[mips] [IAS] Add support for the .insn directive.

Summary:
This assembler directive marks the current label as an instruction label in microMIPS and MIPS16.

This initial implementation works only for microMIPS.

Reviewers: dsanders

Reviewed By: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8006

llvm-svn: 235084

5 files changed, 47 insertions, 2 deletions

diff --git a/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp b/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
index 6086e9f8bb8..6f7e3c16a9b 100644
--- a/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ b/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -220,6 +220,7 @@ class MipsAsmParser : public MCTargetAsmParser {
   bool parseDirectiveNaN();
   bool parseDirectiveSet();
   bool parseDirectiveOption();
+  bool parseInsnDirective();
 
   bool parseSetAtDirective();
   bool parseSetNoAtDirective();
@@ -4045,6 +4046,23 @@ bool MipsAsmParser::parseDirectiveOption() {
   return false;
 }
 
+/// parseInsnDirective
+///  ::= .insn
+bool MipsAsmParser::parseInsnDirective() {
+  // If this is not the end of the statement, report an error.
+  if (getLexer().isNot(AsmToken::EndOfStatement)) {
+    reportParseError("unexpected token, expected end of statement");
+    return false;
+  }
+
+  // The actual label marking happens in
+  // MipsELFStreamer::createPendingLabelRelocs().
+  getTargetStreamer().emitDirectiveInsn();
+
+  getParser().Lex(); // Eat EndOfStatement token.
+  return false;
+}
+
 /// parseDirectiveModule
 ///  ::= .module oddspreg
 ///  ::= .module nooddspreg
@@ -4438,6 +4456,9 @@ bool MipsAsmParser::ParseDirective(AsmToken DirectiveID) {
   if (IDVal == ".llvm_internal_mips_reallow_module_directive")
     return parseInternalDirectiveReallowModule();
 
+  if (IDVal == ".insn")
+    return parseInsnDirective();
+
   return true;
 }
 
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsELFStreamer.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsELFStreamer.cpp
index 8eb29074a22..6d1d9f4f223 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsELFStreamer.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsELFStreamer.cpp
@@ -21,8 +21,6 @@ void MipsELFStreamer::EmitInstruction(const MCInst &Inst,
 
   MCContext &Context = getContext();
   const MCRegisterInfo *MCRegInfo = Context.getRegisterInfo();
-  MipsTargetELFStreamer *ELFTargetStreamer =
-      static_cast<MipsTargetELFStreamer *>(getTargetStreamer());
 
   for (unsigned OpIndex = 0; OpIndex < Inst.getNumOperands(); ++OpIndex) {
     const MCOperand &Op = Inst.getOperand(OpIndex);
@@ -34,6 +32,14 @@ void MipsELFStreamer::EmitInstruction(const MCInst &Inst,
     RegInfoRecord->SetPhysRegUsed(Reg, MCRegInfo);
   }
 
+  createPendingLabelRelocs();
+}
+
+void MipsELFStreamer::createPendingLabelRelocs() {
+  MipsTargetELFStreamer *ELFTargetStreamer =
+      static_cast<MipsTargetELFStreamer *>(getTargetStreamer());
+
+  // FIXME: Also mark labels when in MIPS16 mode.
   if (ELFTargetStreamer->isMicroMipsEnabled()) {
     for (auto Label : Labels) {
       MCSymbolData &Data = getOrCreateSymbolData(Label);
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsELFStreamer.h b/llvm/lib/Target/Mips/MCTargetDesc/MipsELFStreamer.h
index 68ff751dd14..4e3090171e3 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsELFStreamer.h
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsELFStreamer.h
@@ -65,6 +65,9 @@ public:
 
   /// Emits all the option records stored up until the point it's called.
   void EmitMipsOptionRecords();
+
+  /// Mark labels as microMIPS, if necessary for the subtarget.
+  void createPendingLabelRelocs();
 };
 
 MCELFStreamer *createMipsELFStreamer(MCContext &Context, MCAsmBackend &MAB,
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
index 5790a5c649a..ccc019e86aa 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
@@ -54,6 +54,7 @@ void MipsTargetStreamer::emitDirectiveNaN2008() {}
 void MipsTargetStreamer::emitDirectiveNaNLegacy() {}
 void MipsTargetStreamer::emitDirectiveOptionPic0() {}
 void MipsTargetStreamer::emitDirectiveOptionPic2() {}
+void MipsTargetStreamer::emitDirectiveInsn() { forbidModuleDirective(); }
 void MipsTargetStreamer::emitFrame(unsigned StackReg, unsigned StackSize,
                                    unsigned ReturnReg) {}
 void MipsTargetStreamer::emitMask(unsigned CPUBitmask, int CPUTopSavedRegOff) {}
@@ -189,6 +190,11 @@ void MipsTargetAsmStreamer::emitDirectiveOptionPic2() {
   OS << "\t.option\tpic2\n";
 }
 
+void MipsTargetAsmStreamer::emitDirectiveInsn() {
+  MipsTargetStreamer::emitDirectiveInsn();
+  OS << "\t.insn\n";
+}
+
 void MipsTargetAsmStreamer::emitFrame(unsigned StackReg, unsigned StackSize,
                                       unsigned ReturnReg) {
   OS << "\t.frame\t$"
@@ -637,6 +643,12 @@ void MipsTargetELFStreamer::emitDirectiveOptionPic2() {
   MCA.setELFHeaderEFlags(Flags);
 }
 
+void MipsTargetELFStreamer::emitDirectiveInsn() {
+  MipsTargetStreamer::emitDirectiveInsn();
+  MipsELFStreamer &MEF = static_cast<MipsELFStreamer &>(Streamer);
+  MEF.createPendingLabelRelocs();
+}
+
 void MipsTargetELFStreamer::emitFrame(unsigned StackReg, unsigned StackSize,
                                       unsigned ReturnReg_) {
   MCContext &Context = getStreamer().getAssembler().getContext();
diff --git a/llvm/lib/Target/Mips/MipsTargetStreamer.h b/llvm/lib/Target/Mips/MipsTargetStreamer.h
index 1ff041dc08e..22b0c6c6685 100644
--- a/llvm/lib/Target/Mips/MipsTargetStreamer.h
+++ b/llvm/lib/Target/Mips/MipsTargetStreamer.h
@@ -45,6 +45,7 @@ public:
   virtual void emitDirectiveNaNLegacy();
   virtual void emitDirectiveOptionPic0();
   virtual void emitDirectiveOptionPic2();
+  virtual void emitDirectiveInsn();
   virtual void emitFrame(unsigned StackReg, unsigned StackSize,
                          unsigned ReturnReg);
   virtual void emitMask(unsigned CPUBitmask, int CPUTopSavedRegOff);
@@ -160,6 +161,7 @@ public:
   void emitDirectiveNaNLegacy() override;
   void emitDirectiveOptionPic0() override;
   void emitDirectiveOptionPic2() override;
+  void emitDirectiveInsn() override;
   void emitFrame(unsigned StackReg, unsigned StackSize,
                  unsigned ReturnReg) override;
   void emitMask(unsigned CPUBitmask, int CPUTopSavedRegOff) override;
@@ -227,6 +229,7 @@ public:
   void emitDirectiveNaNLegacy() override;
   void emitDirectiveOptionPic0() override;
   void emitDirectiveOptionPic2() override;
+  void emitDirectiveInsn() override;
   void emitFrame(unsigned StackReg, unsigned StackSize,
                  unsigned ReturnReg) override;
   void emitMask(unsigned CPUBitmask, int CPUTopSavedRegOff) override;