diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 21c1644..21b2358 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -1260,7 +1260,15 @@
   MachineFunction *F = BB->getParent();
   F->getBasicBlockList().insert(It, copy0MBB);
   F->getBasicBlockList().insert(It, sinkMBB);
-  // Update machine-CFG edges
+  // Update machine-CFG edges by first adding all successors of the current
+  // block to the new block which will contain the Phi node for the select.
+  for(MachineBasicBlock::succ_iterator i = BB->succ_begin(), 
+      e = BB->succ_end(); i != e; ++i)
+    sinkMBB->addSuccessor(*i);
+  // Next, remove all successors of the current block, and add the true
+  // and fallthrough blocks as its successors.
+  while(!BB->succ_empty())
+    BB->removeSuccessor(BB->succ_begin());
   BB->addSuccessor(copy0MBB);
   BB->addSuccessor(sinkMBB);
   
diff --git a/lib/Target/Sparc/SparcISelDAGToDAG.cpp b/lib/Target/Sparc/SparcISelDAGToDAG.cpp
index 71f2ace..0390238 100644
--- a/lib/Target/Sparc/SparcISelDAGToDAG.cpp
+++ b/lib/Target/Sparc/SparcISelDAGToDAG.cpp
@@ -916,7 +916,15 @@
   MachineFunction *F = BB->getParent();
   F->getBasicBlockList().insert(It, copy0MBB);
   F->getBasicBlockList().insert(It, sinkMBB);
-  // Update machine-CFG edges
+  // Update machine-CFG edges by first adding all successors of the current
+  // block to the new block which will contain the Phi node for the select.
+  for(MachineBasicBlock::succ_iterator i = BB->succ_begin(), 
+      e = BB->succ_end(); i != e; ++i)
+    sinkMBB->addSuccessor(*i);
+  // Next, remove all successors of the current block, and add the true
+  // and fallthrough blocks as its successors.
+  while(!BB->succ_empty())
+    BB->removeSuccessor(BB->succ_begin());
   BB->addSuccessor(copy0MBB);
   BB->addSuccessor(sinkMBB);
   
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 809d151..dd8ed73 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -1275,7 +1275,15 @@
     MachineFunction *F = BB->getParent();
     F->getBasicBlockList().insert(It, copy0MBB);
     F->getBasicBlockList().insert(It, sinkMBB);
-    // Update machine-CFG edges
+    // Update machine-CFG edges by first adding all successors of the current
+    // block to the new block which will contain the Phi node for the select.
+    for(MachineBasicBlock::succ_iterator i = BB->succ_begin(), 
+        e = BB->succ_end(); i != e; ++i)
+      sinkMBB->addSuccessor(*i);
+    // Next, remove all successors of the current block, and add the true
+    // and fallthrough blocks as its successors.
+    while(!BB->succ_empty())
+      BB->removeSuccessor(BB->succ_begin());
     BB->addSuccessor(copy0MBB);
     BB->addSuccessor(sinkMBB);
   
diff --git a/lib/Target/X86/X86TargetMachine.cpp b/lib/Target/X86/X86TargetMachine.cpp
index f6d34ea..44877d9 100644
--- a/lib/Target/X86/X86TargetMachine.cpp
+++ b/lib/Target/X86/X86TargetMachine.cpp
@@ -36,7 +36,8 @@
   cl::opt<bool> DisableOutput("disable-x86-llc-output", cl::Hidden,
                               cl::desc("Disable the X86 asm printer, for use "
                                        "when profiling the code generator."));
-
+  cl::opt<bool> DisableLowerSwitch("disable-lower-switch", cl::Hidden,
+                                   cl::desc("Disable the LowerSwitch pass"));
   // Register the target.
   RegisterTarget<X86TargetMachine> X("x86", "  IA-32 (Pentium and above)");
 }
@@ -100,8 +101,9 @@
   PM.add(createLowerInvokePass());
 
   // FIXME: Implement the switch instruction in the instruction selector!
-  PM.add(createLowerSwitchPass());
-
+  if (!DisableLowerSwitch)
+    PM.add(createLowerSwitchPass());
+  
   // Make sure that no unreachable blocks are instruction selected.
   PM.add(createUnreachableBlockEliminationPass());
 
@@ -168,7 +170,8 @@
   PM.add(createLowerInvokePass());
 
   // FIXME: Implement the switch instruction in the instruction selector!
-  PM.add(createLowerSwitchPass());
+  if (!DisableLowerSwitch)
+    PM.add(createLowerSwitchPass());
 
   // Make sure that no unreachable blocks are instruction selected.
   PM.add(createUnreachableBlockEliminationPass());