Remove redundant code in MachineBasicBlock.cpp. NFC.

[oota-llvm.git] / lib / CodeGen / MachineBasicBlock.cpp

diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index 1fdaf329075decaed0ac104fd7518bae6c5e9933..354bd3ef3e8b061ddfac0a420114161dc7eed682 100644 (file)
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -52,6 +52,7 @@ MCSymbol *MachineBasicBlock::getSymbol() const {
     const MachineFunction *MF = getParent();
     MCContext &Ctx = MF->getContext();
     const char *Prefix = Ctx.getAsmInfo()->getPrivateLabelPrefix();
+    assert(getNumber() >= 0 && "cannot get label for unreachable MBB");
     CachedMCSymbol = Ctx.getOrCreateSymbol(Twine(Prefix) + "BB" +
                                            Twine(MF->getFunctionNumber()) +
                                            "_" + Twine(getNumber()));
@@ -543,24 +544,9 @@ void MachineBasicBlock::addSuccessorWithoutProb(MachineBasicBlock *Succ) {
 }
 
 void MachineBasicBlock::removeSuccessor(MachineBasicBlock *Succ) {
-  Succ->removePredecessor(this);
   succ_iterator I = std::find(Successors.begin(), Successors.end(), Succ);
   assert(I != Successors.end() && "Not a current successor!");
-
-  // If Weight list is empty it means we don't use it (disabled optimization).
-  if (!Weights.empty()) {
-    weight_iterator WI = getWeightIterator(I);
-    Weights.erase(WI);
-  }
-
-  // If probability list is empty it means we don't use it (disabled
-  // optimization).
-  if (!Probs.empty()) {
-    probability_iterator WI = getProbabilityIterator(I);
-    Probs.erase(WI);
-  }
-
-  Successors.erase(I);
+  removeSuccessor(I);
 }
 
 MachineBasicBlock::succ_iterator
@@ -605,10 +591,10 @@ void MachineBasicBlock::replaceSuccessor(MachineBasicBlock *Old,
     }
   }
   assert(OldI != E && "Old is not a successor of this block");
-  Old->removePredecessor(this);
 
   // If New isn't already a successor, let it take Old's place.
   if (NewI == E) {
+    Old->removePredecessor(this);
     New->addPredecessor(this);
     *OldI = New;
     return;
@@ -616,18 +602,13 @@ void MachineBasicBlock::replaceSuccessor(MachineBasicBlock *Old,
 
   // New is already a successor.
   // Update its weight instead of adding a duplicate edge.
-  if (!Weights.empty()) {
-    weight_iterator OldWI = getWeightIterator(OldI);
-    *getWeightIterator(NewI) += *OldWI;
-    Weights.erase(OldWI);
-  }
+  if (!Weights.empty())
+    *getWeightIterator(NewI) += *getWeightIterator(OldI);
   // Update its probability instead of adding a duplicate edge.
-  if (!Probs.empty()) {
-    probability_iterator OldPI = getProbabilityIterator(OldI);
-    *getProbabilityIterator(NewI) += *OldPI;
-    Probs.erase(OldPI);
-  }
-  Successors.erase(OldI);
+  if (!Probs.empty())
+    *getProbabilityIterator(NewI) += *getProbabilityIterator(OldI);
+
+  removeSuccessor(OldI);
 }
 
 void MachineBasicBlock::addPredecessor(MachineBasicBlock *Pred) {
@@ -1301,3 +1282,17 @@ MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI,
   // At this point we have no idea of the liveness of the register.
   return LQR_Unknown;
 }
+
+const uint32_t *
+MachineBasicBlock::getBeginClobberMask(const TargetRegisterInfo *TRI) const {
+  // EH funclet entry does not preserve any registers.
+  return isEHFuncletEntry() ? TRI->getNoPreservedMask() : nullptr;
+}
+
+const uint32_t *
+MachineBasicBlock::getEndClobberMask(const TargetRegisterInfo *TRI) const {
+  // If we see a return block with successors, this must be a funclet return,
+  // which does not preserve any registers. If there are no successors, we don't
+  // care what kind of return it is, putting a mask after it is a no-op.
+  return isReturnBlock() && !succ_empty() ? TRI->getNoPreservedMask() : nullptr;
+}