Implement support for ISRs.

Clone functions that are shared between the Main thread and Interrupt thread.
CallSites are changed in AsmPrinter currently. A better solution would have been to modify the legalizer (SoftenFloat) to allow targets to change the name of libcalls for float operations. But that currently breaks other targets.
Also, cloing of automatic variables is done AsmPrinter, a better approach would
be to use the ValueMap in CloneFunction itself.

llvm-svn: 79562

2 files changed, 45 insertions, 12 deletions

diff --git a/llvm/lib/Target/PIC16/AsmPrinter/PIC16AsmPrinter.cpp b/llvm/lib/Target/PIC16/AsmPrinter/PIC16AsmPrinter.cpp
index 1522e4ca2e6..b96ae54005e 100644
--- a/llvm/lib/Target/PIC16/AsmPrinter/PIC16AsmPrinter.cpp
+++ b/llvm/lib/Target/PIC16/AsmPrinter/PIC16AsmPrinter.cpp
@@ -39,6 +39,7 @@ PIC16AsmPrinter::PIC16AsmPrinter(formatted_raw_ostream &O, TargetMachine &TM,
   PTLI = static_cast<PIC16TargetLowering*>(TM.getTargetLowering());
   PTAI = static_cast<const PIC16TargetAsmInfo*>(T);
   PTOF = (PIC16TargetObjectFile*)&PTLI->getObjFileLowering();
+  CurrentFnPtr = NULL;
 }
 
 bool PIC16AsmPrinter::printMachineInstruction(const MachineInstr *MI) {
@@ -60,6 +61,11 @@ bool PIC16AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
   // Get the mangled name.
   const Function *F = MF.getFunction();
   CurrentFnName = Mang->getMangledName(F);
+  CurrentFnPtr = F;
+
+  // Current function name was mangled in llvm-ld for both
+  // MainLine and InterruptLine and should be demangled here 
+  PAN::updateCallLineSymbol(CurrentFnName, CurrentFnPtr);
 
   // Emit the function frame (args and temps).
   EmitFunctionFrame(MF);
@@ -71,18 +77,23 @@ bool PIC16AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
 
   // Now emit the instructions of function in its code section.
   const MCSection *fCodeSection = 
-    getObjFileLowering().getSectionForFunction(CurrentFnName);
+    getObjFileLowering().getSectionForFunction(CurrentFnName, 
+                                               PAN::isISR(F));
   // Start the Code Section.
   O <<  "\n";
   OutStreamer.SwitchSection(fCodeSection);
-
-  // Emit the frame address of the function at the beginning of code.
-  O << "\tretlw  low(" << PAN::getFrameLabel(CurrentFnName) << ")\n";
-  O << "\tretlw  high(" << PAN::getFrameLabel(CurrentFnName) << ")\n";
+  
+  // If it is not an interrupt function then emit the data address
+  // retrieval code in function code itself.
+  if (!(PAN::isISR(F))) {
+     // Emit the frame address of the function at the beginning of code.
+     O << "\tretlw  low(" << PAN::getFrameLabel(CurrentFnName) << ")\n";
+     O << "\tretlw  high(" << PAN::getFrameLabel(CurrentFnName) << ")\n";
+  }
 
   // Emit function start label.
   O << CurrentFnName << ":\n";
-
+  
   DebugLoc CurDL;
   O << "\n"; 
   // Print out code for the function.
@@ -142,7 +153,9 @@ void PIC16AsmPrinter::printOperand(const MachineInstr *MI, int opNum) {
       if (PAN::isMemIntrinsic(Sname)) {
         LibcallDecls.push_back(createESName(Sname));
       }
-
+      // All the call sites were mangled in llvm-ld pass hence the 
+      // operands for call instructions should be demangled here.
+      PAN::updateCallLineSymbol(Sname, CurrentFnPtr);
       O << Sname;
       break;
     }
@@ -151,7 +164,9 @@ void PIC16AsmPrinter::printOperand(const MachineInstr *MI, int opNum) {
 
       // If its a libcall name, record it to decls section.
       if (PAN::getSymbolTag(Sname) == PAN::LIBCALL) {
-        LibcallDecls.push_back(Sname);
+         // LibCallDecls for InterruptLine functions should have ".IL" suffix 
+         const char *NewName= PAN::getUpdatedLibCallDecl(Sname, CurrentFnPtr);
+         LibcallDecls.push_back(NewName);
       }
 
       // Record a call to intrinsic to print the extern declaration for it.
@@ -160,9 +175,13 @@ void PIC16AsmPrinter::printOperand(const MachineInstr *MI, int opNum) {
         Sym = PAN::addPrefix(Sym);
         LibcallDecls.push_back(createESName(Sym));
       }
-
-      O  << Sym;
-      break;
+      // Update the library call symbols. Library calls to InterruptLine
+      // functions are different. (They have ".IL" in their names)
+      // Also other symbols (frame and temp) for the cloned function
+      // should be updated here.
+      PAN::updateCallLineSymbol(Sym, CurrentFnPtr);
+      O << Sym; 
+     break;
     }
     case MachineOperand::MO_MachineBasicBlock:
       printBasicBlockLabel(MO.getMBB());
@@ -274,7 +293,11 @@ void PIC16AsmPrinter::EmitFunctionDecls(Module &M) {
 
     const char *directive = I->isDeclaration() ? TAI->getExternDirective() :
                                                  TAI->getGlobalDirective();
-      
+   
+    // This is called in initialization. Hence information of the current
+    // function line is not available. Hence UnspecifiedLine. UnspecifiedLine
+    // will be treated as MainLine. 
+    PAN::updateCallLineSymbol(Name, PAN::UnspecifiedLine);
     O << directive << Name << "\n";
     O << directive << PAN::getRetvalLabel(Name) << "\n";
     O << directive << PAN::getArgsLabel(Name) << "\n";
@@ -423,6 +446,13 @@ void PIC16AsmPrinter::EmitAutos(std::string FunctName) {
 
   // Now print Autos section for this function.
   std::string SectionName = PAN::getAutosSectionName(FunctName);
+
+  // If this function is a cloned function then the name of auto section 
+  // will not be present in the list of existing section. Hence this section
+  // should be cloned. 
+  // This function will check and clone
+  PTOF->createClonedSectionForAutos(SectionName);
+
   const std::vector<PIC16Section*> &AutosSections = PTOF->AutosSections;
   for (unsigned i = 0; i < AutosSections.size(); i++) {
     O << "\n";
@@ -436,6 +466,8 @@ void PIC16AsmPrinter::EmitAutos(std::string FunctName) {
         Constant *C = Items[j]->getInitializer();
         const Type *Ty = C->getType();
         unsigned Size = TD->getTypeAllocSize(Ty);
+        // Auto variables should be cloned for the cloned function 
+        PAN::updateCallLineAutos(VarName, CurrentFnName);
         // Emit memory reserve directive.
         O << VarName << "  RES  " << Size << "\n";
       }
diff --git a/llvm/lib/Target/PIC16/AsmPrinter/PIC16AsmPrinter.h b/llvm/lib/Target/PIC16/AsmPrinter/PIC16AsmPrinter.h
index 3eea880a20a..55a2fcf85a6 100644
--- a/llvm/lib/Target/PIC16/AsmPrinter/PIC16AsmPrinter.h
+++ b/llvm/lib/Target/PIC16/AsmPrinter/PIC16AsmPrinter.h
@@ -73,6 +73,7 @@ namespace llvm {
     PIC16DbgInfo DbgInfo;
     const PIC16TargetAsmInfo *PTAI;
     std::list<const char *> LibcallDecls; // List of extern decls.
+    const Function *CurrentFnPtr;   // Hold the pointer to current Function 
   };
 } // end of namespace