diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index 57f3e34d0c5..68946a2c9d1 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -485,6 +485,30 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) {
         << " -- BB#" << NMBB->getNumber()
         << " -- BB#" << Succ->getNumber() << '\n');
 
+  // On some targets like Mips, branches may kill virtual registers. Make sure
+  // that LiveVariables is properly updated after updateTerminator replaces the
+  // terminators.
+  LiveVariables *LV = P->getAnalysisIfAvailable<LiveVariables>();
+
+  // Collect a list of virtual registers killed by the terminators.
+  SmallVector<unsigned, 4> KilledRegs;
+  if (LV)
+    for (iterator I = getFirstTerminator(), E = end(); I != E; ++I) {
+      MachineInstr *MI = I;
+      for (MachineInstr::mop_iterator OI = MI->operands_begin(),
+           OE = MI->operands_end(); OI != OE; ++OI) {
+        if (!OI->isReg() || !OI->isUse() || !OI->isKill() || OI->isUndef())
+          continue;
+        unsigned Reg = OI->getReg();
+        if (TargetRegisterInfo::isVirtualRegister(Reg) &&
+            LV->getVarInfo(Reg).removeKill(MI)) {
+          KilledRegs.push_back(Reg);
+          DEBUG(dbgs() << "Removing terminator kill: " << *MI);
+          OI->setIsKill(false);
+        }
+      }
+    }
+
   ReplaceUsesOfBlockWith(Succ, NMBB);
   updateTerminator();
 
@@ -502,9 +526,22 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) {
       if (i->getOperand(ni+1).getMBB() == this)
         i->getOperand(ni+1).setMBB(NMBB);
 
-  if (LiveVariables *LV =
-        P->getAnalysisIfAvailable<LiveVariables>())
+  // Update LiveVariables.
+  if (LV) {
+    // Restore kills of virtual registers that were killed by the terminators.
+    while (!KilledRegs.empty()) {
+      unsigned Reg = KilledRegs.pop_back_val();
+      for (iterator I = end(), E = begin(); I != E;) {
+        if (!(--I)->addRegisterKilled(Reg, NULL, /* addIfNotFound= */ false))
+          continue;
+        LV->getVarInfo(Reg).Kills.push_back(I);
+        DEBUG(dbgs() << "Restored terminator kill: " << *I);
+        break;
+      }
+    }
+    // Update relevant live-through information.
     LV->addNewBlock(NMBB, this, Succ);
+  }
 
   if (MachineDominatorTree *MDT =
       P->getAnalysisIfAvailable<MachineDominatorTree>()) {
diff --git a/test/CodeGen/Mips/2011-05-26-BranchKillsVreg.ll b/test/CodeGen/Mips/2011-05-26-BranchKillsVreg.ll
new file mode 100644
index 00000000000..1255949740f
--- /dev/null
+++ b/test/CodeGen/Mips/2011-05-26-BranchKillsVreg.ll
@@ -0,0 +1,43 @@
+; RUN: llc < %s -verify-coalescing
+; PR10046
+;
+; PHI elimination splits the critical edge from %while.end415 to %if.end427.
+; This requires updating the BNE-J terminators to a BEQ. The BNE instruction
+; kills a virtual register, and LiveVariables must be updated with the new kill
+; instruction.
+
+target datalayout = "E-p:32:32:32-i1:8:8-i8:8:32-i16:16:32-i32:32:32-i64:32:64-f32:32:32-f64:64:64-v64:64:64-n32"
+target triple = "mips-ellcc-linux"
+
+define i32 @mergesort(i8* %base, i32 %nmemb, i32 %size, i32 (i8*, i8*)* nocapture %cmp) nounwind {
+entry:
+  br i1 undef, label %return, label %if.end13
+
+if.end13:                                         ; preds = %entry
+  br label %while.body
+
+while.body:                                       ; preds = %while.body, %if.end13
+  %list1.0482 = phi i8* [ %base, %if.end13 ], [ null, %while.body ]
+  br i1 undef, label %while.end415, label %while.body
+
+while.end415:                                     ; preds = %while.body
+  br i1 undef, label %if.then419, label %if.end427
+
+if.then419:                                       ; preds = %while.end415
+  %call425 = tail call i8* @memmove(i8* %list1.0482, i8* undef, i32 undef) nounwind
+  br label %if.end427
+
+if.end427:                                        ; preds = %if.then419, %while.end415
+  %list2.1 = phi i8* [ undef, %if.then419 ], [ %list1.0482, %while.end415 ]
+  tail call void @free(i8* %list2.1)
+  unreachable
+
+return:                                           ; preds = %entry
+  ret i32 -1
+}
+
+
+declare i8* @memmove(i8*, i8*, i32)
+
+declare void @free(i8*)
+