1. Add a pass to fold debug label instructions so a debug info client can detect
empty ranges.
2. Reorg how MachineDebugInfo maintains changes to debug labels.
3. Have dwarf writer use debug label info to simplify scopes and source line
coorespondence.
4. Revert the merging of compile units until I can get the bugs ironed out.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31507 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/DwarfWriter.cpp b/lib/CodeGen/DwarfWriter.cpp
index 81c8963..c8a1333 100644
--- a/lib/CodeGen/DwarfWriter.cpp
+++ b/lib/CodeGen/DwarfWriter.cpp
@@ -1695,15 +1695,18 @@
return Unit;
}
+ /// GetBaseCompileUnit - Get the main compile unit.
+ ///
+ CompileUnit *GetBaseCompileUnit() const {
+ CompileUnit *Unit = CompileUnits[0];
+ assert(Unit && "Missing compile unit.");
+ return Unit;
+ }
+
/// FindCompileUnit - Get the compile unit for the given descriptor.
///
CompileUnit *FindCompileUnit(CompileUnitDesc *UnitDesc) {
-#if 1
- // FIXME - Using only one compile unit. Needs to me fixed at the FE.
- CompileUnit *Unit = CompileUnits[0];
-#else
CompileUnit *Unit = DescToUnitMap[UnitDesc];
-#endif
assert(Unit && "Missing compile unit.");
return Unit;
}
@@ -1859,13 +1862,12 @@
// FIXME - Ignore inlined functions for the time being.
if (!Scope->getParent()) continue;
- unsigned StartID = Scope->getStartLabelID();
- unsigned EndID = Scope->getEndLabelID();
+ unsigned StartID = DebugInfo->MappedLabel(Scope->getStartLabelID());
+ unsigned EndID = DebugInfo->MappedLabel(Scope->getEndLabelID());
- // Widen scope if label is discarded.
- // FIXME - really need to find a GOOD label if a block is dead.
- if (StartID && !DebugInfo->isLabelValid(StartID)) StartID = 0;
- if (EndID && !DebugInfo->isLabelValid(EndID)) EndID = 0;
+ // Ignore empty scopes.
+ if (StartID == EndID && StartID != 0) continue;
+ if (Scope->getScopes().empty() && Scope->getVariables().empty()) continue;
DIE *ScopeDie = new DIE(DW_TAG_lexical_block);
@@ -2084,10 +2086,10 @@
std::vector<MachineMove *> &Moves) {
for (unsigned i = 0, N = Moves.size(); i < N; ++i) {
MachineMove *Move = Moves[i];
- unsigned LabelID = Move->getLabelID();
+ unsigned LabelID = DebugInfo->MappedLabel(Move->getLabelID());
// Throw out move if the label is invalid.
- if (LabelID && !DebugInfo->isLabelValid(LabelID)) continue;
+ if (!LabelID) continue;
const MachineLocation &Dst = Move->getDestination();
const MachineLocation &Src = Move->getSource();
@@ -2307,9 +2309,8 @@
// Construct rows of the address, source, line, column matrix.
for (unsigned i = 0, N = LineInfos.size(); i < N; ++i) {
const SourceLineInfo &LineInfo = LineInfos[i];
- unsigned LabelID = LineInfo.getLabelID();
-
- // Source line labels are validated at the MachineDebugInfo level.
+ unsigned LabelID = DebugInfo->MappedLabel(LineInfo.getLabelID());
+ if (!LabelID) continue;
if (DwarfVerbose) {
unsigned SourceID = LineInfo.getSourceID();
@@ -2420,6 +2421,7 @@
void EmitFunctionDebugFrame() {
if (!TAI->getDwarfRequiresFrameSection())
return;
+
// Start the dwarf frame section.
Asm->SwitchToDataSection(TAI->getDwarfFrameSection());
@@ -2588,7 +2590,8 @@
const UniqueVector<CompileUnitDesc *> CUW = DebugInfo->getCompileUnits();
for (unsigned i = 1, N = CUW.size(); i <= N; ++i) {
- CompileUnit *Unit = NewCompileUnit(CUW[i], i);
+ unsigned ID = DebugInfo->RecordSource(CUW[i]);
+ CompileUnit *Unit = NewCompileUnit(CUW[i], ID);
CompileUnits.push_back(Unit);
}
}
diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index b12634a..ae13625 100644
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -66,6 +66,9 @@
// Branch folding must be run after regalloc and prolog/epilog insertion.
if (!Fast)
PM.add(createBranchFoldingPass());
+
+ // Fold redundant debug labels.
+ PM.add(createDebugLabelFoldingPass());
if (PrintMachineCode) // Print the register-allocated code
PM.add(createMachineFunctionPrinterPass(&std::cerr));
diff --git a/lib/CodeGen/MachineDebugInfo.cpp b/lib/CodeGen/MachineDebugInfo.cpp
index 490e48d..bdbdd14 100644
--- a/lib/CodeGen/MachineDebugInfo.cpp
+++ b/lib/CodeGen/MachineDebugInfo.cpp
@@ -10,7 +10,11 @@
#include "llvm/CodeGen/MachineDebugInfo.h"
#include "llvm/Constants.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineLocation.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetMachine.h"
#include "llvm/DerivedTypes.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Intrinsics.h"
@@ -1448,10 +1452,9 @@
, Directories()
, SourceFiles()
, Lines()
-, LabelID(0)
+, LabelIDList()
, ScopeMap()
, RootScope(NULL)
-, DeletedLabelIDs()
, FrameMoves()
{}
MachineDebugInfo::~MachineDebugInfo() {
@@ -1544,35 +1547,6 @@
return ID;
}
-static bool LabelUIDComparison(const SourceLineInfo &LI, unsigned UID) {
- return LI.getLabelID() < UID;
-}
-
-/// InvalidateLabel - Inhibit use of the specified label # from
-/// MachineDebugInfo, for example because the code was deleted.
-void MachineDebugInfo::InvalidateLabel(unsigned LabelID) {
- // Check source line list first. SourceLineInfo is sorted by LabelID.
- std::vector<SourceLineInfo>::iterator I =
- std::lower_bound(Lines.begin(), Lines.end(), LabelID, LabelUIDComparison);
- if (I != Lines.end() && I->getLabelID() == LabelID) {
- Lines.erase(I);
- return;
- }
-
- // Otherwise add for use by isLabelValid.
- std::vector<unsigned>::iterator J =
- std::lower_bound(DeletedLabelIDs.begin(), DeletedLabelIDs.end(), LabelID);
- DeletedLabelIDs.insert(J, LabelID);
-}
-
-/// isLabelValid - Check to make sure the label is still valid before
-/// attempting to use.
-bool MachineDebugInfo::isLabelValid(unsigned LabelID) {
- std::vector<unsigned>::iterator I =
- std::lower_bound(DeletedLabelIDs.begin(), DeletedLabelIDs.end(), LabelID);
- return I == DeletedLabelIDs.end() || *I != LabelID;
-}
-
/// RecordSource - Register a source file with debug info. Returns an source
/// ID.
unsigned MachineDebugInfo::RecordSource(const std::string &Directory,
@@ -1642,4 +1616,70 @@
return Slot;
}
+//===----------------------------------------------------------------------===//
+/// DebugLabelFolding pass - This pass prunes out redundant debug labels. This
+/// allows a debug emitter to determine if the range of two labels is empty,
+/// by seeing if the labels map to the same reduced label.
+
+namespace llvm {
+
+struct DebugLabelFolder : public MachineFunctionPass {
+ virtual bool runOnMachineFunction(MachineFunction &MF);
+ virtual const char *getPassName() const { return "Debug Label Folder"; }
+};
+
+bool DebugLabelFolder::runOnMachineFunction(MachineFunction &MF) {
+ // Get machine debug info.
+ MachineDebugInfo *MDI = getAnalysisToUpdate<MachineDebugInfo>();
+ if (!MDI) return false;
+ // Get target instruction info.
+ const TargetInstrInfo *TII = MF.getTarget().getInstrInfo();
+ if (!TII) return false;
+ // Get target version of the debug label opcode.
+ unsigned DWARF_LABELOpc = TII->getDWARF_LABELOpcode();
+ if (!DWARF_LABELOpc) return false;
+
+ // Track if change is made.
+ bool MadeChange = false;
+ // No prior label to begin.
+ unsigned PriorLabel = 0;
+
+ // Iterate through basic blocks.
+ for (MachineFunction::iterator BB = MF.begin(), E = MF.end();
+ BB != E; ++BB) {
+ // Iterate through instructions.
+ for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
+ // Is it a debug label.
+ if ((unsigned)I->getOpcode() == DWARF_LABELOpc) {
+ // The label ID # is always operand #0, an immediate.
+ unsigned NextLabel = I->getOperand(0).getImm();
+
+ // If there was an immediate prior label.
+ if (PriorLabel) {
+ // Remap the current label to prior label.
+ MDI->RemapLabel(NextLabel, PriorLabel);
+ // Delete the current label.
+ I = BB->erase(I);
+ // Indicate a change has been made.
+ MadeChange = true;
+ continue;
+ } else {
+ // Start a new round.
+ PriorLabel = NextLabel;
+ }
+ } else {
+ // No consecutive labels.
+ PriorLabel = 0;
+ }
+
+ ++I;
+ }
+ }
+
+ return MadeChange;
+}
+
+FunctionPass *createDebugLabelFoldingPass() { return new DebugLabelFolder(); }
+
+}