Index: lib/Target/X86/X86FastISel.cpp
===================================================================
--- lib/Target/X86/X86FastISel.cpp
+++ lib/Target/X86/X86FastISel.cpp
@@ -3344,6 +3344,17 @@
   if (!Result)
     return false;
 
+  MCInstrDesc MCID = Result->getDesc();
+  for (size_t i = 0; i < AddrOps.size(); ++i) {
+      MachineOperand &MO = AddrOps[i];
+      if (MO.getType() != MachineOperand::MO_Register)
+        continue;
+      unsigned Reg = MO.getReg();
+      if (!Reg || TargetRegisterInfo::isPhysicalRegister(Reg))
+        continue;
+      MRI.constrainRegClass(Reg, TII.getRegClass(MCID, i, &TRI, *FuncInfo.MF));
+  }
+
   Result->addMemOperand(*FuncInfo.MF, createMachineMemOperandFor(LI));
   FuncInfo.MBB->insert(FuncInfo.InsertPt, Result);
   MI->eraseFromParent();
Index: test/CodeGen/X86/fast-isel-regclass.ll
===================================================================
--- /dev/null
+++ test/CodeGen/X86/fast-isel-regclass.ll
@@ -0,0 +1,30 @@
+; RUN: llc < %s -fast-isel -mcpu=core2 -O3 -verify-machineinstrs
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-darwin14.0.0"
+
+define void @julia_ht_keyindex219890() {
+top:
+  br i1 undef, label %idxend, label %oob
+
+if3:                                              ; preds = %idxend
+  br i1 undef, label %L5, label %if4
+
+oob:                                              ; preds = %top
+  unreachable
+
+idxend:                                           ; preds = %top
+  %0 = getelementptr i8* undef, i64 undef
+  %1 = load i8* %0
+  %2 = icmp eq i8 %1, undef
+  %3 = xor i1 %2, true
+  br i1 %3, label %oob9, label %if3
+
+if4:                                              ; preds = %if3
+  ret void
+
+L5:                                               ; preds = %if3
+  ret void
+
+oob9:                                             ; preds = %idxend
+  unreachable
+}