1 files changed, 34 insertions, 5 deletions

diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index 50f3f67..31d12eb 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -17,6 +17,7 @@
 #include "llvm/CodeGen/MachineDominators.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineLoopInfo.h"
+#include "llvm/CodeGen/SlotIndexes.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/Target/TargetRegisterInfo.h"
@@ -146,6 +147,13 @@ MachineBasicBlock::iterator MachineBasicBlock::getFirstNonPHI() {
   return I;
 }
 
+MachineBasicBlock::iterator
+MachineBasicBlock::SkipPHIsAndLabels(MachineBasicBlock::iterator I) {
+  while (I != end() && (I->isPHI() || I->isLabel() || I->isDebugValue()))
+    ++I;
+  return I;
+}
+
 MachineBasicBlock::iterator MachineBasicBlock::getFirstTerminator() {
   iterator I = end();
   while (I != begin() && (--I)->getDesc().isTerminator())
@@ -176,7 +184,7 @@ StringRef MachineBasicBlock::getName() const {
     return "(null)";
 }
 
-void MachineBasicBlock::print(raw_ostream &OS) const {
+void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) const {
   const MachineFunction *MF = getParent();
   if (!MF) {
     OS << "Can't print out MachineBasicBlock because parent MachineFunction"
@@ -186,6 +194,9 @@ void MachineBasicBlock::print(raw_ostream &OS) const {
 
   if (Alignment) { OS << "Alignment " << Alignment << "\n"; }
 
+  if (Indexes)
+    OS << Indexes->getMBBStartIdx(this) << '\t';
+
   OS << "BB#" << getNumber() << ": ";
 
   const char *Comma = "";
@@ -198,8 +209,9 @@ void MachineBasicBlock::print(raw_ostream &OS) const {
   if (hasAddressTaken()) { OS << Comma << "ADDRESS TAKEN"; Comma = ", "; }
   OS << '\n';
 
-  const TargetRegisterInfo *TRI = MF->getTarget().getRegisterInfo();  
+  const TargetRegisterInfo *TRI = MF->getTarget().getRegisterInfo();
   if (!livein_empty()) {
+    if (Indexes) OS << '\t';
     OS << "    Live Ins:";
     for (livein_iterator I = livein_begin(),E = livein_end(); I != E; ++I)
       OutputReg(OS, *I, TRI);
@@ -207,19 +219,26 @@ void MachineBasicBlock::print(raw_ostream &OS) const {
   }
   // Print the preds of this block according to the CFG.
   if (!pred_empty()) {
+    if (Indexes) OS << '\t';
     OS << "    Predecessors according to CFG:";
     for (const_pred_iterator PI = pred_begin(), E = pred_end(); PI != E; ++PI)
       OS << " BB#" << (*PI)->getNumber();
     OS << '\n';
   }
-  
+
   for (const_iterator I = begin(); I != end(); ++I) {
+    if (Indexes) {
+      if (Indexes->hasIndex(I))
+        OS << Indexes->getInstructionIndex(I);
+      OS << '\t';
+    }
     OS << '\t';
     I->print(OS, &getParent()->getTarget());
   }
 
   // Print the successors of this block according to the CFG.
   if (!succ_empty()) {
+    if (Indexes) OS << '\t';
     OS << "    Successors according to CFG:";
     for (const_succ_iterator SI = succ_begin(), E = succ_end(); SI != E; ++SI)
       OS << " BB#" << (*SI)->getNumber();
@@ -431,14 +450,24 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) {
   MachineFunction *MF = getParent();
   DebugLoc dl;  // FIXME: this is nowhere
 
-  // We may need to update this's terminator, but we can't do that if AnalyzeBranch
-  // fails. If this uses a jump table, we won't touch it.
+  // We may need to update this's terminator, but we can't do that if
+  // AnalyzeBranch fails. If this uses a jump table, we won't touch it.
   const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
   MachineBasicBlock *TBB = 0, *FBB = 0;
   SmallVector<MachineOperand, 4> Cond;
   if (TII->AnalyzeBranch(*this, TBB, FBB, Cond))
     return NULL;
 
+  // Avoid bugpoint weirdness: A block may end with a conditional branch but
+  // jumps to the same MBB is either case. We have duplicate CFG edges in that
+  // case that we can't handle. Since this never happens in properly optimized
+  // code, just skip those edges.
+  if (TBB && TBB == FBB) {
+    DEBUG(dbgs() << "Won't split critical edge after degenerate BB#"
+                 << getNumber() << '\n');
+    return NULL;
+  }
+
   MachineBasicBlock *NMBB = MF->CreateMachineBasicBlock();
   MF->insert(llvm::next(MachineFunction::iterator(this)), NMBB);
   DEBUG(dbgs() << "Splitting critical edge:"