk/test/MC/AArch64/SVE/prfh-diagnostics.s
===================================================================
--- llvm/trunk/test/MC/AArch64/SVE/prfh-diagnostics.s
+++ llvm/trunk/test/MC/AArch64/SVE/prfh-diagnostics.s
@@ -26,7 +26,7 @@
 
 
 // --------------------------------------------------------------------------//
-// invalid addressing modes
+// invalid scalar + scalar addressing modes
 
 prfh #0, p0, [x0, #-33, mul vl]
 // CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be an integer in range [-32, 31].
@@ -55,6 +55,98 @@
 
 
 // --------------------------------------------------------------------------//
+// Invalid scalar + vector addressing modes
+
+prfh #0, p0, [x0, z0.h]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #1'
+// CHECK-NEXT: prfh #0, p0, [x0, z0.h]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [x0, z0.s]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #1'
+// CHECK-NEXT: prfh #0, p0, [x0, z0.s]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [x0, z0.s]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #1'
+// CHECK-NEXT: prfh #0, p0, [x0, z0.s]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [x0, z0.s, uxtw #2]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #1'
+// CHECK-NEXT: prfh #0, p0, [x0, z0.s, uxtw #2]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [x0, z0.s, lsl #1]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #1'
+// CHECK-NEXT: prfh #0, p0, [x0, z0.s, lsl #1]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [x0, z0.d, lsl #2]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #1'
+// CHECK-NEXT: prfh #0, p0, [x0, z0.d, lsl #2]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [x0, z0.d, sxtw #2]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #1'
+// CHECK-NEXT: prfh #0, p0, [x0, z0.d, sxtw #2]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+
+// --------------------------------------------------------------------------//
+// Invalid vector + immediate addressing modes
+
+prfh #0, p0, [z0.s, #-2]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 2 in range [0, 62].
+// CHECK-NEXT: prfh #0, p0, [z0.s, #-2]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [z0.s, #-1]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 2 in range [0, 62].
+// CHECK-NEXT: prfh #0, p0, [z0.s, #-1]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [z0.s, #63]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 2 in range [0, 62].
+// CHECK-NEXT: prfh #0, p0, [z0.s, #63]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [z0.s, #64]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 2 in range [0, 62].
+// CHECK-NEXT: prfh #0, p0, [z0.s, #64]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [z0.s, #3]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 2 in range [0, 62].
+// CHECK-NEXT: prfh #0, p0, [z0.s, #3]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [z0.d, #-2]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 2 in range [0, 62].
+// CHECK-NEXT: prfh #0, p0, [z0.d, #-2]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [z0.d, #-1]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 2 in range [0, 62].
+// CHECK-NEXT: prfh #0, p0, [z0.d, #-1]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [z0.d, #63]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 2 in range [0, 62].
+// CHECK-NEXT: prfh #0, p0, [z0.d, #63]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [z0.d, #64]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 2 in range [0, 62].
+// CHECK-NEXT: prfh #0, p0, [z0.d, #64]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfh #0, p0, [z0.d, #3]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 2 in range [0, 62].
+// CHECK-NEXT: prfh #0, p0, [z0.d, #3]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+// --------------------------------------------------------------------------//
 // invalid predicate
 
 prfh #0, p8, [x0]
Index: llvm/trunk/test/MC/AArch64/SVE/prfh.s
===================================================================
--- llvm/trunk/test/MC/AArch64/SVE/prfh.s
+++ llvm/trunk/test/MC/AArch64/SVE/prfh.s
@@ -192,3 +192,57 @@
 // CHECK-ENCODING: [0x01,0x20,0xdf,0x85]
 // CHECK-ERROR: instruction requires: sve
 // CHECK-UNKNOWN: 01 20 df 85
+
+prfh    pldl3strm, p5, [x10, z21.s, uxtw #1]
+// CHECK-INST: prfh    pldl3strm, p5, [x10, z21.s, uxtw #1]
+// CHECK-ENCODING: [0x45,0x35,0x35,0x84]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 45 35 35 84 <unknown>
+
+prfh    pldl3strm, p5, [x10, z21.s, sxtw #1]
+// CHECK-INST: prfh    pldl3strm, p5, [x10, z21.s, sxtw #1]
+// CHECK-ENCODING: [0x45,0x35,0x75,0x84]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 45 35 75 84 <unknown>
+
+prfh    pldl3strm, p5, [x10, z21.d, uxtw #1]
+// CHECK-INST: prfh    pldl3strm, p5, [x10, z21.d, uxtw #1]
+// CHECK-ENCODING: [0x45,0x35,0x35,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 45 35 35 c4 <unknown>
+
+prfh    pldl3strm, p5, [x10, z21.d, sxtw #1]
+// CHECK-INST: prfh    pldl3strm, p5, [x10, z21.d, sxtw #1]
+// CHECK-ENCODING: [0x45,0x35,0x75,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 45 35 75 c4 <unknown>
+
+prfh    pldl1keep, p0, [x0, z0.d, lsl #1]
+// CHECK-INST: prfh    pldl1keep, p0, [x0, z0.d, lsl #1]
+// CHECK-ENCODING: [0x00,0xa0,0x60,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 00 a0 60 c4 <unknown>
+
+prfh    #15, p7, [z31.s, #0]
+// CHECK-INST: prfh    #15, p7, [z31.s]
+// CHECK-ENCODING: [0xef,0xff,0x80,0x84]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: ef ff 80 84 <unknown>
+
+prfh    #15, p7, [z31.s, #62]
+// CHECK-INST: prfh    #15, p7, [z31.s, #62]
+// CHECK-ENCODING: [0xef,0xff,0x9f,0x84]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: ef ff 9f 84 <unknown>
+
+prfh    #15, p7, [z31.d, #0]
+// CHECK-INST: prfh    #15, p7, [z31.d]
+// CHECK-ENCODING: [0xef,0xff,0x80,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: ef ff 80 c4 <unknown>
+
+prfh    #15, p7, [z31.d, #62]
+// CHECK-INST: prfh    #15, p7, [z31.d, #62]
+// CHECK-ENCODING: [0xef,0xff,0x9f,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: ef ff 9f c4 <unknown>
Index: llvm/trunk/test/MC/AArch64/SVE/prfw-diagnostics.s
===================================================================
--- llvm/trunk/test/MC/AArch64/SVE/prfw-diagnostics.s
+++ llvm/trunk/test/MC/AArch64/SVE/prfw-diagnostics.s
@@ -26,7 +26,7 @@
 
 
 // --------------------------------------------------------------------------//
-// invalid addressing modes
+// invalid scalar + scalar addressing modes
 
 prfw #0, p0, [x0, #-33, mul vl]
 // CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be an integer in range [-32, 31].
@@ -55,6 +55,99 @@
 
 
 // --------------------------------------------------------------------------//
+// Invalid scalar + vector addressing modes
+
+prfw #0, p0, [x0, z0.h]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #2'
+// CHECK-NEXT: prfw #0, p0, [x0, z0.h]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [x0, z0.s]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #2'
+// CHECK-NEXT: prfw #0, p0, [x0, z0.s]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [x0, z0.s]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #2'
+// CHECK-NEXT: prfw #0, p0, [x0, z0.s]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [x0, z0.s, uxtw #3]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #2'
+// CHECK-NEXT: prfw #0, p0, [x0, z0.s, uxtw #3]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [x0, z0.s, lsl #2]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #2'
+// CHECK-NEXT: prfw #0, p0, [x0, z0.s, lsl #2]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [x0, z0.d, lsl #3]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #2'
+// CHECK-NEXT: prfw #0, p0, [x0, z0.d, lsl #3]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [x0, z0.d, sxtw #3]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid shift/extend specified, expected 'z[0..31].d, (lsl|uxtw|sxtw) #2'
+// CHECK-NEXT: prfw #0, p0, [x0, z0.d, sxtw #3]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+
+// --------------------------------------------------------------------------//
+// Invalid vector + immediate addressing modes
+
+prfw #0, p0, [z0.s, #-4]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 4 in range [0, 124].
+// CHECK-NEXT: prfw #0, p0, [z0.s, #-4]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [z0.s, #-1]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 4 in range [0, 124].
+// CHECK-NEXT: prfw #0, p0, [z0.s, #-1]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [z0.s, #125]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 4 in range [0, 124].
+// CHECK-NEXT: prfw #0, p0, [z0.s, #125]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [z0.s, #128]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 4 in range [0, 124].
+// CHECK-NEXT: prfw #0, p0, [z0.s, #128]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [z0.s, #3]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 4 in range [0, 124].
+// CHECK-NEXT: prfw #0, p0, [z0.s, #3]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [z0.d, #-4]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 4 in range [0, 124].
+// CHECK-NEXT: prfw #0, p0, [z0.d, #-4]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [z0.d, #-1]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 4 in range [0, 124].
+// CHECK-NEXT: prfw #0, p0, [z0.d, #-1]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [z0.d, #125]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 4 in range [0, 124].
+// CHECK-NEXT: prfw #0, p0, [z0.d, #125]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [z0.d, #128]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 4 in range [0, 124].
+// CHECK-NEXT: prfw #0, p0, [z0.d, #128]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+prfw #0, p0, [z0.d, #3]
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: index must be a multiple of 4 in range [0, 124].
+// CHECK-NEXT: prfw #0, p0, [z0.d, #3]
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+
+// --------------------------------------------------------------------------//
 // invalid predicate
 
 prfw #0, p8, [x0]
Index: llvm/trunk/test/MC/AArch64/SVE/prfw.s
===================================================================
--- llvm/trunk/test/MC/AArch64/SVE/prfw.s
+++ llvm/trunk/test/MC/AArch64/SVE/prfw.s
@@ -192,3 +192,57 @@
 // CHECK-ENCODING: [0x01,0x40,0xdf,0x85]
 // CHECK-ERROR: instruction requires: sve
 // CHECK-UNKNOWN: 01 40 df 85
+
+prfw    pldl1keep, p0, [x0, z0.s, uxtw #2]
+// CHECK-INST: prfw    pldl1keep, p0, [x0, z0.s, uxtw #2]
+// CHECK-ENCODING: [0x00,0x40,0x20,0x84]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 00 40 20 84 <unknown>
+
+prfw    pldl3strm, p5, [x10, z21.s, sxtw #2]
+// CHECK-INST: prfw    pldl3strm, p5, [x10, z21.s, sxtw #2]
+// CHECK-ENCODING: [0x45,0x55,0x75,0x84]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 45 55 75 84 <unknown>
+
+prfw    #7, p3, [x13, z8.d, uxtw #2]
+// CHECK-INST: prfw    #7, p3, [x13, z8.d, uxtw #2]
+// CHECK-ENCODING: [0xa7,0x4d,0x28,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: a7 4d 28 c4 <unknown>
+
+prfw    pldl1keep, p0, [x0, z0.d, sxtw #2]
+// CHECK-INST: prfw    pldl1keep, p0, [x0, z0.d, sxtw #2]
+// CHECK-ENCODING: [0x00,0x40,0x60,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 00 40 60 c4 <unknown>
+
+prfw    pldl3strm, p5, [x10, z21.d, lsl #2]
+// CHECK-INST: prfw    pldl3strm, p5, [x10, z21.d, lsl #2]
+// CHECK-ENCODING: [0x45,0xd5,0x75,0xc4]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: 45 d5 75 c4 <unknown>
+
+prfw    #15, p7, [z31.s, #0]
+// CHECK-INST: prfw    #15, p7, [z31.s]
+// CHECK-ENCODING: [0xef,0xff,0x00,0x85]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: ef ff 00 85 <unknown>
+
+prfw    #15, p7, [z31.s, #124]
+// CHECK-INST: prfw    #15, p7, [z31.s, #124]
+// CHECK-ENCODING: [0xef,0xff,0x1f,0x85]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: ef ff 1f 85 <unknown>
+
+prfw    #15, p7, [z31.d, #0]
+// CHECK-INST: prfw    #15, p7, [z31.d]
+// CHECK-ENCODING: [0xef,0xff,0x00,0xc5]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: ef ff 00 c5 <unknown>
+
+prfw    #15, p7, [z31.d, #124]
+// CHECK-INST: prfw    #15, p7, [z31.d, #124]
+// CHECK-ENCODING: [0xef,0xff,0x1f,0xc5]
+// CHECK-ERROR: instruction requires: sve
+// CHECK-UNKNOWN: ef ff 1f c5 <unknown>