diff --git a/gen/classes.cpp b/gen/classes.cpp
index b386a82789..096506d88a 100644
--- a/gen/classes.cpp
+++ b/gen/classes.cpp
@@ -34,8 +34,8 @@
 
 void DtoResolveClass(ClassDeclaration* cd)
 {
-    if (cd->ir.resolved) return;
-    cd->ir.resolved = true;
+    if (cd->ir.isResolved()) return;
+    cd->ir.setResolved();
 
     IF_LOG Logger::println("DtoResolveClass(%s): %s", cd->toPrettyChars(), cd->loc.toChars());
     LOG_SCOPE;
diff --git a/gen/declarations.cpp b/gen/declarations.cpp
index 87e3fb3a88..60d192e957 100644
--- a/gen/declarations.cpp
+++ b/gen/declarations.cpp
@@ -55,8 +55,8 @@ public:
         IF_LOG Logger::println("InterfaceDeclaration::codegen: '%s'", decl->toPrettyChars());
         LOG_SCOPE
 
-        if (decl->ir.defined) return;
-        decl->ir.defined = true;
+        if (decl->ir.isDefined()) return;
+        decl->ir.setDefined();
 
         if (decl->type->ty == Terror)
         {   error(decl->loc, "had semantic errors when compiling");
@@ -92,9 +92,8 @@ public:
         IF_LOG Logger::println("StructDeclaration::codegen: '%s'", decl->toPrettyChars());
         LOG_SCOPE
 
-        IrDsymbol &ir = decl->ir;
-        if (ir.defined) return;
-        ir.defined = true;
+        if (decl->ir.isDefined()) return;
+        decl->ir.setDefined();
 
         if (decl->type->ty == Terror)
         {   error(decl->loc, "had semantic errors when compiling");
@@ -135,8 +134,8 @@ public:
         IF_LOG Logger::println("ClassDeclaration::codegen: '%s'", decl->toPrettyChars());
         LOG_SCOPE
 
-        if (decl->ir.defined) return;
-        decl->ir.defined = true;
+        if (decl->ir.isDefined()) return;
+        decl->ir.setDefined();
 
         if (decl->type->ty == Terror)
         {   error(decl->loc, "had semantic errors when compiling");
@@ -179,8 +178,8 @@ public:
         IF_LOG Logger::println("TupleDeclaration::codegen(): '%s'", decl->toPrettyChars());
         LOG_SCOPE
 
-        if (decl->ir.defined) return;
-        decl->ir.defined = true;
+        if (decl->ir.isDefined()) return;
+        decl->ir.setDefined();
 
         assert(decl->isexp);
         assert(decl->objects);
@@ -201,8 +200,8 @@ public:
         IF_LOG Logger::println("VarDeclaration::codegen(): '%s'", decl->toPrettyChars());
         LOG_SCOPE;
 
-        if (decl->ir.defined) return;
-        decl->ir.defined = true;
+        if (decl->ir.isDefined()) return;
+        decl->ir.setDefined();
 
         if (decl->type->ty == Terror)
         {   error(decl->loc, "had semantic errors when compiling");
@@ -288,8 +287,8 @@ public:
         IF_LOG Logger::println("TypedefDeclaration::codegen: '%s'", decl->toPrettyChars());
         LOG_SCOPE;
 
-        if (decl->ir.defined) return;
-        decl->ir.defined = true;
+        if (decl->ir.isDefined()) return;
+        decl->ir.setDefined();
 
         if (decl->type->ty == Terror)
         {   error(decl->loc, "had semantic errors when compiling");
@@ -327,8 +326,8 @@ public:
         IF_LOG Logger::println("TemplateInstance::codegen: '%s'", decl->toPrettyChars());
         LOG_SCOPE
 
-        if (decl->ir.defined) return;
-        decl->ir.defined = true;
+        if (decl->ir.isDefined()) return;
+        decl->ir.setDefined();
 
         if (!decl->errors && decl->members)
         {
@@ -347,8 +346,8 @@ public:
         IF_LOG Logger::println("TemplateInstance::codegen: '%s'", decl->toPrettyChars());
         LOG_SCOPE
 
-        if (decl->ir.defined) return;
-        decl->ir.defined = true;
+        if (decl->ir.isDefined()) return;
+        decl->ir.setDefined();
 
         if (!decl->errors && decl->members)
         {
diff --git a/gen/functions.cpp b/gen/functions.cpp
index 8f6c3e9987..70f9c6315c 100644
--- a/gen/functions.cpp
+++ b/gen/functions.cpp
@@ -514,8 +514,8 @@ void DtoResolveFunction(FuncDeclaration* fdecl)
         return; // ignore declaration completely
     }
 
-    if (fdecl->ir.resolved) return;
-    fdecl->ir.resolved = true;
+    if (fdecl->ir.isResolved()) return;
+    fdecl->ir.setResolved();
 
     Type *type = fdecl->type;
     // If errors occurred compiling it, such as bugzilla 6118
@@ -536,10 +536,10 @@ void DtoResolveFunction(FuncDeclaration* fdecl)
             {
                 Logger::println("magic va_arg found");
                 fdecl->llvmInternal = LLVMva_arg;
-                fdecl->ir.resolved = true;
-                fdecl->ir.declared = true;
-                fdecl->ir.initialized = true;
-                fdecl->ir.defined = true;
+                fdecl->ir.setResolved();
+                fdecl->ir.setDeclared();
+                fdecl->ir.setInitialized();
+                fdecl->ir.setDefined();
                 return; // this gets mapped to an instruction so a declaration makes no sence
             }
             else if (tempdecl->llvmInternal == LLVMva_start)
@@ -563,17 +563,17 @@ void DtoResolveFunction(FuncDeclaration* fdecl)
                     fatal();
                 }
                 fdecl->llvmInternal = LLVMinline_asm;
-                fdecl->ir.resolved = true;
-                fdecl->ir.declared = true;
-                fdecl->ir.initialized = true;
-                fdecl->ir.defined = true;
+                fdecl->ir.setResolved();
+                fdecl->ir.setDeclared();
+                fdecl->ir.setInitialized();
+                fdecl->ir.setDefined();
                 return; // this gets mapped to a special inline asm call, no point in going on.
             }
             else if (tempdecl->llvmInternal == LLVMinline_ir)
             {
                 fdecl->llvmInternal = LLVMinline_ir;
                 fdecl->linkage = LINKc;
-                fdecl->ir.defined = true;
+                fdecl->ir.setDefined();
                 Type* type = fdecl->type;
                 assert(type->ty == Tfunction);
                 static_cast<TypeFunction*>(type)->linkage = LINKc;
@@ -743,8 +743,8 @@ void DtoDeclareFunction(FuncDeclaration* fdecl)
 {
     DtoResolveFunction(fdecl);
 
-    if (fdecl->ir.declared) return;
-    fdecl->ir.declared = true;
+    if (fdecl->ir.isDeclared()) return;
+    fdecl->ir.setDeclared();
 
     IF_LOG Logger::println("DtoDeclareFunction(%s): %s", fdecl->toPrettyChars(), fdecl->loc.toChars());
     LOG_SCOPE;
@@ -932,21 +932,21 @@ void DtoDefineFunction(FuncDeclaration* fd)
     IF_LOG Logger::println("DtoDefineFunction(%s): %s", fd->toPrettyChars(), fd->loc.toChars());
     LOG_SCOPE;
 
-    if (fd->ir.defined) return;
+    if (fd->ir.isDefined()) return;
 
     if ((fd->type && fd->type->ty == Terror) ||
         (fd->type && fd->type->ty == Tfunction && static_cast<TypeFunction *>(fd->type)->next == NULL) ||
         (fd->type && fd->type->ty == Tfunction && static_cast<TypeFunction *>(fd->type)->next->ty == Terror))
     {
         IF_LOG Logger::println("Ignoring; has error type, no return type or returns error type");
-        fd->ir.defined = true;
+        fd->ir.setDefined();
         return;
     }
 
     if (fd->isUnitTestDeclaration() && !global.params.useUnitTests)
     {
         IF_LOG Logger::println("No code generation for unit test declaration %s", fd->toChars());
-        fd->ir.defined = true;
+        fd->ir.setDefined();
         return;
     }
 
@@ -957,7 +957,7 @@ void DtoDefineFunction(FuncDeclaration* fd)
          * Try to reproduce those errors, and then fail.
          */
         error(fd->loc, "errors compiling function %s", fd->toPrettyChars());
-        fd->ir.defined = true;
+        fd->ir.setDefined();
         return;
     }
 
@@ -969,17 +969,17 @@ void DtoDefineFunction(FuncDeclaration* fd)
     if (!fd->needsCodegen())
     {
         IF_LOG Logger::println("No code generation for %s", fd->toChars());
-        fd->ir.defined = true;
+        fd->ir.setDefined();
         return;
     }
 
     DtoDeclareFunction(fd);
-    assert(fd->ir.declared);
+    assert(fd->ir.isDeclared());
 
     // DtoResolveFunction might also set the defined flag for functions we
     // should not touch.
-    if (fd->ir.defined) return;
-    fd->ir.defined = true;
+    if (fd->ir.isDefined()) return;
+    fd->ir.setDefined();
 
     // We cannot emit nested functions with parents that have not gone through
     // semantic analysis. This can happen as DMD leaks some template instances
diff --git a/gen/llvmhelpers.cpp b/gen/llvmhelpers.cpp
index 4d6566149a..251fc780d2 100644
--- a/gen/llvmhelpers.cpp
+++ b/gen/llvmhelpers.cpp
@@ -1028,9 +1028,9 @@ void DtoResolveVariable(VarDeclaration* vd)
     #endif
 
         // don't duplicate work
-        if (vd->ir.resolved) return;
-        vd->ir.resolved = true;
-        vd->ir.declared = true;
+        if (vd->ir.isResolved()) return;
+        vd->ir.setResolved();
+        vd->ir.setDeclared();
 
         getIrGlobal(vd, true);
 
@@ -1043,8 +1043,9 @@ void DtoResolveVariable(VarDeclaration* vd)
 
         const bool isLLConst = (vd->isConst() || vd->isImmutable()) && vd->init;
 
-        assert(!vd->ir.initialized);
-        vd->ir.initialized = gIR->dmodule;
+        assert(!vd->ir.isInitialized());
+        if (gIR->dmodule)
+            vd->ir.setInitialized();
         std::string llName(vd->mangle());
 
         // Since the type of a global must exactly match the type of its
diff --git a/gen/structs.cpp b/gen/structs.cpp
index 6c4c55e368..bb9b7e8281 100644
--- a/gen/structs.cpp
+++ b/gen/structs.cpp
@@ -36,8 +36,8 @@ void DtoResolveStruct(StructDeclaration* sd)
 void DtoResolveStruct(StructDeclaration* sd, Loc& callerLoc)
 {
     // Make sure to resolve each struct type exactly once.
-    if (sd->ir.resolved) return;
-    sd->ir.resolved = true;
+    if (sd->ir.isResolved()) return;
+    sd->ir.setResolved();
 
     IF_LOG Logger::println("Resolving struct type: %s (%s)", sd->toChars(), sd->loc.toChars());
     LOG_SCOPE;
diff --git a/gen/typinf.cpp b/gen/typinf.cpp
index 336b855b01..eded0bdeb8 100644
--- a/gen/typinf.cpp
+++ b/gen/typinf.cpp
@@ -320,8 +320,8 @@ static void emitTypeMetadata(TypeInfoDeclaration *tid)
 
 void DtoResolveTypeInfo(TypeInfoDeclaration* tid)
 {
-    if (tid->ir.resolved) return;
-    tid->ir.resolved = true;
+    if (tid->ir.isResolved()) return;
+    tid->ir.setResolved();
 
     // TypeInfo instances (except ClassInfo ones) are always emitted as weak
     // symbols when they are used.
@@ -333,8 +333,8 @@ void TypeInfoDeclaration_codegen(TypeInfoDeclaration *decl, IRState* p)
     IF_LOG Logger::println("TypeInfoDeclaration::codegen(%s)", decl->toPrettyChars());
     LOG_SCOPE;
 
-    if (decl->ir.defined) return;
-    decl->ir.defined = true;
+    if (decl->ir.isDefined()) return;
+    decl->ir.setDefined();
 
     std::string mangled(decl->mangle());
     IF_LOG {
diff --git a/ir/irdsymbol.cpp b/ir/irdsymbol.cpp
index b24ec4228c..fd8e3b2466 100644
--- a/ir/irdsymbol.cpp
+++ b/ir/irdsymbol.cpp
@@ -32,12 +32,9 @@ IrDsymbol::IrDsymbol() :
 IrDsymbol::IrDsymbol(const IrDsymbol& s)
 {
     list.push_back(this);
-    irData   = s.irData;
-    m_type     = s.m_type;
-    resolved = s.resolved;
-    declared = s.declared;
-    initialized = s.initialized;
-    defined  = s.defined;
+    irData  = s.irData;
+    m_type  = s.m_type;
+    m_flags = s.m_flags;
 }
 
 IrDsymbol::~IrDsymbol()
@@ -55,6 +52,7 @@ IrDsymbol::~IrDsymbol()
 
 void IrDsymbol::reset()
 {
-    irData = NULL;
-    resolved = declared = initialized = defined = false;
+    irData  = NULL;
+    m_type  = NotSet;
+    m_flags = 0;
 }
diff --git a/ir/irdsymbol.h b/ir/irdsymbol.h
index 24b0fe4de5..7749513db6 100644
--- a/ir/irdsymbol.h
+++ b/ir/irdsymbol.h
@@ -48,6 +48,14 @@ struct IrDsymbol
         FieldType
     };
 
+    enum Flag
+    {
+        Resolved    = 0x1,
+        Declared    = 0x2,
+        Initialized = 0x4,
+        Defined     = 0x8
+    };
+
     static std::vector<IrDsymbol*> list;
     static void resetAll();
 
@@ -61,10 +69,15 @@ struct IrDsymbol
 
     Type type() const { return m_type; }
 
-    bool resolved;
-    bool declared;
-    bool initialized;
-    bool defined;
+    bool isResolved() const { return m_flags & Resolved; }
+    bool isDeclared() const { return m_flags & Declared; }
+    bool isInitialized() const { return m_flags & Initialized; }
+    bool isDefined() const { return m_flags & Defined; }
+
+    void setResolved() { m_flags |= Resolved; }
+    void setDeclared() { m_flags |= Declared; }
+    void setInitialized() { m_flags |= Initialized; }
+    void setDefined() { m_flags |= Defined; }
 private:
     friend IrModule* getIrModule(Module *m);
     friend IrAggr *getIrAggr(AggregateDeclaration *decl, bool create);
@@ -75,7 +88,6 @@ private:
     friend IrParameter *getIrParameter(VarDeclaration *decl, bool create);
     friend IrField *getIrField(VarDeclaration *decl, bool create);
 
-    Type m_type;
     union {
         void*        irData;
         IrModule*    irModule;
@@ -87,6 +99,8 @@ private:
         IrParameter* irParam;
         IrField*     irField;
     };
+    Type m_type;
+    int m_flags;
 };
 
 #endif