[ARM] Add a batch of similarly encoded MVE instructions.

Summary:
This adds the `MVE_qDest_qSrc` superclass and all instructions that
inherit from it. It's not the complete class of _everything_ with a
q-register as both destination and source; it's a subset of them that
all have similar encodings (but it would have been hopelessly unwieldy
to call it anything like MVE_111x11100).

This category includes add/sub with carry; long multiplies; halving
multiplies; multiply and accumulate, and some more complex
instructions.

Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover

Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62677

llvm-svn: 364037

3 files changed, 345 insertions, 1 deletions

diff --git a/llvm/lib/Target/ARM/ARMInstrMVE.td b/llvm/lib/Target/ARM/ARMInstrMVE.td
index 83c2375836f..10900d84fa8 100644
--- a/llvm/lib/Target/ARM/ARMInstrMVE.td
+++ b/llvm/lib/Target/ARM/ARMInstrMVE.td
@@ -2404,6 +2404,284 @@ def MVE_VCMPs32r : MVE_VCMPqrs<"s32", 0b10>;
 
 // end of MVE compares
 
+// start of MVE_qDest_qSrc
+
+class MVE_qDest_qSrc<string iname, string suffix, dag oops, dag iops,
+                     string ops, vpred_ops vpred, string cstr,
+                     list<dag> pattern=[]>
+  : MVE_p<oops, iops, NoItinerary, iname, suffix,
+          ops, vpred, cstr, pattern> {
+  bits<4> Qd;
+  bits<4> Qm;
+
+  let Inst{25-23} = 0b100;
+  let Inst{22} = Qd{3};
+  let Inst{15-13} = Qd{2-0};
+  let Inst{11-9} = 0b111;
+  let Inst{6} = 0b0;
+  let Inst{5} = Qm{3};
+  let Inst{4} = 0b0;
+  let Inst{3-1} = Qm{2-0};
+}
+
+class MVE_VQxDMLxDH<string iname, bit exch, bit round, bit subtract,
+                    string suffix, bits<2> size, list<dag> pattern=[]>
+  : MVE_qDest_qSrc<iname, suffix, (outs MQPR:$Qd),
+                   (ins MQPR:$Qn, MQPR:$Qm), "$Qd, $Qn, $Qm",
+                   vpred_r, "", pattern> {
+  bits<4> Qn;
+
+  let Inst{28} = subtract;
+  let Inst{21-20} = size;
+  let Inst{19-17} = Qn{2-0};
+  let Inst{16} = 0b0;
+  let Inst{12} = exch;
+  let Inst{8} = 0b0;
+  let Inst{7} = Qn{3};
+  let Inst{0} = round;
+}
+
+multiclass MVE_VQxDMLxDH_multi<string iname, bit exch,
+                               bit round, bit subtract> {
+  def s8  : MVE_VQxDMLxDH<iname, exch, round, subtract, "s8",  0b00>;
+  def s16 : MVE_VQxDMLxDH<iname, exch, round, subtract, "s16", 0b01>;
+  def s32 : MVE_VQxDMLxDH<iname, exch, round, subtract, "s32", 0b10>;
+}
+
+defm MVE_VQDMLADH   : MVE_VQxDMLxDH_multi<"vqdmladh",   0b0, 0b0, 0b0>;
+defm MVE_VQDMLADHX  : MVE_VQxDMLxDH_multi<"vqdmladhx",  0b1, 0b0, 0b0>;
+defm MVE_VQRDMLADH  : MVE_VQxDMLxDH_multi<"vqrdmladh",  0b0, 0b1, 0b0>;
+defm MVE_VQRDMLADHX : MVE_VQxDMLxDH_multi<"vqrdmladhx", 0b1, 0b1, 0b0>;
+defm MVE_VQDMLSDH   : MVE_VQxDMLxDH_multi<"vqdmlsdh",   0b0, 0b0, 0b1>;
+defm MVE_VQDMLSDHX  : MVE_VQxDMLxDH_multi<"vqdmlsdhx",  0b1, 0b0, 0b1>;
+defm MVE_VQRDMLSDH  : MVE_VQxDMLxDH_multi<"vqrdmlsdh",  0b0, 0b1, 0b1>;
+defm MVE_VQRDMLSDHX : MVE_VQxDMLxDH_multi<"vqrdmlsdhx", 0b1, 0b1, 0b1>;
+
+class MVE_VCMUL<string iname, string suffix, bit size, list<dag> pattern=[]>
+  : MVE_qDest_qSrc<iname, suffix, (outs MQPR:$Qd),
+                   (ins MQPR:$Qn, MQPR:$Qm, complexrotateop:$rot),
+                   "$Qd, $Qn, $Qm, $rot", vpred_r, "", pattern> {
+  bits<4> Qn;
+  bits<2> rot;
+
+  let Inst{28} = size;
+  let Inst{21-20} = 0b11;
+  let Inst{19-17} = Qn{2-0};
+  let Inst{16} = 0b0;
+  let Inst{12} = rot{1};
+  let Inst{8} = 0b0;
+  let Inst{7} = Qn{3};
+  let Inst{0} = rot{0};
+
+  let Predicates = [HasMVEFloat];
+}
+
+def MVE_VCMULf16 : MVE_VCMUL<"vcmul", "f16", 0b0>;
+def MVE_VCMULf32 : MVE_VCMUL<"vcmul", "f32", 0b1>;
+
+class MVE_VMULL<string iname, string suffix, bit bit_28, bits<2> bits_21_20,
+                bit T, list<dag> pattern=[]>
+  : MVE_qDest_qSrc<iname, suffix, (outs MQPR:$Qd),
+                   (ins MQPR:$Qn, MQPR:$Qm), "$Qd, $Qn, $Qm",
+                   vpred_r, "", pattern> {
+  bits<4> Qd;
+  bits<4> Qn;
+  bits<4> Qm;
+
+  let Inst{28} = bit_28;
+  let Inst{21-20} = bits_21_20;
+  let Inst{19-17} = Qn{2-0};
+  let Inst{16} = 0b1;
+  let Inst{12} = T;
+  let Inst{8} = 0b0;
+  let Inst{7} = Qn{3};
+  let Inst{0} = 0b0;
+}
+
+multiclass MVE_VMULL_multi<string iname, string suffix,
+                           bit bit_28, bits<2> bits_21_20> {
+  def bh : MVE_VMULL<iname # "b", suffix, bit_28, bits_21_20, 0b0>;
+  def th : MVE_VMULL<iname # "t", suffix, bit_28, bits_21_20, 0b1>;
+}
+
+// For integer multiplies, bits 21:20 encode size, and bit 28 signedness.
+// For polynomial multiplies, bits 21:20 take the unused value 0b11, and
+// bit 28 switches to encoding the size.
+
+defm MVE_VMULLs8  : MVE_VMULL_multi<"vmull", "s8",  0b0, 0b00>;
+defm MVE_VMULLs16 : MVE_VMULL_multi<"vmull", "s16", 0b0, 0b01>;
+defm MVE_VMULLs32 : MVE_VMULL_multi<"vmull", "s32", 0b0, 0b10>;
+defm MVE_VMULLu8  : MVE_VMULL_multi<"vmull", "u8",  0b1, 0b00>;
+defm MVE_VMULLu16 : MVE_VMULL_multi<"vmull", "u16", 0b1, 0b01>;
+defm MVE_VMULLu32 : MVE_VMULL_multi<"vmull", "u32", 0b1, 0b10>;
+defm MVE_VMULLp8  : MVE_VMULL_multi<"vmull", "p8",  0b0, 0b11>;
+defm MVE_VMULLp16 : MVE_VMULL_multi<"vmull", "p16", 0b1, 0b11>;
+
+class MVE_VxMULH<string iname, string suffix, bit U, bits<2> size,
+                 bit round, list<dag> pattern=[]>
+  : MVE_qDest_qSrc<iname, suffix, (outs MQPR:$Qd),
+                   (ins MQPR:$Qn, MQPR:$Qm), "$Qd, $Qn, $Qm",
+                   vpred_r, "", pattern> {
+  bits<4> Qn;
+
+  let Inst{28} = U;
+  let Inst{21-20} = size;
+  let Inst{19-17} = Qn{2-0};
+  let Inst{16} = 0b1;
+  let Inst{12} = round;
+  let Inst{8} = 0b0;
+  let Inst{7} = Qn{3};
+  let Inst{0} = 0b1;
+}
+
+def MVE_VMULHs8   : MVE_VxMULH<"vmulh",  "s8",  0b0, 0b00, 0b0>;
+def MVE_VMULHs16  : MVE_VxMULH<"vmulh",  "s16", 0b0, 0b01, 0b0>;
+def MVE_VMULHs32  : MVE_VxMULH<"vmulh",  "s32", 0b0, 0b10, 0b0>;
+def MVE_VMULHu8   : MVE_VxMULH<"vmulh",  "u8",  0b1, 0b00, 0b0>;
+def MVE_VMULHu16  : MVE_VxMULH<"vmulh",  "u16", 0b1, 0b01, 0b0>;
+def MVE_VMULHu32  : MVE_VxMULH<"vmulh",  "u32", 0b1, 0b10, 0b0>;
+
+def MVE_VRMULHs8  : MVE_VxMULH<"vrmulh", "s8",  0b0, 0b00, 0b1>;
+def MVE_VRMULHs16 : MVE_VxMULH<"vrmulh", "s16", 0b0, 0b01, 0b1>;
+def MVE_VRMULHs32 : MVE_VxMULH<"vrmulh", "s32", 0b0, 0b10, 0b1>;
+def MVE_VRMULHu8  : MVE_VxMULH<"vrmulh", "u8",  0b1, 0b00, 0b1>;
+def MVE_VRMULHu16 : MVE_VxMULH<"vrmulh", "u16", 0b1, 0b01, 0b1>;
+def MVE_VRMULHu32 : MVE_VxMULH<"vrmulh", "u32", 0b1, 0b10, 0b1>;
+
+class MVE_VxMOVxN<string iname, string suffix, bit bit_28, bit bit_17,
+                  bits<2> size, bit T, list<dag> pattern=[]>
+  : MVE_qDest_qSrc<iname, suffix, (outs MQPR:$Qd),
+                   (ins MQPR:$Qd_src, MQPR:$Qm), "$Qd, $Qm",
+                   vpred_n, "$Qd = $Qd_src", pattern> {
+
+  let Inst{28} = bit_28;
+  let Inst{21-20} = 0b11;
+  let Inst{19-18} = size;
+  let Inst{17} = bit_17;
+  let Inst{16} = 0b1;
+  let Inst{12} = T;
+  let Inst{8} = 0b0;
+  let Inst{7} = !if(!eq(bit_17, 0), 1, 0);
+  let Inst{0} = 0b1;
+}
+
+multiclass MVE_VxMOVxN_halves<string iname, string suffix,
+                              bit bit_28, bit bit_17, bits<2> size> {
+  def bh : MVE_VxMOVxN<iname # "b", suffix, bit_28, bit_17, size, 0b0>;
+  def th : MVE_VxMOVxN<iname # "t", suffix, bit_28, bit_17, size, 0b1>;
+}
+
+defm MVE_VMOVNi16   : MVE_VxMOVxN_halves<"vmovn",   "i16", 0b1, 0b0, 0b00>;
+defm MVE_VMOVNi32   : MVE_VxMOVxN_halves<"vmovn",   "i32", 0b1, 0b0, 0b01>;
+defm MVE_VQMOVNs16  : MVE_VxMOVxN_halves<"vqmovn",  "s16", 0b0, 0b1, 0b00>;
+defm MVE_VQMOVNs32  : MVE_VxMOVxN_halves<"vqmovn",  "s32", 0b0, 0b1, 0b01>;
+defm MVE_VQMOVNu16  : MVE_VxMOVxN_halves<"vqmovn",  "u16", 0b1, 0b1, 0b00>;
+defm MVE_VQMOVNu32  : MVE_VxMOVxN_halves<"vqmovn",  "u32", 0b1, 0b1, 0b01>;
+defm MVE_VQMOVUNs16 : MVE_VxMOVxN_halves<"vqmovun", "s16", 0b0, 0b0, 0b00>;
+defm MVE_VQMOVUNs32 : MVE_VxMOVxN_halves<"vqmovun", "s32", 0b0, 0b0, 0b01>;
+
+class MVE_VCVT_ff<string iname, string suffix, bit op, bit T,
+                  list<dag> pattern=[]>
+  : MVE_qDest_qSrc<iname, suffix, (outs MQPR:$Qd), (ins MQPR:$Qd_src, MQPR:$Qm),
+                   "$Qd, $Qm", vpred_n, "$Qd = $Qd_src", pattern> {
+  let Inst{28} = op;
+  let Inst{21-16} = 0b111111;
+  let Inst{12} = T;
+  let Inst{8-7} = 0b00;
+  let Inst{0} = 0b1;
+
+  let Predicates = [HasMVEFloat];
+}
+
+multiclass MVE_VCVT_ff_halves<string suffix, bit op> {
+  def bh : MVE_VCVT_ff<"vcvtb", suffix, op, 0b0>;
+  def th : MVE_VCVT_ff<"vcvtt", suffix, op, 0b1>;
+}
+
+defm MVE_VCVTf16f32 : MVE_VCVT_ff_halves<"f16.f32", 0b0>;
+defm MVE_VCVTf32f16 : MVE_VCVT_ff_halves<"f32.f16", 0b1>;
+
+class MVE_VxCADD<string iname, string suffix, bits<2> size, bit halve,
+                 list<dag> pattern=[]>
+  : MVE_qDest_qSrc<iname, suffix, (outs MQPR:$Qd),
+                   (ins MQPR:$Qn, MQPR:$Qm, complexrotateopodd:$rot),
+                   "$Qd, $Qn, $Qm, $rot", vpred_r, "",
+          pattern> {
+  bits<4> Qn;
+  bit rot;
+
+  let Inst{28} = halve;
+  let Inst{21-20} = size;
+  let Inst{19-17} = Qn{2-0};
+  let Inst{16} = 0b0;
+  let Inst{12} = rot;
+  let Inst{8} = 0b1;
+  let Inst{7} = Qn{3};
+  let Inst{0} = 0b0;
+}
+
+def MVE_VCADDi8   : MVE_VxCADD<"vcadd", "i8", 0b00, 0b1>;
+def MVE_VCADDi16  : MVE_VxCADD<"vcadd", "i16", 0b01, 0b1>;
+def MVE_VCADDi32  : MVE_VxCADD<"vcadd", "i32", 0b10, 0b1>;
+
+def MVE_VHCADDs8  : MVE_VxCADD<"vhcadd", "s8", 0b00, 0b0>;
+def MVE_VHCADDs16 : MVE_VxCADD<"vhcadd", "s16", 0b01, 0b0>;
+def MVE_VHCADDs32 : MVE_VxCADD<"vhcadd", "s32", 0b10, 0b0>;
+
+class MVE_VADCSBC<string iname, bit I, bit subtract,
+                  dag carryin, list<dag> pattern=[]>
+  : MVE_qDest_qSrc<iname, "i32", (outs MQPR:$Qd, cl_FPSCR_NZCV:$carryout),
+                   !con((ins MQPR:$Qn, MQPR:$Qm), carryin),
+                   "$Qd, $Qn, $Qm", vpred_r, "", pattern> {
+  bits<4> Qn;
+
+  let Inst{28} = subtract;
+  let Inst{21-20} = 0b11;
+  let Inst{19-17} = Qn{2-0};
+  let Inst{16} = 0b0;
+  let Inst{12} = I;
+  let Inst{8} = 0b1;
+  let Inst{7} = Qn{3};
+  let Inst{0} = 0b0;
+
+  // Custom decoder method in order to add the FPSCR operand(s), which
+  // Tablegen won't do right
+  let DecoderMethod = "DecodeMVEVADCInstruction";
+}
+
+def MVE_VADC  : MVE_VADCSBC<"vadc",  0b0, 0b0, (ins cl_FPSCR_NZCV:$carryin)>;
+def MVE_VADCI : MVE_VADCSBC<"vadci", 0b1, 0b0, (ins)>;
+
+def MVE_VSBC  : MVE_VADCSBC<"vsbc",  0b0, 0b1, (ins cl_FPSCR_NZCV:$carryin)>;
+def MVE_VSBCI : MVE_VADCSBC<"vsbci", 0b1, 0b1, (ins)>;
+
+class MVE_VQDMULL<string iname, string suffix, bit size, bit T,
+                  list<dag> pattern=[]>
+  : MVE_qDest_qSrc<iname, suffix, (outs MQPR:$Qd),
+                   (ins MQPR:$Qn, MQPR:$Qm), "$Qd, $Qn, $Qm",
+                   vpred_r, "", pattern> {
+  bits<4> Qn;
+
+  let Inst{28} = size;
+  let Inst{21-20} = 0b11;
+  let Inst{19-17} = Qn{2-0};
+  let Inst{16} = 0b0;
+  let Inst{12} = T;
+  let Inst{8} = 0b1;
+  let Inst{7} = Qn{3};
+  let Inst{0} = 0b1;
+}
+
+multiclass MVE_VQDMULL_halves<string suffix, bit size> {
+  def bh : MVE_VQDMULL<"vqdmullb", suffix, size, 0b0>;
+  def th : MVE_VQDMULL<"vqdmullt", suffix, size, 0b1>;
+}
+
+defm MVE_VQDMULLs16 : MVE_VQDMULL_halves<"s16", 0b0>;
+defm MVE_VQDMULLs32 : MVE_VQDMULL_halves<"s32", 0b1>;
+
+// end of mve_qDest_qSrc
+
 class MVE_VPT<string suffix, bits<2> size, dag iops, string asm, list<dag> pattern=[]>
   : MVE_MI<(outs ), iops, NoItinerary, !strconcat("vpt", "${Mk}", ".", suffix), asm, "", pattern> {
   bits<3> fc;
diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 28c0f4cbc2b..4f76732fed0 100644
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -5966,6 +5966,7 @@ StringRef ARMAsmParser::splitMnemonic(StringRef Mnemonic,
          Mnemonic == "vnege" || Mnemonic == "vnegt" ||
          Mnemonic == "vmule" || Mnemonic == "vmult" ||
          Mnemonic == "vrintne" ||
+         Mnemonic == "vcmult" || Mnemonic == "vcmule" ||
          Mnemonic.startswith("vq")))) {
     unsigned CC = ARMCondCodeFromString(Mnemonic.substr(Mnemonic.size()-2));
     if (CC != ~0U) {
@@ -6010,7 +6011,10 @@ StringRef ARMAsmParser::splitMnemonic(StringRef Mnemonic,
   if (isMnemonicVPTPredicable(Mnemonic, ExtraToken) && Mnemonic != "vmovlt" &&
       Mnemonic != "vshllt" && Mnemonic != "vrshrnt" && Mnemonic != "vshrnt" &&
       Mnemonic != "vqrshrunt" && Mnemonic != "vqshrunt" &&
-      Mnemonic != "vqrshrnt" && Mnemonic != "vqshrnt" && Mnemonic != "vcvt") {
+      Mnemonic != "vqrshrnt" && Mnemonic != "vqshrnt" && Mnemonic != "vmullt" &&
+      Mnemonic != "vqmovnt" && Mnemonic != "vqmovunt" &&
+      Mnemonic != "vqmovnt" && Mnemonic != "vmovnt" && Mnemonic != "vqdmullt" &&
+      Mnemonic != "vcvtt" && Mnemonic != "vcvt") {
     unsigned CC = ARMVectorCondCodeFromString(Mnemonic.substr(Mnemonic.size()-1));
     if (CC != ~0U) {
       Mnemonic = Mnemonic.slice(0, Mnemonic.size()-1);
@@ -6683,6 +6687,16 @@ bool ARMAsmParser::ParseInstruction(ParseInstructionInfo &Info, StringRef Name,
                       ARMOperand::CreateVPTPred(ARMVCC::Else, PLoc));
       Operands.insert(Operands.begin(),
                       ARMOperand::CreateToken(StringRef("vcvtn"), MLoc));
+    } else if (Mnemonic == "vmul" && PredicationCode == ARMCC::LT &&
+               !shouldOmitVectorPredicateOperand(Mnemonic, Operands)) {
+      // Another hack, this time to distinguish between scalar predicated vmul
+      // with 'lt' predication code and the vector instruction vmullt with
+      // vector predication code "none"
+      Operands.erase(Operands.begin() + 1);
+      Operands.erase(Operands.begin());
+      SMLoc MLoc = SMLoc::getFromPointer(NameLoc.getPointer());
+      Operands.insert(Operands.begin(),
+                      ARMOperand::CreateToken(StringRef("vmullt"), MLoc));
     }
     // For vmov and vcmp, as mentioned earlier, we did not add the vector
     // predication code, since these may contain operands that require
@@ -7541,6 +7555,31 @@ bool ARMAsmParser::validateInstruction(MCInst &Inst,
                    "list of registers must be at least 1 and at most 16");
     break;
   }
+  case ARM::MVE_VQDMULLs32bh:
+  case ARM::MVE_VQDMULLs32th:
+  case ARM::MVE_VCMULf32:
+  case ARM::MVE_VMULLs32bh:
+  case ARM::MVE_VMULLs32th:
+  case ARM::MVE_VMULLu32bh:
+  case ARM::MVE_VMULLu32th:
+  case ARM::MVE_VQDMLADHs32:
+  case ARM::MVE_VQDMLADHXs32:
+  case ARM::MVE_VQRDMLADHs32:
+  case ARM::MVE_VQRDMLADHXs32:
+  case ARM::MVE_VQDMLSDHs32:
+  case ARM::MVE_VQDMLSDHXs32:
+  case ARM::MVE_VQRDMLSDHs32:
+  case ARM::MVE_VQRDMLSDHXs32: {
+    if (Operands[3]->getReg() == Operands[4]->getReg()) {
+      return Error (Operands[3]->getStartLoc(),
+                    "Qd register and Qn register can't be identical");
+    }
+    if (Operands[3]->getReg() == Operands[5]->getReg()) {
+      return Error (Operands[3]->getStartLoc(),
+                    "Qd register and Qm register can't be identical");
+    }
+    break;
+  }
   }
 
   return false;
diff --git a/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index 3d224b6c322..29fa674b3ed 100644
--- a/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -312,6 +312,8 @@ static DecodeStatus DecodeNEONModImmInstruction(MCInst &Inst,unsigned Val,
                                uint64_t Address, const void *Decoder);
 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst,unsigned Val,
                                uint64_t Address, const void *Decoder);
+static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
+                               uint64_t Address, const void *Decoder);
 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
                                uint64_t Address, const void *Decoder);
 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
@@ -3462,6 +3464,31 @@ DecodeMVEModImmInstruction(MCInst &Inst, unsigned Insn,
   return S;
 }
 
+static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
+                               uint64_t Address, const void *Decoder) {
+  DecodeStatus S = MCDisassembler::Success;
+
+  unsigned Qd = fieldFromInstruction(Insn, 13, 3);
+  Qd |= fieldFromInstruction(Insn, 22, 1) << 3;
+  if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
+    return MCDisassembler::Fail;
+  Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
+
+  unsigned Qn = fieldFromInstruction(Insn, 17, 3);
+  Qn |= fieldFromInstruction(Insn, 7, 1) << 3;
+  if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
+    return MCDisassembler::Fail;
+  unsigned Qm = fieldFromInstruction(Insn, 1, 3);
+  Qm |= fieldFromInstruction(Insn, 5, 1) << 3;
+  if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
+    return MCDisassembler::Fail;
+  if (!fieldFromInstruction(Insn, 12, 1)) // I bit clear => need input FPSCR
+    Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
+  Inst.addOperand(MCOperand::createImm(Qd));
+
+  return S;
+}
+
 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
                                         uint64_t Address, const void *Decoder) {
   DecodeStatus S = MCDisassembler::Success;