diff --git a/dmd/mtype.c b/dmd/mtype.c
index 4f38a0fd..0e5927b7 100644
--- a/dmd/mtype.c
+++ b/dmd/mtype.c
@@ -1769,18 +1769,8 @@ Expression *TypeArray::dotExp(Scope *sc, Expression *e, Identifier *ident)
             args->push(new Parameter(STCin, Type::typeinfo->type, NULL, NULL));
             adSort_fd = FuncDeclaration::genCfunc(args, Type::tvoid->arrayOf(), "_adSort");
         }
-        static FuncDeclaration *adSortBit_fd = NULL;
-        if(!adSortBit_fd) {
-            Parameters* args = new Parameters;
-            args->push(new Parameter(STCin, Type::tvoid->arrayOf(), NULL, NULL));
-            args->push(new Parameter(STCin, Type::typeinfo->type, NULL, NULL));
-            adSortBit_fd = FuncDeclaration::genCfunc(args, Type::tvoid->arrayOf(), "_adSortBit");
-        }
 
-        if(isBit)
-            ec = new VarExp(0, adSortBit_fd);
-        else
-            ec = new VarExp(0, adSort_fd);
+        ec = new VarExp(0, adSort_fd);
         e = e->castTo(sc, n->arrayOf());        // convert to dynamic array
         arguments = new Expressions();
 
@@ -2476,7 +2466,7 @@ Expression *TypeAArray::dotExp(Scope *sc, Expression *e, Identifier *ident)
         static FuncDeclaration *aaLen_fd = NULL;
         if(!aaLen_fd) {
             Parameters* args = new Parameters;
-            args->push(new Parameter(STCin, Type::tvoid->pointerTo(), NULL, NULL));
+            args->push(new Parameter(STCin, Type::tvoid->pointerTo(), NULL, NULL)); // FIXME: Real parameter type is AA.
             aaLen_fd = FuncDeclaration::genCfunc(args, Type::tsize_t, Id::aaLen);
         }
 
@@ -2497,7 +2487,7 @@ Expression *TypeAArray::dotExp(Scope *sc, Expression *e, Identifier *ident)
         static FuncDeclaration *aaKeys_fd = NULL;
         if(!aaKeys_fd) {
             Parameters* args = new Parameters;
-            args->push(new Parameter(STCin, Type::tvoid->pointerTo(), NULL, NULL));
+            args->push(new Parameter(STCin, Type::tvoid->pointerTo(), NULL, NULL)); // FIXME: Real parameter type is AA.
             args->push(new Parameter(STCin, Type::tsize_t, NULL, NULL));
             aaKeys_fd = FuncDeclaration::genCfunc(args, Type::tvoid->arrayOf(), Id::aaKeys);
         }
@@ -2518,7 +2508,7 @@ Expression *TypeAArray::dotExp(Scope *sc, Expression *e, Identifier *ident)
         static FuncDeclaration *aaValues_fd = NULL;
         if(!aaValues_fd) {
             Parameters* args = new Parameters;
-            args->push(new Parameter(STCin, Type::tvoid->pointerTo(), NULL, NULL));
+            args->push(new Parameter(STCin, Type::tvoid->pointerTo(), NULL, NULL)); // FIXME: Real parameter type is AA.
             args->push(new Parameter(STCin, Type::tsize_t, NULL, NULL));
             args->push(new Parameter(STCin, Type::tsize_t, NULL, NULL));
             aaValues_fd = FuncDeclaration::genCfunc(args, Type::tvoid->arrayOf(), Id::aaValues);
@@ -2543,7 +2533,7 @@ Expression *TypeAArray::dotExp(Scope *sc, Expression *e, Identifier *ident)
         static FuncDeclaration *aaRehash_fd = NULL;
         if(!aaRehash_fd) {
             Parameters* args = new Parameters;
-            args->push(new Parameter(STCin, Type::tvoid->pointerTo(), NULL, NULL));
+            args->push(new Parameter(STCin, Type::tvoid->pointerTo(), NULL, NULL)); // FIXME: Real parameter type is AA*.
             args->push(new Parameter(STCin, Type::typeinfo->type, NULL, NULL));
             aaRehash_fd = FuncDeclaration::genCfunc(args, Type::tvoidptr, Id::aaRehash);
         }
diff --git a/dmd/statement.c b/dmd/statement.c
index b88c4761..bb64b66f 100644
--- a/dmd/statement.c
+++ b/dmd/statement.c
@@ -1801,21 +1801,21 @@ Statement *ForeachStatement::semantic(Scope *sc)
                     Parameters* dgargs = new Parameters;
                     dgargs->push(new Parameter(STCin, Type::tvoidptr, NULL, NULL));
                     dgargs->push(new Parameter(STCin, Type::tvoidptr, NULL, NULL));
-                    aaApply2_dg = new TypeDelegate(new TypeFunction(dgargs, Type::tindex, 0, LINKd));
+                    aaApply2_dg = new TypeDelegate(new TypeFunction(dgargs, Type::tint32, 0, LINKd));
                     args->push(new Parameter(STCin, aaApply2_dg, NULL, NULL));
-                    aaApply2_fd = FuncDeclaration::genCfunc(args, Type::tindex, "_aaApply2");
+                    aaApply2_fd = FuncDeclaration::genCfunc(args, Type::tint32, "_aaApply2");
                 }
                 static FuncDeclaration *aaApply_fd = NULL;
         static TypeDelegate* aaApply_dg;
                 if(!aaApply_fd) {
                     Parameters* args = new Parameters;
-                    args->push(new Parameter(STCin, Type::tvoid->pointerTo(), NULL, NULL));
+                    args->push(new Parameter(STCin, Type::tvoid->pointerTo(), NULL, NULL)); // FIXME: Real parameter type is AA.
                     args->push(new Parameter(STCin, Type::tsize_t, NULL, NULL));
                     Parameters* dgargs = new Parameters;
                     dgargs->push(new Parameter(STCin, Type::tvoidptr, NULL, NULL));
-                    aaApply_dg = new TypeDelegate(new TypeFunction(dgargs, Type::tindex, 0, LINKd));
+                    aaApply_dg = new TypeDelegate(new TypeFunction(dgargs, Type::tint32, 0, LINKd));
                     args->push(new Parameter(STCin, aaApply_dg, NULL, NULL));
-                    aaApply_fd = FuncDeclaration::genCfunc(args, Type::tindex, "_aaApply");
+                    aaApply_fd = FuncDeclaration::genCfunc(args, Type::tint32, "_aaApply");
                 }
                 FuncDeclaration *fdapply;
                 if (dim == 2) {
@@ -1840,7 +1840,7 @@ Statement *ForeachStatement::semantic(Scope *sc)
         }
                 exps->push(flde);
                 e = new CallExp(loc, ec, exps);
-                e->type = Type::tindex; // don't run semantic() on e
+                e->type = Type::tint32; // don't run semantic() on e
             }
             else if (tab->ty == Tarray || tab->ty == Tsarray)
             {
@@ -1884,15 +1884,15 @@ Statement *ForeachStatement::semantic(Scope *sc)
                     Parameters* dgargs = new Parameters;
                     dgargs->push(new Parameter(STCin, Type::tvoidptr, NULL, NULL));
                     dgargs->push(new Parameter(STCin, Type::tvoidptr, NULL, NULL));
-                    dgty = new TypeDelegate(new TypeFunction(dgargs, Type::tindex, 0, LINKd));
+                    dgty = new TypeDelegate(new TypeFunction(dgargs, Type::tint32, 0, LINKd));
                     args->push(new Parameter(STCin, dgty, NULL, NULL));
-                    fdapply = FuncDeclaration::genCfunc(args, Type::tindex, fdname);
+                    fdapply = FuncDeclaration::genCfunc(args, Type::tint32, fdname);
                 } else {
                     Parameters* dgargs = new Parameters;
                     dgargs->push(new Parameter(STCin, Type::tvoidptr, NULL, NULL));
-                    dgty = new TypeDelegate(new TypeFunction(dgargs, Type::tindex, 0, LINKd));
+                    dgty = new TypeDelegate(new TypeFunction(dgargs, Type::tint32, 0, LINKd));
                     args->push(new Parameter(STCin, dgty, NULL, NULL));
-                    fdapply = FuncDeclaration::genCfunc(args, Type::tindex, fdname);
+                    fdapply = FuncDeclaration::genCfunc(args, Type::tint32, fdname);
                 }
 
                 ec = new VarExp(0, fdapply);
@@ -1909,7 +1909,7 @@ Statement *ForeachStatement::semantic(Scope *sc)
         }
                 exps->push(flde);
                 e = new CallExp(loc, ec, exps);
-                e->type = Type::tindex; // don't run semantic() on e
+                e->type = Type::tint32; // don't run semantic() on e
             }
             else if (tab->ty == Tdelegate)
             {
@@ -3787,14 +3787,14 @@ Statement *SynchronizedStatement::semantic(Scope *sc)
         cs->push(new DeclarationStatement(loc, new DeclarationExp(loc, tmp)));
 
         Parameters* enterargs = new Parameters;
-        enterargs->push(new Parameter(STCin, Type::tvoidptr, NULL, NULL));
+        enterargs->push(new Parameter(STCin, ClassDeclaration::object->type, NULL, NULL));
         FuncDeclaration *fdenter = FuncDeclaration::genCfunc(enterargs, Type::tvoid, Id::monitorenter);
         Expression *e = new CallExp(loc, new VarExp(loc, fdenter), new VarExp(loc, tmp));
         e->type = Type::tvoid;                  // do not run semantic on e
         cs->push(new ExpStatement(loc, e));
 
         Parameters* exitargs = new Parameters;
-        exitargs->push(new Parameter(STCin, Type::tvoidptr, NULL, NULL));
+        exitargs->push(new Parameter(STCin, ClassDeclaration::object->type, NULL, NULL));
         FuncDeclaration *fdexit = FuncDeclaration::genCfunc(exitargs, Type::tvoid, Id::monitorexit);
         e = new CallExp(loc, new VarExp(loc, fdexit), new VarExp(loc, tmp));
         e->type = Type::tvoid;                  // do not run semantic on e
diff --git a/gen/functions.cpp b/gen/functions.cpp
index 94d63e22..5bfb8797 100644
--- a/gen/functions.cpp
+++ b/gen/functions.cpp
@@ -474,8 +474,11 @@ void DtoDeclareFunction(FuncDeclaration* fdecl)
     // construct function
     const llvm::FunctionType* functype = DtoFunctionType(fdecl);
     llvm::Function* func = vafunc ? vafunc : gIR->module->getFunction(mangled_name);
-    if (!func)
+    if (!func) {
         func = llvm::Function::Create(functype, DtoLinkage(fdecl), mangled_name, gIR->module);
+    } else if (func->getFunctionType() != functype) {
+        error(fdecl->loc, "Function type does not match previously declared function with the same mangled name: %s", fdecl->mangle());
+    }
 
     if (Logger::enabled())
         Logger::cout() << "func = " << *func << std::endl;