Index: lib/CodeGen/ExecutionDepsFix.cpp
===================================================================
--- lib/CodeGen/ExecutionDepsFix.cpp
+++ lib/CodeGen/ExecutionDepsFix.cpp
@@ -721,7 +721,7 @@
 
   // Kill off any remaining uses that don't match available, and build a list of
   // incoming DomainValues that we want to merge.
-  SmallVector<LiveReg, 4> Regs;
+  SmallVector<const LiveReg*, 4> Regs;
   for (SmallVectorImpl<int>::iterator i=used.begin(), e=used.end(); i!=e; ++i) {
     int rx = *i;
     assert(LiveRegs && "no space allocated for live registers");
@@ -733,15 +733,15 @@
     }
     // Sorted insertion.
     bool Inserted = false;
-    for (SmallVectorImpl<LiveReg>::iterator i = Regs.begin(), e = Regs.end();
-           i != e && !Inserted; ++i) {
-      if (LR.Def < i->Def) {
+    for (SmallVectorImpl<const LiveReg*>::iterator i = Regs.begin(),
+           e = Regs.end(); i != e && !Inserted; ++i) {
+      if (LR.Def < (*i)->Def) {
         Inserted = true;
-        Regs.insert(i, LR);
+        Regs.insert(i, &LR);
       }
     }
     if (!Inserted)
-      Regs.push_back(LR);
+      Regs.push_back(&LR);
   }
 
   // doms are now sorted in order of appearance. Try to merge them all, giving
@@ -749,14 +749,14 @@
   DomainValue *dv = nullptr;
   while (!Regs.empty()) {
     if (!dv) {
-      dv = Regs.pop_back_val().Value;
+      dv = Regs.pop_back_val()->Value;
       // Force the first dv to match the current instruction.
       dv->AvailableDomains = dv->getCommonDomains(available);
       assert(dv->AvailableDomains && "Domain should have been filtered");
       continue;
     }
 
-    DomainValue *Latest = Regs.pop_back_val().Value;
+    DomainValue *Latest = Regs.pop_back_val()->Value;
     // Skip already merged values.
     if (Latest == dv || Latest->Next)
       continue;
Index: test/CodeGen/X86/pr30284.ll
===================================================================
--- /dev/null
+++ test/CodeGen/X86/pr30284.ll
@@ -0,0 +1,21 @@
+; ModuleID = 'bugpoint-reduced-simplified.bc'
+source_filename = "bugpoint-output-21f4d9f.bc"
+target datalayout = "e-m:e-p:32:32-f64:32:64-f80:32-n8:16:32-S128"
+target triple = "i386-unknown-linux-gnu"
+
+; Function Attrs: nounwind
+define void @f_f___un_3C_unf_3E_un_3C_unf_3E_() #0 {
+allocas:
+  %a_load22 = load <16 x i64>, <16 x i64>* null, align 1
+  %bitop = or <16 x i64> %a_load22, <i64 68719476736, i64 68719476736, i64 68719476736, i64 68719476736, i64 68719476736, i64 68719476736, i64 68719476736, i64 68719476736, i64 68719476736, i64 68719476736, i64 68719476736, i64 68719476736, i64 68719476736, i64 68719476736, i64 68719476736, i64 68719476736>
+  %v.i = load <16 x i64>, <16 x i64>* null
+  %v1.i41 = select <16 x i1> undef, <16 x i64> %bitop, <16 x i64> %v.i
+  store <16 x i64> %v1.i41, <16 x i64>* null
+  unreachable
+}
+
+attributes #0 = { nounwind }
+
+!llvm.ident = !{!0}
+
+!0 = !{!"clang version 4.0.0 (trunk 278097)"}