Vendor import of llvm release_30 branch r142614:vendor/llvm/llvm-r142614

http://llvm.org/svn/llvm-project/llvm/branches/release_30@142614

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) {