Adding support for placing global objects in shared data memory.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85006 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/PIC16/AsmPrinter/PIC16AsmPrinter.cpp

@@ -298,6 +298,7 @@ bool PIC16AsmPrinter::doInitialization(Module &M) {
   EmitIData(M);
   EmitUData(M);
   EmitRomData(M);
+  EmitSharedUdata(M);
   EmitUserSections(M);
   return Result;
 }
@@ -370,6 +371,11 @@ void PIC16AsmPrinter::EmitRomData(Module &M) {
   EmitSingleSection(PTOF->ROMDATASection());
 }
 
+// Emit Shared section udata.
+void PIC16AsmPrinter::EmitSharedUdata(Module &M) {
+  EmitSingleSection(PTOF->SHAREDUDATASection());
+}
+
 bool PIC16AsmPrinter::doFinalization(Module &M) {
   EmitAllAutos(M);
   printLibcallDecls();

lib/Target/PIC16/AsmPrinter/PIC16AsmPrinter.h

@@ -55,6 +55,7 @@ namespace llvm {
     void EmitUData (Module &M);
     void EmitAllAutos (Module &M);
     void EmitRomData (Module &M);
+    void EmitSharedUdata(Module &M);
     void EmitUserSections (Module &M);
     void EmitFunctionFrame(MachineFunction &MF);
     void printLibcallDecls();

lib/Target/PIC16/PIC16ABINames.h

@@ -234,6 +234,12 @@ namespace llvm {
       return "romdata.#";
     }
 
+    static std::string getSharedUDataSectionName() {
+       std::ostringstream o;
+       o << getTagName(PREFIX_SYMBOL)  << "udata_shr" << ".#";
+       return o.str();
+    }
+
     static std::string getRomdataSectionName(unsigned num,
                                              std::string prefix = "") {
        std::ostringstream o;

lib/Target/PIC16/PIC16MemSelOpt.cpp

@@ -144,7 +144,7 @@ bool MemSelOpt::processInstruction(MachineInstr *MI) {
   }
 
   // Get the section name(NewBank) for MemOp.
-  // This assumes that the section names for globals are laready set by
+  // This assumes that the section names for globals are already set by
   // AsmPrinter->doInitialization.
   std::string NewBank = CurBank;
   if (Op.getType() ==  MachineOperand::MO_GlobalAddress &&
@@ -156,7 +156,11 @@ bool MemSelOpt::processInstruction(MachineInstr *MI) {
     std::string Sym = Op.getSymbolName();
     NewBank = PAN::getSectionNameForSym(Sym);
   }
- 
+
+  // If the section is shared section, do not emit banksel.
+  if (NewBank == PAN::getSharedUDataSectionName())
+    return Changed;
+
   // If the previous and new section names are same, we don't need to
   // emit banksel. 
   if (NewBank.compare(CurBank) != 0 ) {

lib/Target/PIC16/PIC16TargetObjectFile.cpp

@@ -72,6 +72,7 @@ getPIC16DataSection(const std::string &Name, PIC16SectionType Ty,
   case UDATA: UDATASections_.push_back(Entry); break;
   case IDATA: IDATASections_.push_back(Entry); break;
   case ROMDATA: ROMDATASection_ = Entry; break;
+  case UDATA_SHR: SHAREDUDATASection_ = Entry; break;
   }
 
   return Entry;
@@ -279,7 +280,10 @@ getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
     std::string AddrStr = "Address=";
     if (SectName.compare(0, AddrStr.length(), AddrStr) == 0) {
       std::string SectAddr = SectName.substr(AddrStr.length());
-      return allocateAtGivenAddress(GVar, SectAddr);
+      if (SectAddr.compare("NEAR") == 0)
+        return allocateSHARED(GVar, Mang);
+      else
+        return allocateAtGivenAddress(GVar, SectAddr);
     }
      
     // Create the section specified with section attribute. 
@@ -289,6 +293,25 @@ getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
   return getPIC16DataSection(GV->getSection().c_str(), UDATA);
 }
 
+const MCSection *
+PIC16TargetObjectFile::allocateSHARED(const GlobalVariable *GV,
+                                      Mangler *Mang) const {
+  // Make sure that this is an uninitialized global.
+  assert(GV->hasInitializer() && "This global doesn't need space");
+  if (!GV->getInitializer()->isNullValue()) {
+    // FIXME: Generate a warning in this case that near qualifier will be 
+    // ignored.
+    return SelectSectionForGlobal(GV, SectionKind::getDataRel(), Mang, *TM); 
+  } 
+  std::string Name = PAN::getSharedUDataSectionName(); 
+
+  PIC16Section *SharedUDataSect = getPIC16DataSection(Name.c_str(), UDATA_SHR); 
+  // Insert the GV into shared section.
+  SharedUDataSect->Items.push_back(GV);
+  return SharedUDataSect;
+}
+
+
 // Interface used by AsmPrinter to get a code section for a function.
 const PIC16Section *
 PIC16TargetObjectFile::SectionForCode(const std::string &FnName) const {

lib/Target/PIC16/PIC16TargetObjectFile.h

@@ -56,6 +56,7 @@ namespace llvm {
     mutable std::vector<PIC16Section *> UDATASections_;
     mutable std::vector<PIC16Section *> IDATASections_;
     mutable PIC16Section * ROMDATASection_;
+    mutable PIC16Section * SHAREDUDATASection_;
 
     /// Standard Auto Sections.
     mutable std::vector<PIC16Section *> AUTOSections_;
@@ -110,6 +111,10 @@ namespace llvm {
     /// Allocate DATA at user specified address.
     const MCSection *allocateAtGivenAddress(const GlobalVariable *GV,
                                             const std::string &Addr) const;
+
+    /// Allocate a shared variable to SHARED section.
+    const MCSection *allocateSHARED(const GlobalVariable *GV,
+                                    Mangler *Mang) const;
    
     public:
     PIC16TargetObjectFile();
@@ -147,6 +152,9 @@ namespace llvm {
     const PIC16Section *ROMDATASection() const {
       return ROMDATASection_;
     }
+    const PIC16Section *SHAREDUDATASection() const {
+      return SHAREDUDATASection_;
+    }
     const std::vector<PIC16Section *> &AUTOSections() const {
       return AUTOSections_;
     }