Map stack based frameindices for spills to zero based indices that can be accessed based on an external symbol defining the location of temporary data for a function. For example: we have spill slots addressed as foo.tmp + 0, foo.tmp + 1 etc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68442 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 62 insertions, 33 deletions

diff --git a/lib/Target/PIC16/PIC16AsmPrinter.cpp b/lib/Target/PIC16/PIC16AsmPrinter.cpp
index b4950436ce..c0b1f6e860 100644
--- a/lib/Target/PIC16/PIC16AsmPrinter.cpp
+++ b/lib/Target/PIC16/PIC16AsmPrinter.cpp
@@ -343,7 +343,6 @@ bool PIC16AsmPrinter::doFinalization(Module &M) {
 void PIC16AsmPrinter::emitFunctionData(MachineFunction &MF) {
   const Function *F = MF.getFunction();
   std::string FuncName = Mang->getValueName(F);
-  MachineFrameInfo *MFI= MF.getFrameInfo();
   Module *M = const_cast<Module *>(F->getParent());
   const TargetData *TD = TM.getTargetData();
   unsigned FrameSize = 0;
@@ -406,15 +405,7 @@ void PIC16AsmPrinter::emitFunctionData(MachineFunction &MF) {
     O << VarName << "  RES  " << Size << "\n";
   }
 
-
-  // Emit the variable to hold the space for temporary locations
-  // in function frame.
-  if (MFI->hasStackObjects()) {
-    int indexBegin = MFI->getObjectIndexBegin();
-    int indexEnd = MFI->getObjectIndexEnd();
-    if (indexBegin < indexEnd) {
-      int TempSize = indexEnd - indexBegin; 
-      O << CurrentFnName << ".tmp       RES  " << TempSize <<"\n";
-    }
-  }
+  int TempSize = PTLI->GetTmpSize();
+  if (TempSize > 0 )
+    O << CurrentFnName << ".tmp       RES  " << TempSize <<"\n";
 }
diff --git a/lib/Target/PIC16/PIC16AsmPrinter.h b/lib/Target/PIC16/PIC16AsmPrinter.h
index 5286dd2e7a..05f6eff70d 100644
--- a/lib/Target/PIC16/PIC16AsmPrinter.h
+++ b/lib/Target/PIC16/PIC16AsmPrinter.h
@@ -24,11 +24,12 @@
 
 namespace llvm {
   struct VISIBILITY_HIDDEN PIC16AsmPrinter : public AsmPrinter {
-  PIC16AsmPrinter(raw_ostream &O, TargetMachine &TM,
+  PIC16AsmPrinter(raw_ostream &O, PIC16TargetMachine &TM,
                     const TargetAsmInfo *T, bool F, bool V)
       : AsmPrinter(O, TM, T, F, V) {
       CurBank = "";
       IsRomData = false;
+      PTLI = TM.getTargetLowering();
     }
     private :
     virtual const char *getPassName() const {
@@ -51,6 +52,7 @@ namespace llvm {
     bool doFinalization(Module &M);
 
     private:
+    PIC16TargetLowering *PTLI;
     std::string CurBank;
     bool IsRomData;
   };
diff --git a/lib/Target/PIC16/PIC16ISelLowering.cpp b/lib/Target/PIC16/PIC16ISelLowering.cpp
index f196b14dc8..473e9d745d 100644
--- a/lib/Target/PIC16/PIC16ISelLowering.cpp
+++ b/lib/Target/PIC16/PIC16ISelLowering.cpp
@@ -31,7 +31,7 @@ using namespace llvm;
 
 // PIC16TargetLowering Constructor.
 PIC16TargetLowering::PIC16TargetLowering(PIC16TargetMachine &TM)
-  : TargetLowering(TM) {
+  : TargetLowering(TM), TmpSize(0) {
   
   Subtarget = &TM.getSubtarget<PIC16Subtarget>();
 
@@ -154,6 +154,17 @@ static SDValue getOutFlag(SDValue &Op) {
 
   return Flag;
 }
+// Get the TmpOffset for FrameIndex
+unsigned PIC16TargetLowering::GetTmpOffsetForFI(unsigned FI) {
+  std::map<unsigned, unsigned>::iterator 
+            MapIt = FiTmpOffsetMap.find(FI);
+  if (MapIt != FiTmpOffsetMap.end())
+      return MapIt->second;
+
+  // This FI (FrameIndex) is not yet mapped, so map it
+  FiTmpOffsetMap[FI] = TmpSize; 
+  return TmpSize++;
+}
 
 // To extract chain value from the SDValue Nodes
 // This function will help to maintain the chain extracting
@@ -541,9 +552,9 @@ PIC16TargetLowering::LegalizeFrameIndex(SDValue Op, SelectionDAG &DAG,
 //         and non-constant operand of ADD will be treated as pointer.
 // Returns the high and lo part of the address, and the offset(in case of ADD).
 
-void PIC16TargetLowering:: LegalizeAddress(SDValue Ptr, SelectionDAG &DAG, 
-                                           SDValue &Lo, SDValue &Hi,
-                                           unsigned &Offset, DebugLoc dl) {
+void PIC16TargetLowering::LegalizeAddress(SDValue Ptr, SelectionDAG &DAG, 
+                                          SDValue &Lo, SDValue &Hi,
+                                          unsigned &Offset, DebugLoc dl) {
 
   // Offset, by default, should be 0
   Offset = 0;
@@ -849,13 +860,15 @@ SDValue PIC16TargetLowering::ConvertToMemOperand(SDValue Op,
                                DAG.getEntryNode(),
                                Op, ES, 
                                DAG.getConstant (1, MVT::i8), // Banksel.
-                               DAG.getConstant (FI, MVT::i8));
+                               DAG.getConstant (GetTmpOffsetForFI(FI), 
+                                                MVT::i8));
 
   // Load the value from ES.
   SDVTList Tys = DAG.getVTList(MVT::i8, MVT::Other);
   SDValue Load = DAG.getNode(PIC16ISD::PIC16Load, dl, Tys, Store,
                              ES, DAG.getConstant (1, MVT::i8),
-                             DAG.getConstant (FI, MVT::i8));
+                             DAG.getConstant (GetTmpOffsetForFI(FI), 
+                             MVT::i8));
     
   return Load.getValue(0);
 }
@@ -1212,40 +1225,45 @@ SDValue PIC16TargetLowering::LowerSUB(SDValue Op, SelectionDAG &DAG) {
     return DAG.getNode(Op.getOpcode(), dl, Tys, NewVal, Op.getOperand(1));
 }
 
-// LowerFORMAL_ARGUMENTS - In Lowering FORMAL ARGUMENTS - MERGE_VALUES nodes
-// is returned. MERGE_VALUES nodes number of operands and number of values are
-// equal. Therefore to construct MERGE_VALUE node, UNDEF nodes equal to the
-// number of arguments of function have been created.
+// LowerFORMAL_ARGUMENTS - Argument values are loaded from the
+// <fname>.args + offset. All arguments are already broken to leaglized
+// types, so the offset just runs from 0 to NumArgVals - 1.
 
 SDValue PIC16TargetLowering::LowerFORMAL_ARGUMENTS(SDValue Op, 
-                                                    SelectionDAG &DAG) {
+                                                   SelectionDAG &DAG) {
   SmallVector<SDValue, 8> ArgValues;
-  unsigned NumArgs = Op.getNode()->getNumValues()-1;
+  unsigned NumArgVals = Op.getNode()->getNumValues() - 1;
   DebugLoc dl = Op.getDebugLoc();
   SDValue Chain = Op.getOperand(0);    // Formal arguments' chain
 
+
+  // Reset the map of FI and TmpOffset 
+  ResetTmpOffsetMap();
+  // Get the callee's name to create the <fname>.args label to pass args.
   MachineFunction &MF = DAG.getMachineFunction();
-  //const TargetData *TD = getTargetData();
   const Function *F = MF.getFunction();
   std::string FuncName = F->getName();
 
+  // Create the <fname>.args external symbol.
   char *tmpName = new char [strlen(FuncName.c_str()) +  6];
   sprintf(tmpName, "%s.args", FuncName.c_str());
-  SDVTList VTs  = DAG.getVTList (MVT::i8, MVT::Other);
   SDValue ES = DAG.getTargetExternalSymbol(tmpName, MVT::i8);
+
+  // Load arg values from the label + offset.
+  SDVTList VTs  = DAG.getVTList (MVT::i8, MVT::Other);
   SDValue BS = DAG.getConstant(1, MVT::i8);
-  for (unsigned i=0; i<NumArgs ; ++i) {
+  for (unsigned i = 0; i < NumArgVals ; ++i) {
     SDValue Offset = DAG.getConstant(i, MVT::i8);
     SDValue PICLoad = DAG.getNode(PIC16ISD::PIC16LdArg, dl, VTs, Chain, ES, BS,
-                                     Offset);
+                                  Offset);
     Chain = getChain(PICLoad);
     ArgValues.push_back(PICLoad);
   }
 
+  // Return a MERGE_VALUE node.
   ArgValues.push_back(Op.getOperand(0));
   return DAG.getNode(ISD::MERGE_VALUES, dl, Op.getNode()->getVTList(), 
-                     &ArgValues[0],
-                     ArgValues.size()).getValue(Op.getResNo());
+                     &ArgValues[0], ArgValues.size()).getValue(Op.getResNo());
 }
 
 // Perform DAGCombine of PIC16Load.
diff --git a/lib/Target/PIC16/PIC16ISelLowering.h b/lib/Target/PIC16/PIC16ISelLowering.h
index 3dae35277f..498610a975 100644
--- a/lib/Target/PIC16/PIC16ISelLowering.h
+++ b/lib/Target/PIC16/PIC16ISelLowering.h
@@ -19,6 +19,7 @@
 #include "PIC16Subtarget.h"
 #include "llvm/CodeGen/SelectionDAG.h"
 #include "llvm/Target/TargetLowering.h"
+#include <map>
 
 namespace llvm {
   namespace PIC16ISD {
@@ -117,6 +118,16 @@ namespace llvm {
     SDValue PerformPIC16LoadCombine(SDNode *N, DAGCombinerInfo &DCI) const; 
     SDValue PerformStoreCombine(SDNode *N, DAGCombinerInfo &DCI) const; 
 
+    // This function returns the Tmp Offset for FrameIndex. If any TmpOffset 
+    // already exists for the FI then it returns the same else it creates the 
+    // new offset and returns.
+    unsigned GetTmpOffsetForFI(unsigned FI); 
+    void ResetTmpOffsetMap() { FiTmpOffsetMap.clear(); SetTmpSize(0); }
+
+    // Return the size of Tmp variable 
+    unsigned GetTmpSize() { return TmpSize; }
+    void SetTmpSize(unsigned Size) { TmpSize = Size; }
+
   private:
     // If the Node is a BUILD_PAIR representing a direct Address,
     // then this function will return true.
@@ -170,6 +181,11 @@ namespace llvm {
     // Check if operation has a direct load operand.
     inline bool isDirectLoad(const SDValue Op);
 
+  private:
+    // The frameindexes generated for spill/reload are stack based.
+    // This maps maintain zero based indexes for these FIs.
+    std::map<unsigned, unsigned> FiTmpOffsetMap;
+    unsigned TmpSize;
   };
 } // namespace llvm
 
diff --git a/lib/Target/PIC16/PIC16InstrInfo.cpp b/lib/Target/PIC16/PIC16InstrInfo.cpp
index 0066e67209..99c27fdac7 100644
--- a/lib/Target/PIC16/PIC16InstrInfo.cpp
+++ b/lib/Target/PIC16/PIC16InstrInfo.cpp
@@ -69,6 +69,7 @@ void PIC16InstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
                                          MachineBasicBlock::iterator I,
                                          unsigned SrcReg, bool isKill, int FI,
                                          const TargetRegisterClass *RC) const {
+  PIC16TargetLowering *PTLI = TM.getTargetLowering();
   DebugLoc DL = DebugLoc::getUnknownLoc();
   if (I != MBB.end()) DL = I->getDebugLoc();
 
@@ -84,7 +85,7 @@ void PIC16InstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
     //MachineRegisterInfo &RI = MF.getRegInfo();
     BuildMI(MBB, I, DL, get(PIC16::movwf))
       .addReg(SrcReg, false, false, isKill)
-      .addImm(FI)
+      .addImm(PTLI->GetTmpOffsetForFI(FI))
       .addExternalSymbol(tmpName)
       .addImm(1); // Emit banksel for it.
   }
@@ -98,6 +99,7 @@ void PIC16InstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
                                           MachineBasicBlock::iterator I,
                                           unsigned DestReg, int FI,
                                           const TargetRegisterClass *RC) const {
+  PIC16TargetLowering *PTLI = TM.getTargetLowering();
   DebugLoc DL = DebugLoc::getUnknownLoc();
   if (I != MBB.end()) DL = I->getDebugLoc();
 
@@ -112,7 +114,7 @@ void PIC16InstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
     //MachineFunction &MF = *MBB.getParent();
     //MachineRegisterInfo &RI = MF.getRegInfo();
     BuildMI(MBB, I, DL, get(PIC16::movf), DestReg)
-      .addImm(FI)
+      .addImm(PTLI->GetTmpOffsetForFI(FI))
       .addExternalSymbol(tmpName)
       .addImm(1); // Emit banksel for it.
   }