py: Store bytecode arg names in bytecode (were in own array).
This saves a lot of RAM for 2 reasons:
1. For functions that don't have default values, var args or var kw
args (which is a large number of functions in the general case), the
mp_obj_fun_bc_t type now fits in 1 GC block (previously needed 2 because
of the extra pointer to point to the arg_names array). So this saves 16
bytes per function (32 bytes on 64-bit machines).
2. Combining separate memory regions generally saves RAM because the
unused bytes at the end of the GC block are saved for 1 of the blocks
(since that block doesn't exist on its own anymore). So generally this
saves 8 bytes per function.
Tested by importing lots of modules:
- 64-bit Linux gave about an 8% RAM saving for 86k of used RAM.
- pyboard gave about a 6% RAM saving for 31k of used RAM.
diff --git a/py/objfun.h b/py/objfun.h
index cc8035e..e23fe8d 100644
--- a/py/objfun.h
+++ b/py/objfun.h
@@ -27,14 +27,13 @@
typedef struct _mp_obj_fun_bc_t {
mp_obj_base_t base;
mp_obj_dict_t *globals; // the context within which this function was defined
- mp_uint_t n_pos_args : 16; // number of arguments this function takes
- mp_uint_t n_kwonly_args : 16; // number of arguments this function takes
- mp_uint_t n_def_args : 16; // number of default arguments
+ mp_uint_t n_pos_args : 8; // number of arguments this function takes
+ mp_uint_t n_kwonly_args : 8; // number of keyword-only arguments this function takes
+ mp_uint_t n_def_args : 8; // number of default arguments
mp_uint_t has_def_kw_args : 1; // set if this function has default keyword args
mp_uint_t takes_var_args : 1; // set if this function takes variable args
mp_uint_t takes_kw_args : 1; // set if this function takes keyword args
const byte *bytecode; // bytecode for the function
- qstr *args; // argument names (needed to resolve positional args passed as keywords)
// the following extra_args array is allocated space to take (in order):
// - values of positional default args (if any)
// - a single slot for default kw args dict (if it has them)