diff options
| -rw-r--r-- | py/persistentcode.c | 19 | ||||
| -rw-r--r-- | py/smallint.h | 7 |
2 files changed, 9 insertions, 17 deletions
diff --git a/py/persistentcode.c b/py/persistentcode.c index 6110ae97f..f64e383a6 100644 --- a/py/persistentcode.c +++ b/py/persistentcode.c @@ -48,21 +48,6 @@ #define MPY_FEATURE_ARCH_DYNAMIC MPY_FEATURE_ARCH #endif -#if MICROPY_PERSISTENT_CODE_LOAD || (MICROPY_PERSISTENT_CODE_SAVE && !MICROPY_DYNAMIC_COMPILER) -// The bytecode will depend on the number of bits in a small-int, and -// this function computes that (could make it a fixed constant, but it -// would need to be defined in mpconfigport.h). -STATIC int mp_small_int_bits(void) { - mp_int_t i = MP_SMALL_INT_MAX; - int n = 1; - while (i != 0) { - i >>= 1; - ++n; - } - return n; -} -#endif - typedef struct _bytecode_prelude_t { uint n_state; uint n_exc_stack; @@ -420,7 +405,7 @@ mp_compiled_module_t mp_raw_code_load(mp_reader_t *reader, mp_module_context_t * if (header[0] != 'M' || header[1] != MPY_VERSION || MPY_FEATURE_DECODE_FLAGS(header[2]) != MPY_FEATURE_FLAGS - || header[3] > mp_small_int_bits()) { + || header[3] > MP_SMALL_INT_BITS) { mp_raise_ValueError(MP_ERROR_TEXT("incompatible .mpy file")); } if (MPY_FEATURE_DECODE_ARCH(header[2]) != MP_NATIVE_ARCH_NONE) { @@ -609,7 +594,7 @@ void mp_raw_code_save(mp_compiled_module_t *cm, mp_print_t *print) { #if MICROPY_DYNAMIC_COMPILER mp_dynamic_compiler.small_int_bits, #else - mp_small_int_bits(), + MP_SMALL_INT_BITS, #endif }; if (cm->has_native) { diff --git a/py/smallint.h b/py/smallint.h index 67daf9b9f..584e0018d 100644 --- a/py/smallint.h +++ b/py/smallint.h @@ -61,6 +61,13 @@ #define MP_SMALL_INT_MAX ((mp_int_t)(~(MP_SMALL_INT_MIN))) +// https://stackoverflow.com/a/4589384/1976323 +// Number of bits in inttype_MAX, or in any (1<<k)-1 where 0 <= k < 2040 +#define MP_IMAX_BITS(m) ((m) / ((m) % 255 + 1) / 255 % 255 * 8 + 7 - 86 / ((m) % 255 + 12)) + +// The number of bits in a MP_SMALL_INT including the sign bit. +#define MP_SMALL_INT_BITS (MP_IMAX_BITS(MP_SMALL_INT_MAX) + 1) + bool mp_small_int_mul_overflow(mp_int_t x, mp_int_t y); mp_int_t mp_small_int_modulo(mp_int_t dividend, mp_int_t divisor); mp_int_t mp_small_int_floor_divide(mp_int_t num, mp_int_t denom); |