diff --git a/src/codegen.cpp b/src/codegen.cpp
index 69cf58a2c814f..770115df8ddf0 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -568,6 +568,10 @@ static Value *global_binding_pointer(jl_module_t *m, jl_sym_t *s,
 static Value *emit_checked_var(Value *bp, jl_sym_t *name, jl_codectx_t *ctx, bool isvol=false);
 static bool might_need_root(jl_value_t *ex);
 static Value *emit_condition(jl_value_t *cond, const std::string &msg, jl_codectx_t *ctx);
+static Value *emit_call_function_object(jl_function_t *f, Value *theF,
+                                        Value *theFptr, bool specialized,
+                                        jl_value_t **args, size_t nargs,
+                                        jl_codectx_t *ctx);
 
 // NoopType
 static Type *NoopType;
@@ -2346,6 +2350,52 @@ static Value *emit_known_call(jl_value_t *ff, jl_value_t **args, size_t nargs,
             }
         }
     }
+    else if (f->fptr == &jl_f_invoke && nargs >= 2 &&
+             expr_type(args[1], ctx) == (jl_value_t*)jl_function_type) {
+        // Get function
+        rt1 = static_eval(args[1], ctx);
+        f = (jl_function_t*)rt1;
+        if (!f || !jl_is_gf(f)) {
+            JL_GC_POP();
+            return NULL;
+        }
+        // Get types
+        jl_value_t *type_types = expr_type(args[2], ctx);
+        rt2 = type_types;
+        // Only accept Type{Tuple{...}}
+        if (!jl_is_type_type(type_types) ||
+            !jl_is_tuple_type(jl_tparam0(type_types))) {
+            JL_GC_POP();
+            return NULL;
+        }
+        rt2 = jl_tparam0(type_types);
+        // Get types of real arguments
+        jl_svec_t *aty = call_arg_types(&args[3], nargs - 2, ctx);
+        if (!aty) {
+            JL_GC_POP();
+            return NULL;
+        }
+        rt3 = (jl_value_t*)aty;
+        rt3 = (jl_value_t*)jl_apply_tuple_type(aty);
+        jl_function_t *mfunc =
+            jl_gf_invoke_get_specialization(f, (jl_tupletype_t*)rt2,
+                                            (jl_tupletype_t*)rt3);
+        JL_GC_POP();
+        if (mfunc == NULL) {
+            return NULL;
+        }
+        if (!is_constant(args[2], ctx))
+            emit_expr(args[2], ctx);
+        assert(mfunc->linfo->functionObject != NULL);
+        Value *_theF = literal_pointer_val((jl_value_t*)mfunc);
+        Value *_theFptr = emit_nthptr_recast(
+            _theF,
+            (ssize_t)(offsetof(jl_function_t, fptr) / sizeof(void*)),
+            tbaa_func,
+            jl_pfptr_llvmt);
+        return emit_call_function_object(mfunc, _theF, _theFptr, true,
+                                         args + 2, nargs - 2, ctx);
+    }
     // TODO: other known builtins
     JL_GC_POP();
     return NULL;
diff --git a/src/gf.c b/src/gf.c
index c8d080889e9cd..8d73c544ab97f 100644
--- a/src/gf.c
+++ b/src/gf.c
@@ -1782,6 +1782,85 @@ DLLEXPORT jl_value_t *jl_gf_invoke_lookup(jl_function_t *gf, jl_datatype_t *type
     return (jl_value_t*)m;
 }
 
+static jl_function_t*
+invoke_specialize(jl_methlist_t *m, jl_methtable_t *mt, jl_tupletype_t *tt)
+{
+    jl_svec_t *tpenv = jl_emptysvec;
+    jl_tupletype_t *newsig = NULL;
+    JL_GC_PUSH2(&tpenv, &newsig);
+
+    if (m->invokes == (void*)jl_nothing) {
+        m->invokes = new_method_table(mt->name);
+        gc_wb(m, m->invokes);
+        update_max_args(m->invokes, tt);
+        // this private method table has just this one definition
+        jl_method_list_insert(&m->invokes->defs, m->sig, m->func,
+                              m->tvars, 0, 0, (jl_value_t*)m->invokes);
+    }
+
+    newsig = m->sig;
+
+    if (m->tvars != jl_emptysvec) {
+        jl_value_t *ti = lookup_match((jl_value_t*)tt, (jl_value_t*)m->sig,
+                                      &tpenv, m->tvars);
+        assert(ti != (jl_value_t*)jl_bottom_type);
+        (void)ti;
+        // don't bother computing this if no arguments are tuples
+        for (size_t i = 0;i < jl_nparams(tt);i++) {
+            if (jl_is_tuple_type(jl_tparam(tt, i))) {
+                newsig = (jl_tupletype_t*)jl_instantiate_type_with(
+                    (jl_value_t*)m->sig,
+                    jl_svec_data(tpenv),
+                    jl_svec_len(tpenv) / 2);
+                break;
+            }
+        }
+    }
+    jl_function_t *mfunc =
+        cache_method(m->invokes, tt, m->func, newsig, tpenv, m->isstaged);
+    JL_GC_POP();
+    return mfunc;
+}
+
+// compile-time method lookup
+jl_function_t*
+jl_gf_invoke_get_specialization(jl_function_t *gf, jl_tupletype_t *types,
+                                jl_tupletype_t *tt)
+{
+    assert(jl_is_gf(gf));
+    jl_methtable_t *mt = jl_gf_mtable(gf);
+    jl_methlist_t *m = (jl_methlist_t*)jl_gf_invoke_lookup(gf, types);
+    size_t i;
+
+    if ((jl_value_t*)m == jl_nothing) {
+        return NULL;
+    }
+
+    // now we have found the matching definition.
+    // next look for or create a specialization of this definition.
+
+    jl_function_t *mfunc;
+    if (m->invokes == (void*)jl_nothing)
+        mfunc = jl_bottom_func;
+    else
+        mfunc = jl_method_table_assoc_exact_by_type(m->invokes, tt);
+    if (mfunc != jl_bottom_func) {
+        if (mfunc->linfo == NULL || mfunc->linfo->inInference ||
+            mfunc->linfo->inCompile) {
+            return NULL;
+        }
+    } else {
+        mfunc = invoke_specialize(m, mt, tt);
+    }
+    if (mfunc->linfo->functionObject == NULL) {
+        if (mfunc->fptr != &jl_trampoline) {
+            return NULL;
+        }
+        jl_compile(mfunc);
+    }
+    return mfunc;
+}
+
 // invoke()
 // this does method dispatch with a set of types to match other than the
 // types of the actual arguments. this means it sometimes does NOT call the
@@ -1828,38 +1907,9 @@ jl_value_t *jl_gf_invoke(jl_function_t *gf, jl_tupletype_t *types,
         }
     }
     else {
-        jl_svec_t *tpenv=jl_emptysvec;
-        jl_tupletype_t *newsig=NULL;
-        jl_tupletype_t *tt=NULL;
-        JL_GC_PUSH3(&tpenv, &newsig, &tt);
-        tt = arg_type_tuple(args, nargs);
-        if (m->invokes == (void*)jl_nothing) {
-            m->invokes = new_method_table(mt->name);
-            gc_wb(m, m->invokes);
-            update_max_args(m->invokes, tt);
-            // this private method table has just this one definition
-            jl_method_list_insert(&m->invokes->defs,m->sig,m->func,m->tvars,0,0,(jl_value_t*)m->invokes);
-        }
-
-        newsig = m->sig;
-
-        if (m->tvars != jl_emptysvec) {
-            jl_value_t *ti =
-                lookup_match((jl_value_t*)tt, (jl_value_t*)m->sig, &tpenv, m->tvars);
-            assert(ti != (jl_value_t*)jl_bottom_type);
-            (void)ti;
-            // don't bother computing this if no arguments are tuples
-            for(i=0; i < jl_nparams(tt); i++) {
-                if (jl_is_tuple_type(jl_tparam(tt,i)))
-                    break;
-            }
-            if (i < jl_nparams(tt)) {
-                newsig = (jl_tupletype_t*)jl_instantiate_type_with((jl_value_t*)m->sig,
-                                                                   jl_svec_data(tpenv),
-                                                                   jl_svec_len(tpenv)/2);
-            }
-        }
-        mfunc = cache_method(m->invokes, tt, m->func, newsig, tpenv, m->isstaged);
+        jl_tupletype_t *tt = arg_type_tuple(args, nargs);
+        JL_GC_PUSH1(&tt);
+        mfunc = invoke_specialize(m, mt, tt);
         JL_GC_POP();
     }
 
diff --git a/src/julia_internal.h b/src/julia_internal.h
index 4dc90f14b3619..9b1a63001584b 100644
--- a/src/julia_internal.h
+++ b/src/julia_internal.h
@@ -127,6 +127,9 @@ DLLEXPORT void jl_read_sonames(void);
 jl_lambda_info_t *jl_add_static_parameters(jl_lambda_info_t *l, jl_svec_t *sp);
 jl_function_t *jl_get_specialization(jl_function_t *f, jl_tupletype_t *types);
 jl_function_t *jl_module_get_initializer(jl_module_t *m);
+jl_function_t *jl_gf_invoke_get_specialization(jl_function_t *gf,
+                                               jl_tupletype_t *types,
+                                               jl_tupletype_t *tt);
 void jl_generate_fptr(jl_function_t *f);
 void jl_fptr_to_llvm(void *fptr, jl_lambda_info_t *lam, int specsig);