py, compiler: Refactor load/store/delete_id logic to reduce code size.

Saves around 230 bytes on Thumb2 and 750 bytes on x86.

7 files changed, 186 insertions, 272 deletions

diff --git a/py/compile.c b/py/compile.c
index 554d74b30c..4b78b7f37c 100644
--- a/py/compile.c
+++ b/py/compile.c
@@ -51,6 +51,8 @@ typedef enum {
 
 #define EMIT(fun) (comp->emit_method_table->fun(comp->emit))
 #define EMIT_ARG(fun, ...) (comp->emit_method_table->fun(comp->emit, __VA_ARGS__))
+#define EMIT_LOAD_FAST(qst, local_num) (comp->emit_method_table->load_id.fast(comp->emit, qst, local_num))
+#define EMIT_LOAD_GLOBAL(qst) (comp->emit_method_table->load_id.global(comp->emit, qst))
 #define EMIT_INLINE_ASM(fun) (comp->emit_inline_asm_method_table->fun(comp->emit_inline_asm))
 #define EMIT_INLINE_ASM_ARG(fun, ...) (comp->emit_inline_asm_method_table->fun(comp->emit_inline_asm, __VA_ARGS__))
 
@@ -400,6 +402,30 @@ STATIC void compile_generic_all_nodes(compiler_t *comp, mp_parse_node_struct_t *
     }
 }
 
+STATIC void compile_load_id(compiler_t *comp, qstr qst) {
+    if (comp->pass == MP_PASS_SCOPE) {
+        mp_emit_common_get_id_for_load(comp->scope_cur, qst);
+    } else {
+        mp_emit_common_id_op(comp->emit, &comp->emit_method_table->load_id, comp->scope_cur, qst);
+    }
+}
+
+STATIC void compile_store_id(compiler_t *comp, qstr qst) {
+    if (comp->pass == MP_PASS_SCOPE) {
+        mp_emit_common_get_id_for_modification(comp->scope_cur, qst);
+    } else {
+        mp_emit_common_id_op(comp->emit, &comp->emit_method_table->store_id, comp->scope_cur, qst);
+    }
+}
+
+STATIC void compile_delete_id(compiler_t *comp, qstr qst) {
+    if (comp->pass == MP_PASS_SCOPE) {
+        mp_emit_common_get_id_for_modification(comp->scope_cur, qst);
+    } else {
+        mp_emit_common_id_op(comp->emit, &comp->emit_method_table->delete_id, comp->scope_cur, qst);
+    }
+}
+
 #if MICROPY_EMIT_CPYTHON
 STATIC bool cpython_c_tuple_is_const(mp_parse_node_t pn) {
     if (MP_PARSE_NODE_IS_STRUCT_KIND(pn, PN_string)) {
@@ -823,11 +849,11 @@ STATIC void c_assign(compiler_t *comp, mp_parse_node_t pn, assign_kind_t assign_
             switch (assign_kind) {
                 case ASSIGN_STORE:
                 case ASSIGN_AUG_STORE:
-                    EMIT_ARG(store_id, arg);
+                    compile_store_id(comp, arg);
                     break;
                 case ASSIGN_AUG_LOAD:
                 default:
-                    EMIT_ARG(load_id, arg);
+                    compile_load_id(comp, arg);
                     break;
             }
         } else {
@@ -951,7 +977,7 @@ STATIC void close_over_variables_etc(compiler_t *comp, scope_t *this_scope, int
                         EMIT_ARG(load_closure, id->qst, id->local_num);
 #else
                         // in Micro Python we load closures using LOAD_FAST
-                        EMIT_ARG(load_fast, id->qst, id->local_num);
+                        EMIT_LOAD_FAST(id->qst, id->local_num);
 #endif
                         nfree += 1;
                     }
@@ -1226,18 +1252,18 @@ STATIC void compile_decorated(compiler_t *comp, mp_parse_node_struct_t *pns) {
     }
 
     // store func/class object into name
-    EMIT_ARG(store_id, body_name);
+    compile_store_id(comp, body_name);
 }
 
 STATIC void compile_funcdef(compiler_t *comp, mp_parse_node_struct_t *pns) {
     qstr fname = compile_funcdef_helper(comp, pns, comp->scope_cur->emit_options);
     // store function object into function name
-    EMIT_ARG(store_id, fname);
+    compile_store_id(comp, fname);
 }
 
 STATIC void c_del_stmt(compiler_t *comp, mp_parse_node_t pn) {
     if (MP_PARSE_NODE_IS_ID(pn)) {
-        EMIT_ARG(delete_id, MP_PARSE_NODE_LEAF_ARG(pn));
+        compile_delete_id(comp, MP_PARSE_NODE_LEAF_ARG(pn));
     } else if (MP_PARSE_NODE_IS_STRUCT_KIND(pn, PN_power)) {
         mp_parse_node_struct_t *pns = (mp_parse_node_struct_t*)pn;
 
@@ -1446,7 +1472,7 @@ STATIC void compile_dotted_as_name(compiler_t *comp, mp_parse_node_t pn) {
     EMIT_ARG(load_const_tok, MP_TOKEN_KW_NONE); // not importing from anything
     qstr q_base;
     do_import_name(comp, pn, &q_base);
-    EMIT_ARG(store_id, q_base);
+    compile_store_id(comp, q_base);
 }
 
 STATIC void compile_import_name(compiler_t *comp, mp_parse_node_struct_t *pns) {
@@ -1555,9 +1581,9 @@ STATIC void compile_import_from(compiler_t *comp, mp_parse_node_struct_t *pns) {
             qstr id2 = MP_PARSE_NODE_LEAF_ARG(pns3->nodes[0]); // should be id
             EMIT_ARG(import_from, id2);
             if (MP_PARSE_NODE_IS_NULL(pns3->nodes[1])) {
-                EMIT_ARG(store_id, id2);
+                compile_store_id(comp, id2);
             } else {
-                EMIT_ARG(store_id, MP_PARSE_NODE_LEAF_ARG(pns3->nodes[1]));
+                compile_store_id(comp, MP_PARSE_NODE_LEAF_ARG(pns3->nodes[1]));
             }
         }
         EMIT(pop_top);
@@ -1625,7 +1651,7 @@ STATIC void compile_nonlocal_stmt(compiler_t *comp, mp_parse_node_struct_t *pns)
 STATIC void compile_assert_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) {
     uint l_end = comp_next_label(comp);
     c_if_cond(comp, pns->nodes[0], true, l_end);
-    EMIT_ARG(load_global, MP_QSTR_AssertionError); // we load_global instead of load_id, to be consistent with CPython
+    EMIT_LOAD_GLOBAL(MP_QSTR_AssertionError); // we load_global instead of load_id, to be consistent with CPython
     if (!MP_PARSE_NODE_IS_NULL(pns->nodes[1])) {
         // assertion message
         compile_node(comp, pns->nodes[1]);
@@ -1972,7 +1998,7 @@ STATIC void compile_try_except(compiler_t *comp, mp_parse_node_t pn_body, int n_
         if (qstr_exception_local == 0) {
             EMIT(pop_top);
         } else {
-            EMIT_ARG(store_id, qstr_exception_local);
+            compile_store_id(comp, qstr_exception_local);
         }
 
         EMIT(pop_top);
@@ -1992,8 +2018,8 @@ STATIC void compile_try_except(compiler_t *comp, mp_parse_node_t pn_body, int n_
             EMIT_ARG(load_const_tok, MP_TOKEN_KW_NONE);
             EMIT_ARG(label_assign, l3);
             EMIT_ARG(load_const_tok, MP_TOKEN_KW_NONE);
-            EMIT_ARG(store_id, qstr_exception_local);
-            EMIT_ARG(delete_id, qstr_exception_local);
+            compile_store_id(comp, qstr_exception_local);
+            compile_delete_id(comp, qstr_exception_local);
 
             compile_decrease_except_level(comp);
             EMIT(end_finally);
@@ -2107,7 +2133,7 @@ STATIC void compile_expr_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) {
     if (MP_PARSE_NODE_IS_NULL(pns->nodes[1])) {
         if (comp->is_repl && comp->scope_cur->kind == SCOPE_MODULE) {
             // for REPL, evaluate then print the expression
-            EMIT_ARG(load_id, MP_QSTR___repl_print__);
+            compile_load_id(comp, MP_QSTR___repl_print__);
             compile_node(comp, pns->nodes[0]);
             EMIT_ARG(call_function, 1, 0, 0);
             EMIT(pop_top);
@@ -2424,12 +2450,12 @@ STATIC void compile_trailer_paren_helper(compiler_t *comp, mp_parse_node_t pn_ar
 #if !MICROPY_EMIT_CPYTHON
     // this is to handle special super() call
     if (MP_PARSE_NODE_IS_NULL(pn_arglist) && comp->func_arg_is_super && comp->scope_cur->kind == SCOPE_FUNCTION) {
-        EMIT_ARG(load_id, MP_QSTR___class__);
+        compile_load_id(comp, MP_QSTR___class__);
         // look for first argument to function (assumes it's "self")
         for (int i = 0; i < comp->scope_cur->id_info_len; i++) {
             if (comp->scope_cur->id_info[i].flags & ID_FLAG_IS_PARAM) {
                 // first argument found; load it and call super
-                EMIT_ARG(load_fast, MP_QSTR_, comp->scope_cur->id_info[i].local_num);
+                EMIT_LOAD_FAST(MP_QSTR_, comp->scope_cur->id_info[i].local_num);
                 EMIT_ARG(call_function, 2, 0, 0);
                 return;
             }
@@ -2853,7 +2879,7 @@ STATIC void compile_dictorsetmaker_item(compiler_t *comp, mp_parse_node_struct_t
 STATIC void compile_classdef(compiler_t *comp, mp_parse_node_struct_t *pns) {
     qstr cname = compile_classdef_helper(comp, pns, comp->scope_cur->emit_options);
     // store class object into class name
-    EMIT_ARG(store_id, cname);
+    compile_store_id(comp, cname);
 }
 
 STATIC void compile_yield_expr(compiler_t *comp, mp_parse_node_struct_t *pns) {
@@ -2922,7 +2948,7 @@ STATIC void compile_node(compiler_t *comp, mp_parse_node_t pn) {
     } else if (MP_PARSE_NODE_IS_LEAF(pn)) {
         mp_uint_t arg = MP_PARSE_NODE_LEAF_ARG(pn);
         switch (MP_PARSE_NODE_LEAF_KIND(pn)) {
-            case MP_PARSE_NODE_ID: EMIT_ARG(load_id, arg); break;
+            case MP_PARSE_NODE_ID: compile_load_id(comp, arg); break;
             case MP_PARSE_NODE_STRING: EMIT_ARG(load_const_str, arg, false); break;
             case MP_PARSE_NODE_BYTES: EMIT_ARG(load_const_str, arg, true); break;
             case MP_PARSE_NODE_TOKEN: default:
@@ -3145,7 +3171,7 @@ STATIC void check_for_doc_string(compiler_t *comp, mp_parse_node_t pn) {
                 // compile the doc string
                 compile_node(comp, pns->nodes[0]);
                 // store the doc string
-                EMIT_ARG(store_id, MP_QSTR___doc__);
+                compile_store_id(comp, MP_QSTR___doc__);
         }
     }
 #else
@@ -3283,7 +3309,7 @@ STATIC void compile_scope(compiler_t *comp, scope_t *scope, pass_kind_t pass) {
 
         uint l_end = comp_next_label(comp);
         uint l_top = comp_next_label(comp);
-        EMIT_ARG(load_id, qstr_arg);
+        compile_load_id(comp, qstr_arg);
         EMIT_ARG(label_assign, l_top);
         EMIT_ARG(for_iter, l_end);
         c_assign(comp, pns_comp_for->nodes[0], ASSIGN_STORE);
@@ -3309,10 +3335,10 @@ STATIC void compile_scope(compiler_t *comp, scope_t *scope, pass_kind_t pass) {
             id_info->kind = ID_INFO_KIND_LOCAL;
         }
 
-        EMIT_ARG(load_id, MP_QSTR___name__);
-        EMIT_ARG(store_id, MP_QSTR___module__);
+        compile_load_id(comp, MP_QSTR___name__);
+        compile_store_id(comp, MP_QSTR___module__);
         EMIT_ARG(load_const_str, MP_PARSE_NODE_LEAF_ARG(pns->nodes[0]), false); // 0 is class name
-        EMIT_ARG(store_id, MP_QSTR___qualname__);
+        compile_store_id(comp, MP_QSTR___qualname__);
 
         check_for_doc_string(comp, pns->nodes[2]);
         compile_node(comp, pns->nodes[2]); // 2 is class body
@@ -3325,7 +3351,7 @@ STATIC void compile_scope(compiler_t *comp, scope_t *scope, pass_kind_t pass) {
 #if MICROPY_EMIT_CPYTHON
             EMIT_ARG(load_closure, MP_QSTR___class__, 0); // XXX check this is the correct local num
 #else
-            EMIT_ARG(load_fast, MP_QSTR___class__, id->local_num);
+            EMIT_LOAD_FAST(MP_QSTR___class__, id->local_num);
 #endif
         }
         EMIT(return_value);
@@ -3622,7 +3648,7 @@ mp_obj_t mp_compile(mp_parse_node_t pn, qstr source_file, uint emit_opt, bool is
     mp_map_deinit(&consts);
 
     // compile pass 1
-    comp->emit = emit_pass1_new();
+    comp->emit = NULL;
     comp->emit_method_table = &emit_pass1_method_table;
     #if MICROPY_EMIT_INLINE_THUMB
     comp->emit_inline_asm = NULL;
@@ -3650,9 +3676,6 @@ mp_obj_t mp_compile(mp_parse_node_t pn, qstr source_file, uint emit_opt, bool is
         scope_compute_things(s);
     }
 
-    // finish with pass 1
-    emit_pass1_free(comp->emit);
-
     // compile pass 2 and 3
 #if !MICROPY_EMIT_CPYTHON
     emit_t *emit_bc = NULL;
diff --git a/py/emit.h b/py/emit.h
index f350f89343..47ef16256d 100644
--- a/py/emit.h
+++ b/py/emit.h
@@ -59,6 +59,13 @@ typedef enum {
 
 typedef struct _emit_t emit_t;
 
+typedef struct _mp_emit_method_table_id_ops_t {
+    void (*fast)(emit_t *emit, qstr qst, mp_uint_t local_num);
+    void (*deref)(emit_t *emit, qstr qst, mp_uint_t local_num);
+    void (*name)(emit_t *emit, qstr qst);
+    void (*global)(emit_t *emit, qstr qst);
+} mp_emit_method_table_id_ops_t;
+
 typedef struct _emit_method_table_t {
     void (*set_native_type)(emit_t *emit, mp_uint_t op, mp_uint_t arg1, qstr arg2);
     void (*start_pass)(emit_t *emit, pass_kind_t pass, scope_t *scope);
@@ -67,9 +74,9 @@ typedef struct _emit_method_table_t {
     void (*adjust_stack_size)(emit_t *emit, mp_int_t delta);
     void (*set_line_number)(emit_t *emit, mp_uint_t line);
 
-    void (*load_id)(emit_t *emit, qstr qst);
-    void (*store_id)(emit_t *emit, qstr qst);
-    void (*delete_id)(emit_t *emit, qstr qst);
+    mp_emit_method_table_id_ops_t load_id;
+    mp_emit_method_table_id_ops_t store_id;
+    mp_emit_method_table_id_ops_t delete_id;
 
     void (*label_assign)(emit_t *emit, mp_uint_t l);
     void (*import_name)(emit_t *emit, qstr qst);
@@ -80,24 +87,12 @@ typedef struct _emit_method_table_t {
     void (*load_const_str)(emit_t *emit, qstr qst, bool bytes);
     void (*load_const_obj)(emit_t *emit, void *obj);
     void (*load_null)(emit_t *emit);
-    void (*load_fast)(emit_t *emit, qstr qst, mp_uint_t local_num);
-    void (*load_deref)(emit_t *emit, qstr qst, mp_uint_t local_num);
-    void (*load_name)(emit_t *emit, qstr qst);
-    void (*load_global)(emit_t *emit, qstr qst);
     void (*load_attr)(emit_t *emit, qstr qst);
     void (*load_method)(emit_t *emit, qstr qst);
     void (*load_build_class)(emit_t *emit);
     void (*load_subscr)(emit_t *emit);
-    void (*store_fast)(emit_t *emit, qstr qst, mp_uint_t local_num);
-    void (*store_deref)(emit_t *emit, qstr qst, mp_uint_t local_num);
-    void (*store_name)(emit_t *emit, qstr qst);
-    void (*store_global)(emit_t *emit, qstr qst);
     void (*store_attr)(emit_t *emit, qstr qst);
     void (*store_subscr)(emit_t *emit);
-    void (*delete_fast)(emit_t *emit, qstr qst, mp_uint_t local_num);
-    void (*delete_deref)(emit_t *emit, qstr qst, mp_uint_t local_num);
-    void (*delete_name)(emit_t *emit, qstr qst);
-    void (*delete_global)(emit_t *emit, qstr qst);
     void (*delete_attr)(emit_t *emit, qstr qst);
     void (*delete_subscr)(emit_t *emit);
     void (*dup_top)(emit_t *emit);
@@ -160,9 +155,9 @@ typedef struct _emit_method_table_t {
 
 } emit_method_table_t;
 
-void emit_common_load_id(emit_t *emit, const emit_method_table_t *emit_method_table, scope_t *scope, qstr qst);
-void emit_common_store_id(emit_t *emit, const emit_method_table_t *emit_method_table, scope_t *scope, qstr qst);
-void emit_common_delete_id(emit_t *emit, const emit_method_table_t *emit_method_table, scope_t *scope, qstr qst);
+void mp_emit_common_get_id_for_load(scope_t *scope, qstr qst);
+void mp_emit_common_get_id_for_modification(scope_t *scope, qstr qst);
+void mp_emit_common_id_op(emit_t *emit, const mp_emit_method_table_id_ops_t *emit_method_table, scope_t *scope, qstr qst);
 
 extern const emit_method_table_t emit_pass1_method_table;
 extern const emit_method_table_t emit_cpython_method_table;
@@ -172,7 +167,6 @@ extern const emit_method_table_t emit_native_x86_method_table;
 extern const emit_method_table_t emit_native_thumb_method_table;
 extern const emit_method_table_t emit_native_arm_method_table;
 
-emit_t *emit_pass1_new(void);
 emit_t *emit_cpython_new(mp_uint_t max_num_labels);
 emit_t *emit_bc_new(mp_uint_t max_num_labels);
 emit_t *emit_native_x64_new(mp_uint_t max_num_labels);
@@ -180,7 +174,6 @@ emit_t *emit_native_x86_new(mp_uint_t max_num_labels);
 emit_t *emit_native_thumb_new(mp_uint_t max_num_labels);
 emit_t *emit_native_arm_new(mp_uint_t max_num_labels);
 
-void emit_pass1_free(emit_t *emit);
 void emit_bc_free(emit_t *emit);
 void emit_native_x64_free(emit_t *emit);
 void emit_native_x86_free(emit_t *emit);
diff --git a/py/emitbc.c b/py/emitbc.c
index 60da170fce..53437a8f86 100644
--- a/py/emitbc.c
+++ b/py/emitbc.c
@@ -402,18 +402,6 @@ STATIC void emit_bc_set_source_line(emit_t *emit, mp_uint_t source_line) {
 #endif
 }
 
-STATIC void emit_bc_load_id(emit_t *emit, qstr qst) {
-    emit_common_load_id(emit, &emit_bc_method_table, emit->scope, qst);
-}
-
-STATIC void emit_bc_store_id(emit_t *emit, qstr qst) {
-    emit_common_store_id(emit, &emit_bc_method_table, emit->scope, qst);
-}
-
-STATIC void emit_bc_delete_id(emit_t *emit, qstr qst) {
-    emit_common_delete_id(emit, &emit_bc_method_table, emit->scope, qst);
-}
-
 STATIC void emit_bc_pre(emit_t *emit, mp_int_t stack_size_delta) {
     assert((mp_int_t)emit->stack_size + stack_size_delta >= 0);
     emit->stack_size += stack_size_delta;
@@ -910,9 +898,24 @@ const emit_method_table_t emit_bc_method_table = {
     emit_bc_adjust_stack_size,
     emit_bc_set_source_line,
 
-    emit_bc_load_id,
-    emit_bc_store_id,
-    emit_bc_delete_id,
+    {
+        emit_bc_load_fast,
+        emit_bc_load_deref,
+        emit_bc_load_name,
+        emit_bc_load_global,
+    },
+    {
+        emit_bc_store_fast,
+        emit_bc_store_deref,
+        emit_bc_store_name,
+        emit_bc_store_global,
+    },
+    {
+        emit_bc_delete_fast,
+        emit_bc_delete_deref,
+        emit_bc_delete_name,
+        emit_bc_delete_global,
+    },
 
     emit_bc_label_assign,
     emit_bc_import_name,
@@ -923,24 +926,12 @@ const emit_method_table_t emit_bc_method_table = {
     emit_bc_load_const_str,
     emit_bc_load_const_obj,
     emit_bc_load_null,
-    emit_bc_load_fast,
-    emit_bc_load_deref,
-    emit_bc_load_name,
-    emit_bc_load_global,
     emit_bc_load_attr,
     emit_bc_load_method,
     emit_bc_load_build_class,
     emit_bc_load_subscr,
-    emit_bc_store_fast,
-    emit_bc_store_deref,
-    emit_bc_store_name,
-    emit_bc_store_global,
     emit_bc_store_attr,
     emit_bc_store_subscr,
-    emit_bc_delete_fast,
-    emit_bc_delete_deref,
-    emit_bc_delete_name,
-    emit_bc_delete_global,
     emit_bc_delete_attr,
     emit_bc_delete_subscr,
     emit_bc_dup_top,
diff --git a/py/emitcommon.c b/py/emitcommon.c
index 8011c0fb0b..7eda5e05fd 100644
--- a/py/emitcommon.c
+++ b/py/emitcommon.c
@@ -24,70 +24,72 @@
  * THE SOFTWARE.
  */
 
-#include <string.h>
-#include <stdint.h>
 #include <assert.h>
 
 #include "py/emit.h"
 
-#define EMIT(fun, ...) (emit_method_table->fun(emit, __VA_ARGS__))
-
-void emit_common_load_id(emit_t *emit, const emit_method_table_t *emit_method_table, scope_t *scope, qstr qst) {
-    // assumes pass is greater than 1, ie that all identifiers are defined in the scope
-
-    id_info_t *id = scope_find(scope, qst);
-    assert(id != NULL); // TODO can this ever fail?
-
-    // call the emit backend with the correct code
-    if (id == NULL || id->kind == ID_INFO_KIND_GLOBAL_IMPLICIT) {
-        EMIT(load_name, qst);
-    } else if (id->kind == ID_INFO_KIND_GLOBAL_EXPLICIT) {
-        EMIT(load_global, qst);
-    } else if (id->kind == ID_INFO_KIND_LOCAL) {
-        EMIT(load_fast, qst, id->local_num);
-    } else if (id->kind == ID_INFO_KIND_CELL || id->kind == ID_INFO_KIND_FREE) {
-        EMIT(load_deref, qst, id->local_num);
-    } else {
-        assert(0);
+void mp_emit_common_get_id_for_load(scope_t *scope, qstr qst) {
+    // name adding/lookup
+    bool added;
+    id_info_t *id = scope_find_or_add_id(scope, qst, &added);
+    if (added) {
+#if MICROPY_EMIT_CPYTHON
+        if (qst == MP_QSTR_super && scope->kind == SCOPE_FUNCTION) {
+            // special case, super is a global, and also counts as use of __class__
+            id->kind = ID_INFO_KIND_GLOBAL_EXPLICIT;
+            id_info_t *id2 = scope_find_local_in_parent(scope, MP_QSTR___class__);
+            if (id2 != NULL) {
+                id2 = scope_find_or_add_id(scope, MP_QSTR___class__, &added);
+                if (added) {
+                    id2->kind = ID_INFO_KIND_FREE;
+                    scope_close_over_in_parents(scope, MP_QSTR___class__);
+                }
+            }
+        } else
+#endif
+        {
+            id_info_t *id2 = scope_find_local_in_parent(scope, qst);
+            if (id2 != NULL && (id2->kind == ID_INFO_KIND_LOCAL || id2->kind == ID_INFO_KIND_CELL || id2->kind == ID_INFO_KIND_FREE)) {
+                id->kind = ID_INFO_KIND_FREE;
+                scope_close_over_in_parents(scope, qst);
+            } else {
+                id->kind = ID_INFO_KIND_GLOBAL_IMPLICIT;
+            }
+        }
     }
 }
 
-void emit_common_store_id(emit_t *emit, const emit_method_table_t *emit_method_table, scope_t *scope, qstr qst) {
-    // assumes pass is greater than 1, ie that all identifiers are defined in the scope
-
-    id_info_t *id = scope_find(scope, qst);
-    assert(id != NULL); // TODO can this ever fail?
-
-    // call the emit backend with the correct code
-    if (id == NULL || id->kind == ID_INFO_KIND_GLOBAL_IMPLICIT) {
-        EMIT(store_name, qst);
-    } else if (id->kind == ID_INFO_KIND_GLOBAL_EXPLICIT) {
-        EMIT(store_global, qst);
-    } else if (id->kind == ID_INFO_KIND_LOCAL) {
-        EMIT(store_fast, qst, id->local_num);
-    } else if (id->kind == ID_INFO_KIND_CELL || id->kind == ID_INFO_KIND_FREE) {
-        EMIT(store_deref, qst, id->local_num);
-    } else {
-        assert(0);
+void mp_emit_common_get_id_for_modification(scope_t *scope, qstr qst) {
+    // name adding/lookup
+    bool added;
+    id_info_t *id = scope_find_or_add_id(scope, qst, &added);
+    if (added) {
+        if (scope->kind == SCOPE_MODULE || scope->kind == SCOPE_CLASS) {
+            id->kind = ID_INFO_KIND_GLOBAL_IMPLICIT;
+        } else {
+            id->kind = ID_INFO_KIND_LOCAL;
+        }
+    } else if (scope->kind >= SCOPE_FUNCTION && scope->kind <= SCOPE_GEN_EXPR && id->kind == ID_INFO_KIND_GLOBAL_IMPLICIT) {
+        // rebind as a local variable
+        id->kind = ID_INFO_KIND_LOCAL;
     }
 }
 
-void emit_common_delete_id(emit_t *emit, const emit_method_table_t *emit_method_table, scope_t *scope, qstr qst) {
+void mp_emit_common_id_op(emit_t *emit, const mp_emit_method_table_id_ops_t *emit_method_table, scope_t *scope, qstr qst) {
     // assumes pass is greater than 1, ie that all identifiers are defined in the scope
 
     id_info_t *id = scope_find(scope, qst);
-    assert(id != NULL); // TODO can this ever fail?
+    assert(id != NULL);
 
     // call the emit backend with the correct code
-    if (id == NULL || id->kind == ID_INFO_KIND_GLOBAL_IMPLICIT) {
-        EMIT(delete_name, qst);
+    if (id->kind == ID_INFO_KIND_GLOBAL_IMPLICIT) {
+        emit_method_table->name(emit, qst);
     } else if (id->kind == ID_INFO_KIND_GLOBAL_EXPLICIT) {
-        EMIT(delete_global, qst);
+        emit_method_table->global(emit, qst);
     } else if (id->kind == ID_INFO_KIND_LOCAL) {
-        EMIT(delete_fast, qst, id->local_num);
-    } else if (id->kind == ID_INFO_KIND_CELL || id->kind == ID_INFO_KIND_FREE) {
-        EMIT(delete_deref, qst, id->local_num);
+        emit_method_table->fast(emit, qst, id->local_num);
     } else {
-        assert(0);
+        assert(id->kind == ID_INFO_KIND_CELL || id->kind == ID_INFO_KIND_FREE);
+        emit_method_table->deref(emit, qst, id->local_num);
     }
 }
diff --git a/py/emitcpy.c b/py/emitcpy.c
index be469f45d0..0e040b0e9e 100644
--- a/py/emitcpy.c
+++ b/py/emitcpy.c
@@ -86,18 +86,6 @@ STATIC void emit_cpy_adjust_stack_size(emit_t *emit, mp_int_t delta) {
 STATIC void emit_cpy_set_source_line(emit_t *emit, mp_uint_t source_line) {
 }
 
-STATIC void emit_cpy_load_id(emit_t *emit, qstr qst) {
-    emit_common_load_id(emit, &emit_cpython_method_table, emit->scope, qst);
-}
-
-STATIC void emit_cpy_store_id(emit_t *emit, qstr qst) {
-    emit_common_store_id(emit, &emit_cpython_method_table, emit->scope, qst);
-}
-
-STATIC void emit_cpy_delete_id(emit_t *emit, qstr qst) {
-    emit_common_delete_id(emit, &emit_cpython_method_table, emit->scope, qst);
-}
-
 // TODO: module-polymorphic function (read: name clash if made global)
 static void emit_pre(emit_t *emit, int stack_size_delta, int bytecode_size) {
     emit->stack_size += stack_size_delta;
@@ -809,9 +797,24 @@ const emit_method_table_t emit_cpython_method_table = {
     emit_cpy_adjust_stack_size,
     emit_cpy_set_source_line,
 
-    emit_cpy_load_id,
-    emit_cpy_store_id,
-    emit_cpy_delete_id,
+    {
+        emit_cpy_load_fast,
+        emit_cpy_load_deref,
+        emit_cpy_load_name,
+        emit_cpy_load_global,
+    },
+    {
+        emit_cpy_store_fast,
+        emit_cpy_store_deref,
+        emit_cpy_store_name,
+        emit_cpy_store_global,
+    },
+    {
+        emit_cpy_delete_fast,
+        emit_cpy_delete_deref,
+        emit_cpy_delete_name,
+        emit_cpy_delete_global,
+    },
 
     emit_cpy_label_assign,
     emit_cpy_import_name,
@@ -822,24 +825,12 @@ const emit_method_table_t emit_cpython_method_table = {
     emit_cpy_load_const_str,
     emit_cpy_load_const_obj,
     emit_cpy_load_null,
-    emit_cpy_load_fast,
-    emit_cpy_load_deref,
-    emit_cpy_load_name,
-    emit_cpy_load_global,
     emit_cpy_load_attr,
     emit_cpy_load_method,
     emit_cpy_load_build_class,
     emit_cpy_load_subscr,
-    emit_cpy_store_fast,
-    emit_cpy_store_deref,
-    emit_cpy_store_name,
-    emit_cpy_store_global,
     emit_cpy_store_attr,
     emit_cpy_store_subscr,
-    emit_cpy_delete_fast,
-    emit_cpy_delete_deref,
-    emit_cpy_delete_name,
-    emit_cpy_delete_global,
     emit_cpy_delete_attr,
     emit_cpy_delete_subscr,
     emit_cpy_dup_top,
diff --git a/py/emitnative.c b/py/emitnative.c
index dcf6822ffc..d16b919dc1 100644
--- a/py/emitnative.c
+++ b/py/emitnative.c
@@ -1051,18 +1051,6 @@ STATIC void emit_get_stack_pointer_to_reg_for_push(emit_t *emit, mp_uint_t reg_d
     adjust_stack(emit, n_push);
 }
 
-STATIC void emit_native_load_id(emit_t *emit, qstr qst) {
-    emit_common_load_id(emit, &EXPORT_FUN(method_table), emit->scope, qst);
-}
-
-STATIC void emit_native_store_id(emit_t *emit, qstr qst) {
-    emit_common_store_id(emit, &EXPORT_FUN(method_table), emit->scope, qst);
-}
-
-STATIC void emit_native_delete_id(emit_t *emit, qstr qst) {
-    emit_common_delete_id(emit, &EXPORT_FUN(method_table), emit->scope, qst);
-}
-
 STATIC void emit_native_label_assign(emit_t *emit, mp_uint_t l) {
     DEBUG_printf("label_assign(" UINT_FMT ")\n", l);
     emit_native_pre(emit);
@@ -2283,9 +2271,24 @@ const emit_method_table_t EXPORT_FUN(method_table) = {
     emit_native_adjust_stack_size,
     emit_native_set_source_line,
 
-    emit_native_load_id,
-    emit_native_store_id,
-    emit_native_delete_id,
+    {
+        emit_native_load_fast,
+        emit_native_load_deref,
+        emit_native_load_name,
+        emit_native_load_global,
+    },
+    {
+        emit_native_store_fast,
+        emit_native_store_deref,
+        emit_native_store_name,
+        emit_native_store_global,
+    },
+    {
+        emit_native_delete_fast,
+        emit_native_delete_deref,
+        emit_native_delete_name,
+        emit_native_delete_global,
+    },
 
     emit_native_label_assign,
     emit_native_import_name,
@@ -2296,24 +2299,12 @@ const emit_method_table_t EXPORT_FUN(method_table) = {
     emit_native_load_const_str,
     emit_native_load_const_obj,
     emit_native_load_null,
-    emit_native_load_fast,
-    emit_native_load_deref,
-    emit_native_load_name,
-    emit_native_load_global,
     emit_native_load_attr,
     emit_native_load_method,
     emit_native_load_build_class,
     emit_native_load_subscr,
-    emit_native_store_fast,
-    emit_native_store_deref,
-    emit_native_store_name,
-    emit_native_store_global,
     emit_native_store_attr,
     emit_native_store_subscr,
-    emit_native_delete_fast,
-    emit_native_delete_deref,
-    emit_native_delete_name,
-    emit_native_delete_global,
     emit_native_delete_attr,
     emit_native_delete_subscr,
     emit_native_dup_top,
diff --git a/py/emitpass1.c b/py/emitpass1.c
index b31973b7df..995aceddef 100644
--- a/py/emitpass1.c
+++ b/py/emitpass1.c
@@ -28,30 +28,12 @@
 
 #include "py/emit.h"
 
-struct _emit_t {
-    scope_t *scope;
-};
-
-emit_t *emit_pass1_new(void) {
-    emit_t *emit = m_new(emit_t, 1);
-    return emit;
-}
-
-void emit_pass1_free(emit_t *emit) {
-    m_del_obj(emit_t, emit);
-}
-
 STATIC void emit_pass1_dummy(emit_t *emit) {
     (void)emit;
 }
 
 STATIC void emit_pass1_start_pass(emit_t *emit, pass_kind_t pass, scope_t *scope) {
     assert(pass == MP_PASS_SCOPE);
-    emit->scope = scope;
-}
-
-STATIC void emit_pass1_end_pass(emit_t *emit) {
-    (void)emit;
 }
 
 STATIC bool emit_pass1_last_emit_was_return_value(emit_t *emit) {
@@ -59,79 +41,32 @@ STATIC bool emit_pass1_last_emit_was_return_value(emit_t *emit) {
     return false;
 }
 
-STATIC void emit_pass1_load_id(emit_t *emit, qstr qst) {
-    // name adding/lookup
-    bool added;
-    id_info_t *id = scope_find_or_add_id(emit->scope, qst, &added);
-    if (added) {
-#if MICROPY_EMIT_CPYTHON
-        if (qst == MP_QSTR_super && emit->scope->kind == SCOPE_FUNCTION) {
-            // special case, super is a global, and also counts as use of __class__
-            id->kind = ID_INFO_KIND_GLOBAL_EXPLICIT;
-            id_info_t *id2 = scope_find_local_in_parent(emit->scope, MP_QSTR___class__);
-            if (id2 != NULL) {
-                id2 = scope_find_or_add_id(emit->scope, MP_QSTR___class__, &added);
-                if (added) {
-                    id2->kind = ID_INFO_KIND_FREE;
-                    scope_close_over_in_parents(emit->scope, MP_QSTR___class__);
-                }
-            }
-        } else
-#endif
-        {
-            id_info_t *id2 = scope_find_local_in_parent(emit->scope, qst);
-            if (id2 != NULL && (id2->kind == ID_INFO_KIND_LOCAL || id2->kind == ID_INFO_KIND_CELL || id2->kind == ID_INFO_KIND_FREE)) {
-                id->kind = ID_INFO_KIND_FREE;
-                scope_close_over_in_parents(emit->scope, qst);
-            } else {
-                id->kind = ID_INFO_KIND_GLOBAL_IMPLICIT;
-            }
-        }
-    }
-}
-
-STATIC id_info_t *get_id_for_modification(scope_t *scope, qstr qst) {
-    // name adding/lookup
-    bool added;
-    id_info_t *id = scope_find_or_add_id(scope, qst, &added);
-    if (added) {
-        if (scope->kind == SCOPE_MODULE || scope->kind == SCOPE_CLASS) {
-            id->kind = ID_INFO_KIND_GLOBAL_IMPLICIT;
-        } else {
-            id->kind = ID_INFO_KIND_LOCAL;
-        }
-    } else if (scope->kind >= SCOPE_FUNCTION && scope->kind <= SCOPE_GEN_EXPR && id->kind == ID_INFO_KIND_GLOBAL_IMPLICIT) {
-        // rebind as a local variable
-        id->kind = ID_INFO_KIND_LOCAL;
-    }
-
-    assert(id != NULL); // TODO can this ever fail?
-
-    return id;
-}
-
-STATIC void emit_pass1_store_id(emit_t *emit, qstr qst) {
-    get_id_for_modification(emit->scope, qst);
-}
-
-STATIC void emit_pass1_delete_id(emit_t *emit, qstr qst) {
-    id_info_t *id = get_id_for_modification(emit->scope, qst);
-    // this flag is unused
-    //id->flags |= ID_FLAG_IS_DELETED;
-    (void)id; // suppress compiler warning
-}
-
 const emit_method_table_t emit_pass1_method_table = {
     (void*)emit_pass1_dummy,
     emit_pass1_start_pass,
-    emit_pass1_end_pass,
+    emit_pass1_dummy,
     emit_pass1_last_emit_was_return_value,
     (void*)emit_pass1_dummy,
     (void*)emit_pass1_dummy,
 
-    emit_pass1_load_id,
-    emit_pass1_store_id,
-    emit_pass1_delete_id,
+    {
+        (void*)emit_pass1_dummy,
+        (void*)emit_pass1_dummy,
+        (void*)emit_pass1_dummy,
+        (void*)emit_pass1_dummy,
+    },
+    {
+        (void*)emit_pass1_dummy,
+        (void*)emit_pass1_dummy,
+        (void*)emit_pass1_dummy,
+        (void*)emit_pass1_dummy,
+    },
+    {
+        (void*)emit_pass1_dummy,
+        (void*)emit_pass1_dummy,
+        (void*)emit_pass1_dummy,
+        (void*)emit_pass1_dummy,
+    },
 
     (void*)emit_pass1_dummy,
     (void*)emit_pass1_dummy,
@@ -178,18 +113,6 @@ const emit_method_table_t emit_pass1_method_table = {
     (void*)emit_pass1_dummy,
     (void*)emit_pass1_dummy,
     (void*)emit_pass1_dummy,
-    (void*)emit_pass1_dummy,
-    (void*)emit_pass1_dummy,
-    (void*)emit_pass1_dummy,
-    (void*)emit_pass1_dummy,
-    (void*)emit_pass1_dummy,
-    (void*)emit_pass1_dummy,
-    (void*)emit_pass1_dummy,
-    (void*)emit_pass1_dummy,
-    (void*)emit_pass1_dummy,
-    (void*)emit_pass1_dummy,
-    (void*)emit_pass1_dummy,
-    (void*)emit_pass1_dummy,
     #if MICROPY_PY_BUILTINS_SET
     (void*)emit_pass1_dummy,
     (void*)emit_pass1_dummy,