[mips] [IAS] Refactor the emitDirectiveModuleOddSPReg() functions. NFC.

[tomatabacu]

Summary

We can simplify emitDirectiveModuleOddSPReg() by having it print the current OddSPReg information
from MipsABIFlagsSection and doing an updateABIInfo() before such calls.

This prevents us from forgetting to update the STI.FeatureBits, because updateABIInfo() uses those to update the MipsABIFlagsSection object,
and also makes sure we use the update mechanism from MipsABIFlagsSection.

[dsanders]

LGTM.

I thought for a moment that there was a risk of making '.set' directives permanent but this is impossible because .module must appear before all code/data/directives.

lib/Target/Mips/AsmParser/MipsAsmParser.cpp

bool MipsAsmParser::parseDirectiveModule() {
 
   StringRef Option;
   if (Parser.parseIdentifier(Option)) {
     reportParseError("expected .module option identifier");
     return false;
   }
 
   if (Option == "oddspreg") {
-    getTargetStreamer().emitDirectiveModuleOddSPReg(true, isABI_O32());
     clearFeatureBits(Mips::FeatureNoOddSPReg, "nooddspreg");
 
+    // Synchronize the abiflags information with the FeatureBits information we
+    // changed above.
+    getTargetStreamer().updateABIInfo(*this);
+
+    // If printing assembly, use the recently updated abiflags information.
+    // If generating ELF, don't do anything (the .MIPS.abiflags section gets
+    // emitted at the end).
+    getTargetStreamer().emitDirectiveModuleOddSPReg();
+
     // 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;
     }
 
     return false; // parseDirectiveModule has finished successfully.
   } else if (Option == "nooddspreg") {
     if (!isABI_O32()) {
       Error(L, "'.module nooddspreg' requires the O32 ABI");
       return false;
     }
 
-    getTargetStreamer().emitDirectiveModuleOddSPReg(false, isABI_O32());
     setFeatureBits(Mips::FeatureNoOddSPReg, "nooddspreg");
 
+    // Synchronize the abiflags information with the FeatureBits information we
+    // changed above.
+    getTargetStreamer().updateABIInfo(*this);
+
+    // If printing assembly, use the recently updated abiflags information.
+    // If generating ELF, don't do anything (the .MIPS.abiflags section gets
+    // emitted at the end).
+    getTargetStreamer().emitDirectiveModuleOddSPReg();
+
     // 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;
     }
 
     return false; // parseDirectiveModule has finished successfully.
   } else if (Option == "fp") {

lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp

MipsTargetStreamer::emitDirectiveModuleFP(MipsABIFlagsSection::FpABIKind Value,
                                           bool Is32BitABI) {
   ABIFlagsSection.setFpABI(Value, Is32BitABI);
 }
 
 void MipsTargetStreamer::emitDirectiveModuleFP() {
   emitDirectiveModuleFP(ABIFlagsSection.getFpABI(), ABIFlagsSection.Is32BitABI);
 }
 
-void MipsTargetStreamer::emitDirectiveModuleOddSPReg(bool Enabled,
-                                                     bool IsO32ABI) {
-  if (!Enabled && !IsO32ABI)
+void MipsTargetStreamer::emitDirectiveModuleOddSPReg() {
+  if (!ABIFlagsSection.OddSPReg && !ABIFlagsSection.Is32BitABI)
     report_fatal_error("+nooddspreg is only valid for O32");
 }
 void MipsTargetStreamer::emitDirectiveSetFp(
     MipsABIFlagsSection::FpABIKind Value) {
   forbidModuleDirective();
 }
 
 MipsTargetAsmStreamer::MipsTargetAsmStreamer(MCStreamer &S,

 void MipsTargetAsmStreamer::emitDirectiveSetFp(
     MipsABIFlagsSection::FpABIKind Value) {
   MipsTargetStreamer::emitDirectiveSetFp(Value);
 
   OS << "\t.set\tfp=";
   OS << ABIFlagsSection.getFpABIString(Value) << "\n";
 }
 
-void MipsTargetAsmStreamer::emitDirectiveModuleOddSPReg(bool Enabled,
-                                                        bool IsO32ABI) {
-  MipsTargetStreamer::emitDirectiveModuleOddSPReg(Enabled, IsO32ABI);
+void MipsTargetAsmStreamer::emitDirectiveModuleOddSPReg() {
+  MipsTargetStreamer::emitDirectiveModuleOddSPReg();
 
-  OS << "\t.module\t" << (Enabled ? "" : "no") << "oddspreg\n";
+  OS << "\t.module\t" << (ABIFlagsSection.OddSPReg ? "" : "no") << "oddspreg\n";
 }
 
 // This part is for ELF object output.
 MipsTargetELFStreamer::MipsTargetELFStreamer(MCStreamer &S,
                                              const MCSubtargetInfo &STI)
     : MipsTargetStreamer(S), MicroMipsEnabled(false), STI(STI) {
   MCAssembler &MCA = getStreamer().getAssembler();
   Pic = MCA.getContext().getObjectFileInfo()->getRelocM() == Reloc::PIC_;
void MipsTargetELFStreamer::emitMipsAbiFlags() {
   MCSectionELF *Sec = Context.getELFSection(
       ".MIPS.abiflags", ELF::SHT_MIPS_ABIFLAGS, ELF::SHF_ALLOC, 24, "");
   MCA.registerSection(*Sec);
   Sec->setAlignment(8);
   OS.SwitchSection(Sec);
 
   OS << ABIFlagsSection;
 }
-
-void MipsTargetELFStreamer::emitDirectiveModuleOddSPReg(bool Enabled,
-                                                        bool IsO32ABI) {
-  MipsTargetStreamer::emitDirectiveModuleOddSPReg(Enabled, IsO32ABI);
-
-  ABIFlagsSection.OddSPReg = Enabled;
-}

lib/Target/Mips/MipsAsmPrinter.cpp

void MipsAsmPrinter::EmitStartOfAsmFile(Module &M) {
   // -mfp64) and omit it otherwise.
   if (ABI.IsO32() && (STI.isABI_FPXX() || STI.isFP64bit()))
     getTargetStreamer().emitDirectiveModuleFP();
 
   // We should always emit a '.module [no]oddspreg' but binutils 2.24 does not
   // accept it. We therefore emit it when it contradicts the default or an
   // option has changed the default (i.e. FPXX) and omit it otherwise.
   if (ABI.IsO32() && (!STI.useOddSPReg() || STI.isABI_FPXX()))
-    getTargetStreamer().emitDirectiveModuleOddSPReg(STI.useOddSPReg(),
-                                                    ABI.IsO32());
+    getTargetStreamer().emitDirectiveModuleOddSPReg();
 }
 
 void MipsAsmPrinter::emitInlineAsmStart() const {
   MipsTargetStreamer &TS = getTargetStreamer();
 
   // GCC's choice of assembler options for inline assembly code ('at', 'macro'
   // and 'reorder') is different from LLVM's choice for generated code ('noat',
   // 'nomacro' and 'noreorder').

lib/Target/Mips/MipsTargetStreamer.h

public:
   /// Emit a '.module fp=value' directive using the given values.
   /// Updates the .MIPS.abiflags section
   virtual void emitDirectiveModuleFP(MipsABIFlagsSection::FpABIKind Value,
                                      bool Is32BitABI);
   /// Emit a '.module fp=value' directive using the current values of the
   /// .MIPS.abiflags section.
   void emitDirectiveModuleFP();
 
-  virtual void emitDirectiveModuleOddSPReg(bool Enabled, bool IsO32ABI);
+  virtual void emitDirectiveModuleOddSPReg();
   virtual void emitDirectiveSetFp(MipsABIFlagsSection::FpABIKind Value);
   void forbidModuleDirective() { ModuleDirectiveAllowed = false; }
   void reallowModuleDirective() { ModuleDirectiveAllowed = true; }
   bool isModuleDirectiveAllowed() { return ModuleDirectiveAllowed; }
 
   // This method enables template classes to set internal abi flags
   // structure values.
   template <class PredicateLibrary>
public:
   // PIC support
   void emitDirectiveCpLoad(unsigned RegNo) override;
   void emitDirectiveCpsetup(unsigned RegNo, int RegOrOffset,
                             const MCSymbol &Sym, bool IsReg) override;
 
   // ABI Flags
   void emitDirectiveModuleFP(MipsABIFlagsSection::FpABIKind Value,
                              bool Is32BitABI) override;
-  void emitDirectiveModuleOddSPReg(bool Enabled, bool IsO32ABI) override;
+  void emitDirectiveModuleOddSPReg() override;
   void emitDirectiveSetFp(MipsABIFlagsSection::FpABIKind Value) override;
 };
 
 // This part is for ELF object output
 class MipsTargetELFStreamer : public MipsTargetStreamer {
   bool MicroMipsEnabled;
   const MCSubtargetInfo &STI;
   bool Pic;
public:
   void emitMask(unsigned CPUBitmask, int CPUTopSavedRegOff) override;
   void emitFMask(unsigned FPUBitmask, int FPUTopSavedRegOff) override;
 
   // PIC support
   void emitDirectiveCpLoad(unsigned RegNo) override;
   void emitDirectiveCpsetup(unsigned RegNo, int RegOrOffset,
                             const MCSymbol &Sym, bool IsReg) override;
 
-  // ABI Flags
-  void emitDirectiveModuleOddSPReg(bool Enabled, bool IsO32ABI) override;
   void emitMipsAbiFlags();
 };
 } // namespace llvm
 #endif