[Sparc] Add membar assembler tags

Summary: The Sparc V9 membar instruction can enforce different types of
memory orderings depending on the value in its immediate field.  In the
architectural manual the type is selected by combining different assembler
tags into a mask. This patch adds support for these tags.

Reviewers: jyknight, venkatra, brad

Reviewed By: jyknight

Subscribers: fedor.sergeev, jrtc27, jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D53491

llvm-svn: 349048

1 files changed, 55 insertions, 0 deletions

diff --git a/llvm/lib/Target/Sparc/AsmParser/SparcAsmParser.cpp b/llvm/lib/Target/Sparc/AsmParser/SparcAsmParser.cpp
index 35f52f7d279..691421e533e 100644
--- a/llvm/lib/Target/Sparc/AsmParser/SparcAsmParser.cpp
+++ b/llvm/lib/Target/Sparc/AsmParser/SparcAsmParser.cpp
@@ -78,6 +78,8 @@ class SparcAsmParser : public MCTargetAsmParser {
   // Custom parse functions for Sparc specific operands.
   OperandMatchResultTy parseMEMOperand(OperandVector &Operands);
 
+  OperandMatchResultTy parseMembarTag(OperandVector &Operands);
+
   OperandMatchResultTy parseOperand(OperandVector &Operands, StringRef Name);
 
   OperandMatchResultTy
@@ -256,6 +258,7 @@ public:
   bool isMem() const override { return isMEMrr() || isMEMri(); }
   bool isMEMrr() const { return Kind == k_MemoryReg; }
   bool isMEMri() const { return Kind == k_MemoryImm; }
+  bool isMembarTag() const { return Kind == k_Immediate; }
 
   bool isIntReg() const {
     return (Kind == k_Register && Reg.Kind == rk_IntReg);
@@ -366,6 +369,12 @@ public:
     addExpr(Inst, Expr);
   }
 
+  void addMembarTagOperands(MCInst &Inst, unsigned N) const {
+    assert(N == 1 && "Invalid number of operands!");
+    const MCExpr *Expr = getImm();
+    addExpr(Inst, Expr);
+  }
+
   static std::unique_ptr<SparcOperand> CreateToken(StringRef Str, SMLoc S) {
     auto Op = make_unique<SparcOperand>(k_Token);
     Op->Tok.Data = Str.data();
@@ -742,6 +751,52 @@ SparcAsmParser::parseMEMOperand(OperandVector &Operands) {
   return MatchOperand_Success;
 }
 
+OperandMatchResultTy SparcAsmParser::parseMembarTag(OperandVector &Operands) {
+  SMLoc S = Parser.getTok().getLoc();
+  const MCExpr *EVal;
+  int64_t ImmVal = 0;
+
+  std::unique_ptr<SparcOperand> Mask;
+  if (parseSparcAsmOperand(Mask) == MatchOperand_Success) {
+    if (!Mask->isImm() || !Mask->getImm()->evaluateAsAbsolute(ImmVal) ||
+        ImmVal < 0 || ImmVal > 127) {
+      Error(S, "invalid membar mask number");
+      return MatchOperand_ParseFail;
+    }
+  }
+
+  while (getLexer().getKind() == AsmToken::Hash) {
+    SMLoc TagStart = getLexer().getLoc();
+    Parser.Lex(); // Eat the '#'.
+    unsigned MaskVal = StringSwitch<unsigned>(Parser.getTok().getString())
+      .Case("LoadLoad", 0x1)
+      .Case("StoreLoad", 0x2)
+      .Case("LoadStore", 0x4)
+      .Case("StoreStore", 0x8)
+      .Case("Lookaside", 0x10)
+      .Case("MemIssue", 0x20)
+      .Case("Sync", 0x40)
+      .Default(0);
+
+    Parser.Lex(); // Eat the identifier token.
+
+    if (!MaskVal) {
+      Error(TagStart, "unknown membar tag");
+      return MatchOperand_ParseFail;
+    }
+
+    ImmVal |= MaskVal;
+
+    if (getLexer().getKind() == AsmToken::Pipe)
+      Parser.Lex(); // Eat the '|'.
+  }
+
+  EVal = MCConstantExpr::create(ImmVal, getContext());
+  SMLoc E = SMLoc::getFromPointer(Parser.getTok().getLoc().getPointer() - 1);
+  Operands.push_back(SparcOperand::CreateImm(EVal, S, E));
+  return MatchOperand_Success;
+}
+
 OperandMatchResultTy
 SparcAsmParser::parseOperand(OperandVector &Operands, StringRef Mnemonic) {