diff --git a/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp b/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
--- a/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
+++ b/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
@@ -51,6 +51,7 @@
           "Number of RISC-V Compressed instructions emitted");
 
 namespace {
+struct InsnMatchEntry;
 struct RISCVOperand;
 
 struct ParserOptionsSet {
@@ -169,6 +170,9 @@
 
   bool parseDirectiveOption();
   bool parseDirectiveAttribute();
+  bool parseDirectiveInsn(SMLoc L);
+  bool parseInsnOpcode(OperandVector &Operands);
+  bool parseInsnOperand(OperandVector &Operands, const InsnMatchEntry *Entry);
 
   void setFeatureBits(uint64_t Feature, StringRef FeatureString) {
     if (!(getSTI().getFeatureBits()[Feature])) {
@@ -504,6 +508,24 @@
     return (isRV64() && isUInt<5>(Imm)) || isUInt<4>(Imm);
   }
 
+  bool isUImm2() const {
+    int64_t Imm;
+    RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
+    if (!isImm())
+      return false;
+    bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
+    return IsConstantImm && isUInt<2>(Imm) && VK == RISCVMCExpr::VK_RISCV_None;
+  }
+
+  bool isUImm3() const {
+    int64_t Imm;
+    RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
+    if (!isImm())
+      return false;
+    bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
+    return IsConstantImm && isUInt<3>(Imm) && VK == RISCVMCExpr::VK_RISCV_None;
+  }
+
   bool isUImm5() const {
     int64_t Imm;
     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
@@ -513,6 +535,15 @@
     return IsConstantImm && isUInt<5>(Imm) && VK == RISCVMCExpr::VK_RISCV_None;
   }
 
+  bool isUImm7() const {
+    int64_t Imm;
+    RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
+    if (!isImm())
+      return false;
+    bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
+    return IsConstantImm && isUInt<7>(Imm) && VK == RISCVMCExpr::VK_RISCV_None;
+  }
+
   bool isSImm5() const {
     if (!isImm())
       return false;
@@ -1002,7 +1033,7 @@
   }
   case Match_InvalidOperand: {
     SMLoc ErrorLoc = IDLoc;
-    if (ErrorInfo != ~0U) {
+    if (ErrorInfo != ~0ULL) {
       if (ErrorInfo >= Operands.size())
         return Error(ErrorLoc, "too few operands for instruction");
 
@@ -1835,8 +1866,10 @@
 
   if (IDVal == ".option")
     return parseDirectiveOption();
-  else if (IDVal == ".attribute")
+  if (IDVal == ".attribute")
     return parseDirectiveAttribute();
+  if (IDVal == ".insn")
+    return parseDirectiveInsn(DirectiveID.getLoc());
 
   return true;
 }
@@ -2200,6 +2233,248 @@
   return false;
 }
 
+namespace {
+// Used for the .insn directives; contains information needed to parse the
+// operands in the directive.
+struct InsnMatchEntry {
+  StringRef Format;
+  uint32_t Opcode;
+  MatchClassKind OperandKinds[7];
+};
+
+// For equal_range comparison.
+struct CompareInsn {
+  bool operator()(const InsnMatchEntry &LHS, StringRef RHS) {
+    return LHS.Format < RHS;
+  }
+  bool operator()(StringRef LHS, const InsnMatchEntry &RHS) {
+    return LHS < RHS.Format;
+  }
+  bool operator()(const InsnMatchEntry &LHS, const InsnMatchEntry &RHS) {
+    return LHS.Format < RHS.Format;
+  }
+};
+} // namespace
+
+// Table initializing information for parsing the .insn directive.
+static const InsnMatchEntry InsnMatchTable[] = {
+    /* Format, Opcode, NumOperands, OperandKinds */
+    {"b",
+     RISCV::InsnB,
+     {MCK_UImm7, MCK_UImm3, MCK_AnyReg, MCK_AnyReg, MCK_SImm13Lsb0}},
+    {"i",
+     RISCV::InsnI,
+     {MCK_UImm7, MCK_UImm3, MCK_AnyReg, MCK_AnyReg, MCK_SImm12}},
+    {"i",
+     RISCV::InsnI_Mem,
+     {MCK_UImm7, MCK_UImm3, MCK_AnyReg, MCK_SImm12, MCK__40_, MCK_AnyReg,
+      MCK__41_}},
+    {"j", RISCV::InsnJ, {MCK_UImm7, MCK_AnyReg, MCK_SImm21Lsb0JAL}},
+    {"r",
+     RISCV::InsnR,
+     {MCK_UImm7, MCK_UImm3, MCK_UImm7, MCK_AnyReg, MCK_AnyReg, MCK_AnyReg}},
+    // Accept r with 4 registers as an alias for r4.
+    {"r",
+     RISCV::InsnR4,
+     {MCK_UImm7, MCK_UImm3, MCK_UImm2, MCK_AnyReg, MCK_AnyReg, MCK_AnyReg,
+      MCK_AnyReg}},
+    {"r4",
+     RISCV::InsnR4,
+     {MCK_UImm7, MCK_UImm3, MCK_UImm2, MCK_AnyReg, MCK_AnyReg, MCK_AnyReg,
+      MCK_AnyReg}},
+    {"s",
+     RISCV::InsnS,
+     {MCK_UImm7, MCK_UImm3, MCK_AnyReg, MCK_SImm12, MCK__40_, MCK_AnyReg,
+      MCK__41_}},
+    // Accept sb as an alias for b.
+    {"sb",
+     RISCV::InsnB,
+     {MCK_UImm7, MCK_UImm3, MCK_AnyReg, MCK_AnyReg, MCK_SImm13Lsb0}},
+    {"u", RISCV::InsnU, {MCK_UImm7, MCK_AnyReg, MCK_UImm20LUI}},
+    // Accept uj as an alias for j.
+    {"uj", RISCV::InsnJ, {MCK_UImm7, MCK_AnyReg, MCK_SImm21Lsb0JAL}},
+};
+
+// Parse opcode for .insn directive.
+// TODO: Handle named opcodes.
+bool RISCVAsmParser::parseInsnOpcode(OperandVector &Operands) {
+  MCAsmParser &Parser = getParser();
+
+  const MCExpr *Expr;
+  SMLoc StartLoc = Parser.getTok().getLoc();
+
+  // Expect immediate expression.
+  if (Parser.parseExpression(Expr))
+    return Error(StartLoc, "unexpected token in directive");
+
+  SMLoc EndLoc =
+      SMLoc::getFromPointer(Parser.getTok().getLoc().getPointer() - 1);
+
+  Operands.push_back(RISCVOperand::createImm(Expr, StartLoc, EndLoc, isRV64()));
+  return false;
+}
+
+bool RISCVAsmParser::parseInsnOperand(OperandVector &Operands,
+                                      const InsnMatchEntry *Entry) {
+  unsigned NextOpNum = Operands.size();
+  if (NextOpNum < array_lengthof(Entry->OperandKinds)) {
+    MatchClassKind Kind = Entry->OperandKinds[NextOpNum];
+    if (Kind == MCK_SImm21Lsb0JAL)
+      return parseJALOffset(Operands) != MatchOperand_Success;
+  }
+
+  // Attempt to parse token as a register.
+  if (parseRegister(Operands, true) == MatchOperand_Success)
+    return false;
+
+  // Attempt to parse token as an immediate
+  if (parseImmediate(Operands) == MatchOperand_Success) {
+    // Parse memory base register if present
+    if (getLexer().is(AsmToken::LParen))
+      return parseMemOpBaseReg(Operands) != MatchOperand_Success;
+    return false;
+  }
+
+  // Finally we have exhausted all options and must declare defeat.
+  Error(getLoc(), "unknown operand");
+  return true;
+}
+
+/// parseDirectiveInsn
+/// ::= .insn [ format, encoding, (operands (, operands)*) ]
+bool RISCVAsmParser::parseDirectiveInsn(SMLoc L) {
+  MCAsmParser &Parser = getParser();
+
+  // Expect instruction format as identifier.
+  StringRef Format;
+  SMLoc ErrorLoc = Parser.getTok().getLoc();
+  if (Parser.parseIdentifier(Format))
+    return Error(ErrorLoc, "expected instruction format");
+
+  SmallVector<std::unique_ptr<MCParsedAsmOperand>, 8> Operands;
+
+  // Find entry for this format in InsnMatchTable.
+  auto EntryRange =
+      std::equal_range(std::begin(InsnMatchTable), std::end(InsnMatchTable),
+                       Format, CompareInsn());
+
+  // If first == second, couldn't find a match in the table.
+  if (EntryRange.first == EntryRange.second)
+    return Error(ErrorLoc, "unrecognized format");
+
+  // Format should match from equal_range.
+  assert(EntryRange.first->Format == Format);
+
+  // First operand is an opcode.
+  if (parseInsnOpcode(Operands))
+    return true;
+
+  while (getLexer().is(AsmToken::Comma)) {
+    // Consume comma token
+    getLexer().Lex();
+
+    // Parse next operand. Assume we can determine custom operands from the
+    // first table entry.
+    if (parseInsnOperand(Operands, EntryRange.first))
+      return true;
+  }
+
+  if (getLexer().isNot(AsmToken::EndOfStatement)) {
+    SMLoc Loc = getLexer().getLoc();
+    getParser().eatToEndOfStatement();
+    return Error(Loc, "unexpected token");
+  }
+
+  // Reject any directives with too many operands.
+  size_t MaxOperands = array_lengthof(EntryRange.first->OperandKinds);
+  if (Operands.size() > MaxOperands)
+    return Error(
+        static_cast<RISCVOperand &>(*Operands[MaxOperands]).getStartLoc(),
+        "invalid operand for directive");
+
+  // Build the instruction with the parsed operands.
+  MCInst Inst;
+
+  // Keep track of which operand had an error for later diagnostic.
+  uint64_t ErrorInfo = ~0ULL;
+  for (const InsnMatchEntry *it = EntryRange.first, *ie = EntryRange.second;
+       it != ie; ++it) {
+    // Format should match from equal_range.
+    assert(it->Format == Format);
+    bool OperandsValid = true;
+    for (unsigned FormalIdx = 0, ActualIdx = 0; FormalIdx != MaxOperands;
+         ++FormalIdx) {
+      MatchClassKind Formal = it->OperandKinds[FormalIdx];
+      // If we've handled all the parsed operands, we're done. If the formal
+      // operand is invalid, we successfuly matched all parsed operands.
+      // Otherwise, we didn't have enough parsed operands for this match.
+      if (ActualIdx >= Operands.size()) {
+        OperandsValid = (Formal == InvalidMatchClass);
+        if (!OperandsValid)
+          ErrorInfo = ActualIdx;
+        break;
+      }
+      // Verify the operand.
+      MCParsedAsmOperand &Actual = *Operands[ActualIdx];
+      unsigned Diag = validateOperandClass(Actual, Formal);
+      if (Diag == Match_Success) {
+        ++ActualIdx;
+        continue;
+      }
+      // If this is the first match we're checking, update the error info.
+      // If we're checking an alternate match, update the error info if we
+      // failed on a later operand since that means the earlier failure was
+      // valid for a different match.
+      if ((it == EntryRange.first || ErrorInfo <= ActualIdx))
+        ErrorInfo = ActualIdx;
+      OperandsValid = false;
+      break;
+    }
+
+    if (!OperandsValid)
+      continue;
+
+    Inst.clear();
+    Inst.setOpcode(it->Opcode);
+
+    for (size_t i = 0; i < Operands.size(); ++i) {
+      RISCVOperand &Operand = static_cast<RISCVOperand &>(*Operands[i]);
+      MatchClassKind Kind = it->OperandKinds[i];
+
+      // Verify operand.
+      unsigned Res = validateOperandClass(Operand, Kind);
+      if (Res != Match_Success)
+        return Error(Operand.getStartLoc(), "unexpected operand type");
+
+      // Add operands to instruction.
+      if (Operand.isReg()) {
+        Operand.addRegOperands(Inst, 1);
+      } else if (Operand.isImm()) {
+        Operand.addImmOperands(Inst, 1);
+      } else if (Operand.isToken()) {
+        // Ignore tokens.
+      } else {
+        llvm_unreachable("unexpected operand type");
+      }
+    }
+
+    // Emit as a regular instruction.
+    Parser.getStreamer().emitInstruction(Inst, getSTI());
+    return false;
+  }
+
+  if (ErrorInfo != ~0ULL) {
+    if (ErrorInfo >= Operands.size())
+      return Error(ErrorLoc, "too few operands for directive");
+
+    SMLoc OpLoc =
+        static_cast<RISCVOperand &>(*Operands[ErrorInfo]).getStartLoc();
+    if (OpLoc != SMLoc())
+      ErrorLoc = OpLoc;
+  }
+  return Error(ErrorLoc, "invalid operand for directive");
+}
+
 void RISCVAsmParser::emitToStreamer(MCStreamer &S, const MCInst &Inst) {
   MCInst CInst;
   bool Res = compressInst(CInst, Inst, getSTI(), S.getContext());
diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVBaseInfo.h b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVBaseInfo.h
--- a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVBaseInfo.h
+++ b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVBaseInfo.h
@@ -168,8 +168,11 @@
 namespace RISCVOp {
 enum OperandType : unsigned {
   OPERAND_FIRST_RISCV_IMM = MCOI::OPERAND_FIRST_TARGET,
-  OPERAND_UIMM4 = OPERAND_FIRST_RISCV_IMM,
+  OPERAND_UIMM2 = OPERAND_FIRST_RISCV_IMM,
+  OPERAND_UIMM3,
+  OPERAND_UIMM4,
   OPERAND_UIMM5,
+  OPERAND_UIMM7,
   OPERAND_UIMM12,
   OPERAND_SIMM12,
   OPERAND_UIMM20,
diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCCodeEmitter.cpp b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCCodeEmitter.cpp
--- a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCCodeEmitter.cpp
+++ b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCCodeEmitter.cpp
@@ -276,6 +276,9 @@
   if (MO.isImm())
     return MO.getImm();
 
+  if (!MO.isExpr())
+    dbgs() << "ctopper opno " << OpNo << "\n";
+
   assert(MO.isExpr() &&
          "getImmOpValue expects only expressions or immediates");
   const MCExpr *Expr = MO.getExpr();
@@ -358,7 +361,7 @@
     }
   } else if (Kind == MCExpr::SymbolRef &&
              cast<MCSymbolRefExpr>(Expr)->getKind() == MCSymbolRefExpr::VK_None) {
-    if (Desc.getOpcode() == RISCV::JAL) {
+    if (MIFrm == RISCVII::InstFormatJ) {
       FixupKind = RISCV::fixup_riscv_jal;
     } else if (MIFrm == RISCVII::InstFormatB) {
       FixupKind = RISCV::fixup_riscv_branch;
diff --git a/llvm/lib/Target/RISCV/RISCVInstrFormats.td b/llvm/lib/Target/RISCV/RISCVInstrFormats.td
--- a/llvm/lib/Target/RISCV/RISCVInstrFormats.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrFormats.td
@@ -409,3 +409,135 @@
   let Inst{11-7} = rd;
   let Opcode = opcode.Value;
 }
+
+//===----------------------------------------------------------------------===//
+// Instruction classes for .insn directives
+//===----------------------------------------------------------------------===//
+
+class DirectiveInsnR<dag outs, dag ins, string asmstr>
+  : RVInst<outs, ins, "", "", [], InstFormatR> {
+  bits<7> opcode;
+  bits<7> funct7;
+  bits<3> funct3;
+
+  bits<5> rs2;
+  bits<5> rs1;
+  bits<5> rd;
+
+  let Inst{31-25} = funct7;
+  let Inst{24-20} = rs2;
+  let Inst{19-15} = rs1;
+  let Inst{14-12} = funct3;
+  let Inst{11-7} = rd;
+  let Opcode = opcode;
+
+  let AsmString = asmstr;
+}
+
+class DirectiveInsnR4<dag outs, dag ins, string asmstr>
+  : RVInst<outs, ins, "", "", [], InstFormatR4> {
+  bits<7> opcode;
+  bits<2> funct2;
+  bits<3> funct3;
+
+  bits<5> rs3;
+  bits<5> rs2;
+  bits<5> rs1;
+  bits<5> rd;
+
+  let Inst{31-27} = rs3;
+  let Inst{26-25} = funct2;
+  let Inst{24-20} = rs2;
+  let Inst{19-15} = rs1;
+  let Inst{14-12} = funct3;
+  let Inst{11-7} = rd;
+  let Opcode = opcode;
+
+  let AsmString = asmstr;
+}
+
+class DirectiveInsnI<dag outs, dag ins, string asmstr>
+  : RVInst<outs, ins, "", "", [], InstFormatI> {
+  bits<7> opcode;
+  bits<3> funct3;
+
+  bits<12> imm12;
+  bits<5> rs1;
+  bits<5> rd;
+
+  let Inst{31-20} = imm12;
+  let Inst{19-15} = rs1;
+  let Inst{14-12} = funct3;
+  let Inst{11-7} = rd;
+  let Opcode = opcode;
+
+  let AsmString = asmstr;
+}
+
+class DirectiveInsnS<dag outs, dag ins, string asmstr>
+  : RVInst<outs, ins, "", "", [], InstFormatS> {
+  bits<7> opcode;
+  bits<3> funct3;
+
+  bits<12> imm12;
+  bits<5> rs2;
+  bits<5> rs1;
+
+  let Inst{31-25} = imm12{11-5};
+  let Inst{24-20} = rs2;
+  let Inst{19-15} = rs1;
+  let Inst{14-12} = funct3;
+  let Inst{11-7} = imm12{4-0};
+  let Opcode = opcode;
+
+  let AsmString = asmstr;
+}
+
+class DirectiveInsnB<dag outs, dag ins, string asmstr>
+  : RVInst<outs, ins, "", "", [], InstFormatB> {
+  bits<7> opcode;
+  bits<3> funct3;
+
+  bits<12> imm12;
+  bits<5> rs2;
+  bits<5> rs1;
+
+  let Inst{31} = imm12{11};
+  let Inst{30-25} = imm12{9-4};
+  let Inst{24-20} = rs2;
+  let Inst{19-15} = rs1;
+  let Inst{14-12} = funct3;
+  let Inst{11-8} = imm12{3-0};
+  let Inst{7} = imm12{10};
+  let Opcode = opcode;
+
+  let AsmString = asmstr;
+}
+
+class DirectiveInsnU<dag outs, dag ins, string asmstr>
+  : RVInst<outs, ins, "", "", [], InstFormatU> {
+  bits<7> opcode;
+
+  bits<20> imm20;
+  bits<5> rd;
+
+  let Inst{31-12} = imm20;
+  let Inst{11-7} = rd;
+  let Opcode = opcode;
+
+  let AsmString = asmstr;
+}
+
+class DirectiveInsnJ<dag outs, dag ins, string asmstr>
+  : RVInst<outs, ins, "", "", [], InstFormatJ> {
+  bits<7> opcode;
+
+  bits<20> imm20;
+  bits<5> rd;
+
+  let Inst{31-12} = imm20;
+  let Inst{11-7} = rd;
+  let Opcode = opcode;
+
+  let AsmString = asmstr;
+}
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.td b/llvm/lib/Target/RISCV/RISCVInstrInfo.td
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.td
@@ -1337,6 +1337,67 @@
 }
 
 //===----------------------------------------------------------------------===//
+// .insn directive instructions
+//===----------------------------------------------------------------------===//
+
+def uimm2 : Operand<XLenVT> {
+  let ParserMatchClass = UImmAsmOperand<2>;
+  let DecoderMethod = "decodeUImmOperand<2>";
+  let OperandType = "OPERAND_UIMM2";
+  let OperandNamespace = "RISCVOp";
+}
+
+def uimm3 : Operand<XLenVT> {
+  let ParserMatchClass = UImmAsmOperand<3>;
+  let DecoderMethod = "decodeUImmOperand<3>";
+  let OperandType = "OPERAND_UIMM3";
+  let OperandNamespace = "RISCVOp";
+}
+
+def uimm7 : Operand<XLenVT> {
+  let ParserMatchClass = UImmAsmOperand<7>;
+  let DecoderMethod = "decodeUImmOperand<7>";
+  let OperandType = "OPERAND_UIMM7";
+  let OperandNamespace = "RISCVOp";
+}
+
+let isCodeGenOnly = 1, hasSideEffects = 1, mayLoad = 1, mayStore = 1,
+    hasNoSchedulingInfo = 1 in {
+  def InsnR : DirectiveInsnR<(outs), (ins uimm7:$opcode, uimm3:$funct3,
+                                          uimm7:$funct7, AnyReg:$rd,
+                                          AnyReg:$rs1, AnyReg:$rs2),
+                          ".insn r $opcode, $funct3, $funct7, $rd, $rs1, $rs2">;
+  def InsnR4 : DirectiveInsnR4<(outs), (ins uimm7:$opcode, uimm3:$funct3,
+                                            uimm2:$funct2, AnyReg:$rd,
+                                            AnyReg:$rs1, AnyReg:$rs2,
+                                            AnyReg:$rs3),
+                   ".insn r4 $opcode, $funct3, $funct2, $rd, $rs1, $rs2, $rs3">;
+  def InsnI : DirectiveInsnI<(outs), (ins uimm7:$opcode, uimm3:$funct3,
+                                          AnyReg:$rd, AnyReg:$rs1,
+                                          simm12:$imm12),
+                             ".insn i $opcode, $funct3, $rd, $rs1, $imm12">;
+  // Alternate form using memory op syntax.
+  def InsnI_Mem : DirectiveInsnI<(outs), (ins uimm7:$opcode, uimm3:$funct3,
+                                          AnyReg:$rd, simm12:$imm12,
+                                          AnyReg:$rs1),
+                             ".insn i $opcode, $funct3, $rd, ${imm12}(${rs1})">;
+  def InsnB : DirectiveInsnB<(outs), (ins uimm7:$opcode, uimm3:$funct3,
+                                          AnyReg:$rs1, AnyReg:$rs2,
+                                          simm13_lsb0:$imm12),
+                             ".insn b $opcode, $funct3, $rs1, $rs2, $imm12">;
+  def InsnU : DirectiveInsnU<(outs), (ins uimm7:$opcode, AnyReg:$rd,
+                                          uimm20_lui:$imm20),
+                             ".insn u $opcode, $rd, $imm20">;
+  def InsnJ : DirectiveInsnJ<(outs), (ins uimm7:$opcode, AnyReg:$rd,
+                                          simm21_lsb0_jal:$imm20),
+                             ".insn j $opcode, $rd, $imm20">;
+  def InsnS : DirectiveInsnS<(outs), (ins uimm7:$opcode, uimm3:$funct3,
+                                          AnyReg:$rs2, simm12:$imm12,
+                                          AnyReg:$rs1),
+                             ".insn i $opcode, $funct3, $rs2, ${imm12}(${rs1})">;
+}
+
+//===----------------------------------------------------------------------===//
 // Standard extensions
 //===----------------------------------------------------------------------===//
 
diff --git a/llvm/lib/Target/RISCV/RISCVRegisterInfo.td b/llvm/lib/Target/RISCV/RISCVRegisterInfo.td
--- a/llvm/lib/Target/RISCV/RISCVRegisterInfo.td
+++ b/llvm/lib/Target/RISCV/RISCVRegisterInfo.td
@@ -557,3 +557,13 @@
 def FFLAGS : RISCVReg<0, "fflags">;
 def FRM    : RISCVReg<0, "frm">;
 def FCSR   : RISCVReg<0, "fcsr">;
+
+// Any type register. Used for .insn directives when we don't know what the
+// register types could be.
+let isAllocatable = 0 in
+def AnyReg : RegisterClass<"RISCV", [XLenVT], 32,
+                           (add (sequence "X%u", 0, 31),
+                                (sequence "F%u_D", 0, 31),
+                                (sequence "V%u", 0, 31))> {
+  let RegInfos = XLenRI;
+}
diff --git a/llvm/test/MC/RISCV/insn-invalid.s b/llvm/test/MC/RISCV/insn-invalid.s
new file mode 100644
--- /dev/null
+++ b/llvm/test/MC/RISCV/insn-invalid.s
@@ -0,0 +1,12 @@
+# RUN: not llvm-mc -triple riscv32 < %s 2>&1 | FileCheck %s
+
+# Too many operands
+.insn i  0x13,  0,  a0, a1, 13, 14 # CHECK: :[[@LINE]]:33: error: invalid operand for directive
+.insn r  0x43,  0,  0, fa0, fa1, fa2, fa3, fa4 # CHECK: :[[@LINE]]:44: error: invalid operand for directive
+
+# Too few operands
+.insn r  0x33,  0,  0, a0, a1 # CHECK: :[[@LINE]]:7: error: too few operands for directive
+.insn i  0x13,  0,  a0, a1 # CHECK: :[[@LINE]]:7: error: too few operands for directive
+
+.insn r  0x33,  0,  0, a0, 13 # CHECK: :[[@LINE]]:28: error: invalid operand for directive
+.insn i  0x13,  0, a0, a1, a2 # CHECK: :[[@LINE]]:28: error: invalid operand for directive
diff --git a/llvm/test/MC/RISCV/insn.s b/llvm/test/MC/RISCV/insn.s
new file mode 100644
--- /dev/null
+++ b/llvm/test/MC/RISCV/insn.s
@@ -0,0 +1,77 @@
+# RUN: llvm-mc %s -triple=riscv32 -mattr=+f -riscv-no-aliases -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ASM %s
+# RUN: llvm-mc %s -triple riscv64 -mattr=+f -riscv-no-aliases -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ASM %s
+# RUN: llvm-mc -filetype=obj -triple=riscv32 -mattr=+f < %s \
+# RUN:     | llvm-objdump --mattr=+f -M no-aliases -d -r - \
+# RUN:     | FileCheck -check-prefixes=CHECK-OBJ %s
+# RUN: llvm-mc -filetype=obj -triple=riscv64 -mattr=+f < %s \
+# RUN:     | llvm-objdump --mattr=+f -M no-aliases -d -r - \
+# RUN:     | FileCheck -check-prefixes=CHECK-OBJ %s
+
+target:
+
+# CHECK-ASM: .insn r 51, 0, 0, a0, a1, a2
+# CHECK-ASM: encoding: [0x33,0x85,0xc5,0x00]
+# CHECK-OBJ: add a0, a1, a2
+.insn r  0x33,  0,  0, a0, a1, a2
+
+# CHECK-ASM: .insn i 19, 0, a0, a1, 13
+# CHECK-ASM: encoding: [0x13,0x85,0xd5,0x00]
+# CHECK-OBJ: addi a0, a1, 13
+.insn i  0x13,  0, a0, a1, 13
+
+# CHECK-ASM: .insn i 103, 0, a0, 10(a1)
+# CHECK-ASM: encoding: [0x67,0x85,0xa5,0x00]
+# CHECK-OBJ: jalr a0, 10(a1)
+.insn i  0x67,  0, a0, 10(a1)
+
+# CHECK-ASM: .insn i 3, 0, a0, 4(a1)
+# CHECK-ASM: encoding: [0x03,0x85,0x45,0x00]
+# CHECK-OBJ: lb a0, 4(a1)
+.insn i   0x3,  0, a0, 4(a1)
+
+# CHECK-ASM: .insn b 99, 0, a0, a1, target
+# CHECK-ASM: [0x63'A',A,0xb5'A',A]
+# CHECK-OBJ: beq a0, a1, 0x0 <target>
+.insn sb 0x63,  0, a0, a1, target
+
+# CHECK-ASM: .insn b 99, 0, a0, a1, target
+# CHECK-ASM: [0x63'A',A,0xb5'A',A]
+# CHECK-OBJ: beq a0, a1, 0x0 <target>
+.insn b  0x63,  0, a0, a1, target
+
+# CHECK-ASM: .insn i 35, 0, a0, 4(a1)
+# CHECK-ASM: encoding: [0x23,0x82,0xa5,0x00]
+# CHECK-OBJ: sb a0, 4(a1)
+.insn s  0x23,  0, a0, 4(a1)
+
+# CHECK-ASM: .insn u 55, a0, 4095
+# CHECK-ASM: encoding: [0x37,0xf5,0xff,0x00]
+# CHECK-OBJ: lui a0, 4095
+.insn u  0x37, a0, 0xfff
+
+# CHECK-ASM: .insn j 111, a0, target
+# CHECK-ASM: encoding: [0x6f,0bAAAA0101,A,A]
+# CHECK-OBJ: jal a0, 0x0 <target>
+.insn uj 0x6f, a0, target
+
+# CHECK-ASM: .insn j 111, a0, target
+# CHECK-ASM: encoding: [0x6f,0bAAAA0101,A,A]
+# CHECK-OBJ: jal a0, 0x0 <target>
+.insn j  0x6f, a0, target
+
+# CHECK-ASM: .insn r4 67, 0, 0, fa0, fa1, fa2, fa3
+# CHECK-ASM: encoding: [0x43,0x85,0xc5,0x68]
+# CHECK-OBJ: fmadd.s fa0, fa1, fa2, fa3, rne
+.insn r  0x43,  0,  0, fa0, fa1, fa2, fa3
+
+# CHECK-ASM: .insn r4 67, 0, 0, fa0, fa1, fa2, fa3
+# CHECK-ASM: encoding: [0x43,0x85,0xc5,0x68]
+# CHECK-OBJ: fmadd.s fa0, fa1, fa2, fa3, rne
+.insn r4 0x43,  0,  0, fa0, fa1, fa2, fa3
+
+# CHECK-ASM: .insn i 3, 5, t1, -2048(t2)
+# CHECK-ASM: encoding: [0x03,0xd3,0x03,0x80]
+# CHECK-OBJ: lhu t1, -2048(t2)
+.insn i 0x3, 0x5, x6, %lo(2048)(x7)