Right now, Debugging information to encode scopes (DW_TAG_lexical_block) relies on DBG_LABEL. Unfortunately this intefers with the quality of optimized code.

This patch updates dwarf writer to encode scoping information in DWARF only in FastISel mode.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68973 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 24 insertions, 21 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfWriter.cpp b/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
index c619bc5..c4191e5 100644
--- a/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
@@ -3296,7 +3296,7 @@ public:
   }
 
   /// ValidDebugInfo - Return true if V represents valid debug info value.
-  bool ValidDebugInfo(Value *V) {
+  bool ValidDebugInfo(Value *V, bool FastISel) {
     if (!V)
       return false;
 
@@ -3335,6 +3335,11 @@ public:
     case DW_TAG_subprogram:
       assert(DISubprogram(GV).Verify() && "Invalid DebugInfo value");
       break;
+    case DW_TAG_lexical_block:
+      /// FIXME. This interfers with the qualitfy of generated code when 
+      /// during optimization.
+      if (FastISel == false)
+        return false;
     default:
       break;
     }
@@ -4621,8 +4626,8 @@ void DwarfWriter::EndFunction(MachineFunction *MF) {
 }
 
 /// ValidDebugInfo - Return true if V represents valid debug info value.
-bool DwarfWriter::ValidDebugInfo(Value *V) {
-  return DD && DD->ValidDebugInfo(V);
+bool DwarfWriter::ValidDebugInfo(Value *V, bool FastISel) {
+  return DD && DD->ValidDebugInfo(V, FastISel);
 }
 
 /// RecordSourceLine - Records location information and associates it with a 
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index cc425e5..f48ff52 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -326,7 +326,7 @@ bool FastISel::SelectCall(User *I) {
   default: break;
   case Intrinsic::dbg_stoppoint: {
     DbgStopPointInst *SPI = cast<DbgStopPointInst>(I);
-    if (DW && DW->ValidDebugInfo(SPI->getContext())) {
+    if (DW && DW->ValidDebugInfo(SPI->getContext(), true)) {
       DICompileUnit CU(cast<GlobalVariable>(SPI->getContext()));
       std::string Dir, FN;
       unsigned SrcFile = DW->getOrCreateSourceID(CU.getDirectory(Dir),
@@ -343,7 +343,7 @@ bool FastISel::SelectCall(User *I) {
   }
   case Intrinsic::dbg_region_start: {
     DbgRegionStartInst *RSI = cast<DbgRegionStartInst>(I);
-    if (DW && DW->ValidDebugInfo(RSI->getContext())) {
+    if (DW && DW->ValidDebugInfo(RSI->getContext(), true)) {
       unsigned ID = 
         DW->RecordRegionStart(cast<GlobalVariable>(RSI->getContext()));
       const TargetInstrDesc &II = TII.get(TargetInstrInfo::DBG_LABEL);
@@ -353,7 +353,7 @@ bool FastISel::SelectCall(User *I) {
   }
   case Intrinsic::dbg_region_end: {
     DbgRegionEndInst *REI = cast<DbgRegionEndInst>(I);
-    if (DW && DW->ValidDebugInfo(REI->getContext())) {
+    if (DW && DW->ValidDebugInfo(REI->getContext(), true)) {
       unsigned ID = 
         DW->RecordRegionEnd(cast<GlobalVariable>(REI->getContext()));
       const TargetInstrDesc &II = TII.get(TargetInstrInfo::DBG_LABEL);
@@ -366,7 +366,7 @@ bool FastISel::SelectCall(User *I) {
     DbgFuncStartInst *FSI = cast<DbgFuncStartInst>(I);
     Value *SP = FSI->getSubprogram();
 
-    if (DW->ValidDebugInfo(SP)) {
+    if (DW->ValidDebugInfo(SP, true)) {
       // llvm.dbg.func.start implicitly defines a dbg_stoppoint which is what
       // (most?) gdb expects.
       DISubprogram Subprogram(cast<GlobalVariable>(SP));
@@ -401,7 +401,7 @@ bool FastISel::SelectCall(User *I) {
   case Intrinsic::dbg_declare: {
     DbgDeclareInst *DI = cast<DbgDeclareInst>(I);
     Value *Variable = DI->getVariable();
-    if (DW && DW->ValidDebugInfo(Variable)) {
+    if (DW && DW->ValidDebugInfo(Variable, true)) {
       // Determine the address of the declared object.
       Value *Address = DI->getAddress();
       if (BitCastInst *BCI = dyn_cast<BitCastInst>(Address))
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
index b596643..a7d7b5c 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
@@ -332,7 +332,7 @@ void FunctionLoweringInfo::set(Function &fn, MachineFunction &mf,
             DwarfWriter *DW = DAG.getDwarfWriter();
             DbgStopPointInst *SPI = cast<DbgStopPointInst>(I);
 
-            if (DW && DW->ValidDebugInfo(SPI->getContext())) {
+            if (DW && DW->ValidDebugInfo(SPI->getContext(), false)) {
               DICompileUnit CU(cast<GlobalVariable>(SPI->getContext()));
               std::string Dir, FN;
               unsigned SrcFile = DW->getOrCreateSourceID(CU.getDirectory(Dir),
@@ -351,7 +351,7 @@ void FunctionLoweringInfo::set(Function &fn, MachineFunction &mf,
               DbgFuncStartInst *FSI = cast<DbgFuncStartInst>(I);
               Value *SP = FSI->getSubprogram();
 
-              if (DW->ValidDebugInfo(SP)) {
+              if (DW->ValidDebugInfo(SP, false)) {
                 DISubprogram Subprogram(cast<GlobalVariable>(SP));
                 DICompileUnit CU(Subprogram.getCompileUnit());
                 std::string Dir, FN;
@@ -3921,7 +3921,7 @@ SelectionDAGLowering::visitIntrinsicCall(CallInst &I, unsigned Intrinsic) {
   case Intrinsic::dbg_stoppoint: {
     DwarfWriter *DW = DAG.getDwarfWriter();
     DbgStopPointInst &SPI = cast<DbgStopPointInst>(I);
-    if (DW && DW->ValidDebugInfo(SPI.getContext())) {
+    if (DW && DW->ValidDebugInfo(SPI.getContext(), Fast)) {
       MachineFunction &MF = DAG.getMachineFunction();
       if (Fast)
         DAG.setRoot(DAG.getDbgStopPoint(getRoot(),
@@ -3941,12 +3941,11 @@ SelectionDAGLowering::visitIntrinsicCall(CallInst &I, unsigned Intrinsic) {
   case Intrinsic::dbg_region_start: {
     DwarfWriter *DW = DAG.getDwarfWriter();
     DbgRegionStartInst &RSI = cast<DbgRegionStartInst>(I);
-    if (DW && DW->ValidDebugInfo(RSI.getContext())) {
+    if (DW && DW->ValidDebugInfo(RSI.getContext(), Fast)) {
       unsigned LabelID =
         DW->RecordRegionStart(cast<GlobalVariable>(RSI.getContext()));
-      if (Fast)
-        DAG.setRoot(DAG.getLabel(ISD::DBG_LABEL, getCurDebugLoc(),
-                                 getRoot(), LabelID));
+      DAG.setRoot(DAG.getLabel(ISD::DBG_LABEL, getCurDebugLoc(),
+                               getRoot(), LabelID));
     }
 
     return 0;
@@ -3954,7 +3953,7 @@ SelectionDAGLowering::visitIntrinsicCall(CallInst &I, unsigned Intrinsic) {
   case Intrinsic::dbg_region_end: {
     DwarfWriter *DW = DAG.getDwarfWriter();
     DbgRegionEndInst &REI = cast<DbgRegionEndInst>(I);
-    if (DW && DW->ValidDebugInfo(REI.getContext())) {
+    if (DW && DW->ValidDebugInfo(REI.getContext(), Fast)) {
 
       MachineFunction &MF = DAG.getMachineFunction();
       DISubprogram Subprogram(cast<GlobalVariable>(REI.getContext()));
@@ -3969,9 +3968,8 @@ SelectionDAGLowering::visitIntrinsicCall(CallInst &I, unsigned Intrinsic) {
 
       unsigned LabelID =
         DW->RecordRegionEnd(cast<GlobalVariable>(REI.getContext()));
-      if (Fast)
-        DAG.setRoot(DAG.getLabel(ISD::DBG_LABEL, getCurDebugLoc(),
-                                 getRoot(), LabelID));
+      DAG.setRoot(DAG.getLabel(ISD::DBG_LABEL, getCurDebugLoc(),
+                               getRoot(), LabelID));
     }
 
     return 0;
@@ -3981,7 +3979,7 @@ SelectionDAGLowering::visitIntrinsicCall(CallInst &I, unsigned Intrinsic) {
     if (!DW) return 0;
     DbgFuncStartInst &FSI = cast<DbgFuncStartInst>(I);
     Value *SP = FSI.getSubprogram();
-    if (SP && DW->ValidDebugInfo(SP)) {
+    if (SP && DW->ValidDebugInfo(SP, Fast)) {
       // llvm.dbg.func.start implicitly defines a dbg_stoppoint which is
       // what (most?) gdb expects.
       MachineFunction &MF = DAG.getMachineFunction();
@@ -4023,7 +4021,7 @@ SelectionDAGLowering::visitIntrinsicCall(CallInst &I, unsigned Intrinsic) {
       DwarfWriter *DW = DAG.getDwarfWriter();
       DbgDeclareInst &DI = cast<DbgDeclareInst>(I);
       Value *Variable = DI.getVariable();
-      if (DW && DW->ValidDebugInfo(Variable))
+      if (DW && DW->ValidDebugInfo(Variable, Fast))
         DAG.setRoot(DAG.getNode(ISD::DECLARE, dl, MVT::Other, getRoot(),
                                 getValue(DI.getAddress()), getValue(Variable)));
     } else {