Re-commit r277988: [mips][ias] Fix all the hacks related to MIPS-specific unary operators (%hi/%lo/%gp_rel/etc.).

Hopefully with the MSVC builds fixed. I've added a missing '#include <tuple>'
that gcc and clang don't seem to need.

llvm-svn: 277995

8 files changed, 171 insertions, 167 deletions

diff --git a/llvm/lib/MC/MCParser/AsmLexer.cpp b/llvm/lib/MC/MCParser/AsmLexer.cpp
index 7037bb1d5fa..832c39a2c75 100644
--- a/llvm/lib/MC/MCParser/AsmLexer.cpp
+++ b/llvm/lib/MC/MCParser/AsmLexer.cpp
@@ -11,6 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/ADT/StringSwitch.h"
 #include "llvm/MC/MCParser/AsmLexer.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/Support/MemoryBuffer.h"
@@ -19,6 +20,8 @@
 #include <cerrno>
 #include <cstdio>
 #include <cstdlib>
+#include <tuple>
+
 using namespace llvm;
 
 AsmLexer::AsmLexer(const MCAsmInfo &MAI) : MAI(MAI) {
@@ -600,7 +603,46 @@ AsmToken AsmLexer::LexToken() {
       return AsmToken(AsmToken::ExclaimEqual, StringRef(TokStart, 2));
     }
     return AsmToken(AsmToken::Exclaim, StringRef(TokStart, 1));
-  case '%': return AsmToken(AsmToken::Percent, StringRef(TokStart, 1));
+  case '%':
+    if (MAI.hasMipsExpressions()) {
+      AsmToken::TokenKind Operator;
+      unsigned OperatorLength;
+
+      std::tie(Operator, OperatorLength) =
+          StringSwitch<std::pair<AsmToken::TokenKind, unsigned>>(
+              StringRef(CurPtr))
+              .StartsWith("call16", {AsmToken::PercentCall16, 7})
+              .StartsWith("call_hi", {AsmToken::PercentCall_Hi, 8})
+              .StartsWith("call_lo", {AsmToken::PercentCall_Lo, 8})
+              .StartsWith("dtprel_hi", {AsmToken::PercentDtprel_Hi, 10})
+              .StartsWith("dtprel_lo", {AsmToken::PercentDtprel_Lo, 10})
+              .StartsWith("got_disp", {AsmToken::PercentGot_Disp, 9})
+              .StartsWith("got_hi", {AsmToken::PercentGot_Hi, 7})
+              .StartsWith("got_lo", {AsmToken::PercentGot_Lo, 7})
+              .StartsWith("got_ofst", {AsmToken::PercentGot_Ofst, 9})
+              .StartsWith("got_page", {AsmToken::PercentGot_Page, 9})
+              .StartsWith("gottprel", {AsmToken::PercentGottprel, 9})
+              .StartsWith("got", {AsmToken::PercentGot, 4})
+              .StartsWith("gp_rel", {AsmToken::PercentGp_Rel, 7})
+              .StartsWith("higher", {AsmToken::PercentHigher, 7})
+              .StartsWith("highest", {AsmToken::PercentHighest, 8})
+              .StartsWith("hi", {AsmToken::PercentHi, 3})
+              .StartsWith("lo", {AsmToken::PercentLo, 3})
+              .StartsWith("neg", {AsmToken::PercentNeg, 4})
+              .StartsWith("pcrel_hi", {AsmToken::PercentPcrel_Hi, 9})
+              .StartsWith("pcrel_lo", {AsmToken::PercentPcrel_Lo, 9})
+              .StartsWith("tlsgd", {AsmToken::PercentTlsgd, 6})
+              .StartsWith("tlsldm", {AsmToken::PercentTlsldm, 7})
+              .StartsWith("tprel_hi", {AsmToken::PercentTprel_Hi, 9})
+              .StartsWith("tprel_lo", {AsmToken::PercentTprel_Lo, 9})
+              .Default({AsmToken::Percent, 1});
+
+      if (Operator != AsmToken::Percent) {
+        CurPtr += OperatorLength - 1;
+        return AsmToken(Operator, StringRef(TokStart, OperatorLength));
+      }
+    }
+    return AsmToken(AsmToken::Percent, StringRef(TokStart, 1));
   case '/':
     IsAtStartOfStatement = OldIsAtStartOfStatement;
     return LexSlash();
diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index 6d3240a3e11..7a6d5dbd2d3 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -1064,6 +1064,43 @@ bool AsmParser::parsePrimaryExpr(const MCExpr *&Res, SMLoc &EndLoc) {
       return true;
     Res = MCUnaryExpr::createNot(Res, getContext());
     return false;
+  // MIPS unary expression operators. The lexer won't generate these tokens if
+  // MCAsmInfo::HasMipsExpressions is false for the target.
+  case AsmToken::PercentCall16:
+  case AsmToken::PercentCall_Hi:
+  case AsmToken::PercentCall_Lo:
+  case AsmToken::PercentDtprel_Hi:
+  case AsmToken::PercentDtprel_Lo:
+  case AsmToken::PercentGot:
+  case AsmToken::PercentGot_Disp:
+  case AsmToken::PercentGot_Hi:
+  case AsmToken::PercentGot_Lo:
+  case AsmToken::PercentGot_Ofst:
+  case AsmToken::PercentGot_Page:
+  case AsmToken::PercentGottprel:
+  case AsmToken::PercentGp_Rel:
+  case AsmToken::PercentHi:
+  case AsmToken::PercentHigher:
+  case AsmToken::PercentHighest:
+  case AsmToken::PercentLo:
+  case AsmToken::PercentNeg:
+  case AsmToken::PercentPcrel_Hi:
+  case AsmToken::PercentPcrel_Lo:
+  case AsmToken::PercentTlsgd:
+  case AsmToken::PercentTlsldm:
+  case AsmToken::PercentTprel_Hi:
+  case AsmToken::PercentTprel_Lo:
+    Lex(); // Eat the operator.
+    if (Lexer.isNot(AsmToken::LParen))
+      return TokError("expected '(' after operator");
+    Lex(); // Eat the operator.
+    if (parseExpression(Res, EndLoc))
+      return true;
+    if (Lexer.isNot(AsmToken::RParen))
+      return TokError("expected ')'");
+    Lex(); // Eat the operator.
+    Res = getTargetParser().createTargetUnaryExpr(Res, FirstTokenKind, Ctx);
+    return !Res;
   }
 }
 
diff --git a/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp b/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
index 0291ef929e2..e3f0d16d660 100644
--- a/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ b/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -252,9 +252,6 @@ class MipsAsmParser : public MCTargetAsmParser {
   bool reportParseError(SMLoc Loc, Twine ErrorMsg);
 
   bool parseMemOffset(const MCExpr *&Res, bool isParenExpr);
-  bool parseRelocOperand(const MCExpr *&Res);
-
-  const MCExpr *evaluateRelocExpr(const MCExpr *Expr, StringRef RelocStr);
 
   bool isEvaluated(const MCExpr *Expr);
   bool parseSetMips0Directive();
@@ -552,6 +549,64 @@ public:
   void warnIfNoMacro(SMLoc Loc);
 
   bool isLittle() const { return IsLittleEndian; }
+
+  const MCExpr *createTargetUnaryExpr(const MCExpr *E,
+                                      AsmToken::TokenKind OperatorToken,
+                                      MCContext &Ctx) override {
+    switch(OperatorToken) {
+    default:
+      llvm_unreachable("Unknown token");
+      return nullptr;
+    case AsmToken::PercentCall16:
+      return MipsMCExpr::create(MipsMCExpr::MEK_GOT_CALL, E, Ctx);
+    case AsmToken::PercentCall_Hi:
+      return MipsMCExpr::create(MipsMCExpr::MEK_CALL_HI16, E, Ctx);
+    case AsmToken::PercentCall_Lo:
+      return MipsMCExpr::create(MipsMCExpr::MEK_CALL_LO16, E, Ctx);
+    case AsmToken::PercentDtprel_Hi:
+      return MipsMCExpr::create(MipsMCExpr::MEK_DTPREL_HI, E, Ctx);
+    case AsmToken::PercentDtprel_Lo:
+      return MipsMCExpr::create(MipsMCExpr::MEK_DTPREL_LO, E, Ctx);
+    case AsmToken::PercentGot:
+      return MipsMCExpr::create(MipsMCExpr::MEK_GOT, E, Ctx);
+    case AsmToken::PercentGot_Disp:
+      return MipsMCExpr::create(MipsMCExpr::MEK_GOT_DISP, E, Ctx);
+    case AsmToken::PercentGot_Hi:
+      return MipsMCExpr::create(MipsMCExpr::MEK_GOT_HI16, E, Ctx);
+    case AsmToken::PercentGot_Lo:
+      return MipsMCExpr::create(MipsMCExpr::MEK_GOT_LO16, E, Ctx);
+    case AsmToken::PercentGot_Ofst:
+      return MipsMCExpr::create(MipsMCExpr::MEK_GOT_OFST, E, Ctx);
+    case AsmToken::PercentGot_Page:
+      return MipsMCExpr::create(MipsMCExpr::MEK_GOT_PAGE, E, Ctx);
+    case AsmToken::PercentGottprel:
+      return MipsMCExpr::create(MipsMCExpr::MEK_GOTTPREL, E, Ctx);
+    case AsmToken::PercentGp_Rel:
+      return MipsMCExpr::create(MipsMCExpr::MEK_GPREL, E, Ctx);
+    case AsmToken::PercentHi:
+      return MipsMCExpr::create(MipsMCExpr::MEK_HI, E, Ctx);
+    case AsmToken::PercentHigher:
+      return MipsMCExpr::create(MipsMCExpr::MEK_HIGHER, E, Ctx);
+    case AsmToken::PercentHighest:
+      return MipsMCExpr::create(MipsMCExpr::MEK_HIGHEST, E, Ctx);
+    case AsmToken::PercentLo:
+      return MipsMCExpr::create(MipsMCExpr::MEK_LO, E, Ctx);
+    case AsmToken::PercentNeg:
+      return MipsMCExpr::create(MipsMCExpr::MEK_NEG, E, Ctx);
+    case AsmToken::PercentPcrel_Hi:
+      return MipsMCExpr::create(MipsMCExpr::MEK_PCREL_HI16, E, Ctx);
+    case AsmToken::PercentPcrel_Lo:
+      return MipsMCExpr::create(MipsMCExpr::MEK_PCREL_LO16, E, Ctx);
+    case AsmToken::PercentTlsgd:
+      return MipsMCExpr::create(MipsMCExpr::MEK_TLSGD, E, Ctx);
+    case AsmToken::PercentTlsldm:
+      return MipsMCExpr::create(MipsMCExpr::MEK_TLSLDM, E, Ctx);
+    case AsmToken::PercentTprel_Hi:
+      return MipsMCExpr::create(MipsMCExpr::MEK_TPREL_HI, E, Ctx);
+    case AsmToken::PercentTprel_Lo:
+      return MipsMCExpr::create(MipsMCExpr::MEK_TPREL_LO, E, Ctx);
+    }
+  }
 };
 }
 
@@ -4187,9 +4242,6 @@ bool MipsAsmParser::parseOperand(OperandVector &Operands, StringRef Mnemonic) {
   DEBUG(dbgs() << ".. Generic Parser\n");
 
   switch (getLexer().getKind()) {
-  default:
-    Error(Parser.getTok().getLoc(), "unexpected token in operand");
-    return true;
   case AsmToken::Dollar: {
     // Parse the register.
     SMLoc S = Parser.getTok().getLoc();
@@ -4216,72 +4268,23 @@ bool MipsAsmParser::parseOperand(OperandVector &Operands, StringRef Mnemonic) {
     Operands.push_back(MipsOperand::CreateImm(Res, S, E, *this));
     return false;
   }
-  // Else drop to expression parsing.
-  case AsmToken::LParen:
-  case AsmToken::Minus:
-  case AsmToken::Plus:
-  case AsmToken::Integer:
-  case AsmToken::Tilde:
-  case AsmToken::String: {
-    DEBUG(dbgs() << ".. generic integer\n");
-    OperandMatchResultTy ResTy = parseImm(Operands);
-    return ResTy != MatchOperand_Success;
-  }
-  case AsmToken::Percent: {
-    // It is a symbol reference or constant expression.
-    const MCExpr *IdVal;
+  default: {
+    DEBUG(dbgs() << ".. generic integer expression\n");
+
+    const MCExpr *Expr;
     SMLoc S = Parser.getTok().getLoc(); // Start location of the operand.
-    if (parseRelocOperand(IdVal))
+    if (getParser().parseExpression(Expr))
       return true;
 
     SMLoc E = SMLoc::getFromPointer(Parser.getTok().getLoc().getPointer() - 1);
 
-    Operands.push_back(MipsOperand::CreateImm(IdVal, S, E, *this));
+    Operands.push_back(MipsOperand::CreateImm(Expr, S, E, *this));
     return false;
-  } // case AsmToken::Percent
+  }
   } // switch(getLexer().getKind())
   return true;
 }
 
-const MCExpr *MipsAsmParser::evaluateRelocExpr(const MCExpr *Expr,
-                                               StringRef RelocStr) {
-  if (RelocStr == "hi(%neg(%gp_rel")
-    return MipsMCExpr::createGpOff(MipsMCExpr::MEK_HI, Expr, getContext());
-  else if (RelocStr == "lo(%neg(%gp_rel")
-    return MipsMCExpr::createGpOff(MipsMCExpr::MEK_LO, Expr, getContext());
-
-  MipsMCExpr::MipsExprKind Kind =
-      StringSwitch<MipsMCExpr::MipsExprKind>(RelocStr)
-          .Case("call16", MipsMCExpr::MEK_GOT_CALL)
-          .Case("call_hi", MipsMCExpr::MEK_CALL_HI16)
-          .Case("call_lo", MipsMCExpr::MEK_CALL_LO16)
-          .Case("dtprel_hi", MipsMCExpr::MEK_DTPREL_HI)
-          .Case("dtprel_lo", MipsMCExpr::MEK_DTPREL_LO)
-          .Case("got", MipsMCExpr::MEK_GOT)
-          .Case("got_disp", MipsMCExpr::MEK_GOT_DISP)
-          .Case("got_hi", MipsMCExpr::MEK_GOT_HI16)
-          .Case("got_lo", MipsMCExpr::MEK_GOT_LO16)
-          .Case("got_ofst", MipsMCExpr::MEK_GOT_OFST)
-          .Case("got_page", MipsMCExpr::MEK_GOT_PAGE)
-          .Case("gottprel", MipsMCExpr::MEK_GOTTPREL)
-          .Case("gp_rel", MipsMCExpr::MEK_GPREL)
-          .Case("hi", MipsMCExpr::MEK_HI)
-          .Case("higher", MipsMCExpr::MEK_HIGHER)
-          .Case("highest", MipsMCExpr::MEK_HIGHEST)
-          .Case("lo", MipsMCExpr::MEK_LO)
-          .Case("neg", MipsMCExpr::MEK_NEG)
-          .Case("pcrel_hi", MipsMCExpr::MEK_PCREL_HI16)
-          .Case("pcrel_lo", MipsMCExpr::MEK_PCREL_LO16)
-          .Case("tlsgd", MipsMCExpr::MEK_TLSGD)
-          .Case("tlsldm", MipsMCExpr::MEK_TLSLDM)
-          .Case("tprel_hi", MipsMCExpr::MEK_TPREL_HI)
-          .Case("tprel_lo", MipsMCExpr::MEK_TPREL_LO)
-          .Default(MipsMCExpr::MEK_None);
-
-  assert(Kind != MipsMCExpr::MEK_None);
-  return MipsMCExpr::create(Kind, Expr, getContext());
-}
-
 bool MipsAsmParser::isEvaluated(const MCExpr *Expr) {
 
   switch (Expr->getKind()) {
@@ -4303,49 +4306,6 @@ bool MipsAsmParser::isEvaluated(const MCExpr *Expr) {
   return false;
 }
 
-bool MipsAsmParser::parseRelocOperand(const MCExpr *&Res) {
-  MCAsmParser &Parser = getParser();
-  Parser.Lex();                          // Eat the % token.
-  const AsmToken &Tok = Parser.getTok(); // Get next token, operation.
-  if (Tok.isNot(AsmToken::Identifier))
-    return true;
-
-  std::string Str = Tok.getIdentifier();
-
-  Parser.Lex(); // Eat the identifier.
-  // Now make an expression from the rest of the operand.
-  const MCExpr *IdVal;
-  SMLoc EndLoc;
-
-  if (getLexer().getKind() == AsmToken::LParen) {
-    while (1) {
-      Parser.Lex(); // Eat the '(' token.
-      if (getLexer().getKind() == AsmToken::Percent) {
-        Parser.Lex(); // Eat the % token.
-        const AsmToken &nextTok = Parser.getTok();
-        if (nextTok.isNot(AsmToken::Identifier))
-          return true;
-        Str += "(%";
-        Str += nextTok.getIdentifier();
-        Parser.Lex(); // Eat the identifier.
-        if (getLexer().getKind() != AsmToken::LParen)
-          return true;
-      } else
-        break;
-    }
-    if (getParser().parseParenExpression(IdVal, EndLoc))
-      return true;
-
-    while (getLexer().getKind() == AsmToken::RParen)
-      Parser.Lex(); // Eat the ')' token.
-
-  } else
-    return true; // Parenthesis must follow the relocation operand.
-
-  Res = evaluateRelocExpr(IdVal, Str);
-  return false;
-}
-
 bool MipsAsmParser::ParseRegister(unsigned &RegNo, SMLoc &StartLoc,
                                   SMLoc &EndLoc) {
   SmallVector<std::unique_ptr<MCParsedAsmOperand>, 1> Operands;
@@ -4373,35 +4333,11 @@ bool MipsAsmParser::ParseRegister(unsigned &RegNo, SMLoc &StartLoc,
 }
 
 bool MipsAsmParser::parseMemOffset(const MCExpr *&Res, bool isParenExpr) {
-  MCAsmParser &Parser = getParser();
   SMLoc S;
-  bool Result = true;
-  unsigned NumOfLParen = 0;
-
-  while (getLexer().getKind() == AsmToken::LParen) {
-    Parser.Lex();
-    ++NumOfLParen;
-  }
 
-  switch (getLexer().getKind()) {
-  default:
-    return true;
-  case AsmToken::Identifier:
-  case AsmToken::LParen:
-  case AsmToken::Integer:
-  case AsmToken::Minus:
-  case AsmToken::Plus:
-    if (isParenExpr)
-      Result = getParser().parseParenExprOfDepth(NumOfLParen, Res, S);
-    else
-      Result = (getParser().parseExpression(Res));
-    while (getLexer().getKind() == AsmToken::RParen)
-      Parser.Lex();
-    break;
-  case AsmToken::Percent:
-    Result = parseRelocOperand(Res);
-  }
-  return Result;
+  if (isParenExpr)
+    return getParser().parseParenExprOfDepth(0, Res, S);
+  return getParser().parseExpression(Res);
 }
 
 MipsAsmParser::OperandMatchResultTy
@@ -4632,47 +4568,18 @@ MipsAsmParser::parseAnyRegister(OperandVector &Operands) {
 }
 
 MipsAsmParser::OperandMatchResultTy
-MipsAsmParser::parseImm(OperandVector &Operands) {
-  MCAsmParser &Parser = getParser();
-  switch (getLexer().getKind()) {
-  default:
-    return MatchOperand_NoMatch;
-  case AsmToken::LParen:
-  case AsmToken::Minus:
-  case AsmToken::Plus:
-  case AsmToken::Integer:
-  case AsmToken::Tilde:
-  case AsmToken::String:
-    break;
-  }
-
-  const MCExpr *IdVal;
-  SMLoc S = Parser.getTok().getLoc();
-  if (getParser().parseExpression(IdVal))
-    return MatchOperand_ParseFail;
-
-  SMLoc E = SMLoc::getFromPointer(Parser.getTok().getLoc().getPointer() - 1);
-  Operands.push_back(MipsOperand::CreateImm(IdVal, S, E, *this));
-  return MatchOperand_Success;
-}
-
-MipsAsmParser::OperandMatchResultTy
 MipsAsmParser::parseJumpTarget(OperandVector &Operands) {
   MCAsmParser &Parser = getParser();
   DEBUG(dbgs() << "parseJumpTarget\n");
 
   SMLoc S = getLexer().getLoc();
 
-  // Integers and expressions are acceptable
-  OperandMatchResultTy ResTy = parseImm(Operands);
-  if (ResTy != MatchOperand_NoMatch)
-    return ResTy;
-
   // Registers are a valid target and have priority over symbols.
-  ResTy = parseAnyRegister(Operands);
+  OperandMatchResultTy ResTy = parseAnyRegister(Operands);
   if (ResTy != MatchOperand_NoMatch)
     return ResTy;
 
+  // Integers and expressions are acceptable
   const MCExpr *Expr = nullptr;
   if (Parser.parseExpression(Expr)) {
     // We have no way of knowing if a symbol was consumed so we must ParseFail
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
index 550c2894695..3ee0cd9c7ec 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
@@ -62,6 +62,8 @@ static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
   case FK_GPRel_4:
   case FK_Data_4:
   case FK_Data_8:
+  case Mips::fixup_Mips_SUB:
+  case Mips::fixup_MICROMIPS_SUB:
     break;
   case Mips::fixup_Mips_PC16:
     // The displacement is then divided by 4 to give us an 18 bit
@@ -361,7 +363,9 @@ getFixupKindInfo(MCFixupKind Kind) const {
     { "fixup_MICROMIPS_TLS_DTPREL_HI16", 0,     16,   0 },
     { "fixup_MICROMIPS_TLS_DTPREL_LO16", 0,     16,   0 },
     { "fixup_MICROMIPS_TLS_TPREL_HI16",  0,     16,   0 },
-    { "fixup_MICROMIPS_TLS_TPREL_LO16",  0,     16,   0 }
+    { "fixup_MICROMIPS_TLS_TPREL_LO16",  0,     16,   0 },
+    { "fixup_Mips_SUB",                  0,     64,   0 },
+    { "fixup_MICROMIPS_SUB",             0,     64,   0 }
   };
 
   const static MCFixupKindInfo BigEndianInfos[Mips::NumTargetFixupKinds] = {
@@ -430,7 +434,9 @@ getFixupKindInfo(MCFixupKind Kind) const {
     { "fixup_MICROMIPS_TLS_DTPREL_HI16", 16,     16,   0 },
     { "fixup_MICROMIPS_TLS_DTPREL_LO16", 16,     16,   0 },
     { "fixup_MICROMIPS_TLS_TPREL_HI16",  16,     16,   0 },
-    { "fixup_MICROMIPS_TLS_TPREL_LO16",  16,     16,   0 }
+    { "fixup_MICROMIPS_TLS_TPREL_LO16",  16,     16,   0 },
+    { "fixup_Mips_SUB",                   0,     64,   0 },
+    { "fixup_MICROMIPS_SUB",              0,     64,   0 }
   };
 
   if (Kind < FirstTargetFixupKind)
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp
index 20c5f3691d2..99ba18c972d 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp
@@ -329,6 +329,8 @@ unsigned MipsELFObjectWriter::getRelocType(MCContext &Ctx,
     return ELF::R_MIPS_HIGHER;
   case Mips::fixup_Mips_HIGHEST:
     return ELF::R_MIPS_HIGHEST;
+  case Mips::fixup_Mips_SUB:
+    return ELF::R_MIPS_SUB;
   case Mips::fixup_Mips_GOT_HI16:
     return ELF::R_MIPS_GOT_HI16;
   case Mips::fixup_Mips_GOT_LO16:
@@ -365,6 +367,8 @@ unsigned MipsELFObjectWriter::getRelocType(MCContext &Ctx,
     return ELF::R_MICROMIPS_TLS_TPREL_HI16;
   case Mips::fixup_MICROMIPS_TLS_TPREL_LO16:
     return ELF::R_MICROMIPS_TLS_TPREL_LO16;
+  case Mips::fixup_MICROMIPS_SUB:
+    return ELF::R_MICROMIPS_SUB;
   }
 
   llvm_unreachable("invalid fixup kind!");
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsFixupKinds.h b/llvm/lib/Target/Mips/MCTargetDesc/MipsFixupKinds.h
index b4d8e949465..149296212ec 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsFixupKinds.h
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsFixupKinds.h
@@ -209,6 +209,10 @@ namespace Mips {
     // resulting in - R_MICROMIPS_TLS_TPREL_LO16
     fixup_MICROMIPS_TLS_TPREL_LO16,
 
+    // resulting in - R_MIPS_SUB/R_MICROMIPS_SUB
+    fixup_Mips_SUB,
+    fixup_MICROMIPS_SUB,
+
     // Marker
     LastTargetFixupKind,
     NumTargetFixupKinds = LastTargetFixupKind - FirstTargetFixupKind
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsMCAsmInfo.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsMCAsmInfo.cpp
index 1ce8f07092b..2c01f919bef 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsMCAsmInfo.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsMCAsmInfo.cpp
@@ -49,6 +49,7 @@ MipsMCAsmInfo::MipsMCAsmInfo(const Triple &TheTriple) {
   SupportsDebugInformation = true;
   ExceptionsType = ExceptionHandling::DwarfCFI;
   DwarfRegNumForCFI = true;
+  HasMipsExpressions = true;
 
   // Enable IAS by default for O32.
   if (TheTriple.getArch() == Triple::mips ||
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
index c15c8a929bf..4cc55f86a99 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
@@ -637,7 +637,6 @@ getExprOpValue(const MCExpr *Expr, SmallVectorImpl<MCFixup> &Fixups,
 
     Mips::Fixups FixupKind = Mips::Fixups(0);
     switch (MipsExpr->getKind()) {
-    case MipsMCExpr::MEK_NEG:
     case MipsMCExpr::MEK_None:
     case MipsMCExpr::MEK_Special:
       llvm_unreachable("Unhandled fixup kind!");
@@ -735,6 +734,10 @@ getExprOpValue(const MCExpr *Expr, SmallVectorImpl<MCFixup> &Fixups,
       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_TLS_TPREL_LO16
                                    : Mips::fixup_Mips_TPREL_LO;
       break;
+    case MipsMCExpr::MEK_NEG:
+      FixupKind =
+          isMicroMips(STI) ? Mips::fixup_MICROMIPS_SUB : Mips::fixup_Mips_SUB;
+      break;
     }
     Fixups.push_back(MCFixup::create(0, MipsExpr, MCFixupKind(FixupKind)));
     return 0;