Index: lib/Bitcode/Reader/BitcodeReader.cpp
===================================================================
--- lib/Bitcode/Reader/BitcodeReader.cpp
+++ lib/Bitcode/Reader/BitcodeReader.cpp
@@ -29,7 +29,9 @@
 #include "llvm/IR/OperandTraits.h"
 #include "llvm/IR/Operator.h"
 #include "llvm/IR/ValueHandle.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/DataStream.h"
+#include "llvm/Support/Debug.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/MemoryBuffer.h"
@@ -38,6 +40,11 @@
 
 using namespace llvm;
 
+static cl::opt<bool> PrintSummaryGUIDs(
+    "print-summary-global-ids", cl::init(false), cl::Hidden,
+    cl::desc(
+        "Print the global id for each value when reading the module summary"));
+
 namespace {
 enum {
   SWITCH_INST_MAGIC = 0x4B5 // May 2012 => 1205 => Hex
@@ -5541,8 +5548,11 @@
              "No linkage found for VST entry?");
       std::string GlobalId = GlobalValue::getGlobalIdentifier(
           ValueName, VLI->second, SourceFileName);
-      TheIndex->addGlobalValueInfo(GlobalId, std::move(GlobalValInfo));
-      ValueIdToCallGraphGUIDMap[ValueID] = GlobalValue::getGUID(GlobalId);
+      uint64_t ValueGUID = GlobalValue::getGUID(GlobalId);
+      if (PrintSummaryGUIDs)
+        dbgs() << "GUID " << ValueGUID << " is " << ValueName << "\n";
+      TheIndex->addGlobalValueInfo(ValueGUID, std::move(GlobalValInfo));
+      ValueIdToCallGraphGUIDMap[ValueID] = ValueGUID;
       ValueName.clear();
       break;
     }
@@ -5561,9 +5571,11 @@
              "No linkage found for VST entry?");
       std::string FunctionGlobalId = GlobalValue::getGlobalIdentifier(
           ValueName, VLI->second, SourceFileName);
-      TheIndex->addGlobalValueInfo(FunctionGlobalId, std::move(FuncInfo));
-      ValueIdToCallGraphGUIDMap[ValueID] =
-          GlobalValue::getGUID(FunctionGlobalId);
+      uint64_t FunctionGUID = GlobalValue::getGUID(FunctionGlobalId);
+      if (PrintSummaryGUIDs)
+        dbgs() << "GUID " << FunctionGUID << " is " << ValueName << "\n";
+      TheIndex->addGlobalValueInfo(FunctionGUID, std::move(FuncInfo));
+      ValueIdToCallGraphGUIDMap[ValueID] = FunctionGUID;
 
       ValueName.clear();
       break;
Index: test/Transforms/FunctionImport/funcimport.ll
===================================================================
--- test/Transforms/FunctionImport/funcimport.ll
+++ test/Transforms/FunctionImport/funcimport.ll
@@ -1,7 +1,7 @@
 ; Do setup work for all below tests: generate bitcode and combined index
 ; RUN: llvm-as -module-summary %s -o %t.bc
 ; RUN: llvm-as -module-summary %p/Inputs/funcimport.ll -o %t2.bc
-; RUN: llvm-lto -thinlto -o %t3 %t.bc %t2.bc
+; RUN: llvm-lto -thinlto -print-summary-global-ids -o %t3 %t.bc %t2.bc 2>&1 | FileCheck %s --check-prefix=GUID
 
 ; Do the import now
 ; RUN: opt -function-import -stats -print-imports -summary-file %t3.thinlto.bc %t.bc -S 2>&1 | FileCheck %s --check-prefix=CHECK --check-prefix=INSTLIMDEF
@@ -90,3 +90,38 @@
 
 ; INSTLIMDEF-DAG: Import globalfunc2
 ; INSTLIMDEF-DAG: 11 function-import - Number of functions imported
+
+; The GUID values should be stable unless the global identifier scheme
+; is changed.
+; GUID-DAG: GUID 18438612909910340889 is weakalias
+; GUID-DAG: GUID 10419849736188691048 is referenceglobals
+; GUID-DAG: GUID 9779356664709680872 is weakfunc
+; GUID-DAG: GUID 15822663052811949562 is main
+; GUID-DAG: GUID 1794834399867852914 is referencecommon
+; GUID-DAG: GUID 12695095382722328222 is analias
+; GUID-DAG: GUID 11460932053523480915 is referencestatics
+; GUID-DAG: GUID 17082925359558765443 is linkoncealias
+; GUID-DAG: GUID 16956293738471118660 is setfuncptr
+; GUID-DAG: GUID 800887449839734011 is callfuncptr
+; GUID-DAG: GUID 12108029313449967842 is funcwithpersonality
+; GUID-DAG: GUID 16956293738471118660 is setfuncptr
+; GUID-DAG: GUID 15894399990123115248 is staticfunc2
+; GUID-DAG: GUID 1233668236132380018 is __gxx_personality_v0
+; GUID-DAG: GUID 11460932053523480915 is referencestatics
+; GUID-DAG: GUID 8332887114342655934 is globalfunc1
+; GUID-DAG: GUID 2602152165807499502 is globalfunc2
+; GUID-DAG: GUID 9342344237287280920 is P
+; GUID-DAG: GUID 17578217388980876465 is staticvar
+; GUID-DAG: GUID 3013670425691502549 is commonvar
+; GUID-DAG: GUID 18438612909910340889 is weakalias
+; GUID-DAG: GUID 13921022463002872889 is staticfunc
+; GUID-DAG: GUID 9779356664709680872 is weakfunc
+; GUID-DAG: GUID 10419849736188691048 is referenceglobals
+; GUID-DAG: GUID 8769477226392140800 is weakvar
+; GUID-DAG: GUID 16489816843137310249 is staticconstvar
+; GUID-DAG: GUID 12695095382722328222 is analias
+; GUID-DAG: GUID 12887606300320728018 is globalvar
+; GUID-DAG: GUID 1794834399867852914 is referencecommon
+; GUID-DAG: GUID 17082925359558765443 is linkoncealias
+; GUID-DAG: GUID 800887449839734011 is callfuncptr
+; GUID-DAG: GUID 7812846502172333492 is linkoncefunc