[AArch64][SVE] Asm: Add SVE (Z) Register definitions and parsing support

Patch [3/5] in a series to add assembler/disassembler support for AArch64 SVE unpredicated ADD/SUB instructions.

To summarise, this patch adds:

 * SVE register definitions
 * Methods to parse SVE register operands
 * Methods to print SVE register operands
 * RegKind SVEDataVector to distinguish it from other data types like scalar register or Neon vector.
 * k_SVEDataRegister and SVEDataRegOp to describe SVE registers (which will be extended by further patches with e.g. ElementWidth and the shift-extend type).


Patch by Sander De Smalen.

Reviewed by: rengolin

Differential Revision: https://reviews.llvm.org/D39089

llvm-svn: 317590

lib/Target/AArch64/AArch64RegisterInfo.td

@@ -32,6 +32,12 @@ let Namespace = "AArch64" in {
   def qsub : SubRegIndex<64>;
   def sube64 : SubRegIndex<64>;
   def subo64 : SubRegIndex<64>;
+  // SVE
+  def zsub    : SubRegIndex<128>;
+  // Note: zsub_hi should never be used directly because it represents
+  // the scalable part of the SVE vector and cannot be manipulated as a
+  // subvector in the same way the lower 128bits can.
+  def zsub_hi : SubRegIndex<128>;
   // Note: Code depends on these having consecutive numbers
   def dsub0 : SubRegIndex<64>;
   def dsub1 : SubRegIndex<64>;
@@ -645,3 +651,119 @@ def XSeqPairClassOperand :
 
 
 //===----- END: v8.1a atomic CASP register operands -----------------------===//
+
+// The part of SVE registers that don't overlap Neon registers.
+// These are only used as part of clobber lists.
+def Z0_HI    : AArch64Reg<0,   "z0_hi">;
+def Z1_HI    : AArch64Reg<1,   "z1_hi">;
+def Z2_HI    : AArch64Reg<2,   "z2_hi">;
+def Z3_HI    : AArch64Reg<3,   "z3_hi">;
+def Z4_HI    : AArch64Reg<4,   "z4_hi">;
+def Z5_HI    : AArch64Reg<5,   "z5_hi">;
+def Z6_HI    : AArch64Reg<6,   "z6_hi">;
+def Z7_HI    : AArch64Reg<7,   "z7_hi">;
+def Z8_HI    : AArch64Reg<8,   "z8_hi">;
+def Z9_HI    : AArch64Reg<9,   "z9_hi">;
+def Z10_HI   : AArch64Reg<10, "z10_hi">;
+def Z11_HI   : AArch64Reg<11, "z11_hi">;
+def Z12_HI   : AArch64Reg<12, "z12_hi">;
+def Z13_HI   : AArch64Reg<13, "z13_hi">;
+def Z14_HI   : AArch64Reg<14, "z14_hi">;
+def Z15_HI   : AArch64Reg<15, "z15_hi">;
+def Z16_HI   : AArch64Reg<16, "z16_hi">;
+def Z17_HI   : AArch64Reg<17, "z17_hi">;
+def Z18_HI   : AArch64Reg<18, "z18_hi">;
+def Z19_HI   : AArch64Reg<19, "z19_hi">;
+def Z20_HI   : AArch64Reg<20, "z20_hi">;
+def Z21_HI   : AArch64Reg<21, "z21_hi">;
+def Z22_HI   : AArch64Reg<22, "z22_hi">;
+def Z23_HI   : AArch64Reg<23, "z23_hi">;
+def Z24_HI   : AArch64Reg<24, "z24_hi">;
+def Z25_HI   : AArch64Reg<25, "z25_hi">;
+def Z26_HI   : AArch64Reg<26, "z26_hi">;
+def Z27_HI   : AArch64Reg<27, "z27_hi">;
+def Z28_HI   : AArch64Reg<28, "z28_hi">;
+def Z29_HI   : AArch64Reg<29, "z29_hi">;
+def Z30_HI   : AArch64Reg<30, "z30_hi">;
+def Z31_HI   : AArch64Reg<31, "z31_hi">;
+
+// SVE variable-size vector registers
+let SubRegIndices = [zsub,zsub_hi] in {
+def Z0    : AArch64Reg<0,   "z0",  [Q0,  Z0_HI]>, DwarfRegNum<[96]>;
+def Z1    : AArch64Reg<1,   "z1",  [Q1,  Z1_HI]>, DwarfRegNum<[97]>;
+def Z2    : AArch64Reg<2,   "z2",  [Q2,  Z2_HI]>, DwarfRegNum<[98]>;
+def Z3    : AArch64Reg<3,   "z3",  [Q3,  Z3_HI]>, DwarfRegNum<[99]>;
+def Z4    : AArch64Reg<4,   "z4",  [Q4,  Z4_HI]>, DwarfRegNum<[100]>;
+def Z5    : AArch64Reg<5,   "z5",  [Q5,  Z5_HI]>, DwarfRegNum<[101]>;
+def Z6    : AArch64Reg<6,   "z6",  [Q6,  Z6_HI]>, DwarfRegNum<[102]>;
+def Z7    : AArch64Reg<7,   "z7",  [Q7,  Z7_HI]>, DwarfRegNum<[103]>;
+def Z8    : AArch64Reg<8,   "z8",  [Q8,  Z8_HI]>, DwarfRegNum<[104]>;
+def Z9    : AArch64Reg<9,   "z9",  [Q9,  Z9_HI]>, DwarfRegNum<[105]>;
+def Z10   : AArch64Reg<10, "z10", [Q10, Z10_HI]>, DwarfRegNum<[106]>;
+def Z11   : AArch64Reg<11, "z11", [Q11, Z11_HI]>, DwarfRegNum<[107]>;
+def Z12   : AArch64Reg<12, "z12", [Q12, Z12_HI]>, DwarfRegNum<[108]>;
+def Z13   : AArch64Reg<13, "z13", [Q13, Z13_HI]>, DwarfRegNum<[109]>;
+def Z14   : AArch64Reg<14, "z14", [Q14, Z14_HI]>, DwarfRegNum<[110]>;
+def Z15   : AArch64Reg<15, "z15", [Q15, Z15_HI]>, DwarfRegNum<[111]>;
+def Z16   : AArch64Reg<16, "z16", [Q16, Z16_HI]>, DwarfRegNum<[112]>;
+def Z17   : AArch64Reg<17, "z17", [Q17, Z17_HI]>, DwarfRegNum<[113]>;
+def Z18   : AArch64Reg<18, "z18", [Q18, Z18_HI]>, DwarfRegNum<[114]>;
+def Z19   : AArch64Reg<19, "z19", [Q19, Z19_HI]>, DwarfRegNum<[115]>;
+def Z20   : AArch64Reg<20, "z20", [Q20, Z20_HI]>, DwarfRegNum<[116]>;
+def Z21   : AArch64Reg<21, "z21", [Q21, Z21_HI]>, DwarfRegNum<[117]>;
+def Z22   : AArch64Reg<22, "z22", [Q22, Z22_HI]>, DwarfRegNum<[118]>;
+def Z23   : AArch64Reg<23, "z23", [Q23, Z23_HI]>, DwarfRegNum<[119]>;
+def Z24   : AArch64Reg<24, "z24", [Q24, Z24_HI]>, DwarfRegNum<[120]>;
+def Z25   : AArch64Reg<25, "z25", [Q25, Z25_HI]>, DwarfRegNum<[121]>;
+def Z26   : AArch64Reg<26, "z26", [Q26, Z26_HI]>, DwarfRegNum<[122]>;
+def Z27   : AArch64Reg<27, "z27", [Q27, Z27_HI]>, DwarfRegNum<[123]>;
+def Z28   : AArch64Reg<28, "z28", [Q28, Z28_HI]>, DwarfRegNum<[124]>;
+def Z29   : AArch64Reg<29, "z29", [Q29, Z29_HI]>, DwarfRegNum<[125]>;
+def Z30   : AArch64Reg<30, "z30", [Q30, Z30_HI]>, DwarfRegNum<[126]>;
+def Z31   : AArch64Reg<31, "z31", [Q31, Z31_HI]>, DwarfRegNum<[127]>;
+}
+
+class SVERegOp <string Suffix, AsmOperandClass C,
+                RegisterClass RC> : RegisterOperand<RC> {
+  let PrintMethod = !if(!eq(Suffix, ""),
+                        "printSVERegOp<>",
+                        "printSVERegOp<'" # Suffix # "'>");
+  let ParserMatchClass = C;
+}
+
+class ZPRRegOp <string Suffix, AsmOperandClass C,
+                RegisterClass RC> : SVERegOp<Suffix, C, RC> {}
+
+//******************************************************************************
+
+// SVE vector register class
+def ZPR : RegisterClass<"AArch64",
+                        [nxv16i8, nxv8i16, nxv4i32, nxv2i64,
+                         nxv2f16, nxv4f16, nxv8f16,
+                         nxv1f32, nxv2f32, nxv4f32,
+                         nxv1f64, nxv2f64],
+                        128, (sequence "Z%u", 0, 31)> {
+  let Size = 128;
+}
+
+class ZPRAsmOperand <string name, int Width>: AsmOperandClass {
+  let Name = "SVE" # name # "Reg";
+  let PredicateMethod = "isSVEDataVectorRegOfWidth<" # Width # ">";
+  let RenderMethod = "addRegOperands";
+  let ParserMethod = "tryParseSVEDataVector<"
+                               # !if(!eq(Width, -1), "false", "true") # ">";
+}
+
+def ZPRAsmOpAny : ZPRAsmOperand<"VectorAny", -1>;
+def ZPRAsmOp8   : ZPRAsmOperand<"VectorB",   8>;
+def ZPRAsmOp16  : ZPRAsmOperand<"VectorH",   16>;
+def ZPRAsmOp32  : ZPRAsmOperand<"VectorS",   32>;
+def ZPRAsmOp64  : ZPRAsmOperand<"VectorD",   64>;
+def ZPRAsmOp128 : ZPRAsmOperand<"VectorQ",   128>;
+
+def ZPRAny  : ZPRRegOp<"",  ZPRAsmOpAny, ZPR>;
+def ZPR8    : ZPRRegOp<"b", ZPRAsmOp8,   ZPR>;
+def ZPR16   : ZPRRegOp<"h", ZPRAsmOp16,  ZPR>;
+def ZPR32   : ZPRRegOp<"s", ZPRAsmOp32,  ZPR>;
+def ZPR64   : ZPRRegOp<"d", ZPRAsmOp64,  ZPR>;
+def ZPR128  : ZPRRegOp<"q", ZPRAsmOp128, ZPR>;

lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp

@@ -59,7 +59,7 @@ using namespace llvm;
 
 namespace {
 
-enum class RegKind {Scalar, NeonVector};
+enum class RegKind {Scalar, NeonVector, SVEDataVector};
 
 class AArch64AsmParser : public MCTargetAsmParser {
 private:
@@ -82,6 +82,7 @@ private:
   unsigned matchRegisterNameAlias(StringRef Name, RegKind Kind);
   int tryParseRegister();
   int tryMatchVectorRegister(StringRef &Kind, bool expected);
+  int tryParseSVEDataVectorRegister(const AsmToken &Tok, StringRef &Kind);
   bool parseRegister(OperandVector &Operands);
   bool parseSymbolicImmVal(const MCExpr *&ImmVal);
   bool parseVectorList(OperandVector &Operands);
@@ -130,6 +131,8 @@ private:
   OperandMatchResultTy tryParseGPR64sp0Operand(OperandVector &Operands);
   bool tryParseNeonVectorRegister(OperandVector &Operands);
   OperandMatchResultTy tryParseGPRSeqPair(OperandVector &Operands);
+  template <bool ParseSuffix>
+  OperandMatchResultTy tryParseSVEDataVector(OperandVector &Operands);
 
 public:
   enum AArch64MatchResultTy {
@@ -197,6 +200,8 @@ private:
   struct RegOp {
     unsigned RegNum;
     RegKind Kind;
+
+    int ElementWidth;
   };
 
   struct VectorListOp {
@@ -820,6 +825,17 @@ public:
                Reg.RegNum);
   }
 
+  template <unsigned Class = AArch64::ZPRRegClassID>
+  bool isSVEDataVectorReg() const {
+    return (Kind == k_Register && Reg.Kind == RegKind::SVEDataVector) &&
+           AArch64MCRegisterClasses[Class].contains(getReg());
+  }
+
+  template <int ElementWidth> bool isSVEDataVectorRegOfWidth() const {
+    return isSVEDataVectorReg() &&
+           (ElementWidth == -1 || Reg.ElementWidth == ElementWidth);
+  }
+
   bool isGPR32as64() const {
     return Kind == k_Register && Reg.Kind == RegKind::Scalar &&
       AArch64MCRegisterClasses[AArch64::GPR64RegClassID].contains(Reg.RegNum);
@@ -1580,6 +1596,18 @@ public:
     return Op;
   }
 
+  static std::unique_ptr<AArch64Operand>
+  CreateReg(unsigned RegNum, RegKind Kind, unsigned ElementWidth,
+            SMLoc S, SMLoc E, MCContext &Ctx) {
+    auto Op = make_unique<AArch64Operand>(k_Register, Ctx);
+    Op->Reg.RegNum = RegNum;
+    Op->Reg.ElementWidth = ElementWidth;
+    Op->Reg.Kind = Kind;
+    Op->StartLoc = S;
+    Op->EndLoc = E;
+    return Op;
+  }
+
   static std::unique_ptr<AArch64Operand>
   CreateVectorList(unsigned RegNum, unsigned Count, unsigned NumElements,
                    char ElementKind, SMLoc S, SMLoc E, MCContext &Ctx) {
@@ -1860,6 +1888,57 @@ static bool isValidVectorKind(StringRef Name) {
       .Default(false);
 }
 
+static unsigned matchSVEDataVectorRegName(StringRef Name) {
+  return StringSwitch<unsigned>(Name.lower())
+      .Case("z0", AArch64::Z0)
+      .Case("z1", AArch64::Z1)
+      .Case("z2", AArch64::Z2)
+      .Case("z3", AArch64::Z3)
+      .Case("z4", AArch64::Z4)
+      .Case("z5", AArch64::Z5)
+      .Case("z6", AArch64::Z6)
+      .Case("z7", AArch64::Z7)
+      .Case("z8", AArch64::Z8)
+      .Case("z9", AArch64::Z9)
+      .Case("z10", AArch64::Z10)
+      .Case("z11", AArch64::Z11)
+      .Case("z12", AArch64::Z12)
+      .Case("z13", AArch64::Z13)
+      .Case("z14", AArch64::Z14)
+      .Case("z15", AArch64::Z15)
+      .Case("z16", AArch64::Z16)
+      .Case("z17", AArch64::Z17)
+      .Case("z18", AArch64::Z18)
+      .Case("z19", AArch64::Z19)
+      .Case("z20", AArch64::Z20)
+      .Case("z21", AArch64::Z21)
+      .Case("z22", AArch64::Z22)
+      .Case("z23", AArch64::Z23)
+      .Case("z24", AArch64::Z24)
+      .Case("z25", AArch64::Z25)
+      .Case("z26", AArch64::Z26)
+      .Case("z27", AArch64::Z27)
+      .Case("z28", AArch64::Z28)
+      .Case("z29", AArch64::Z29)
+      .Case("z30", AArch64::Z30)
+      .Case("z31", AArch64::Z31)
+      .Default(0);
+}
+
+static bool isValidSVEKind(StringRef Name) {
+  return StringSwitch<bool>(Name.lower())
+      .Case(".b", true)
+      .Case(".h", true)
+      .Case(".s", true)
+      .Case(".d", true)
+      .Case(".q", true)
+      .Default(false);
+}
+
+static bool isSVEDataVectorRegister(StringRef Name) {
+  return Name[0] == 'z';
+}
+
 static void parseValidVectorKind(StringRef Name, unsigned &NumElements,
                                  char &ElementKind) {
   assert(isValidVectorKind(Name));
@@ -1897,6 +1976,9 @@ unsigned AArch64AsmParser::matchRegisterNameAlias(StringRef Name,
   case RegKind::NeonVector:
     RegNum = MatchNeonVectorRegName(Name);
     break;
+  case RegKind::SVEDataVector:
+    RegNum = matchSVEDataVectorRegName(Name);
+    break;
   }
 
   if (!RegNum) {
@@ -1924,6 +2006,9 @@ int AArch64AsmParser::tryParseRegister() {
     return -1;
 
   std::string lowerCase = Tok.getString().lower();
+  if (isSVEDataVectorRegister(lowerCase))
+    return -1;
+
   unsigned RegNum = matchRegisterNameAlias(lowerCase, RegKind::Scalar);
   // Also handle a few aliases of registers.
   if (RegNum == 0)
@@ -2620,6 +2705,35 @@ bool AArch64AsmParser::tryParseNeonVectorRegister(OperandVector &Operands) {
   return false;
 }
 
+// tryParseSVEDataVectorRegister - Try to parse a SVE vector register name with
+// optional kind specifier. If it is a register specifier, eat the token
+// and return it.
+int AArch64AsmParser::tryParseSVEDataVectorRegister(const AsmToken &Tok,
+                                                StringRef &Kind) {
+  if (Tok.isNot(AsmToken::Identifier))
+    return -1;
+
+  StringRef Name = Tok.getString();
+  // If there is a kind specifier, it's separated from the register name by
+  // a '.'.
+  size_t Start = 0, Next = Name.find('.');
+  StringRef Head = Name.slice(Start, Next);
+  unsigned RegNum = matchRegisterNameAlias(Head, RegKind::SVEDataVector);
+
+  if (RegNum) {
+    if (Next != StringRef::npos) {
+      Kind = Name.slice(Next, StringRef::npos);
+      if (!isValidSVEKind(Kind)) {
+        TokError("invalid sve vector kind qualifier");
+        return -1;
+      }
+    }
+    return RegNum;
+  }
+
+  return -1;
+}
+
 /// parseRegister - Parse a non-vector register operand.
 bool AArch64AsmParser::parseRegister(OperandVector &Operands) {
   SMLoc S = getLoc();
@@ -4188,6 +4302,17 @@ bool AArch64AsmParser::parseDirectiveReq(StringRef Name, SMLoc L) {
       return Error(SRegLoc, "vector register without type specifier expected");
   }
 
+  if (RegNum == static_cast<unsigned>(-1)) {
+    StringRef Kind;
+    RegisterKind = RegKind::SVEDataVector;
+    int RegNumTmp = tryParseSVEDataVectorRegister(Parser.getTok(), Kind);
+    if (RegNumTmp != -1)
+      Parser.Lex();
+    RegNum = RegNumTmp;
+    if (!Kind.empty())
+      return Error(SRegLoc, "sve vector register without type specifier expected");
+  }
+
   if (RegNum == static_cast<unsigned>(-1))
     return Error(SRegLoc, "register name or alias expected");
 
@@ -4413,3 +4538,38 @@ AArch64AsmParser::tryParseGPRSeqPair(OperandVector &Operands) {
 
   return MatchOperand_Success;
 }
+
+template <bool ParseSuffix>
+OperandMatchResultTy
+AArch64AsmParser::tryParseSVEDataVector(OperandVector &Operands) {
+  MCAsmParser &Parser = getParser();
+  const SMLoc S = getLoc();
+  // Check for a SVE vector register specifier first.
+  StringRef Kind;
+  int RegNum = tryParseSVEDataVectorRegister(Parser.getTok(), Kind);
+  if (RegNum == -1)
+    return MatchOperand_NoMatch;
+
+  // Eat the SVE Register Token
+  Parser.Lex();
+
+  if (ParseSuffix && Kind.empty())
+    return MatchOperand_NoMatch;
+
+  unsigned ElementWidth = StringSwitch<unsigned>(Kind.lower())
+                        .Case("", -1)
+                        .Case(".b", 8)
+                        .Case(".h", 16)
+                        .Case(".s", 32)
+                        .Case(".d", 64)
+                        .Case(".q", 128)
+                        .Default(0);
+  if (!ElementWidth)
+    return MatchOperand_NoMatch;
+
+  Operands.push_back(
+    AArch64Operand::CreateReg(RegNum, RegKind::SVEDataVector, ElementWidth,
+                              S, S, getContext()));
+
+  return MatchOperand_Success;
+}

lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp

@@ -85,6 +85,9 @@ static DecodeStatus DecodeDDDRegisterClass(MCInst &Inst, unsigned RegNo,
 static DecodeStatus DecodeDDDDRegisterClass(MCInst &Inst, unsigned RegNo,
                                             uint64_t Address,
                                             const void *Decoder);
+static DecodeStatus DecodeZPRRegisterClass(MCInst &Inst, unsigned RegNo,
+                                           uint64_t Address,
+                                           const void *Decode);
 
 static DecodeStatus DecodeFixedPointScaleImm32(MCInst &Inst, unsigned Imm,
                                                uint64_t Address,
@@ -436,6 +439,27 @@ static DecodeStatus DecodeGPR32spRegisterClass(MCInst &Inst, unsigned RegNo,
   Inst.addOperand(MCOperand::createReg(Register));
   return Success;
 }
+static const unsigned ZPRDecoderTable[] = {
+    AArch64::Z0,  AArch64::Z1,  AArch64::Z2,  AArch64::Z3,
+    AArch64::Z4,  AArch64::Z5,  AArch64::Z6,  AArch64::Z7,
+    AArch64::Z8,  AArch64::Z9,  AArch64::Z10, AArch64::Z11,
+    AArch64::Z12, AArch64::Z13, AArch64::Z14, AArch64::Z15,
+    AArch64::Z16, AArch64::Z17, AArch64::Z18, AArch64::Z19,
+    AArch64::Z20, AArch64::Z21, AArch64::Z22, AArch64::Z23,
+    AArch64::Z24, AArch64::Z25, AArch64::Z26, AArch64::Z27,
+    AArch64::Z28, AArch64::Z29, AArch64::Z30, AArch64::Z31
+};
+
+static DecodeStatus DecodeZPRRegisterClass(MCInst &Inst, unsigned RegNo,
+                                           uint64_t Address,
+                                           const void* Decoder) {
+  if (RegNo > 31)
+    return Fail;
+
+  unsigned Register = ZPRDecoderTable[RegNo];
+  Inst.addOperand(MCOperand::createReg(Register));
+  return Success;
+}
 
 static const unsigned VectorDecoderTable[] = {
     AArch64::Q0,  AArch64::Q1,  AArch64::Q2,  AArch64::Q3,  AArch64::Q4,

lib/Target/AArch64/InstPrinter/AArch64InstPrinter.cpp

@@ -1340,3 +1340,23 @@ void AArch64InstPrinter::printComplexRotationOp(const MCInst *MI, unsigned OpNo,
   O << "#" << (Val * Angle) + Remainder;
 }
 
+template <char suffix>
+void AArch64InstPrinter::printSVERegOp(const MCInst *MI, unsigned OpNum,
+                                       const MCSubtargetInfo &STI,
+                                       raw_ostream &O) {
+  switch (suffix) {
+  case 0:
+  case 'b':
+  case 'h':
+  case 's':
+  case 'd':
+  case 'q':
+    break;
+  default: llvm_unreachable("Invalid kind specifier.");
+  }
+
+  unsigned Reg = MI->getOperand(OpNum).getReg();
+  O << getRegisterName(Reg);
+  if (suffix != 0)
+    O << '.' << suffix;
+}

lib/Target/AArch64/InstPrinter/AArch64InstPrinter.h

@@ -165,6 +165,9 @@ protected:
   void printGPRSeqPairsClassOperand(const MCInst *MI, unsigned OpNum,
                                     const MCSubtargetInfo &STI,
                                     raw_ostream &O);
+  template <char = 0>
+  void printSVERegOp(const MCInst *MI, unsigned OpNum,
+                    const MCSubtargetInfo &STI, raw_ostream &O);
 };
 
 class AArch64AppleInstPrinter : public AArch64InstPrinter {