[Xtensa] Implement Xtensa Floating Point Option.

llvm/lib/Target/Xtensa/AsmParser/XtensaAsmParser.cpp

@@ -35,7 +35,7 @@ using namespace llvm;
 struct XtensaOperand;
 
 class XtensaAsmParser : public MCTargetAsmParser {
-
+  enum XtensaRegisterType { Xtensa_Generic, Xtensa_SR, Xtensa_UR };
   SMLoc getLoc() const { return getParser().getTok().getLoc(); }
 
   XtensaTargetStreamer &getTargetStreamer() {
@@ -63,10 +63,10 @@ class XtensaAsmParser : public MCTargetAsmParser {
 
   ParseStatus parseImmediate(OperandVector &Operands);
   ParseStatus parseRegister(OperandVector &Operands, bool AllowParens = false,
-                            bool SR = false);
+                            XtensaRegisterType SR = Xtensa_Generic);
   ParseStatus parseOperandWithModifier(OperandVector &Operands);
   bool parseOperand(OperandVector &Operands, StringRef Mnemonic,
-                    bool SR = false);
+                    XtensaRegisterType SR = Xtensa_Generic);
   bool ParseInstructionWithSR(ParseInstructionInfo &Info, StringRef Name,
                               SMLoc NameLoc, OperandVector &Operands);
   ParseStatus tryParseRegister(MCRegister &Reg, SMLoc &StartLoc,
@@ -586,7 +586,8 @@ bool XtensaAsmParser::parseRegister(MCRegister &Reg, SMLoc &StartLoc,
 }
 
 ParseStatus XtensaAsmParser::parseRegister(OperandVector &Operands,
-                                           bool AllowParens, bool SR) {
+                                           bool AllowParens,
+                                           XtensaRegisterType RegType) {
   SMLoc FirstS = getLoc();
   bool HadParens = false;
   AsmToken Buf[2];
@@ -596,25 +597,33 @@ ParseStatus XtensaAsmParser::parseRegister(OperandVector &Operands,
   if (AllowParens && getLexer().is(AsmToken::LParen)) {
     size_t ReadCount = getLexer().peekTokens(Buf);
     if (ReadCount == 2 && Buf[1].getKind() == AsmToken::RParen) {
-      if ((Buf[0].getKind() == AsmToken::Integer) && (!SR))
+      if ((Buf[0].getKind() == AsmToken::Integer) &&
+          (RegType == Xtensa_Generic))
         return ParseStatus::NoMatch;
       HadParens = true;
       getParser().Lex(); // Eat '('
     }
   }
 
-  unsigned RegNo = 0;
+  MCRegister RegNo = 0;
 
   switch (getLexer().getKind()) {
   default:
     return ParseStatus::NoMatch;
   case AsmToken::Integer:
-    if (!SR)
+    if (RegType == Xtensa_Generic)
       return ParseStatus::NoMatch;
-    RegName = getLexer().getTok().getString();
-    RegNo = MatchRegisterName(RegName);
-    if (RegNo == 0)
+
+    // Parse case when we expect UR register code as special case,
+    // because SR and UR registers may have the same number
+    // and such situation may lead to confilct
+    if (RegType == Xtensa_UR) {
+      int64_t RegCode = getLexer().getTok().getIntVal();
+      RegNo = Xtensa::getUserRegister(RegCode);
+    } else {
+      RegName = getLexer().getTok().getString();
       RegNo = MatchRegisterAltName(RegName);
+    }
     break;
   case AsmToken::Identifier:
     RegName = getLexer().getTok().getIdentifier();
@@ -691,7 +700,7 @@ ParseStatus XtensaAsmParser::parseOperandWithModifier(OperandVector &Operands) {
 /// from this information, adding to Operands.
 /// If operand was parsed, returns false, else true.
 bool XtensaAsmParser::parseOperand(OperandVector &Operands, StringRef Mnemonic,
-                                   bool SR) {
+                                   XtensaRegisterType RegType) {
   // Check if the current operand has a custom associated parser, if so, try to
   // custom parse the operand, or fallback to the general approach.
   ParseStatus Res = MatchOperandParserImpl(Operands, Mnemonic);
@@ -705,7 +714,7 @@ bool XtensaAsmParser::parseOperand(OperandVector &Operands, StringRef Mnemonic,
     return true;
 
   // Attempt to parse token as register
-  if (parseRegister(Operands, true, SR).isSuccess())
+  if (parseRegister(Operands, true, RegType).isSuccess())
     return false;
 
   // Attempt to parse token as an immediate
@@ -719,11 +728,9 @@ bool XtensaAsmParser::parseOperand(OperandVector &Operands, StringRef Mnemonic,
 bool XtensaAsmParser::ParseInstructionWithSR(ParseInstructionInfo &Info,
                                              StringRef Name, SMLoc NameLoc,
                                              OperandVector &Operands) {
-  if ((Name.starts_with("wsr.") || Name.starts_with("rsr.") ||
-       Name.starts_with("xsr.")) &&
-      (Name.size() > 4)) {
-    // Parse case when instruction name is concatenated with SR register
-    // name, like "wsr.sar a1"
+  if ((Name.size() > 4) && Name[3] == '.') {
+    // Parse case when instruction name is concatenated with SR/UR register
+    // name, like "wsr.sar a1" or "wur.fcr a1"
 
     // First operand is token for instruction
     Operands.push_back(XtensaOperand::createToken(Name.take_front(3), NameLoc));
@@ -759,7 +766,7 @@ bool XtensaAsmParser::ParseInstructionWithSR(ParseInstructionInfo &Info,
     }
 
     // Parse second operand
-    if (parseOperand(Operands, Name, true))
+    if (parseOperand(Operands, Name, Name[1] == 's' ? Xtensa_SR : Xtensa_UR))
       return true;
   }
 
@@ -777,7 +784,8 @@ bool XtensaAsmParser::parseInstruction(ParseInstructionInfo &Info,
                                        StringRef Name, SMLoc NameLoc,
                                        OperandVector &Operands) {
   if (Name.starts_with("wsr") || Name.starts_with("rsr") ||
-      Name.starts_with("xsr")) {
+      Name.starts_with("xsr") || Name.starts_with("rur") ||
+      Name.starts_with("wur")) {
     return ParseInstructionWithSR(Info, Name, NameLoc, Operands);
   }
 

llvm/lib/Target/Xtensa/Disassembler/XtensaDisassembler.cpp

@@ -113,6 +113,39 @@ static DecodeStatus DecodeMR23RegisterClass(MCInst &Inst, uint64_t RegNo,
   return MCDisassembler::Success;
 }
 
+static const MCPhysReg FPRDecoderTable[] = {
+    Xtensa::F0,  Xtensa::F1,  Xtensa::F2,  Xtensa::F3, Xtensa::F4,  Xtensa::F5,
+    Xtensa::F6,  Xtensa::F7,  Xtensa::F8,  Xtensa::F9, Xtensa::F10, Xtensa::F11,
+    Xtensa::F12, Xtensa::F13, Xtensa::F14, Xtensa::F15};
+
+static DecodeStatus DecodeFPRRegisterClass(MCInst &Inst, uint64_t RegNo,
+                                           uint64_t Address,
+                                           const void *Decoder) {
+  if (RegNo >= std::size(FPRDecoderTable))
+    return MCDisassembler::Fail;
+
+  MCPhysReg Reg = FPRDecoderTable[RegNo];
+  Inst.addOperand(MCOperand::createReg(Reg));
+  return MCDisassembler::Success;
+}
+
+static DecodeStatus DecodeURRegisterClass(MCInst &Inst, uint64_t RegNo,
+                                          uint64_t Address,
+                                          const MCDisassembler *Decoder) {
+  const llvm::MCSubtargetInfo STI =
+      ((const MCDisassembler *)Decoder)->getSubtargetInfo();
+
+  if (RegNo > 255)
+    return MCDisassembler::Fail;
+
+  MCPhysReg Reg = Xtensa::getUserRegister(RegNo);
+  if (!Xtensa::checkRegister(Reg, Decoder->getSubtargetInfo().getFeatureBits()))
+    return MCDisassembler::Fail;
+
+  Inst.addOperand(MCOperand::createReg(Reg));
+  return MCDisassembler::Success;
+}
+
 const MCPhysReg SRDecoderTable[] = {
     Xtensa::SAR, 3,  Xtensa::ACCLO,      16, Xtensa::ACCHI,       17,
     Xtensa::M0,  32, Xtensa::M1,         33, Xtensa::M2,          34,

llvm/lib/Target/Xtensa/MCTargetDesc/XtensaMCCodeEmitter.cpp

@@ -307,6 +307,11 @@ XtensaMCCodeEmitter::getMemRegEncoding(const MCInst &MI, unsigned OpNo,
   case Xtensa::L32I:
   case Xtensa::S32I_N:
   case Xtensa::L32I_N:
+  case Xtensa::SSI:
+  case Xtensa::SSIP:
+  case Xtensa::LSI:
+  case Xtensa::LSIP:
+
     if (Res & 0x3) {
       report_fatal_error("Unexpected operand value!");
     }

llvm/lib/Target/Xtensa/MCTargetDesc/XtensaMCTargetDesc.cpp

@@ -83,6 +83,9 @@ bool Xtensa::checkRegister(MCRegister RegNo, const FeatureBitset &FeatureBits) {
   case Xtensa::LEND:
   case Xtensa::LCOUNT:
     return FeatureBits[Xtensa::FeatureLoop];
+  case Xtensa::FCR:
+  case Xtensa::FSR:
+    return FeatureBits[FeatureSingleFloat];
   case Xtensa::WINDOWBASE:
   case Xtensa::WINDOWSTART:
     return FeatureBits[Xtensa::FeatureWindowed];
@@ -93,6 +96,17 @@ bool Xtensa::checkRegister(MCRegister RegNo, const FeatureBitset &FeatureBits) {
   return true;
 }
 
+// Get Xtensa User Register by encoding value.
+MCRegister Xtensa::getUserRegister(unsigned Code) {
+  switch (Code) {
+  case 232:
+    return Xtensa::FCR;
+  case 233:
+    return Xtensa::FSR;
+  }
+  return Xtensa::NoRegister;
+}
+
 static MCAsmInfo *createXtensaMCAsmInfo(const MCRegisterInfo &MRI,
                                         const Triple &TT,
                                         const MCTargetOptions &Options) {

llvm/lib/Target/Xtensa/MCTargetDesc/XtensaMCTargetDesc.h

@@ -57,6 +57,9 @@ bool isValidAddrOffsetForOpcode(unsigned Opcode, int64_t Offset);
 
 // Verify if it's correct to use a special register.
 bool checkRegister(MCRegister RegNo, const FeatureBitset &FeatureBits);
+
+// Get Xtensa User Register by register encoding value.
+MCRegister getUserRegister(unsigned Code);
 } // namespace Xtensa
 } // end namespace llvm
 

llvm/lib/Target/Xtensa/XtensaCallingConv.td

@@ -15,6 +15,7 @@
 def RetCC_Xtensa : CallingConv<[
   // First two return values go in a2, a3, a4, a5
   CCIfType<[i32], CCAssignToReg<[A2, A3, A4, A5]>>,
+  CCIfType<[f32], CCAssignToReg<[A2, A3, A4, A5]>>,
   CCIfType<[i64], CCAssignToRegWithShadow<[A2, A4], [A3, A5]>>
 ]>;
 

llvm/lib/Target/Xtensa/XtensaFeatures.td

@@ -8,6 +8,11 @@ def FeatureDensity : SubtargetFeature<"density", "HasDensity", "true",
 def HasDensity : Predicate<"Subtarget->hasDensity()">,
                  AssemblerPredicate<(all_of FeatureDensity)>;
 
+def FeatureSingleFloat : SubtargetFeature<"fp", "HasSingleFloat", "true",
+                                          "Enable Xtensa Single FP instructions">;
+def HasSingleFloat : Predicate<"Subtarget->hasSingleFloat()">,
+                     AssemblerPredicate<(all_of FeatureSingleFloat)>;
+
 def FeatureWindowed : SubtargetFeature<"windowed", "HasWindowed", "true",
                                        "Enable Xtensa Windowed Register option">;
 def HasWindowed : Predicate<"Subtarget->hasWindowed()">,