Index: lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
===================================================================
--- lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
+++ lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
@@ -50,24 +50,19 @@
 ///
 /// In detail, this pass does following things:
 ///
-/// 1) Assumes the existence of global variables: __THREW__, __threwValue, and
-///    __tempRet0.
-///    __tempRet0 will be set within __cxa_find_matching_catch() function in
-///    JS library, and __THREW__ and __threwValue will be set in invoke wrappers
+/// 1) Assumes the existence of global variables: __THREW__, __threwValue
+///    __THREW__ and __threwValue will be set in invoke wrappers
 ///    in JS glue code. For what invoke wrappers are, refer to 3). These
 ///    variables are used for both exceptions and setjmp/longjmps.
 ///    __THREW__ indicates whether an exception or a longjmp occurred or not. 0
 ///    means nothing occurred, 1 means an exception occurred, and other numbers
 ///    mean a longjmp occurred. In the case of longjmp, __threwValue variable
 ///    indicates the corresponding setjmp buffer the longjmp corresponds to.
-///    In exception handling, __tempRet0 indicates the type of an exception
-///    caught, and in setjmp/longjmp, it means the second argument to longjmp
-///    function.
 ///
 /// * Exception handling
 ///
-/// 2) We assume the existence of setThrew and setTempRet0 functions at link
-///    time.
+/// 2) We assume the existence of setThrew and setTempRet0/getTempRet0 functions
+///    at link time.
 ///    The global variables in 1) will exist in wasm address space,
 ///    but their values should be set in JS code, so these functions
 ///    as interfaces to JS glue code. These functions are equivalent to the
@@ -80,10 +75,12 @@
 ///        __threwValue = value;
 ///      }
 ///    }
+//
+///    setTempRet0 is called from __cxa_find_matching_catch() in JS glue code.
 ///
-///    function setTempRet0(value) {
-///      __tempRet0 = value;
-///    }
+///    In exception handling, getTempRet0 indicates the type of an exception
+///    caught, and in setjmp/longjmp, it means the second argument to longjmp
+///    function.
 ///
 /// 3) Lower
 ///      invoke @func(arg1, arg2) to label %invoke.cont unwind label %lpad
@@ -120,11 +117,10 @@
 ///      ... use %val ...
 ///    into
 ///      %fmc = call @__cxa_find_matching_catch_N(c1, c2, c3, ...)
-///      %val = {%fmc, __tempRet0}
+///      %val = {%fmc, getTempRet0()}
 ///      ... use %val ...
 ///    Here N is a number calculated based on the number of clauses.
-///    Global variable __tempRet0 is set within __cxa_find_matching_catch() in
-///    JS glue code.
+///    setTempRet0 is called from __cxa_find_matching_catch() in JS glue code.
 ///
 /// 5) Lower
 ///      resume {%a, %b}
@@ -152,13 +148,13 @@
 ///      setjmp(buf)
 ///    into
 ///      setjmpTable = saveSetjmp(buf, label, setjmpTable, setjmpTableSize);
-///      setjmpTableSize = __tempRet0;
+///      setjmpTableSize = getTempRet0();
 ///    For each dynamic setjmp call, setjmpTable stores its ID (a number which
 ///    is incrementally assigned from 0) and its label (a unique number that
 ///    represents each callsite of setjmp). When we need more entries in
 ///    setjmpTable, it is reallocated in saveSetjmp() in JS code and it will
 ///    return the new table address, and assign the new table size in
-///    __tempRet0. saveSetjmp also stores the setjmp's ID into the buffer buf.
+///    setTempRet0(). saveSetjmp also stores the setjmp's ID into the buffer buf.
 ///    A BB with setjmp is split into two after setjmp call in order to make the
 ///    post-setjmp BB the possible destination of longjmp BB.
 ///
@@ -178,11 +174,11 @@
 ///                            setjmpTableSize);
 ///        if (%label == 0)
 ///          emscripten_longjmp(%__THREW__.val, __threwValue);
-///        __tempRet0 = __threwValue;
+///        setTempRet0(__threwValue);
 ///      } else {
 ///        %label = -1;
 ///      }
-///      longjmp_result = __tempRet0;
+///      longjmp_result = getTempRet0();
 ///      switch label {
 ///        label 1: goto post-setjmp BB 1
 ///        label 2: goto post-setjmp BB 2
@@ -241,7 +237,8 @@
 
   GlobalVariable *ThrewGV;
   GlobalVariable *ThrewValueGV;
-  GlobalVariable *TempRet0GV;
+  Function *GetTempRet0Func;
+  Function *SetTempRet0Func;
   Function *ResumeF;
   Function *EHTypeIDF;
   Function *EmLongjmpF;
@@ -281,7 +278,7 @@
 
   WebAssemblyLowerEmscriptenEHSjLj(bool EnableEH = true, bool EnableSjLj = true)
       : ModulePass(ID), EnableEH(EnableEH), EnableSjLj(EnableSjLj),
-        ThrewGV(nullptr), ThrewValueGV(nullptr), TempRet0GV(nullptr),
+        ThrewGV(nullptr), ThrewValueGV(nullptr), GetTempRet0Func(nullptr), SetTempRet0Func(nullptr),
         ResumeF(nullptr), EHTypeIDF(nullptr), EmLongjmpF(nullptr),
         EmLongjmpJmpbufF(nullptr), SaveSetjmpF(nullptr), TestSetjmpF(nullptr) {
     EHWhitelistSet.insert(EHWhitelist.begin(), EHWhitelist.end());
@@ -509,7 +506,8 @@
   Function *ThrowF = M.getFunction("__cxa_throw");
   Function *TerminateF = M.getFunction("__clang_call_terminate");
   if (Callee == BeginCatchF || Callee == EndCatchF ||
-      Callee == AllocExceptionF || Callee == ThrowF || Callee == TerminateF)
+      Callee == AllocExceptionF || Callee == ThrowF || Callee == TerminateF ||
+      Callee == GetTempRet0Func || Callee == SetTempRet0Func)
     return false;
 
   // Otherwise we don't know
@@ -522,11 +520,11 @@
 //   %label = _testSetjmp(mem[%__THREW__.val], setjmpTable, setjmpTableSize);
 //   if (%label == 0)
 //     emscripten_longjmp(%__THREW__.val, threwValue);
-//   __tempRet0 = threwValue;
+//   setTempRet0(threwValue);
 // } else {
 //   %label = -1;
 // }
-// %longjmp_result = __tempRet0;
+// %longjmp_result = getTempRet0();
 //
 // As output parameters. returns %label, %longjmp_result, and the BB the last
 // instruction (%longjmp_result = ...) is in.
@@ -570,15 +568,15 @@
   IRB.CreateCall(EmLongjmpF, {Threw, ThrewValue});
   IRB.CreateUnreachable();
 
-  // __tempRet0 = threwValue;
+  // setTempRet0(threwValue);
   IRB.SetInsertPoint(EndBB2);
-  IRB.CreateStore(ThrewValue, TempRet0GV);
+  IRB.CreateCall(SetTempRet0Func, ThrewValue);
   IRB.CreateBr(EndBB1);
 
   IRB.SetInsertPoint(ElseBB1);
   IRB.CreateBr(EndBB1);
 
-  // longjmp_result = __tempRet0;
+  // longjmp_result = getTempRet0();
   IRB.SetInsertPoint(EndBB1);
   PHINode *LabelPHI = IRB.CreatePHI(IRB.getInt32Ty(), 2, "label");
   LabelPHI->addIncoming(ThenLabel, EndBB2);
@@ -588,7 +586,7 @@
   // Output parameter assignment
   Label = LabelPHI;
   EndBB = EndBB1;
-  LongjmpResult = IRB.CreateLoad(TempRet0GV, "longjmp_result");
+  LongjmpResult = IRB.CreateCall(GetTempRet0Func, None, "longjmp_result");
 }
 
 void WebAssemblyLowerEmscriptenEHSjLj::rebuildSSA(Function &F) {
@@ -628,12 +626,15 @@
   bool LongjmpUsed = LongjmpF && !LongjmpF->use_empty();
   bool DoSjLj = EnableSjLj && (SetjmpUsed || LongjmpUsed);
 
-  // Declare (or get) global variables __THREW__, __threwValue, and __tempRet0,
-  // which are used in common for both exception handling and setjmp/longjmp
-  // handling
+  // Declare (or get) global variables __THREW__, __threwValue, and 
+  // getTempRet0/setTempRet0 function which are used in common for both
+  // exception handling and setjmp/longjmp handling
   ThrewGV = getGlobalVariableI32(M, IRB, "__THREW__");
   ThrewValueGV = getGlobalVariableI32(M, IRB, "__threwValue");
-  TempRet0GV = getGlobalVariableI32(M, IRB, "__tempRet0");
+  GetTempRet0Func = Function::Create(FunctionType::get(IRB.getInt32Ty(), false), GlobalValue::ExternalLinkage, "getTempRet0", &M);
+  SetTempRet0Func = Function::Create(FunctionType::get(IRB.getVoidTy(), IRB.getInt32Ty(), false), GlobalValue::ExternalLinkage, "setTempRet0", &M);
+  GetTempRet0Func->setDoesNotThrow();
+  SetTempRet0Func->setDoesNotThrow();
 
   bool Changed = false;
 
@@ -840,8 +841,7 @@
     CallInst *FMCI = IRB.CreateCall(FMCF, FMCArgs, "fmc");
     Value *Undef = UndefValue::get(LPI->getType());
     Value *Pair0 = IRB.CreateInsertValue(Undef, FMCI, 0, "pair0");
-    Value *TempRet0 =
-        IRB.CreateLoad(TempRet0GV, TempRet0GV->getName() + ".val");
+    Value *TempRet0 = IRB.CreateCall(GetTempRet0Func, None, "tempret0");
     Value *Pair1 = IRB.CreateInsertValue(Pair0, TempRet0, 1, "pair1");
 
     LPI->replaceAllUsesWith(Pair1);
@@ -922,7 +922,7 @@
     Instruction *NewSetjmpTable =
         IRB.CreateCall(SaveSetjmpF, Args, "setjmpTable");
     Instruction *NewSetjmpTableSize =
-        IRB.CreateLoad(TempRet0GV, "setjmpTableSize");
+        IRB.CreateCall(GetTempRet0Func, None, "setjmpTableSize");
     SetjmpTableInsts.push_back(NewSetjmpTable);
     SetjmpTableSizeInsts.push_back(NewSetjmpTableSize);
     ToErase.push_back(CI);
@@ -1044,7 +1044,7 @@
   // ...
   // somebb:
   //   setjmpTable = saveSetjmp(buf, label, setjmpTable, setjmpTableSize);
-  //   setjmpTableSize = __tempRet0;
+  //   setjmpTableSize = getTempRet0();
   // So we need to make sure the SSA for these variables is valid so that every
   // saveSetjmp and testSetjmp calls have the correct arguments.
   SSAUpdater SetjmpTableSSA;
Index: test/CodeGen/WebAssembly/lower-em-exceptions.ll
===================================================================
--- test/CodeGen/WebAssembly/lower-em-exceptions.ll
+++ test/CodeGen/WebAssembly/lower-em-exceptions.ll
@@ -7,7 +7,6 @@
 @_ZTIc = external constant i8*
 ; CHECK-DAG: __THREW__ = external global i32
 ; CHECK-DAG: __threwValue = external global i32
-; CHECK-DAG: __tempRet0 = external global i32
 
 ; Test invoke instruction with clauses (try-catch block)
 define void @clause() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
@@ -36,7 +35,7 @@
 ; CHECK: lpad:
 ; CHECK-NEXT: %[[FMC:.*]] = call i8* @__cxa_find_matching_catch_4(i8* bitcast (i8** @_ZTIi to i8*), i8* null)
 ; CHECK-NEXT: %[[IVI1:.*]] = insertvalue { i8*, i32 } undef, i8* %[[FMC]], 0
-; CHECK-NEXT: %[[TEMPRET0_VAL:.*]] = load i32, i32* @__tempRet0
+; CHECK-NEXT: %[[TEMPRET0_VAL:.*]] = call i32 @getTempRet0()
 ; CHECK-NEXT: %[[IVI2:.*]] = insertvalue { i8*, i32 } %[[IVI1]], i32 %[[TEMPRET0_VAL]], 1
 ; CHECK-NEXT: extractvalue { i8*, i32 } %[[IVI2]], 0
 ; CHECK-NEXT: %[[CDR:.*]] = extractvalue { i8*, i32 } %[[IVI2]], 1
@@ -91,7 +90,7 @@
 ; CHECK: lpad:
 ; CHECK-NEXT: %[[FMC:.*]] = call i8* @__cxa_find_matching_catch_4(i8* bitcast (i8** @_ZTIi to i8*), i8* bitcast (i8** @_ZTIc to i8*))
 ; CHECK-NEXT: %[[IVI1:.*]] = insertvalue { i8*, i32 } undef, i8* %[[FMC]], 0
-; CHECK-NEXT: %[[TEMPRET0_VAL:.*]] = load i32, i32* @__tempRet0
+; CHECK-NEXT: %[[TEMPRET0_VAL:.*]] = call i32 @getTempRet0()
 ; CHECK-NEXT: %[[IVI2:.*]] = insertvalue { i8*, i32 } %[[IVI1]], i32 %[[TEMPRET0_VAL]], 1
 ; CHECK-NEXT: extractvalue { i8*, i32 } %[[IVI2]], 0
 ; CHECK-NEXT: extractvalue { i8*, i32 } %[[IVI2]], 1
@@ -168,6 +167,8 @@
 declare void @__cxa_call_unexpected(i8*)
 
 ; JS glue functions and invoke wrappers declaration
+; CHECK-DAG: declare i32 @getTempRet0()
+; CHECK-DAG: declare void @setTempRet0(i32)
 ; CHECK-DAG: declare void @__resumeException(i8*)
 ; CHECK-DAG: declare void @__invoke_void_i32(void (i32)*, i32)
 ; CHECK-DAG: declare i8* @__cxa_find_matching_catch_4(i8*, i8*)
Index: test/CodeGen/WebAssembly/lower-em-sjlj.ll
===================================================================
--- test/CodeGen/WebAssembly/lower-em-sjlj.ll
+++ test/CodeGen/WebAssembly/lower-em-sjlj.ll
@@ -8,7 +8,6 @@
 @global_var = hidden global i32 0, align 4
 ; CHECK-DAG: __THREW__ = external global i32
 ; CHECK-DAG: __threwValue = external global i32
-; CHECK-DAG: __tempRet0 = external global i32
 
 ; Test a simple setjmp - longjmp sequence
 define hidden void @setjmp_longjmp() {
@@ -28,7 +27,7 @@
 ; CHECK-NEXT: %[[BUF:.*]] = alloca [1 x %struct.__jmp_buf_tag]
 ; CHECK-NEXT: %[[ARRAYDECAY:.*]] = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %[[BUF]], i32 0, i32 0
 ; CHECK-NEXT: %[[SETJMP_TABLE1:.*]] = call i32* @saveSetjmp(%struct.__jmp_buf_tag* %[[ARRAYDECAY]], i32 1, i32* %[[SETJMP_TABLE]], i32 %[[SETJMP_TABLE_SIZE]])
-; CHECK-NEXT: %[[SETJMP_TABLE_SIZE1:.*]] = load i32, i32* @__tempRet0
+; CHECK-NEXT: %[[SETJMP_TABLE_SIZE1:.*]] = call i32 @getTempRet0()
 ; CHECK-NEXT: br label %entry.split
 
 ; CHECK: entry.split:
@@ -59,7 +58,7 @@
 
 ; CHECK: if.end:
 ; CHECK-NEXT: %[[LABEL_PHI:.*]] = phi i32 [ %[[LABEL:.*]], %if.end2 ], [ -1, %if.else1 ]
-; CHECK-NEXT: %[[LONGJMP_RESULT]] = load i32, i32* @__tempRet0
+; CHECK-NEXT: %[[LONGJMP_RESULT]] = call i32 @getTempRet0()
 ; CHECK-NEXT: switch i32 %[[LABEL_PHI]], label %entry.split.split [
 ; CHECK-NEXT:   i32 1, label %entry.split
 ; CHECK-NEXT: ]
@@ -69,7 +68,7 @@
 ; CHECK-NEXT: unreachable
 
 ; CHECK: if.end2:
-; CHECK-NEXT: store i32 %[[THREWVALUE_VAL]], i32* @__tempRet0
+; CHECK-NEXT: call void  @setTempRet0(i32 %[[THREWVALUE_VAL]])
 ; CHECK-NEXT: br label %if.end
 }
 
@@ -152,7 +151,7 @@
 ; CHECK: if.then:
 ; CHECK: %[[VAR0:.*]] = load i32, i32* @global_var, align 4
 ; CHECK: %[[SETJMP_TABLE1:.*]] = call i32* @saveSetjmp(
-; CHECK-NEXT: %[[SETJMP_TABLE_SIZE1:.*]] = load i32, i32* @__tempRet0
+; CHECK-NEXT: %[[SETJMP_TABLE_SIZE1:.*]] = call i32 @getTempRet0()
 
 ; CHECK: if.then.split:
 ; CHECK: %[[VAR1:.*]] = phi i32 [ %[[VAR0]], %if.then ], [ %[[VAR2:.*]], %if.end3 ]
@@ -201,6 +200,8 @@
 declare void @free(i8*)
 
 ; JS glue functions and invoke wrappers declaration
+; CHECK-DAG: declare i32 @getTempRet0()
+; CHECK-DAG: declare void @setTempRet0(i32)
 ; CHECK-DAG: declare i32* @saveSetjmp(%struct.__jmp_buf_tag*, i32, i32*, i32)
 ; CHECK-DAG: declare i32 @testSetjmp(i32, i32*, i32)
 ; CHECK-DAG: declare void @emscripten_longjmp_jmpbuf(%struct.__jmp_buf_tag*, i32)