Index: lib/CodeGen/PHIElimination.cpp
===================================================================
--- lib/CodeGen/PHIElimination.cpp
+++ lib/CodeGen/PHIElimination.cpp
@@ -46,6 +46,10 @@
                       cl::Hidden, cl::desc("Split all critical edges during "
                                            "PHI elimination"));
 
+static cl::opt<bool> NoPhiElimLiveOutEarlyExit(
+    "no-phi-elim-live-out-early-exit", cl::init(false), cl::Hidden,
+    cl::desc("Do not use an early exit if isLiveOutPastPHIs returns true."));
+
 namespace {
   class PHIElimination : public MachineFunctionPass {
     MachineRegisterInfo *MRI; // Machine register information
@@ -573,12 +577,14 @@
       // there is a risk it may not be coalesced away.
       //
       // If the copy would be a kill, there is no need to split the edge.
-      if (!isLiveOutPastPHIs(Reg, PreMBB) && !SplitAllCriticalEdges)
+      bool ShouldSplit = isLiveOutPastPHIs(Reg, PreMBB);
+      if (!ShouldSplit && !NoPhiElimLiveOutEarlyExit)
         continue;
-
-      DEBUG(dbgs() << PrintReg(Reg) << " live-out before critical edge BB#"
-                   << PreMBB->getNumber() << " -> BB#" << MBB.getNumber()
-                   << ": " << *BBI);
+      if (ShouldSplit) {
+        DEBUG(dbgs() << PrintReg(Reg) << " live-out before critical edge BB#"
+                     << PreMBB->getNumber() << " -> BB#" << MBB.getNumber()
+                     << ": " << *BBI);
+      }
 
       // If Reg is not live-in to MBB, it means it must be live-in to some
       // other PreMBB successor, and we can avoid the interference by splitting
@@ -588,7 +594,7 @@
       // is likely to be left after coalescing. If we are looking at a loop
       // exiting edge, split it so we won't insert code in the loop, otherwise
       // don't bother.
-      bool ShouldSplit = !isLiveIn(Reg, &MBB) || SplitAllCriticalEdges;
+      ShouldSplit = ShouldSplit && !isLiveIn(Reg, &MBB);
 
       // Check for a loop exiting edge.
       if (!ShouldSplit && CurLoop != PreLoop) {
@@ -603,7 +609,7 @@
         // Split unless this edge is entering CurLoop from an outer loop.
         ShouldSplit = PreLoop && !PreLoop->contains(CurLoop);
       }
-      if (!ShouldSplit)
+      if (!ShouldSplit && !SplitAllCriticalEdges)
         continue;
       if (!PreMBB->SplitCriticalEdge(&MBB, this)) {
         DEBUG(dbgs() << "Failed to split critical edge.\n");
Index: test/CodeGen/X86/phielim-split.ll
===================================================================
--- test/CodeGen/X86/phielim-split.ll
+++ test/CodeGen/X86/phielim-split.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -verify-machineinstrs | FileCheck %s
+; RUN: llc < %s -verify-machineinstrs -no-phi-elim-live-out-early-exit | FileCheck %s
 target triple = "x86_64-apple-macosx10.8.0"
 
 ; The critical edge from for.cond to if.end2 should be split to avoid injecting
@@ -28,3 +28,40 @@
   %add = add nsw i32 %r.0, %b
   ret i32 %add
 }
+
+; CHECK: split_live_out
+; CHECK: %while.body
+; CHECK: cmp
+; CHECK-NEXT: ja
+define i8* @split_live_out(i32 %value, i8* %target) nounwind uwtable readonly ssp {
+entry:
+  %cmp10 = icmp ugt i32 %value, 127
+  br i1 %cmp10, label %while.body.preheader, label %while.end
+
+while.body.preheader:                             ; preds = %entry
+  br label %while.body
+
+while.body:                                       ; preds = %while.body.preheader, %while.body
+  %target.addr.012 = phi i8* [ %incdec.ptr, %while.body ], [ %target, %while.body.preheader ]
+  %value.addr.011 = phi i32 [ %shr, %while.body ], [ %value, %while.body.preheader ]
+  %or = or i32 %value.addr.011, 128
+  %conv = trunc i32 %or to i8
+  store i8 %conv, i8* %target.addr.012, align 1
+  %shr = lshr i32 %value.addr.011, 7
+  %incdec.ptr = getelementptr inbounds i8, i8* %target.addr.012, i64 1
+  %cmp = icmp ugt i32 %value.addr.011, 16383
+  br i1 %cmp, label %while.body, label %while.end.loopexit
+
+while.end.loopexit:                               ; preds = %while.body
+  %incdec.ptr.lcssa = phi i8* [ %incdec.ptr, %while.body ]
+  %shr.lcssa = phi i32 [ %shr, %while.body ]
+  br label %while.end
+
+while.end:                                        ; preds = %while.end.loopexit, %entry
+  %target.addr.0.lcssa = phi i8* [ %target, %entry ], [ %incdec.ptr.lcssa, %while.end.loopexit ]
+  %value.addr.0.lcssa = phi i32 [ %value, %entry ], [ %shr.lcssa, %while.end.loopexit ]
+  %conv1 = trunc i32 %value.addr.0.lcssa to i8
+  store i8 %conv1, i8* %target.addr.0.lcssa, align 1
+  %incdec.ptr3 = getelementptr inbounds i8, i8* %target.addr.0.lcssa, i64 1
+  ret i8* %incdec.ptr3
+}