diff --git a/py/Makefile b/py/Makefile
index 4d36f3c97..0f4483d6a 100644
--- a/py/Makefile
+++ b/py/Makefile
@@ -1,5 +1,5 @@
 CC = gcc
-CFLAGS = -Wall -ansi -std=gnu99 -Os -DEMIT_ENABLE_CPY -DEMIT_ENABLE_X64 -DEMIT_ENABLE_THUMB #-DNDEBUG
+CFLAGS = -Wall -ansi -std=gnu99 -Os -DEMIT_ENABLE_CPY -DEMIT_ENABLE_THUMB #-DNDEBUG
 LDFLAGS =
 
 SRC = \
@@ -16,8 +16,6 @@ SRC = \
 	emitcpy.c \
 	emitbc.c \
 	asmx64.c \
-	emitx64.c \
-	emitthumb.c \
 	asmthumb.c \
 	emitinlinethumb.c \
 	runtime.c \
@@ -26,7 +24,7 @@ SRC = \
 
 SRC_ASM = \
 
-OBJ = $(SRC:.c=.o) $(SRC_ASM:.s=.o)
+OBJ = $(SRC:.c=.o) $(SRC_ASM:.s=.o) emitnx64.o emitnthumb.o
 LIB =
 PROG = py
 
@@ -36,15 +34,19 @@ $(PROG): $(OBJ)
 runtime.o: runtime.c
 	$(CC) $(CFLAGS) -O3 -c -o $@ $<
 
-bc.o: bc.c
+vm.o: vm.c
 	$(CC) $(CFLAGS) -O3 -c -o $@ $<
 
 parse.o: grammar.h
 compile.o: grammar.h
 emitcpy.o: emit.h
 emitbc.o: emit.h
-emitx64.o: emit.h
-emitthumb.o: emit.h
+
+emitnx64.o: emitnative.c emit.h
+	$(CC) $(CFLAGS) -DN_X64 -c -o $@ $<
+
+emitnthumb.o: emitnative.c emit.h
+	$(CC) $(CFLAGS) -DN_THUMB -c -o $@ $<
 
 clean:
 	/bin/rm $(OBJ)
diff --git a/py/compile.c b/py/compile.c
index 7624b03e3..f4a5886b0 100644
--- a/py/compile.c
+++ b/py/compile.c
@@ -2706,10 +2706,10 @@ void py_compile(py_parse_node_t pn) {
                 case EMIT_OPT_NATIVE_PYTHON:
                 case EMIT_OPT_VIPER:
                     if (emit_native == NULL) {
-                        emit_native = emit_x64_new(max_num_labels);
+                        emit_native = emit_native_x64_new(max_num_labels);
                     }
                     comp->emit = emit_native;
-                    comp->emit_method_table = &emit_x64_method_table;
+                    comp->emit_method_table = &emit_native_x64_method_table;
                     comp->emit_method_table->set_native_types(comp->emit, s->emit_options == EMIT_OPT_VIPER);
                     break;
 
diff --git a/py/emit.h b/py/emit.h
index 74795b5ab..93c7298d3 100644
--- a/py/emit.h
+++ b/py/emit.h
@@ -119,17 +119,15 @@ void emit_common_delete_id(emit_t *emit, const emit_method_table_t *emit_method_
 extern const emit_method_table_t emit_pass1_method_table;
 extern const emit_method_table_t emit_cpython_method_table;
 extern const emit_method_table_t emit_bc_method_table;
-extern const emit_method_table_t emit_x64_method_table;
-extern const emit_method_table_t emit_viper_x64_method_table;
-extern const emit_method_table_t emit_thumb_method_table;
+extern const emit_method_table_t emit_native_x64_method_table;
+extern const emit_method_table_t emit_native_thumb_method_table;
 
 emit_t *emit_pass1_new(qstr qstr___class__);
 void emit_pass1_free(emit_t *emit);
 emit_t *emit_cpython_new(uint max_num_labels);
 emit_t *emit_bc_new(uint max_num_labels);
-emit_t *emit_x64_new(uint max_num_labels);
-emit_t *emit_viper_x64_new(uint max_num_labels);
-emit_t *emit_thumb_new(uint max_num_labels);
+emit_t *emit_native_x64_new(uint max_num_labels);
+emit_t *emit_native_thumb_new(uint max_num_labels);
 
 typedef struct _emit_inline_asm_t emit_inline_asm_t;
 
diff --git a/py/emitnative.c b/py/emitnative.c
new file mode 100644
index 000000000..51ba1ce59
--- /dev/null
+++ b/py/emitnative.c
@@ -0,0 +1,1179 @@
+// Essentially normal Python has 1 type: Python objects
+// Viper has more than 1 type, and is just a more complicated (a superset of) Python.
+// If you declare everything in Viper as a Python object (ie omit type decls) then
+// it should in principle be exactly the same as Python native.
+// Having types means having more opcodes, like binary_op_nat_nat, binary_op_nat_obj etc.
+// In practice we won't have a VM but rather do this in asm which is actually very minimal.
+
+// Because it breaks strict Python equivalence it should be a completely separate
+// decorator.  It breaks equivalence because overflow on integers wraps around.
+// It shouldn't break equivalence if you don't use the new types, but since the
+// type decls might be used in normal Python for other reasons, it's probably safest,
+// cleanest and clearest to make it a separate decorator.
+
+// Actually, it does break equivalence because integers default to native integers,
+// not Python objects.
+
+// for x in l[0:8]: can be compiled into a native loop if l has pointer type
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+#include "misc.h"
+#include "lexer.h"
+#include "machine.h"
+#include "parse.h"
+#include "scope.h"
+#include "runtime.h"
+#include "emit.h"
+
+// select a machine architecture
+#if 0
+#if defined(EMIT_ENABLE_NATIVE_X64)
+#define N_X64
+#elif defined(EMIT_ENABLE_NATIVE_THUMB)
+#define N_THUMB
+#endif
+#endif
+
+// wrapper around everything in this file
+#if defined(N_X64) || defined(N_THUMB)
+
+#if defined(N_X64)
+
+// x64 specific stuff
+
+#include "asmx64.h"
+
+#define REG_LOCAL_1 (REG_RBX)
+#define REG_LOCAL_NUM (1)
+
+#define EXPORT_FUN(name) emit_native_x64_##name
+
+#define REG_TEMP0 (REG_RAX)
+#define REG_TEMP1 (REG_RDI)
+#define REG_TEMP2 (REG_RSI)
+#define ASM_MOV_REG_TO_LOCAL(reg, local_num) asm_x64_mov_r64_to_local(emit->as, (reg), (local_num))
+#define ASM_MOV_IMM_TO_REG(imm, reg) asm_x64_mov_i64_to_r64_optimised(emit->as, (imm), (reg))
+#define ASM_MOV_IMM_TO_LOCAL(imm, local_num) do { asm_x64_mov_i64_to_r64_optimised(emit->as, (imm), REG_RAX); asm_x64_mov_r64_to_local(emit->as, REG_RAX, (local_num)); } while (false)
+#define ASM_MOV_LOCAL_TO_REG(local_num, reg) asm_x64_mov_local_to_r64(emit->as, (local_num), (reg))
+#define ASM_MOV_REG_TO_REG(reg_src, reg_dest) asm_x64_mov_r64_to_r64(emit->as, (reg_src), (reg_dest))
+#define ASM_MOV_LOCAL_ADDR_TO_REG(local_num, reg) asm_x64_mov_local_addr_to_r64(emit->as, (local_num), (reg))
+
+#elif defined(N_THUMB)
+
+// thumb specific stuff
+
+#include "asmthumb.h"
+
+#define REG_LOCAL_1 (REG_R4)
+#define REG_LOCAL_2 (REG_R5)
+#define REG_LOCAL_3 (REG_R6)
+#define REG_LOCAL_NUM (3)
+
+#define EXPORT_FUN(name) emit_native_thumb_##name
+
+#define REG_TEMP0 (REG_R0)
+#define REG_TEMP1 (REG_R1)
+#define REG_TEMP2 (REG_R2)
+#define ASM_MOV_REG_TO_LOCAL(reg, local_num) asm_thumb_mov_local_reg(emit->as, (local_num), (reg))
+#define ASM_MOV_IMM_TO_REG(imm, reg) asm_thumb_mov_reg_i32_optimised(emit->as, (reg), (imm))
+#define ASM_MOV_IMM_TO_LOCAL(imm, local_num) do { asm_thumb_mov_reg_i32_optimised(emit->as, REG_R0, (imm)); asm_thumb_mov_local_reg(emit->as, (local_num), REG_R0); } while (false)
+#define ASM_MOV_LOCAL_TO_REG(local_num, reg) asm_thumb_mov_reg_local(emit->as, (reg), (local_num))
+#define ASM_MOV_REG_TO_REG(reg_src, reg_dest) asm_thumb_mov_reg_reg(emit->as, (reg_dest), (reg_src))
+#define ASM_MOV_LOCAL_ADDR_TO_REG(local_num, reg) asm_thumb_mov_reg_local_addr(emit->as, (reg), (local_num))
+
+#endif
+
+typedef enum {
+    NEED_TO_PUSH_NOTHING,
+    NEED_TO_PUSH_REG,
+    NEED_TO_PUSH_IMM,
+} need_to_push_t;
+
+typedef enum {
+    VTYPE_UNBOUND,
+    VTYPE_PYOBJ,
+    VTYPE_BOOL,
+    VTYPE_INT,
+    VTYPE_PTR,
+    VTYPE_PTR_NONE,
+    VTYPE_BUILTIN_V_INT,
+} vtype_kind_t;
+
+struct _emit_t {
+    int pass;
+
+    bool do_viper_types;
+    int all_vtype_alloc;
+    vtype_kind_t *all_vtype;
+    vtype_kind_t *local_vtype;
+    vtype_kind_t *stack_vtype;
+    int stack_start;
+    int stack_size;
+
+    bool last_emit_was_return_value;
+
+    need_to_push_t need_to_push;
+    vtype_kind_t last_vtype;
+    int last_reg;
+    int64_t last_imm;
+
+    scope_t *scope;
+
+#if defined(N_X64)
+    asm_x64_t *as;
+#elif defined(N_THUMB)
+    asm_thumb_t *as;
+#endif
+};
+
+emit_t *EXPORT_FUN(new)(uint max_num_labels) {
+    emit_t *emit = m_new(emit_t, 1);
+    emit->do_viper_types = false;
+    emit->all_vtype = NULL;
+#if defined(N_X64)
+    emit->as = asm_x64_new(max_num_labels);
+#elif defined(N_THUMB)
+    emit->as = asm_thumb_new(max_num_labels);
+#endif
+    return emit;
+}
+
+static void emit_native_set_viper_types(emit_t *emit, bool do_viper_types) {
+    emit->do_viper_types = do_viper_types;
+}
+
+static void emit_native_start_pass(emit_t *emit, pass_kind_t pass, scope_t *scope) {
+    emit->pass = pass;
+    emit->stack_start = 0;
+    emit->stack_size = 0;
+    emit->last_emit_was_return_value = false;
+    emit->need_to_push = NEED_TO_PUSH_NOTHING;
+    emit->scope = scope;
+
+    if (emit->all_vtype == NULL) {
+        emit->all_vtype_alloc = scope->num_locals + scope->stack_size + 100; // XXX don't know stack size on entry, should be maximum over all scopes
+        emit->all_vtype = m_new(vtype_kind_t, emit->all_vtype_alloc);
+        emit->local_vtype = emit->all_vtype;
+        emit->stack_vtype = emit->all_vtype + scope->num_locals;
+    }
+
+    if (emit->do_viper_types) {
+        for (int i = 0; i < emit->all_vtype_alloc; i++) {
+            emit->all_vtype[i] = VTYPE_UNBOUND;
+        }
+        // TODO set types of arguments based on type signature
+    } else {
+        for (int i = 0; i < emit->all_vtype_alloc; i++) {
+            emit->all_vtype[i] = VTYPE_PYOBJ;
+        }
+    }
+
+#if defined(N_X64)
+    asm_x64_start_pass(emit->as, pass);
+#elif defined(N_THUMB)
+    asm_thumb_start_pass(emit->as, pass);
+#endif
+
+    // entry to function
+    int num_locals = 0;
+    if (pass > PASS_1) {
+        num_locals = scope->num_locals - REG_LOCAL_NUM;
+        if (num_locals < 0) {
+            num_locals = 0;
+        }
+        emit->stack_start = num_locals;
+        num_locals += scope->stack_size;
+    }
+#if defined(N_X64)
+    asm_x64_entry(emit->as, num_locals);
+#elif defined(N_THUMB)
+    asm_thumb_entry(emit->as, num_locals);
+#endif
+
+    // initialise locals from parameters
+#if defined(N_X64)
+    for (int i = 0; i < scope->num_params; i++) {
+        if (i == 0) {
+            asm_x64_mov_r64_to_r64(emit->as, REG_ARG_1, REG_LOCAL_1);
+        } else if (i == 1) {
+            asm_x64_mov_r64_to_local(emit->as, REG_ARG_2, i - 1);
+        } else if (i == 2) {
+            asm_x64_mov_r64_to_local(emit->as, REG_ARG_3, i - 1);
+        } else {
+            // TODO not implemented
+            assert(0);
+        }
+    }
+#elif defined(N_THUMB)
+    for (int i = 0; i < scope->num_params; i++) {
+        if (i == 0) {
+            asm_thumb_mov_reg_reg(emit->as, REG_LOCAL_1, REG_ARG_1);
+        } else if (i == 1) {
+            asm_thumb_mov_reg_reg(emit->as, REG_LOCAL_2, REG_ARG_2);
+        } else if (i == 2) {
+            asm_thumb_mov_reg_reg(emit->as, REG_LOCAL_3, REG_ARG_3);
+        } else if (i == 3) {
+            asm_thumb_mov_local_reg(emit->as, i - REG_LOCAL_NUM, REG_ARG_4);
+        } else {
+            // TODO not implemented
+            assert(0);
+        }
+    }
+
+    asm_thumb_mov_reg_i32(emit->as, REG_R7, (machine_uint_t)rt_fun_table);
+#endif
+}
+
+static void emit_native_end_pass(emit_t *emit) {
+#if defined(N_X64)
+    if (!emit->last_emit_was_return_value) {
+        asm_x64_exit(emit->as);
+    }
+    asm_x64_end_pass(emit->as);
+#elif defined(N_THUMB)
+    if (!emit->last_emit_was_return_value) {
+        asm_thumb_exit(emit->as);
+    }
+    asm_thumb_end_pass(emit->as);
+#endif
+
+    // check stack is back to zero size
+    if (emit->stack_size != 0) {
+        printf("ERROR: stack size not back to zero; got %d\n", emit->stack_size);
+    }
+
+    if (emit->pass == PASS_3) {
+#if defined(N_X64)
+        py_fun_t f = asm_x64_get_code(emit->as);
+        rt_assign_native_code(emit->scope->unique_code_id, f, asm_x64_get_code_size(emit->as), emit->scope->num_params);
+#elif defined(N_THUMB)
+        py_fun_t f = asm_thumb_get_code(emit->as);
+        rt_assign_native_code(emit->scope->unique_code_id, f, asm_thumb_get_code_size(emit->as), emit->scope->num_params);
+#endif
+    }
+}
+
+static bool emit_native_last_emit_was_return_value(emit_t *emit) {
+    return emit->last_emit_was_return_value;
+}
+
+static int emit_native_get_stack_size(emit_t *emit) {
+    return emit->stack_size;
+}
+
+static void emit_native_set_stack_size(emit_t *emit, int size) {
+    emit->stack_size = size;
+}
+
+static void adjust_stack(emit_t *emit, int stack_size_delta) {
+    emit->stack_size += stack_size_delta;
+    assert(emit->stack_size >= 0);
+    if (emit->pass > PASS_1 && emit->stack_size > emit->scope->stack_size) {
+        emit->scope->stack_size = emit->stack_size;
+    }
+}
+
+static void stack_settle(emit_t *emit) {
+    switch (emit->need_to_push) {
+        case NEED_TO_PUSH_NOTHING:
+            break;
+
+        case NEED_TO_PUSH_REG:
+            emit->stack_vtype[emit->stack_size] = emit->last_vtype;
+            ASM_MOV_REG_TO_LOCAL(emit->last_reg, emit->stack_start + emit->stack_size);
+            adjust_stack(emit, 1);
+            break;
+
+        case NEED_TO_PUSH_IMM:
+            emit->stack_vtype[emit->stack_size] = emit->last_vtype;
+            ASM_MOV_IMM_TO_LOCAL(emit->last_imm, emit->stack_start + emit->stack_size);
+            adjust_stack(emit, 1);
+            break;
+    }
+    emit->need_to_push = NEED_TO_PUSH_NOTHING;
+}
+
+static void emit_pre_raw(emit_t *emit, int stack_size_delta) {
+    adjust_stack(emit, stack_size_delta);
+    emit->last_emit_was_return_value = false;
+}
+
+static void emit_pre(emit_t *emit) {
+    stack_settle(emit);
+    emit_pre_raw(emit, 0);
+}
+
+static vtype_kind_t peek_vtype(emit_t *emit) {
+    switch (emit->need_to_push) {
+        case NEED_TO_PUSH_NOTHING:
+            return emit->stack_vtype[emit->stack_size - 1];
+
+        case NEED_TO_PUSH_REG:
+        case NEED_TO_PUSH_IMM:
+            return emit->last_vtype;
+
+        default:
+            assert(0);
+            return VTYPE_UNBOUND;
+    }
+}
+
+static void emit_pre_pop_reg(emit_t *emit, vtype_kind_t *vtype, int reg_dest) {
+    switch (emit->need_to_push) {
+        case NEED_TO_PUSH_NOTHING:
+            *vtype = emit->stack_vtype[emit->stack_size - 1];
+            ASM_MOV_LOCAL_TO_REG(emit->stack_start + emit->stack_size - 1, reg_dest);
+            emit_pre_raw(emit, -1);
+            break;
+
+        case NEED_TO_PUSH_REG:
+            emit_pre_raw(emit, 0);
+            *vtype = emit->last_vtype;
+            if (emit->last_reg != reg_dest) {
+                ASM_MOV_REG_TO_REG(emit->last_reg, reg_dest);
+            }
+            break;
+
+        case NEED_TO_PUSH_IMM:
+            emit_pre_raw(emit, 0);
+            *vtype = emit->last_vtype;
+            ASM_MOV_IMM_TO_REG(emit->last_imm, reg_dest);
+            break;
+    }
+    emit->need_to_push = NEED_TO_PUSH_NOTHING;
+}
+
+static void emit_pre_pop_reg_reg(emit_t *emit, vtype_kind_t *vtypea, int rega, vtype_kind_t *vtypeb, int regb) {
+    emit_pre_pop_reg(emit, vtypea, rega);
+    *vtypeb = emit->stack_vtype[emit->stack_size - 1];
+    ASM_MOV_LOCAL_TO_REG(emit->stack_start + emit->stack_size - 1, regb);
+    adjust_stack(emit, -1);
+}
+
+static void emit_pre_pop_reg_reg_reg(emit_t *emit, vtype_kind_t *vtypea, int rega, vtype_kind_t *vtypeb, int regb, vtype_kind_t *vtypec, int regc) {
+    emit_pre_pop_reg(emit, vtypea, rega);
+    *vtypeb = emit->stack_vtype[emit->stack_size - 1];
+    *vtypec = emit->stack_vtype[emit->stack_size - 2];
+    ASM_MOV_LOCAL_TO_REG(emit->stack_start + emit->stack_size - 1, regb);
+    ASM_MOV_LOCAL_TO_REG(emit->stack_start + emit->stack_size - 2, regc);
+    adjust_stack(emit, -2);
+}
+
+static void emit_post(emit_t *emit) {
+}
+
+static void emit_post_push_reg(emit_t *emit, vtype_kind_t vtype, int reg) {
+    emit->need_to_push = NEED_TO_PUSH_REG;
+    emit->last_vtype = vtype;
+    emit->last_reg = reg;
+}
+
+static void emit_post_push_imm(emit_t *emit, vtype_kind_t vtype, machine_int_t imm) {
+    emit->need_to_push = NEED_TO_PUSH_IMM;
+    emit->last_vtype = vtype;
+    emit->last_imm = imm;
+}
+
+static void emit_post_push_reg_reg(emit_t *emit, vtype_kind_t vtypea, int rega, vtype_kind_t vtypeb, int regb) {
+    emit->stack_vtype[emit->stack_size] = vtypea;
+    ASM_MOV_REG_TO_LOCAL(rega, emit->stack_start + emit->stack_size);
+    emit->need_to_push = NEED_TO_PUSH_REG;
+    emit->last_vtype = vtypeb;
+    emit->last_reg = regb;
+    adjust_stack(emit, 1);
+}
+
+static void emit_post_push_reg_reg_reg(emit_t *emit, vtype_kind_t vtypea, int rega, vtype_kind_t vtypeb, int regb, vtype_kind_t vtypec, int regc) {
+    emit->stack_vtype[emit->stack_size] = vtypea;
+    emit->stack_vtype[emit->stack_size + 1] = vtypeb;
+    emit->stack_vtype[emit->stack_size + 2] = vtypec;
+    ASM_MOV_REG_TO_LOCAL(rega, emit->stack_start + emit->stack_size);
+    ASM_MOV_REG_TO_LOCAL(regb, emit->stack_start + emit->stack_size + 1);
+    ASM_MOV_REG_TO_LOCAL(regc, emit->stack_start + emit->stack_size + 2);
+    adjust_stack(emit, 3);
+}
+
+static void emit_post_push_reg_reg_reg_reg(emit_t *emit, vtype_kind_t vtypea, int rega, vtype_kind_t vtypeb, int regb, vtype_kind_t vtypec, int regc, vtype_kind_t vtyped, int regd) {
+    emit->stack_vtype[emit->stack_size] = vtypea;
+    emit->stack_vtype[emit->stack_size + 1] = vtypeb;
+    emit->stack_vtype[emit->stack_size + 2] = vtypec;
+    emit->stack_vtype[emit->stack_size + 3] = vtyped;
+    ASM_MOV_REG_TO_LOCAL(rega, emit->stack_start + emit->stack_size);
+    ASM_MOV_REG_TO_LOCAL(regb, emit->stack_start + emit->stack_size + 1);
+    ASM_MOV_REG_TO_LOCAL(regc, emit->stack_start + emit->stack_size + 2);
+    ASM_MOV_REG_TO_LOCAL(regd, emit->stack_start + emit->stack_size + 3);
+    adjust_stack(emit, 4);
+}
+
+// vtype of all n_pop objects is VTYPE_PYOBJ
+static void emit_get_stack_pointer_to_reg_for_pop(emit_t *emit, int reg_dest, int n_pop) {
+    ASM_MOV_LOCAL_ADDR_TO_REG(emit->stack_start + emit->stack_size - 1, reg_dest);
+    adjust_stack(emit, -n_pop);
+}
+
+// vtype of all n_push objects is VTYPE_PYOBJ
+static void emit_get_stack_pointer_to_reg_for_push(emit_t *emit, int reg_dest, int n_push) {
+    for (int i = 0; i < n_push; i++) {
+        emit->stack_vtype[emit->stack_size + i] = VTYPE_PYOBJ;
+    }
+    ASM_MOV_LOCAL_ADDR_TO_REG(emit->stack_start + emit->stack_size + n_push - 1, reg_dest);
+    adjust_stack(emit, n_push);
+}
+
+static void emit_call(emit_t *emit, rt_fun_kind_t fun_kind, void *fun) {
+#if defined(N_X64)
+    asm_x64_call_ind(emit->as, fun, REG_RAX);
+#elif defined(N_THUMB)
+    asm_thumb_bl_ind(emit->as, rt_fun_table[fun_kind], fun_kind, REG_R3);
+#endif
+}
+
+static void emit_call_with_imm_arg(emit_t *emit, rt_fun_kind_t fun_kind, void *fun, machine_int_t arg_val, int arg_reg) {
+    ASM_MOV_IMM_TO_REG(arg_val, arg_reg);
+    emit_call(emit, fun_kind, fun);
+}
+
+static void emit_native_load_id(emit_t *emit, qstr qstr) {
+    // check for built-ins
+    if (strcmp(qstr_str(qstr), "v_int") == 0) {
+        emit_pre(emit);
+        //emit_post_push_blank(emit, VTYPE_BUILTIN_V_INT);
+
+    // not a built-in, so do usual thing
+    } else {
+        emit_common_load_id(emit, &EXPORT_FUN(method_table), emit->scope, qstr);
+    }
+}
+
+static void emit_native_store_id(emit_t *emit, qstr qstr) {
+    // TODO check for built-ins and disallow
+    emit_common_store_id(emit, &EXPORT_FUN(method_table), emit->scope, qstr);
+}
+
+static void emit_native_delete_id(emit_t *emit, qstr qstr) {
+    // TODO check for built-ins and disallow
+    emit_common_delete_id(emit, &EXPORT_FUN(method_table), emit->scope, qstr);
+}
+
+static void emit_native_label_assign(emit_t *emit, int l) {
+#if defined(N_X64)
+    asm_x64_label_assign(emit->as, l);
+#elif defined(N_THUMB)
+    asm_thumb_label_assign(emit->as, l);
+#endif
+}
+
+static void emit_native_import_name(emit_t *emit, qstr qstr) {
+    // not implemented
+    assert(0);
+}
+
+static void emit_native_import_from(emit_t *emit, qstr qstr) {
+    // not implemented
+    assert(0);
+}
+
+static void emit_native_import_star(emit_t *emit) {
+    // not implemented
+    assert(0);
+}
+
+static void emit_native_load_const_tok(emit_t *emit, py_token_kind_t tok) {
+    emit_pre(emit);
+    int vtype;
+    machine_uint_t val;
+    if (emit->do_viper_types) {
+        switch (tok) {
+            case PY_TOKEN_KW_NONE: vtype = VTYPE_PTR_NONE; val = 0; break;
+            case PY_TOKEN_KW_FALSE: vtype = VTYPE_BOOL; val = 0; break;
+            case PY_TOKEN_KW_TRUE: vtype = VTYPE_BOOL; val = 1; break;
+            default: assert(0); vtype = 0; val = 0; // shouldn't happen
+        }
+    } else {
+        vtype = VTYPE_PYOBJ;
+        switch (tok) {
+            case PY_TOKEN_KW_NONE: val = (machine_uint_t)py_const_none; break;
+            case PY_TOKEN_KW_FALSE: val = (machine_uint_t)py_const_false; break;
+            case PY_TOKEN_KW_TRUE: val = (machine_uint_t)py_const_true; break;
+            default: assert(0); vtype = 0; val = 0; // shouldn't happen
+        }
+    }
+    emit_post_push_imm(emit, vtype, val);
+}
+
+static void emit_native_load_const_small_int(emit_t *emit, int arg) {
+    emit_pre(emit);
+    if (emit->do_viper_types) {
+        emit_post_push_imm(emit, VTYPE_INT, arg);
+    } else {
+        emit_post_push_imm(emit, VTYPE_PYOBJ, (arg << 1) | 1);
+    }
+}
+
+static void emit_native_load_const_int(emit_t *emit, qstr qstr) {
+    // not implemented
+    // load integer, check fits in 32 bits
+    assert(0);
+}
+
+static void emit_native_load_const_dec(emit_t *emit, qstr qstr) {
+    // not supported for viper (although, could support floats in future)
+    assert(0);
+}
+
+static void emit_native_load_const_id(emit_t *emit, qstr qstr) {
+    // not supported for viper?
+    assert(0);
+}
+
+static void emit_native_load_const_str(emit_t *emit, qstr qstr, bool bytes) {
+    emit_pre(emit);
+    if (emit->do_viper_types) {
+        // not implemented properly
+        // load a pointer to the asciiz string?
+        assert(0);
+        emit_post_push_imm(emit, VTYPE_PTR, (machine_uint_t)qstr_str(qstr));
+    } else {
+        emit_call_with_imm_arg(emit, RT_F_LOAD_CONST_STR, rt_load_const_str, qstr, REG_ARG_1);
+        emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET);
+    }
+}
+
+static void emit_native_load_const_verbatim_start(emit_t *emit) {
+    // not supported/needed for viper
+    assert(0);
+}
+
+static void emit_native_load_const_verbatim_int(emit_t *emit, int val) {
+    // not supported/needed for viper
+    assert(0);
+}
+
+static void emit_native_load_const_verbatim_str(emit_t *emit, const char *str) {
+    // not supported/needed for viper
+    assert(0);
+}
+
+static void emit_native_load_const_verbatim_strn(emit_t *emit, const char *str, int len) {
+    // not supported/needed for viper
+    assert(0);
+}
+
+static void emit_native_load_const_verbatim_quoted_str(emit_t *emit, qstr qstr, bool bytes) {
+    // not supported/needed for viper
+    assert(0);
+}
+
+static void emit_native_load_const_verbatim_end(emit_t *emit) {
+    // not supported/needed for viper
+    assert(0);
+}
+
+static void emit_native_load_fast(emit_t *emit, qstr qstr, int local_num) {
+    vtype_kind_t vtype = emit->local_vtype[local_num];
+    if (vtype == VTYPE_UNBOUND) {
+        printf("ViperTypeError: local %s used before type known\n", qstr_str(qstr));
+    }
+    emit_pre(emit);
+#if defined(N_X64)
+    if (local_num == 0) {
+        emit_post_push_reg(emit, vtype, REG_LOCAL_1);
+    } else {
+        asm_x64_mov_local_to_r64(emit->as, local_num - 1, REG_RAX);
+        emit_post_push_reg(emit, vtype, REG_RAX);
+    }
+#elif defined(N_THUMB)
+    if (local_num == 0) {
+        emit_post_push_reg(emit, vtype, REG_LOCAL_1);
+    } else if (local_num == 1) {
+        emit_post_push_reg(emit, vtype, REG_LOCAL_2);
+    } else if (local_num == 2) {
+        emit_post_push_reg(emit, vtype, REG_LOCAL_3);
+    } else {
+        asm_thumb_mov_reg_local(emit->as, REG_R0, local_num - 1);
+        emit_post_push_reg(emit, vtype, REG_R0);
+    }
+#endif
+}
+
+static void emit_native_load_name(emit_t *emit, qstr qstr) {
+    emit_pre(emit);
+    emit_call_with_imm_arg(emit, RT_F_LOAD_NAME, rt_load_name, qstr, REG_ARG_1);
+    emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET);
+}
+
+static void emit_native_load_global(emit_t *emit, qstr qstr) {
+    emit_pre(emit);
+    emit_call_with_imm_arg(emit, RT_F_LOAD_GLOBAL, rt_load_global, qstr, REG_ARG_1);
+    emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET);
+}
+
+static void emit_native_load_deref(emit_t *emit, qstr qstr) {
+    // not implemented
+    // in principle could support this quite easily (ldr r0, [r0, #0]) and then get closed over variables!
+    assert(0);
+}
+
+static void emit_native_load_closure(emit_t *emit, qstr qstr) {
+    // not implemented
+    assert(0);
+}
+
+static void emit_native_load_attr(emit_t *emit, qstr qstr) {
+    // depends on type of subject:
+    //  - integer, function, pointer to integers: error
+    //  - pointer to structure: get member, quite easy
+    //  - Python object: call rt_load_attr, and needs to be typed to convert result
+    vtype_kind_t vtype_base;
+    emit_pre_pop_reg(emit, &vtype_base, REG_ARG_1); // arg1 = base
+    assert(vtype_base == VTYPE_PYOBJ);
+    emit_call_with_imm_arg(emit, RT_F_LOAD_ATTR, rt_load_attr, qstr, REG_ARG_2); // arg2 = attribute name
+    emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET);
+}
+
+static void emit_native_load_method(emit_t *emit, qstr qstr) {
+    vtype_kind_t vtype_base;
+    emit_pre_pop_reg(emit, &vtype_base, REG_ARG_1); // arg1 = base
+    assert(vtype_base == VTYPE_PYOBJ);
+    emit_get_stack_pointer_to_reg_for_push(emit, REG_ARG_3, 2); // arg3 = dest ptr
+    emit_call_with_imm_arg(emit, RT_F_LOAD_METHOD, rt_load_method, qstr, REG_ARG_2); // arg2 = method name
+}
+
+static void emit_native_load_build_class(emit_t *emit) {
+    // not supported
+   assert(0);
+}
+
+static void emit_native_store_fast(emit_t *emit, qstr qstr, int local_num) {
+    vtype_kind_t vtype;
+#if defined(N_X64)
+    if (local_num == 0) {
+        emit_pre_pop_reg(emit, &vtype, REG_LOCAL_1);
+    } else {
+        emit_pre_pop_reg(emit, &vtype, REG_RAX);
+        asm_x64_mov_r64_to_local(emit->as, REG_RAX, local_num - 1);
+    }
+#elif defined(N_THUMB)
+    if (local_num == 0) {
+        emit_pre_pop_reg(emit, &vtype, REG_LOCAL_1);
+    } else if (local_num == 1) {
+        emit_pre_pop_reg(emit, &vtype, REG_LOCAL_2);
+    } else if (local_num == 2) {
+        emit_pre_pop_reg(emit, &vtype, REG_LOCAL_3);
+    } else {
+        emit_pre_pop_reg(emit, &vtype, REG_R0);
+        asm_thumb_mov_local_reg(emit->as, local_num - 1, REG_R0);
+    }
+#endif
+
+    emit_post(emit);
+
+    // check types
+    if (emit->local_vtype[local_num] == VTYPE_UNBOUND) {
+        // first time this local is assigned, so give it a type of the object stored in it
+        emit->local_vtype[local_num] = vtype;
+    } else if (emit->local_vtype[local_num] != vtype) {
+        // type of local is not the same as object stored in it
+        printf("ViperTypeError: type mismatch, local %s has type %d but source object has type %d\n", qstr_str(qstr), emit->local_vtype[local_num], vtype);
+    }
+}
+
+static void emit_native_store_name(emit_t *emit, qstr qstr) {
+    // rt_store_name, but needs conversion of object (maybe have rt_viper_store_name(obj, type))
+    vtype_kind_t vtype;
+    emit_pre_pop_reg(emit, &vtype, REG_ARG_2);
+    assert(vtype == VTYPE_PYOBJ);
+    emit_call_with_imm_arg(emit, RT_F_STORE_NAME, rt_store_name, qstr, REG_ARG_1); // arg1 = name
+    emit_post(emit);
+}
+
+static void emit_native_store_global(emit_t *emit, qstr qstr) {
+    // not implemented
+    assert(0);
+}
+
+static void emit_native_store_deref(emit_t *emit, qstr qstr) {
+    // not implemented
+    assert(0);
+}
+
+static void emit_native_store_attr(emit_t *emit, qstr qstr) {
+    // not implemented
+    assert(0);
+}
+
+static void emit_native_store_locals(emit_t *emit) {
+    // not supported
+    assert(0);
+}
+
+static void emit_native_store_subscr(emit_t *emit) {
+    // depends on type of subject:
+    //  - integer, function, pointer to structure: error
+    //  - pointer to integers: store as per array
+    //  - Python object: call runtime with converted object or type info
+    vtype_kind_t vtype_index, vtype_base, vtype_value;
+    emit_pre_pop_reg_reg_reg(emit, &vtype_index, REG_ARG_2, &vtype_base, REG_ARG_1, &vtype_value, REG_ARG_3); // index, base, value to store
+    assert(vtype_index == VTYPE_PYOBJ);
+    assert(vtype_base == VTYPE_PYOBJ);
+    assert(vtype_value == VTYPE_PYOBJ);
+    emit_call(emit, RT_F_STORE_SUBSCR, rt_store_subscr);
+}
+
+static void emit_native_delete_fast(emit_t *emit, qstr qstr, int local_num) {
+    // not implemented
+    // could support for Python types, just set to None (so GC can reclaim it)
+    assert(0);
+}
+
+static void emit_native_delete_name(emit_t *emit, qstr qstr) {
+    // not implemented
+    // use rt_delete_name
+    assert(0);
+}
+
+static void emit_native_delete_global(emit_t *emit, qstr qstr) {
+    // not implemented
+    // use rt_delete_global
+    assert(0);
+}
+
+static void emit_native_delete_deref(emit_t *emit, qstr qstr) {
+    // not supported
+    assert(0);
+}
+
+static void emit_native_delete_attr(emit_t *emit, qstr qstr) {
+    // not supported
+    assert(0);
+}
+
+static void emit_native_delete_subscr(emit_t *emit) {
+    // not supported
+    assert(0);
+}
+
+static void emit_native_dup_top(emit_t *emit) {
+    vtype_kind_t vtype;
+    emit_pre_pop_reg(emit, &vtype, REG_TEMP0);
+    emit_post_push_reg_reg(emit, vtype, REG_TEMP0, vtype, REG_TEMP0);
+}
+
+static void emit_native_dup_top_two(emit_t *emit) {
+    vtype_kind_t vtype0, vtype1;
+    emit_pre_pop_reg_reg(emit, &vtype0, REG_TEMP0, &vtype1, REG_TEMP1);
+    emit_post_push_reg_reg_reg_reg(emit, vtype1, REG_TEMP1, vtype0, REG_TEMP0, vtype1, REG_TEMP1, vtype0, REG_TEMP0);
+}
+
+static void emit_native_pop_top(emit_t *emit) {
+    vtype_kind_t vtype;
+    emit_pre_pop_reg(emit, &vtype, REG_TEMP0);
+    emit_post(emit);
+}
+
+static void emit_native_rot_two(emit_t *emit) {
+    assert(0);
+}
+
+static void emit_native_rot_three(emit_t *emit) {
+    vtype_kind_t vtype0, vtype1, vtype2;
+    emit_pre_pop_reg_reg_reg(emit, &vtype0, REG_TEMP0, &vtype1, REG_TEMP1, &vtype2, REG_TEMP2);
+    emit_post_push_reg_reg_reg(emit, vtype0, REG_TEMP0, vtype2, REG_TEMP2, vtype1, REG_TEMP1);
+}
+
+static void emit_native_jump(emit_t *emit, int label) {
+    emit_pre(emit);
+#if defined(N_X64)
+    asm_x64_jmp_label(emit->as, label);
+#elif defined(N_THUMB)
+    asm_thumb_b_label(emit->as, label);
+#endif
+    emit_post(emit);
+}
+
+static void emit_native_pop_jump_if_false(emit_t *emit, int label) {
+    vtype_kind_t vtype = peek_vtype(emit);
+    if (vtype == VTYPE_BOOL) {
+        emit_pre_pop_reg(emit, &vtype, REG_RET);
+    } else if (vtype == VTYPE_PYOBJ) {
+        emit_pre_pop_reg(emit, &vtype, REG_ARG_1);
+        emit_call(emit, RT_F_IS_TRUE, rt_is_true);
+    } else {
+        printf("ViperTypeError: expecting a bool or pyobj, got %d\n", vtype);
+        assert(0);
+    }
+#if defined(N_X64)
+    asm_x64_test_r8_with_r8(emit->as, REG_RET, REG_RET);
+    asm_x64_jcc_label(emit->as, JCC_JZ, label);
+#elif defined(N_THUMB)
+    asm_thumb_cmp_reg_bz_label(emit->as, REG_RET, label);
+#endif
+    emit_post(emit);
+}
+
+static void emit_native_pop_jump_if_true(emit_t *emit, int label) {
+    assert(0);
+}
+static void emit_native_jump_if_true_or_pop(emit_t *emit, int label) {
+    assert(0);
+}
+static void emit_native_jump_if_false_or_pop(emit_t *emit, int label) {
+    assert(0);
+}
+
+static void emit_native_setup_loop(emit_t *emit, int label) {
+    emit_pre(emit);
+    emit_post(emit);
+}
+
+static void emit_native_break_loop(emit_t *emit, int label) {
+    assert(0);
+}
+static void emit_native_continue_loop(emit_t *emit, int label) {
+    assert(0);
+}
+static void emit_native_setup_with(emit_t *emit, int label) {
+    // not supported, or could be with runtime call
+    assert(0);
+}
+static void emit_native_with_cleanup(emit_t *emit) {
+    assert(0);
+}
+static void emit_native_setup_except(emit_t *emit, int label) {
+    assert(0);
+}
+static void emit_native_setup_finally(emit_t *emit, int label) {
+    assert(0);
+}
+static void emit_native_end_finally(emit_t *emit) {
+    assert(0);
+}
+static void emit_native_get_iter(emit_t *emit) {
+    // perhaps the difficult one, as we want to rewrite for loops using native code
+    // in cases where we iterate over a Python object, can we use normal runtime calls?
+    assert(0);
+} // tos = getiter(tos)
+static void emit_native_for_iter(emit_t *emit, int label) {
+    assert(0);
+}
+static void emit_native_for_iter_end(emit_t *emit) {
+    assert(0);
+}
+
+static void emit_native_pop_block(emit_t *emit) {
+    emit_pre(emit);
+    emit_post(emit);
+}
+
+static void emit_native_pop_except(emit_t *emit) {
+    assert(0);
+}
+
+static void emit_native_unary_op(emit_t *emit, rt_unary_op_t op) {
+    vtype_kind_t vtype;
+    emit_pre_pop_reg(emit, &vtype, REG_ARG_2);
+    assert(vtype == VTYPE_PYOBJ);
+    emit_call_with_imm_arg(emit, RT_F_UNARY_OP, rt_unary_op, op, REG_ARG_1);
+    emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET);
+}
+
+static void emit_native_binary_op(emit_t *emit, rt_binary_op_t op) {
+    vtype_kind_t vtype_lhs, vtype_rhs;
+    emit_pre_pop_reg_reg(emit, &vtype_rhs, REG_ARG_3, &vtype_lhs, REG_ARG_2);
+    if (vtype_lhs == VTYPE_INT && vtype_rhs == VTYPE_INT) {
+        assert(op == RT_BINARY_OP_ADD);
+#if defined(N_X64)
+        asm_x64_add_r64_to_r64(emit->as, REG_ARG_3, REG_ARG_2);
+#elif defined(N_THUMB)
+        asm_thumb_add_reg_reg_reg(emit->as, REG_ARG_2, REG_ARG_2, REG_ARG_3);
+#endif
+        emit_post_push_reg(emit, VTYPE_INT, REG_ARG_2);
+    } else if (vtype_lhs == VTYPE_PYOBJ && vtype_rhs == VTYPE_PYOBJ) {
+        emit_call_with_imm_arg(emit, RT_F_BINARY_OP, rt_binary_op, op, REG_ARG_1);
+        emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET);
+    } else {
+        printf("ViperTypeError: can't do binary op between types %d and %d\n", vtype_lhs, vtype_rhs);
+        assert(0);
+    }
+}
+
+static void emit_native_compare_op(emit_t *emit, rt_compare_op_t op) {
+    vtype_kind_t vtype_lhs, vtype_rhs;
+    emit_pre_pop_reg_reg(emit, &vtype_rhs, REG_ARG_3, &vtype_lhs, REG_ARG_2);
+    if (vtype_lhs == VTYPE_INT && vtype_rhs == VTYPE_INT) {
+        assert(op == RT_COMPARE_OP_LESS);
+#if defined(N_X64)
+        asm_x64_xor_r64_to_r64(emit->as, REG_RET, REG_RET);
+        asm_x64_cmp_r64_with_r64(emit->as, REG_ARG_3, REG_ARG_2);
+        asm_x64_setcc_r8(emit->as, JCC_JL, REG_RET);
+#elif defined(N_THUMB)
+        asm_thumb_cmp_reg_reg(emit->as, REG_ARG_2, REG_ARG_3);
+        asm_thumb_ite_ge(emit->as);
+        asm_thumb_movs_rlo_i8(emit->as, REG_RET, 0); // if r0 >= r1
+        asm_thumb_movs_rlo_i8(emit->as, REG_RET, 1); // if r0 < r1
+#endif
+        emit_post_push_reg(emit, VTYPE_BOOL, REG_RET);
+    } else if (vtype_lhs == VTYPE_PYOBJ && vtype_rhs == VTYPE_PYOBJ) {
+        emit_call_with_imm_arg(emit, RT_F_COMPARE_OP, rt_compare_op, op, REG_ARG_1);
+        emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET);
+    } else {
+        printf("ViperTypeError: can't do comparison between types %d and %d\n", vtype_lhs, vtype_rhs);
+        assert(0);
+    }
+}
+
+static void emit_native_build_tuple(emit_t *emit, int n_args) {
+    // call runtime, with types of args
+    // if wrapped in byte_array, or something, allocates memory and fills it
+    assert(0);
+}
+
+static void emit_native_build_list(emit_t *emit, int n_args) {
+    emit_pre(emit);
+    emit_get_stack_pointer_to_reg_for_pop(emit, REG_ARG_2, n_args); // pointer to items in reverse order
+    emit_call_with_imm_arg(emit, RT_F_BUILD_LIST, rt_build_list, n_args, REG_ARG_1);
+    emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET); // new list
+}
+
+static void emit_native_list_append(emit_t *emit, int list_index) {
+    // only used in list comprehension, so call runtime
+    assert(0);
+}
+
+static void emit_native_build_map(emit_t *emit, int n_args) {
+    emit_pre(emit);
+    emit_call_with_imm_arg(emit, RT_F_BUILD_MAP, rt_build_map, n_args, REG_ARG_1);
+    emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET); // new map
+}
+
+static void emit_native_store_map(emit_t *emit) {
+    vtype_kind_t vtype_key, vtype_value, vtype_map;
+    emit_pre_pop_reg_reg_reg(emit, &vtype_key, REG_ARG_2, &vtype_value, REG_ARG_3, &vtype_map, REG_ARG_1); // key, value, map
+    assert(vtype_key == VTYPE_PYOBJ);
+    assert(vtype_value == VTYPE_PYOBJ);
+    assert(vtype_map == VTYPE_PYOBJ);
+    emit_call(emit, RT_F_STORE_MAP, rt_store_map);
+    emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET); // map
+}
+
+static void emit_native_map_add(emit_t *emit, int map_index) {
+    assert(0);
+}
+
+static void emit_native_build_set(emit_t *emit, int n_args) {
+    emit_pre(emit);
+    emit_get_stack_pointer_to_reg_for_pop(emit, REG_ARG_2, n_args); // pointer to items in reverse order
+    emit_call_with_imm_arg(emit, RT_F_BUILD_SET, rt_build_set, n_args, REG_ARG_1);
+    emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET); // new set
+}
+
+static void emit_native_set_add(emit_t *emit, int set_index) {
+    assert(0);
+}
+static void emit_native_build_slice(emit_t *emit, int n_args) {
+    assert(0);
+}
+static void emit_native_unpack_sequence(emit_t *emit, int n_args) {
+    // call runtime, needs type decl
+    assert(0);
+}
+static void emit_native_unpack_ex(emit_t *emit, int n_left, int n_right) {
+    assert(0);
+}
+
+static void emit_native_make_function(emit_t *emit, scope_t *scope, int n_dict_params, int n_default_params) {
+    // call runtime, with type info for args, or don't support dict/default params, or only support Python objects for them
+    assert(n_default_params == 0 && n_dict_params == 0);
+    emit_pre(emit);
+    emit_call_with_imm_arg(emit, RT_F_MAKE_FUNCTION_FROM_ID, rt_make_function_from_id, scope->unique_code_id, REG_ARG_1);
+    emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET);
+}
+
+static void emit_native_make_closure(emit_t *emit, scope_t *scope, int n_dict_params, int n_default_params) {
+    assert(0);
+}
+
+static void emit_native_call_function(emit_t *emit, int n_positional, int n_keyword, bool have_star_arg, bool have_dbl_star_arg) {
+    // call special viper runtime routine with type info for args, and wanted type info for return
+    assert(n_keyword == 0 && !have_star_arg && !have_dbl_star_arg);
+    if (n_positional == 0) {
+        vtype_kind_t vtype_fun;
+        emit_pre_pop_reg(emit, &vtype_fun, REG_ARG_1); // the function
+        assert(vtype_fun == VTYPE_PYOBJ);
+        emit_call(emit, RT_F_CALL_FUNCTION_0, rt_call_function_0);
+    } else if (n_positional == 1) {
+        vtype_kind_t vtype_fun, vtype_arg1;
+        emit_pre_pop_reg_reg(emit, &vtype_arg1, REG_ARG_2, &vtype_fun, REG_ARG_1); // the single argument, the function
+        assert(vtype_fun == VTYPE_PYOBJ);
+        assert(vtype_arg1 == VTYPE_PYOBJ);
+        emit_call(emit, RT_F_CALL_FUNCTION_1, rt_call_function_1);
+    } else if (n_positional == 2) {
+        vtype_kind_t vtype_fun, vtype_arg1, vtype_arg2;
+        emit_pre_pop_reg_reg_reg(emit, &vtype_arg2, REG_ARG_3, &vtype_arg1, REG_ARG_2, &vtype_fun, REG_ARG_1); // the second argument, the first argument, the function
+        assert(vtype_fun == VTYPE_PYOBJ);
+        assert(vtype_arg1 == VTYPE_PYOBJ);
+        assert(vtype_arg2 == VTYPE_PYOBJ);
+        emit_call(emit, RT_F_CALL_FUNCTION_2, rt_call_function_2);
+    } else {
+        assert(0);
+    }
+    emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET);
+}
+
+static void emit_native_call_method(emit_t *emit, int n_positional, int n_keyword, bool have_star_arg, bool have_dbl_star_arg) {
+    assert(n_keyword == 0 && !have_star_arg && !have_dbl_star_arg);
+    if (n_positional == 0) {
+        vtype_kind_t vtype_meth, vtype_self;
+        emit_pre_pop_reg_reg(emit, &vtype_self, REG_ARG_2, &vtype_meth, REG_ARG_1); // the self object (or NULL), the method
+        assert(vtype_meth == VTYPE_PYOBJ);
+        assert(vtype_self == VTYPE_PYOBJ);
+        emit_call(emit, RT_F_CALL_METHOD_1, rt_call_method_1);
+    } else if (n_positional == 1) {
+        vtype_kind_t vtype_meth, vtype_self, vtype_arg1;
+        emit_pre_pop_reg_reg_reg(emit, &vtype_arg1, REG_ARG_3, &vtype_self, REG_ARG_2, &vtype_meth, REG_ARG_1); // the first argument, the self object (or NULL), the method
+        assert(vtype_meth == VTYPE_PYOBJ);
+        assert(vtype_self == VTYPE_PYOBJ);
+        assert(vtype_arg1 == VTYPE_PYOBJ);
+        emit_call(emit, RT_F_CALL_METHOD_2, rt_call_method_2);
+    } else {
+        assert(0);
+    }
+    emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET);
+}
+
+static void emit_native_return_value(emit_t *emit) {
+    // easy.  since we don't know who we return to, just return the raw value.
+    // runtime needs then to know our type signature, but I think that's possible.
+    vtype_kind_t vtype;
+    emit_pre_pop_reg(emit, &vtype, REG_RET);
+    if (emit->do_viper_types) {
+        assert(vtype == VTYPE_PTR_NONE);
+    } else {
+        assert(vtype == VTYPE_PYOBJ);
+    }
+    emit->last_emit_was_return_value = true;
+#if defined(N_X64)
+    //asm_x64_call_ind(emit->as, 0, REG_RAX); to seg fault for debugging with gdb
+    asm_x64_exit(emit->as);
+#elif defined(N_THUMB)
+    //asm_thumb_call_ind(emit->as, 0, REG_R0); to seg fault for debugging with gdb
+    asm_thumb_exit(emit->as);
+#endif
+}
+
+static void emit_native_raise_varargs(emit_t *emit, int n_args) {
+    // call runtime
+    assert(0);
+}
+static void emit_native_yield_value(emit_t *emit) {
+    // not supported (for now)
+    assert(0);
+}
+static void emit_native_yield_from(emit_t *emit) {
+    // not supported (for now)
+    assert(0);
+}
+
+const emit_method_table_t EXPORT_FUN(method_table) = {
+    emit_native_set_viper_types,
+    emit_native_start_pass,
+    emit_native_end_pass,
+    emit_native_last_emit_was_return_value,
+    emit_native_get_stack_size,
+    emit_native_set_stack_size,
+
+    emit_native_load_id,
+    emit_native_store_id,
+    emit_native_delete_id,
+
+    emit_native_label_assign,
+    emit_native_import_name,
+    emit_native_import_from,
+    emit_native_import_star,
+    emit_native_load_const_tok,
+    emit_native_load_const_small_int,
+    emit_native_load_const_int,
+    emit_native_load_const_dec,
+    emit_native_load_const_id,
+    emit_native_load_const_str,
+    emit_native_load_const_verbatim_start,
+    emit_native_load_const_verbatim_int,
+    emit_native_load_const_verbatim_str,
+    emit_native_load_const_verbatim_strn,
+    emit_native_load_const_verbatim_quoted_str,
+    emit_native_load_const_verbatim_end,
+    emit_native_load_fast,
+    emit_native_load_name,
+    emit_native_load_global,
+    emit_native_load_deref,
+    emit_native_load_closure,
+    emit_native_load_attr,
+    emit_native_load_method,
+    emit_native_load_build_class,
+    emit_native_store_fast,
+    emit_native_store_name,
+    emit_native_store_global,
+    emit_native_store_deref,
+    emit_native_store_attr,
+    emit_native_store_locals,
+    emit_native_store_subscr,
+    emit_native_delete_fast,
+    emit_native_delete_name,
+    emit_native_delete_global,
+    emit_native_delete_deref,
+    emit_native_delete_attr,
+    emit_native_delete_subscr,
+    emit_native_dup_top,
+    emit_native_dup_top_two,
+    emit_native_pop_top,
+    emit_native_rot_two,
+    emit_native_rot_three,
+    emit_native_jump,
+    emit_native_pop_jump_if_true,
+    emit_native_pop_jump_if_false,
+    emit_native_jump_if_true_or_pop,
+    emit_native_jump_if_false_or_pop,
+    emit_native_setup_loop,
+    emit_native_break_loop,
+    emit_native_continue_loop,
+    emit_native_setup_with,
+    emit_native_with_cleanup,
+    emit_native_setup_except,
+    emit_native_setup_finally,
+    emit_native_end_finally,
+    emit_native_get_iter,
+    emit_native_for_iter,
+    emit_native_for_iter_end,
+    emit_native_pop_block,
+    emit_native_pop_except,
+    emit_native_unary_op,
+    emit_native_binary_op,
+    emit_native_compare_op,
+    emit_native_build_tuple,
+    emit_native_build_list,
+    emit_native_list_append,
+    emit_native_build_map,
+    emit_native_store_map,
+    emit_native_map_add,
+    emit_native_build_set,
+    emit_native_set_add,
+    emit_native_build_slice,
+    emit_native_unpack_sequence,
+    emit_native_unpack_ex,
+    emit_native_make_function,
+    emit_native_make_closure,
+    emit_native_call_function,
+    emit_native_call_method,
+    emit_native_return_value,
+    emit_native_raise_varargs,
+    emit_native_yield_value,
+    emit_native_yield_from,
+};
+
+#endif // defined(N_X64) || defined(N_THUMB)
diff --git a/py/emitx64.c b/py/emitx64.c
index 5b2b6f0c5..f4ec37d7e 100644
--- a/py/emitx64.c
+++ b/py/emitx64.c
@@ -39,8 +39,8 @@
 
 typedef enum {
     NEED_TO_PUSH_NOTHING,
-    NEED_TO_PUSH_R64,
-    NEED_TO_PUSH_I64,
+    NEED_TO_PUSH_REG,
+    NEED_TO_PUSH_IMM,
 } need_to_push_t;
 
 typedef enum {
@@ -185,13 +185,13 @@ static void stack_settle(emit_t *emit) {
         case NEED_TO_PUSH_NOTHING:
             break;
 
-        case NEED_TO_PUSH_R64:
+        case NEED_TO_PUSH_REG:
             emit->stack_vtype[emit->stack_size] = emit->last_vtype;
             asm_x64_mov_r64_to_local(emit->as, emit->last_reg, emit->stack_start + emit->stack_size);
             adjust_stack(emit, 1);
             break;
 
-        case NEED_TO_PUSH_I64:
+        case NEED_TO_PUSH_IMM:
             emit->stack_vtype[emit->stack_size] = emit->last_vtype;
             asm_x64_mov_i64_to_r64_optimised(emit->as, emit->last_imm, REG_RAX);
             asm_x64_mov_r64_to_local(emit->as, REG_RAX, emit->stack_start + emit->stack_size);
@@ -216,8 +216,8 @@ static vtype_kind_t peek_vtype(emit_t *emit) {
         case NEED_TO_PUSH_NOTHING:
             return emit->stack_vtype[emit->stack_size - 1];
 
-        case NEED_TO_PUSH_R64:
-        case NEED_TO_PUSH_I64:
+        case NEED_TO_PUSH_REG:
+        case NEED_TO_PUSH_IMM:
             return emit->last_vtype;
 
         default:
@@ -234,7 +234,7 @@ static void emit_pre_pop_reg(emit_t *emit, vtype_kind_t *vtype, int reg) {
             emit_pre_raw(emit, -1);
             break;
 
-        case NEED_TO_PUSH_R64:
+        case NEED_TO_PUSH_REG:
             emit_pre_raw(emit, 0);
             *vtype = emit->last_vtype;
             if (emit->last_reg != reg) {
@@ -242,7 +242,7 @@ static void emit_pre_pop_reg(emit_t *emit, vtype_kind_t *vtype, int reg) {
             }
             break;
 
-        case NEED_TO_PUSH_I64:
+        case NEED_TO_PUSH_IMM:
             emit_pre_raw(emit, 0);
             *vtype = emit->last_vtype;
             asm_x64_mov_i64_to_r64_optimised(emit->as, emit->last_imm, reg);
@@ -251,19 +251,19 @@ static void emit_pre_pop_reg(emit_t *emit, vtype_kind_t *vtype, int reg) {
     emit->need_to_push = NEED_TO_PUSH_NOTHING;
 }
 
-static void emit_pre_pop_reg_reg(emit_t *emit, vtype_kind_t *vtypea, int r64a, vtype_kind_t *vtypeb, int r64b) {
-    emit_pre_pop_reg(emit, vtypea, r64a);
+static void emit_pre_pop_reg_reg(emit_t *emit, vtype_kind_t *vtypea, int rega, vtype_kind_t *vtypeb, int regb) {
+    emit_pre_pop_reg(emit, vtypea, rega);
     *vtypeb = emit->stack_vtype[emit->stack_size - 1];
-    asm_x64_mov_local_to_r64(emit->as, emit->stack_start + emit->stack_size - 1, r64b);
+    asm_x64_mov_local_to_r64(emit->as, emit->stack_start + emit->stack_size - 1, regb);
     adjust_stack(emit, -1);
 }
 
-static void emit_pre_pop_reg_reg_reg(emit_t *emit, vtype_kind_t *vtypea, int r64a, vtype_kind_t *vtypeb, int r64b, vtype_kind_t *vtypec, int r64c) {
-    emit_pre_pop_reg(emit, vtypea, r64a);
+static void emit_pre_pop_reg_reg_reg(emit_t *emit, vtype_kind_t *vtypea, int rega, vtype_kind_t *vtypeb, int regb, vtype_kind_t *vtypec, int regc) {
+    emit_pre_pop_reg(emit, vtypea, rega);
     *vtypeb = emit->stack_vtype[emit->stack_size - 1];
     *vtypec = emit->stack_vtype[emit->stack_size - 2];
-    asm_x64_mov_local_to_r64(emit->as, emit->stack_start + emit->stack_size - 1, r64b);
-    asm_x64_mov_local_to_r64(emit->as, emit->stack_start + emit->stack_size - 2, r64c);
+    asm_x64_mov_local_to_r64(emit->as, emit->stack_start + emit->stack_size - 1, regb);
+    asm_x64_mov_local_to_r64(emit->as, emit->stack_start + emit->stack_size - 2, regc);
     adjust_stack(emit, -2);
 }
 
@@ -271,45 +271,45 @@ static void emit_post(emit_t *emit) {
 }
 
 static void emit_post_push_reg(emit_t *emit, vtype_kind_t vtype, int reg) {
-    emit->need_to_push = NEED_TO_PUSH_R64;
+    emit->need_to_push = NEED_TO_PUSH_REG;
     emit->last_vtype = vtype;
     emit->last_reg = reg;
 }
 
 static void emit_post_push_imm(emit_t *emit, vtype_kind_t vtype, int64_t imm) {
-    emit->need_to_push = NEED_TO_PUSH_I64;
+    emit->need_to_push = NEED_TO_PUSH_IMM;
     emit->last_vtype = vtype;
     emit->last_imm = imm;
 }
 
-static void emit_post_push_reg_reg(emit_t *emit, vtype_kind_t vtypea, int r64a, vtype_kind_t vtypeb, int r64b) {
+static void emit_post_push_reg_reg(emit_t *emit, vtype_kind_t vtypea, int rega, vtype_kind_t vtypeb, int regb) {
     emit->stack_vtype[emit->stack_size] = vtypea;
-    asm_x64_mov_r64_to_local(emit->as, r64a, emit->stack_start + emit->stack_size);
-    emit->need_to_push = NEED_TO_PUSH_R64;
+    asm_x64_mov_r64_to_local(emit->as, rega, emit->stack_start + emit->stack_size);
+    emit->need_to_push = NEED_TO_PUSH_REG;
     emit->last_vtype = vtypeb;
-    emit->last_reg = r64b;
+    emit->last_reg = regb;
     adjust_stack(emit, 1);
 }
 
-static void emit_post_push_reg_reg_reg(emit_t *emit, vtype_kind_t vtypea, int r64a, vtype_kind_t vtypeb, int r64b, vtype_kind_t vtypec, int r64c) {
+static void emit_post_push_reg_reg_reg(emit_t *emit, vtype_kind_t vtypea, int rega, vtype_kind_t vtypeb, int regb, vtype_kind_t vtypec, int regc) {
     emit->stack_vtype[emit->stack_size] = vtypea;
     emit->stack_vtype[emit->stack_size + 1] = vtypeb;
     emit->stack_vtype[emit->stack_size + 2] = vtypec;
-    asm_x64_mov_r64_to_local(emit->as, r64a, emit->stack_start + emit->stack_size);
-    asm_x64_mov_r64_to_local(emit->as, r64b, emit->stack_start + emit->stack_size + 1);
-    asm_x64_mov_r64_to_local(emit->as, r64c, emit->stack_start + emit->stack_size + 2);
+    asm_x64_mov_r64_to_local(emit->as, rega, emit->stack_start + emit->stack_size);
+    asm_x64_mov_r64_to_local(emit->as, regb, emit->stack_start + emit->stack_size + 1);
+    asm_x64_mov_r64_to_local(emit->as, regc, emit->stack_start + emit->stack_size + 2);
     adjust_stack(emit, 3);
 }
 
-static void emit_post_push_reg_reg_reg_reg(emit_t *emit, vtype_kind_t vtypea, int r64a, vtype_kind_t vtypeb, int r64b, vtype_kind_t vtypec, int r64c, vtype_kind_t vtyped, int r64d) {
+static void emit_post_push_reg_reg_reg_reg(emit_t *emit, vtype_kind_t vtypea, int rega, vtype_kind_t vtypeb, int regb, vtype_kind_t vtypec, int regc, vtype_kind_t vtyped, int regd) {
     emit->stack_vtype[emit->stack_size] = vtypea;
     emit->stack_vtype[emit->stack_size + 1] = vtypeb;
     emit->stack_vtype[emit->stack_size + 2] = vtypec;
     emit->stack_vtype[emit->stack_size + 3] = vtyped;
-    asm_x64_mov_r64_to_local(emit->as, r64a, emit->stack_start + emit->stack_size);
-    asm_x64_mov_r64_to_local(emit->as, r64b, emit->stack_start + emit->stack_size + 1);
-    asm_x64_mov_r64_to_local(emit->as, r64c, emit->stack_start + emit->stack_size + 2);
-    asm_x64_mov_r64_to_local(emit->as, r64d, emit->stack_start + emit->stack_size + 3);
+    asm_x64_mov_r64_to_local(emit->as, rega, emit->stack_start + emit->stack_size);
+    asm_x64_mov_r64_to_local(emit->as, regb, emit->stack_start + emit->stack_size + 1);
+    asm_x64_mov_r64_to_local(emit->as, regc, emit->stack_start + emit->stack_size + 2);
+    asm_x64_mov_r64_to_local(emit->as, regd, emit->stack_start + emit->stack_size + 3);
     adjust_stack(emit, 4);
 }
 
diff --git a/py/runtime.c b/py/runtime.c
index a93d05d9b..8403a7527 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -419,6 +419,7 @@ void rt_assign_native_code(int unique_code_id, py_fun_t fun, uint len, int n_arg
 
     if (fp_native != NULL) {
         fwrite(fun_data, len, 1, fp_native);
+        fflush(fp_native);
     }
 }