SDIsel processes llvm.dbg.declare by recording the variable debug information descriptor and its corresponding stack frame index in MachineModuleInfo. This only works if the local variable is "homed" in the stack frame. It does not work for byval parameter, etc.

Added ISD::DECLARE node type to represent llvm.dbg.declare intrinsic. Now the intrinsic calls are lowered into a SDNode and lives on through out the codegen passes.
For now, since all the debugging information recording is done at isel time, when a ISD::DECLARE node is selected, it has the side effect of also recording the variable. This is a short term solution that should be fixed in time.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46659 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 51 insertions, 16 deletions

diff --git a/lib/CodeGen/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter.cpp
index 2acf287988..eac574386b 100644
--- a/lib/CodeGen/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter.cpp
@@ -1289,6 +1289,12 @@ void AsmPrinter::printLabel(unsigned Id) const {
   O << "\n" << TAI->getPrivateGlobalPrefix() << "label" << Id << ":\n";
 }
 
+/// printDeclare - This method prints a local variable declaration used by
+/// debug tables.
+void AsmPrinter::printDeclare(const MachineInstr *MI) const {
+  O << "\n";
+}
+
 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
 /// instruction, using the specified assembler variant.  Targets should
 /// overried this to format as appropriate.
diff --git a/lib/CodeGen/MachineModuleInfo.cpp b/lib/CodeGen/MachineModuleInfo.cpp
index 5edeefbfae..6d285bde04 100644
--- a/lib/CodeGen/MachineModuleInfo.cpp
+++ b/lib/CodeGen/MachineModuleInfo.cpp
@@ -1471,6 +1471,14 @@ bool DIVerifier::Verify(GlobalVariable *GV) {
   return true;
 }
 
+/// isVerified - Return true if the specified GV has already been
+/// verified as a debug information descriptor.
+bool DIVerifier::isVerified(GlobalVariable *GV) {
+  unsigned &ValiditySlot = Validity[GV];
+  if (ValiditySlot) return ValiditySlot == Valid;
+  return false;
+}
+
 //===----------------------------------------------------------------------===//
 
 DebugScope::~DebugScope() {
@@ -1554,12 +1562,6 @@ DebugInfoDesc *MachineModuleInfo::getDescFor(Value *V) {
   return DR.Deserialize(V);
 }
 
-/// Verify - Verify that a Value is debug information descriptor.
-///
-bool MachineModuleInfo::Verify(Value *V) {
-  return VR.Verify(V);
-}
-
 /// AnalyzeModule - Scan the module for global debug information.
 ///
 void MachineModuleInfo::AnalyzeModule(Module &M) {
@@ -1657,8 +1659,8 @@ unsigned MachineModuleInfo::RecordRegionEnd(Value *V) {
 
 /// RecordVariable - Indicate the declaration of  a local variable.
 ///
-void MachineModuleInfo::RecordVariable(Value *V, unsigned FrameIndex) {
-  VariableDesc *VD = cast<VariableDesc>(DR.Deserialize(V));
+void MachineModuleInfo::RecordVariable(GlobalValue *GV, unsigned FrameIndex) {
+  VariableDesc *VD = cast<VariableDesc>(DR.Deserialize(GV));
   DebugScope *Scope = getOrCreateScope(VD->getContext());
   DebugVariable *DV = new DebugVariable(VD, FrameIndex);
   Scope->AddVariable(DV);
diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp
index 41efbef54e..f30d7d455d 100644
--- a/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/lib/CodeGen/PrologEpilogInserter.cpp
@@ -513,9 +513,9 @@ void PEI::replaceFrameIndices(MachineFunction &Fn) {
     for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); ) {
       MachineInstr *MI = I;
 
-      // Remember how much SP has been adjustment to create the call frame.
       if (I->getOpcode() == FrameSetupOpcode ||
           I->getOpcode() == FrameDestroyOpcode) {
+        // Remember how much SP has been adjustment to create the call frame.
         int Size = I->getOperand(0).getImm();
         if ((!StackGrowsDown && I->getOpcode() == FrameSetupOpcode) ||
             (StackGrowsDown && I->getOpcode() == FrameDestroyOpcode))
@@ -526,7 +526,10 @@ void PEI::replaceFrameIndices(MachineFunction &Fn) {
         // Visit the instructions created by eliminateCallFramePseudoInstr().
         I = next(PrevI);
         MI = NULL;
-      } else {
+      } else if (I->getOpcode() == TargetInstrInfo::DECLARE)
+        // Ignore it.
+        I++;
+      else {
         I++;
         for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i)
           if (MI->getOperand(i).isFrameIndex()) {
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index fc726e4c41..4749b76344 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -1085,6 +1085,19 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
       break;
     }
     break;
+
+  case ISD::DECLARE:
+    assert(Node->getNumOperands() == 3 && "Invalid DECLARE node!");
+    switch (TLI.getOperationAction(ISD::DECLARE, MVT::Other)) {
+    default: assert(0 && "This action is not supported yet!");
+    case TargetLowering::Legal:
+      Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain.
+      Tmp2 = LegalizeOp(Node->getOperand(1));  // Legalize the address.
+      Tmp3 = LegalizeOp(Node->getOperand(2));  // Legalize the variable.
+      Result = DAG.UpdateNodeOperands(Result, Tmp1, Tmp2, Tmp3);
+      break;
+    }
+    break;    
     
   case ISD::DEBUG_LOC:
     assert(Node->getNumOperands() == 4 && "Invalid DEBUG_LOC node!");
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
index 3ecd623c81..a165b17dff 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
@@ -736,6 +736,7 @@ void ScheduleDAG::EmitNode(SDNode *Node, unsigned InstanceNo,
     case ISD::EntryToken: // fall thru
     case ISD::TokenFactor:
     case ISD::LABEL:
+    case ISD::DECLARE:
       break;
     case ISD::CopyToReg: {
       unsigned InReg;
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 6f0e98d825..afb46476aa 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -20,6 +20,7 @@
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineConstantPool.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Target/MRegisterInfo.h"
 #include "llvm/Target/TargetData.h"
@@ -1620,6 +1621,16 @@ unsigned SelectionDAG::ComputeNumSignBits(SDOperand Op, unsigned Depth) const{
 }
 
 
+bool SelectionDAG::isVerifiedDebugInfoDesc(SDOperand Op) const {
+  GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Op);
+  if (!GA) return false;
+  GlobalVariable *GV = dyn_cast<GlobalVariable>(GA->getGlobal());
+  if (!GV) return false;
+  MachineModuleInfo *MMI = getMachineModuleInfo();
+  return MMI && MMI->hasDebugInfo() && MMI->isVerified(GV);
+}
+
+
 /// getNode - Gets or creates the specified node.
 ///
 SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT) {
@@ -3700,6 +3711,7 @@ std::string SDNode::getOperationName(const SelectionDAG *G) const {
   case ISD::MERGE_VALUES:  return "merge_values";
   case ISD::INLINEASM:     return "inlineasm";
   case ISD::LABEL:         return "label";
+  case ISD::DECLARE:       return "declare";
   case ISD::HANDLENODE:    return "handlenode";
   case ISD::FORMAL_ARGUMENTS: return "formal_arguments";
   case ISD::CALL:          return "call";
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 2d883878ce..55231f34a1 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -2663,12 +2663,10 @@ SelectionDAGLowering::visitIntrinsicCall(CallInst &I, unsigned Intrinsic) {
   case Intrinsic::dbg_declare: {
     MachineModuleInfo *MMI = DAG.getMachineModuleInfo();
     DbgDeclareInst &DI = cast<DbgDeclareInst>(I);
-    if (MMI && DI.getVariable() && MMI->Verify(DI.getVariable())) {
-      SDOperand AddressOp  = getValue(DI.getAddress());
-      if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(AddressOp))
-        MMI->RecordVariable(DI.getVariable(), FI->getIndex());
-    }
-
+    Value *Variable = DI.getVariable();
+    if (MMI && Variable && MMI->Verify(Variable))
+      DAG.setRoot(DAG.getNode(ISD::DECLARE, MVT::Other, getRoot(),
+                              getValue(DI.getAddress()), getValue(Variable)));
     return 0;
   }