Make USE_COMPUTED_GOTO a config option in mpconfig.h.

Disabled by default.  Enabled in unix port.

3 files changed, 10 insertions, 4 deletions

diff --git a/py/mpconfig.h b/py/mpconfig.h
index f9c02a6f02..8f60c997bd 100644
--- a/py/mpconfig.h
+++ b/py/mpconfig.h
@@ -154,6 +154,12 @@ typedef double mp_float_t;
 #define MICROPY_PATH_MAX (512)
 #endif
 
+// Whether to use computed gotos in the VM, or a switch
+// Computed gotos are roughly 10% faster, and increase VM code size by a little
+#ifndef MICROPY_USE_COMPUTED_GOTO
+#define MICROPY_USE_COMPUTED_GOTO (0)
+#endif
+
 // Additional builtin function definitions - see builtintables.c:builtin_object_table for format.
 #ifndef MICROPY_EXTRA_BUILTINS
 #define MICROPY_EXTRA_BUILTINS
diff --git a/py/objstr.c b/py/objstr.c
index 08db2af669..fc1e1c5695 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -662,7 +662,7 @@ mp_obj_t str_format(uint n_args, const mp_obj_t *args) {
             if (arg_i > 0) {
                 nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "cannot switch from automatic field numbering to manual field specification"));
             }
-            int index;
+            int index = 0;
             if (str_to_int(vstr_str(field_name), &index) != vstr_len(field_name) - 1) {
                 nlr_raise(mp_obj_new_exception_msg(&mp_type_KeyError, "attributes not supported yet"));
             }
diff --git a/py/vm.c b/py/vm.c
index f928ad6948..6c117c7cb4 100644
--- a/py/vm.c
+++ b/py/vm.c
@@ -167,7 +167,7 @@ mp_vm_return_kind_t mp_execute_byte_code_2(const byte *code_info, const byte **i
                                            volatile mp_obj_t inject_exc) {
     // careful: be sure to declare volatile any variables read in the exception handler (written is ok, I think)
 
-#ifdef MICROPY_USE_COMPUTED_GOTO
+#if MICROPY_USE_COMPUTED_GOTO
 
 #   define DISPATCH() do { \
       save_ip = ip; \
@@ -299,7 +299,7 @@ outer_dispatch_loop:
             // loop to execute byte code
             for (;;) {
 dispatch_loop:
-#ifdef MICROPY_USE_COMPUTED_GOTO
+#if MICROPY_USE_COMPUTED_GOTO
                 DISPATCH();
 #else
                 save_ip = ip;
@@ -1005,7 +1005,7 @@ yield:
                     nlr_pop();
                     fastn[0] = obj1;
                     return MP_VM_RETURN_EXCEPTION;
-#ifndef MICROPY_USE_COMPUTED_GOTO
+#if !MICROPY_USE_COMPUTED_GOTO
                 }
 #endif
             }