[llvm-commits] [llvm] r128045 - in /llvm/trunk: lib/CodeGen/AsmPrinter/DwarfDebug.cpp lib/CodeGen/AsmPrinter/DwarfDebug.h lib/CodeGen/LiveDebugVariables.cpp test/CodeGen/X86/dbg-value-range.ll
Jakob Stoklund Olesen
stoklund at 2pi.dk
Mon Mar 21 17:21:41 PDT 2011
Author: stoklund
Date: Mon Mar 21 19:21:41 2011
New Revision: 128045
URL: http://llvm.org/viewvc/llvm-project?rev=128045&view=rev
Log:
Dont emit 'DBG_VALUE %noreg, ...' to terminate user variable ranges.
These ranges get completely jumbled by the post-ra scheduler, and it is not
really reasonable to expect it to make sense of them.
Instead, teach DwarfDebug to notice when user variables in registers are
clobbered, and terminate the ranges there.
Modified:
llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h
llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp
llvm/trunk/test/CodeGen/X86/dbg-value-range.ll
Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=128045&r1=128044&r2=128045&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Mon Mar 21 19:21:41 2011
@@ -2424,8 +2424,7 @@
ME = DbgValues.end(); MI != ME; ++MI) {
const MDNode *Var =
(*MI)->getOperand((*MI)->getNumOperands()-1).getMetadata();
- if (Var == DV &&
- !PrevMI->isIdenticalTo(*MI))
+ if (Var == DV && !PrevMI->isIdenticalTo(*MI))
MultipleValues.push_back(*MI);
PrevMI = *MI;
}
@@ -2448,7 +2447,7 @@
DbgVariableToDbgInstMap[AbsVar] = MInsn;
VarToAbstractVarMap[RegVar] = AbsVar;
}
- if (MultipleValues.size() <= 1) {
+ if (MultipleValues.size() <= 1 && !RegClobberInsn.count(MInsn)) {
DbgVariableToDbgInstMap[RegVar] = MInsn;
continue;
}
@@ -2458,16 +2457,11 @@
RegVar->setDotDebugLocOffset(0);
else
RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
- const MachineInstr *Begin = NULL;
- const MachineInstr *End = NULL;
+
for (SmallVector<const MachineInstr *, 4>::iterator
MVI = MultipleValues.begin(), MVE = MultipleValues.end();
MVI != MVE; ++MVI) {
- if (!Begin) {
- Begin = *MVI;
- continue;
- }
- End = *MVI;
+ const MachineInstr *Begin = *MVI;
MachineLocation MLoc;
if (Begin->getNumOperands() == 3) {
if (Begin->getOperand(0).isReg() && Begin->getOperand(1).isImm())
@@ -2475,25 +2469,25 @@
} else
MLoc = Asm->getDebugValueLocation(Begin);
+ if (!MLoc.getReg())
+ continue;
+
+ // Compute the range for a register location.
const MCSymbol *FLabel = getLabelBeforeInsn(Begin);
- const MCSymbol *SLabel = getLabelBeforeInsn(End);
- if (MLoc.getReg())
- DotDebugLocEntries.push_back(DotDebugLocEntry(FLabel, SLabel, MLoc));
-
- Begin = End;
- if (MVI + 1 == MVE) {
- // If End is the last instruction then its value is valid
+ const MCSymbol *SLabel = 0;
+
+ if (const MachineInstr *ClobberMI = RegClobberInsn.lookup(Begin))
+ // The register range starting at Begin may be clobbered.
+ SLabel = getLabelAfterInsn(ClobberMI);
+ else if (MVI + 1 == MVE)
+ // If Begin is the last instruction then its value is valid
// until the end of the funtion.
- MachineLocation EMLoc;
- if (End->getNumOperands() == 3) {
- if (End->getOperand(0).isReg() && Begin->getOperand(1).isImm())
- EMLoc.set(Begin->getOperand(0).getReg(), Begin->getOperand(1).getImm());
- } else
- EMLoc = Asm->getDebugValueLocation(End);
- if (EMLoc.getReg())
- DotDebugLocEntries.
- push_back(DotDebugLocEntry(SLabel, FunctionEndSym, EMLoc));
- }
+ SLabel = FunctionEndSym;
+ else
+ // The value is valid until the next DBG_VALUE.
+ SLabel = getLabelBeforeInsn(MVI[1]);
+
+ DotDebugLocEntries.push_back(DotDebugLocEntry(FLabel, SLabel, MLoc));
}
DotDebugLocEntries.push_back(DotDebugLocEntry());
}
@@ -2568,7 +2562,7 @@
/// endInstruction - Process end of an instruction.
void DwarfDebug::endInstruction(const MachineInstr *MI) {
- if (InsnsEndScopeSet.count(MI) != 0) {
+ if (InsnsNeedsLabelAfter.count(MI) != 0) {
// Emit a label if this instruction ends a scope.
MCSymbol *Label = MMI->getContext().CreateTempSymbol();
Asm->OutStreamer.EmitLabel(Label);
@@ -2833,7 +2827,7 @@
RE = Ranges.end(); RI != RE; ++RI) {
assert(RI->first && "DbgRange does not have first instruction!");
assert(RI->second && "DbgRange does not have second instruction!");
- InsnsEndScopeSet.insert(RI->second);
+ InsnsNeedsLabelAfter.insert(RI->second);
}
}
}
@@ -2914,6 +2908,14 @@
/// ProcessedArgs - Collection of arguments already processed.
SmallPtrSet<const MDNode *, 8> ProcessedArgs;
+ /// LastDbgValue - Refer back to the last DBG_VALUE instruction to mention MD.
+ DenseMap<const MDNode*, const MachineInstr*> LastDbgValue;
+
+ const TargetRegisterInfo *TRI = Asm->TM.getRegisterInfo();
+
+ /// LiveUserVar - Map physreg numbers to the MDNode they contain.
+ std::vector<const MDNode*> LiveUserVar(TRI->getNumRegs());
+
DebugLoc PrevLoc;
for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
I != E; ++I)
@@ -2923,7 +2925,15 @@
DebugLoc DL = MI->getDebugLoc();
if (MI->isDebugValue()) {
assert (MI->getNumOperands() > 1 && "Invalid machine instruction!");
- DIVariable DV(MI->getOperand(MI->getNumOperands() - 1).getMetadata());
+
+ // Keep track of variables in registers.
+ const MDNode *Var =
+ MI->getOperand(MI->getNumOperands() - 1).getMetadata();
+ LastDbgValue[Var] = MI;
+ if (isDbgValueInDefinedReg(MI))
+ LiveUserVar[MI->getOperand(0).getReg()] = Var;
+
+ DIVariable DV(Var);
if (!DV.Verify()) continue;
// If DBG_VALUE is for a local variable then it needs a label.
if (DV.getTag() != dwarf::DW_TAG_arg_variable)
@@ -2944,6 +2954,32 @@
} else if (DL != PrevLoc)
// Otherwise, instruction needs a location only if it is new location.
InsnNeedsLabel.insert(MI);
+
+ // Check if the instruction clobbers any registers with debug vars.
+ for (MachineInstr::const_mop_iterator MOI = MI->operands_begin(),
+ MOE = MI->operands_end(); MOI != MOE; ++MOI) {
+ if (!MOI->isReg() || !MOI->isDef() || !MOI->getReg())
+ continue;
+ for (const unsigned *AI = TRI->getOverlaps(MOI->getReg());
+ unsigned Reg = *AI; ++AI) {
+ const MDNode *Var = LiveUserVar[Reg];
+ if (!Var)
+ continue;
+ // Reg is now clobbered.
+ LiveUserVar[Reg] = 0;
+
+ // Was MD last defined by a DBG_VALUE referring to Reg?
+ const MachineInstr *Last = LastDbgValue.lookup(Var);
+ if (!Last || Last->getParent() != MI->getParent())
+ continue;
+ if (!isDbgValueInDefinedReg(Last) ||
+ Last->getOperand(0).getReg() != Reg)
+ continue;
+ // MD is clobbered. Make sure the next instruction gets a label.
+ InsnsNeedsLabelAfter.insert(MI);
+ RegClobberInsn[Last] = MI;
+ }
+ }
}
if (!DL.isUnknown() || UnknownLocations)
@@ -3013,7 +3049,7 @@
VarToAbstractVarMap.clear();
DbgVariableToDbgInstMap.clear();
DeleteContainerSeconds(DbgScopeMap);
- InsnsEndScopeSet.clear();
+ InsnsNeedsLabelAfter.clear();
ConcreteScopes.clear();
DeleteContainerSeconds(AbstractScopes);
AbstractScopesList.clear();
Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h?rev=128045&r1=128044&r2=128045&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h Mon Mar 21 19:21:41 2011
@@ -200,8 +200,6 @@
typedef SmallVector<DbgScope *, 2> ScopeVector;
- SmallPtrSet<const MachineInstr *, 8> InsnsEndScopeSet;
-
/// InlineInfo - Keep track of inlined functions and their location. This
/// information is used to populate debug_inlined section.
typedef std::pair<const MCSymbol *, DIE *> InlineInfoLabels;
@@ -224,6 +222,16 @@
/// a debuggging information entity.
SmallPtrSet<const MachineInstr *, 8> InsnNeedsLabel;
+ /// InsnsNeedsLabelAfter - Collection of instructions that need a label after
+ /// the instruction because they end a scope of clobber a register.
+ SmallPtrSet<const MachineInstr *, 8> InsnsNeedsLabelAfter;
+
+ /// RegClobberInsn - For each DBG_VALUE instruction referring to a register
+ /// that is clobbered before the variable gets a new DBG_VALUE, map the
+ /// instruction that clobbered the register. This instruction will also be in
+ /// InsnsNeedsLabelAfter.
+ DenseMap<const MachineInstr *, const MachineInstr *> RegClobberInsn;
+
SmallVector<const MCSymbol *, 8> DebugRangeSymbols;
/// Previous instruction's location information. This is used to determine
Modified: llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp?rev=128045&r1=128044&r2=128045&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp (original)
+++ llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp Mon Mar 21 19:21:41 2011
@@ -101,10 +101,6 @@
void insertDebugValue(MachineBasicBlock *MBB, SlotIndex Idx, unsigned LocNo,
LiveIntervals &LIS, const TargetInstrInfo &TII);
- /// insertDebugKill - Insert an undef DBG_VALUE into MBB at Idx.
- void insertDebugKill(MachineBasicBlock *MBB, SlotIndex Idx,
- LiveIntervals &LIS, const TargetInstrInfo &TII);
-
public:
/// UserValue - Create a new UserValue.
UserValue(const MDNode *var, unsigned o, DebugLoc L,
@@ -752,13 +748,6 @@
.addOperand(Loc).addImm(offset).addMetadata(variable);
}
-void UserValue::insertDebugKill(MachineBasicBlock *MBB, SlotIndex Idx,
- LiveIntervals &LIS, const TargetInstrInfo &TII) {
- MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, LIS);
- BuildMI(*MBB, I, findDebugLoc(), TII.get(TargetOpcode::DBG_VALUE)).addReg(0)
- .addImm(offset).addMetadata(variable);
-}
-
void UserValue::emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
const TargetInstrInfo &TII) {
MachineFunction::iterator MFEnd = VRM->getMachineFunction().end();
@@ -790,12 +779,6 @@
break;
++I;
- if (Stop == MBBEnd)
- continue;
- // The current interval ends before MBB.
- // Insert a kill if there is a gap.
- if (!I.valid() || I.start() > Stop)
- insertDebugKill(MBB, Stop, LIS, TII);
}
}
Modified: llvm/trunk/test/CodeGen/X86/dbg-value-range.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/dbg-value-range.ll?rev=128045&r1=128044&r2=128045&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/dbg-value-range.ll (original)
+++ llvm/trunk/test/CodeGen/X86/dbg-value-range.ll Mon Mar 21 19:21:41 2011
@@ -41,15 +41,17 @@
!18 = metadata !{i32 7, i32 2, metadata !12, null}
!19 = metadata !{i32 8, i32 2, metadata !12, null}
-; check that variable bar:b value range is appropriately trucated in debug info. Here Ltmp5 is end of
-; location range.
+; Check that variable bar:b value range is appropriately trucated in debug info.
+; The variable is in %rdi which is clobbered by 'movl %ebx, %edi'
+; Here Ltmp7 is the end of the location range.
;CHECK:Ltmp6
-;CHECK-NEXT: DEBUG_VALUE: bar:b <- undef
+;CHECK-NEXT: movl
+;CHECK-NEXT: Ltmp7
;CHECK:Ldebug_loc0:
;CHECK-NEXT: .quad Ltmp
-;CHECK-NEXT: .quad Ltmp6
+;CHECK-NEXT: .quad Ltmp7
;CHECK-NEXT: .short 1
;CHECK-NEXT: .byte 85
;CHECK-NEXT: .quad 0
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