X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FLiveRangeCalc.cpp;h=bb2877ae31a89f9026d7664c9eb3fb633b84ad7c;hb=f606a6ed992d5e4e2877419b51e2a9b540b5e3f0;hp=e449b240d706542dc183fe548639a15daee3716f;hpb=68445710a2869618faacf6e6e20d6efedea83f8b;p=oota-llvm.git

diff --git a/lib/CodeGen/LiveRangeCalc.cpp b/lib/CodeGen/LiveRangeCalc.cpp
index e449b240d70..bb2877ae31a 100644
--- a/lib/CodeGen/LiveRangeCalc.cpp
+++ b/lib/CodeGen/LiveRangeCalc.cpp
@@ -43,17 +43,14 @@ void LiveRangeCalc::reset(const MachineFunction *mf,
 static void createDeadDef(SlotIndexes &Indexes, VNInfo::Allocator &Alloc,
                           LiveRange &LR, const MachineOperand &MO) {
     const MachineInstr *MI = MO.getParent();
-    SlotIndex DefIdx;
-    if (MI->isPHI())
-      DefIdx = Indexes.getMBBStartIdx(MI->getParent());
-    else
-      DefIdx = Indexes.getInstructionIndex(MI).getRegSlot(MO.isEarlyClobber());
+    SlotIndex DefIdx =
+        Indexes.getInstructionIndex(MI).getRegSlot(MO.isEarlyClobber());
 
     // Create the def in LR. This may find an existing def.
     LR.createDeadDef(DefIdx, Alloc);
 }
 
-void LiveRangeCalc::calculate(LiveInterval &LI) {
+void LiveRangeCalc::calculate(LiveInterval &LI, bool TrackSubRegs) {
   assert(MRI && Indexes && "call reset() first");
 
   // Step 1: Create minimal live segments for every definition of Reg.
@@ -66,7 +63,7 @@ void LiveRangeCalc::calculate(LiveInterval &LI) {
       continue;
 
     unsigned SubReg = MO.getSubReg();
-    if (LI.hasSubRanges() || (SubReg != 0 && MRI->tracksSubRegLiveness())) {
+    if (LI.hasSubRanges() || (SubReg != 0 && TrackSubRegs)) {
       unsigned Mask = SubReg != 0 ? TRI.getSubRegIndexLaneMask(SubReg)
                                   : MRI->getMaxLaneMaskForVReg(Reg);
 
@@ -105,8 +102,9 @@ void LiveRangeCalc::calculate(LiveInterval &LI) {
       }
     }
 
-    // Create the def in the main liverange.
-    if (MO.isDef())
+    // Create the def in the main liverange. We do not have to do this if
+    // subranges are tracked as we recreate the main range later in this case.
+    if (MO.isDef() && !LI.hasSubRanges())
       createDeadDef(*Indexes, *Alloc, LI, MO);
   }
 
@@ -116,13 +114,17 @@ void LiveRangeCalc::calculate(LiveInterval &LI) {
 
   // Step 2: Extend live segments to all uses, constructing SSA form as
   // necessary.
-  for (LiveInterval::SubRange &S : LI.subranges()) {
+  if (LI.hasSubRanges()) {
+    for (LiveInterval::SubRange &S : LI.subranges()) {
+      resetLiveOutMap();
+      extendToUses(S, Reg, S.LaneMask);
+    }
+    LI.clear();
+    LI.constructMainRangeFromSubranges(*Indexes, *Alloc);
+  } else {
     resetLiveOutMap();
-    extendToUses(S, Reg, S.LaneMask);
+    extendToUses(LI, Reg, ~0u);
   }
-
-  resetLiveOutMap();
-  extendToUses(LI, Reg, ~0u);
 }
 
 
@@ -217,23 +219,23 @@ void LiveRangeCalc::updateFromLiveIns() {
 }
 
 
-void LiveRangeCalc::extend(LiveRange &LR, SlotIndex Kill, unsigned PhysReg) {
-  assert(Kill.isValid() && "Invalid SlotIndex");
+void LiveRangeCalc::extend(LiveRange &LR, SlotIndex Use, unsigned PhysReg) {
+  assert(Use.isValid() && "Invalid SlotIndex");
   assert(Indexes && "Missing SlotIndexes");
   assert(DomTree && "Missing dominator tree");
 
-  MachineBasicBlock *KillMBB = Indexes->getMBBFromIndex(Kill.getPrevSlot());
-  assert(KillMBB && "No MBB at Kill");
+  MachineBasicBlock *UseMBB = Indexes->getMBBFromIndex(Use.getPrevSlot());
+  assert(UseMBB && "No MBB at Use");
 
   // Is there a def in the same MBB we can extend?
-  if (LR.extendInBlock(Indexes->getMBBStartIdx(KillMBB), Kill))
+  if (LR.extendInBlock(Indexes->getMBBStartIdx(UseMBB), Use))
     return;
 
-  // Find the single reaching def, or determine if Kill is jointly dominated by
+  // Find the single reaching def, or determine if Use is jointly dominated by
   // multiple values, and we may need to create even more phi-defs to preserve
   // VNInfo SSA form.  Perform a search for all predecessor blocks where we
   // know the dominating VNInfo.
-  if (findReachingDefs(LR, *KillMBB, Kill, PhysReg))
+  if (findReachingDefs(LR, *UseMBB, Use, PhysReg))
     return;
 
   // When there were multiple different values, we may need new PHIs.
@@ -252,12 +254,12 @@ void LiveRangeCalc::calculateValues() {
 }
 
 
-bool LiveRangeCalc::findReachingDefs(LiveRange &LR, MachineBasicBlock &KillMBB,
-                                     SlotIndex Kill, unsigned PhysReg) {
-  unsigned KillMBBNum = KillMBB.getNumber();
+bool LiveRangeCalc::findReachingDefs(LiveRange &LR, MachineBasicBlock &UseMBB,
+                                     SlotIndex Use, unsigned PhysReg) {
+  unsigned UseMBBNum = UseMBB.getNumber();
 
   // Block numbers where LR should be live-in.
-  SmallVector<unsigned, 16> WorkList(1, KillMBBNum);
+  SmallVector<unsigned, 16> WorkList(1, UseMBBNum);
 
   // Remember if we have seen more than one value.
   bool UniqueVNI = true;
@@ -270,13 +272,19 @@ bool LiveRangeCalc::findReachingDefs(LiveRange &LR, MachineBasicBlock &KillMBB,
 #ifndef NDEBUG
     if (MBB->pred_empty()) {
       MBB->getParent()->verify();
+      errs() << "Use of " << PrintReg(PhysReg)
+             << " does not have a corresponding definition on every path:\n";
+      const MachineInstr *MI = Indexes->getInstructionFromIndex(Use);
+      if (MI != nullptr)
+        errs() << Use << " " << *MI;
       llvm_unreachable("Use not jointly dominated by defs.");
     }
 
     if (TargetRegisterInfo::isPhysicalRegister(PhysReg) &&
         !MBB->isLiveIn(PhysReg)) {
       MBB->getParent()->verify();
-      errs() << "The register needs to be live in to BB#" << MBB->getNumber()
+      errs() << "The register " << PrintReg(PhysReg)
+             << " needs to be live in to BB#" << MBB->getNumber()
              << ", but is missing from the live-in list.\n";
       llvm_unreachable("Invalid global physical register");
     }
@@ -311,11 +319,11 @@ bool LiveRangeCalc::findReachingDefs(LiveRange &LR, MachineBasicBlock &KillMBB,
        }
 
        // No, we need a live-in value for Pred as well
-       if (Pred != &KillMBB)
+       if (Pred != &UseMBB)
           WorkList.push_back(Pred->getNumber());
        else
-          // Loopback to KillMBB, so value is really live through.
-         Kill = SlotIndex();
+          // Loopback to UseMBB, so value is really live through.
+         Use = SlotIndex();
     }
   }
 
@@ -333,9 +341,9 @@ bool LiveRangeCalc::findReachingDefs(LiveRange &LR, MachineBasicBlock &KillMBB,
          E = WorkList.end(); I != E; ++I) {
        SlotIndex Start, End;
        std::tie(Start, End) = Indexes->getMBBRange(*I);
-       // Trim the live range in KillMBB.
-       if (*I == KillMBBNum && Kill.isValid())
-         End = Kill;
+       // Trim the live range in UseMBB.
+       if (*I == UseMBBNum && Use.isValid())
+         End = Use;
        else
          Map[MF->getBlockNumbered(*I)] = LiveOutPair(TheVNI, nullptr);
        Updater.add(Start, End, TheVNI);
@@ -350,8 +358,8 @@ bool LiveRangeCalc::findReachingDefs(LiveRange &LR, MachineBasicBlock &KillMBB,
        I = WorkList.begin(), E = WorkList.end(); I != E; ++I) {
     MachineBasicBlock *MBB = MF->getBlockNumbered(*I);
     addLiveInBlock(LR, DomTree->getNode(MBB));
-    if (MBB == &KillMBB)
-      LiveIn.back().Kill = Kill;
+    if (MBB == &UseMBB)
+      LiveIn.back().Kill = Use;
   }
 
   return false;