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-rw-r--r--lib/CodeGen/LiveDebugVariables.cpp71
1 files changed, 58 insertions, 13 deletions
diff --git a/lib/CodeGen/LiveDebugVariables.cpp b/lib/CodeGen/LiveDebugVariables.cpp
index 5d38c83b49c2..3dfe4c0e8cfa 100644
--- a/lib/CodeGen/LiveDebugVariables.cpp
+++ b/lib/CodeGen/LiveDebugVariables.cpp
@@ -25,7 +25,10 @@
#include "llvm/Constants.h"
#include "llvm/Metadata.h"
#include "llvm/Value.h"
+#include "llvm/Analysis/DebugInfo.h"
#include "llvm/ADT/IntervalMap.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/CodeGen/LexicalScopes.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunction.h"
@@ -44,6 +47,7 @@ static cl::opt<bool>
EnableLDV("live-debug-variables", cl::init(true),
cl::desc("Enable the live debug variables pass"), cl::Hidden);
+STATISTIC(NumInsertedDebugValues, "Number of DBG_VALUEs inserted");
char LiveDebugVariables::ID = 0;
INITIALIZE_PASS_BEGIN(LiveDebugVariables, "livedebugvars",
@@ -67,6 +71,29 @@ LiveDebugVariables::LiveDebugVariables() : MachineFunctionPass(ID), pImpl(0) {
/// LocMap - Map of where a user value is live, and its location.
typedef IntervalMap<SlotIndex, unsigned, 4> LocMap;
+namespace {
+/// UserValueScopes - Keeps track of lexical scopes associated with an
+/// user value's source location.
+class UserValueScopes {
+ DebugLoc DL;
+ LexicalScopes &LS;
+ SmallPtrSet<const MachineBasicBlock *, 4> LBlocks;
+
+public:
+ UserValueScopes(DebugLoc D, LexicalScopes &L) : DL(D), LS(L) {}
+
+ /// dominates - Return true if current scope dominates at least one machine
+ /// instruction in a given machine basic block.
+ bool dominates(MachineBasicBlock *MBB) {
+ if (LBlocks.empty())
+ LS.getMachineBasicBlocks(DL, LBlocks);
+ if (LBlocks.count(MBB) != 0 || LS.dominates(DL, MBB))
+ return true;
+ return false;
+ }
+};
+} // end anonymous namespace
+
/// UserValue - A user value is a part of a debug info user variable.
///
/// A DBG_VALUE instruction notes that (a sub-register of) a virtual register
@@ -179,6 +206,9 @@ public:
LocMap::iterator I = locInts.find(Idx);
if (!I.valid() || I.start() != Idx)
I.insert(Idx, Idx.getNextSlot(), getLocationNo(LocMO));
+ else
+ // A later DBG_VALUE at the same SlotIndex overrides the old location.
+ I.setValue(getLocationNo(LocMO));
}
/// extendDef - Extend the current definition as far as possible down the
@@ -195,7 +225,8 @@ public:
void extendDef(SlotIndex Idx, unsigned LocNo,
LiveInterval *LI, const VNInfo *VNI,
SmallVectorImpl<SlotIndex> *Kills,
- LiveIntervals &LIS, MachineDominatorTree &MDT);
+ LiveIntervals &LIS, MachineDominatorTree &MDT,
+ UserValueScopes &UVS);
/// addDefsFromCopies - The value in LI/LocNo may be copies to other
/// registers. Determine if any of the copies are available at the kill
@@ -213,7 +244,8 @@ public:
/// computeIntervals - Compute the live intervals of all locations after
/// collecting all their def points.
void computeIntervals(MachineRegisterInfo &MRI,
- LiveIntervals &LIS, MachineDominatorTree &MDT);
+ LiveIntervals &LIS, MachineDominatorTree &MDT,
+ UserValueScopes &UVS);
/// renameRegister - Update locations to rewrite OldReg as NewReg:SubIdx.
void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx,
@@ -236,6 +268,9 @@ public:
/// Only first one needs DebugLoc to identify variable's lexical scope
/// in source file.
DebugLoc findDebugLoc();
+
+ /// getDebugLoc - Return DebugLoc of this UserValue.
+ DebugLoc getDebugLoc() { return dl;}
void print(raw_ostream&, const TargetMachine*);
};
} // namespace
@@ -247,6 +282,7 @@ class LDVImpl {
LocMap::Allocator allocator;
MachineFunction *MF;
LiveIntervals *LIS;
+ LexicalScopes LS;
MachineDominatorTree *MDT;
const TargetRegisterInfo *TRI;
@@ -312,8 +348,10 @@ public:
} // namespace
void UserValue::print(raw_ostream &OS, const TargetMachine *TM) {
- if (const MDString *MDS = dyn_cast<MDString>(variable->getOperand(2)))
- OS << "!\"" << MDS->getString() << "\"\t";
+ DIVariable DV(variable);
+ OS << "!\"";
+ DV.printExtendedName(OS);
+ OS << "\"\t";
if (offset)
OS << '+' << offset;
for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I) {
@@ -447,10 +485,10 @@ bool LDVImpl::collectDebugValues(MachineFunction &mf) {
void UserValue::extendDef(SlotIndex Idx, unsigned LocNo,
LiveInterval *LI, const VNInfo *VNI,
SmallVectorImpl<SlotIndex> *Kills,
- LiveIntervals &LIS, MachineDominatorTree &MDT) {
+ LiveIntervals &LIS, MachineDominatorTree &MDT,
+ UserValueScopes &UVS) {
SmallVector<SlotIndex, 16> Todo;
Todo.push_back(Idx);
-
do {
SlotIndex Start = Todo.pop_back_val();
MachineBasicBlock *MBB = LIS.getMBBFromIndex(Start);
@@ -497,8 +535,11 @@ void UserValue::extendDef(SlotIndex Idx, unsigned LocNo,
continue;
const std::vector<MachineDomTreeNode*> &Children =
MDT.getNode(MBB)->getChildren();
- for (unsigned i = 0, e = Children.size(); i != e; ++i)
- Todo.push_back(LIS.getMBBStartIdx(Children[i]->getBlock()));
+ for (unsigned i = 0, e = Children.size(); i != e; ++i) {
+ MachineBasicBlock *MBB = Children[i]->getBlock();
+ if (UVS.dominates(MBB))
+ Todo.push_back(LIS.getMBBStartIdx(MBB));
+ }
} while (!Todo.empty());
}
@@ -578,7 +619,8 @@ UserValue::addDefsFromCopies(LiveInterval *LI, unsigned LocNo,
void
UserValue::computeIntervals(MachineRegisterInfo &MRI,
LiveIntervals &LIS,
- MachineDominatorTree &MDT) {
+ MachineDominatorTree &MDT,
+ UserValueScopes &UVS) {
SmallVector<std::pair<SlotIndex, unsigned>, 16> Defs;
// Collect all defs to be extended (Skipping undefs).
@@ -597,10 +639,10 @@ UserValue::computeIntervals(MachineRegisterInfo &MRI,
LiveInterval *LI = &LIS.getInterval(Loc.getReg());
const VNInfo *VNI = LI->getVNInfoAt(Idx);
SmallVector<SlotIndex, 16> Kills;
- extendDef(Idx, LocNo, LI, VNI, &Kills, LIS, MDT);
+ extendDef(Idx, LocNo, LI, VNI, &Kills, LIS, MDT, UVS);
addDefsFromCopies(LI, LocNo, Kills, Defs, MRI, LIS);
} else
- extendDef(Idx, LocNo, 0, 0, 0, LIS, MDT);
+ extendDef(Idx, LocNo, 0, 0, 0, LIS, MDT, UVS);
}
// Finally, erase all the undefs.
@@ -613,7 +655,8 @@ UserValue::computeIntervals(MachineRegisterInfo &MRI,
void LDVImpl::computeIntervals() {
for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
- userValues[i]->computeIntervals(MF->getRegInfo(), *LIS, *MDT);
+ UserValueScopes UVS(userValues[i]->getDebugLoc(), LS);
+ userValues[i]->computeIntervals(MF->getRegInfo(), *LIS, *MDT, UVS);
userValues[i]->mapVirtRegs(this);
}
}
@@ -624,6 +667,7 @@ bool LDVImpl::runOnMachineFunction(MachineFunction &mf) {
MDT = &pass.getAnalysis<MachineDominatorTree>();
TRI = mf.getTarget().getRegisterInfo();
clear();
+ LS.initialize(mf);
DEBUG(dbgs() << "********** COMPUTING LIVE DEBUG VARIABLES: "
<< ((Value*)mf.getFunction())->getName()
<< " **********\n");
@@ -631,6 +675,7 @@ bool LDVImpl::runOnMachineFunction(MachineFunction &mf) {
bool Changed = collectDebugValues(mf);
computeIntervals();
DEBUG(print(dbgs()));
+ LS.releaseMemory();
return Changed;
}
@@ -891,6 +936,7 @@ void UserValue::insertDebugValue(MachineBasicBlock *MBB, SlotIndex Idx,
const TargetInstrInfo &TII) {
MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, LIS);
MachineOperand &Loc = locations[LocNo];
+ ++NumInsertedDebugValues;
// Frame index locations may require a target callback.
if (Loc.isFI()) {
@@ -921,7 +967,6 @@ void UserValue::emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
DEBUG(dbgs() << " BB#" << MBB->getNumber() << '-' << MBBEnd);
insertDebugValue(MBB, Start, LocNo, LIS, TII);
-
// This interval may span multiple basic blocks.
// Insert a DBG_VALUE into each one.
while(Stop > MBBEnd) {
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-31 08:51:04 +0000