diff options
Diffstat (limited to 'py')
| -rw-r--r-- | py/parsenum.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/py/parsenum.c b/py/parsenum.c index 98e7736851..124489c66e 100644 --- a/py/parsenum.c +++ b/py/parsenum.c @@ -172,10 +172,15 @@ mp_obj_t mp_parse_num_decimal(const char *str, size_t len, bool allow_imag, bool #if MICROPY_PY_BUILTINS_FLOAT // DEC_VAL_MAX only needs to be rough and is used to retain precision while not overflowing +// SMALL_NORMAL_VAL is the smallest power of 10 that is still a normal float #if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT #define DEC_VAL_MAX 1e20F +#define SMALL_NORMAL_VAL (1e-37F) +#define SMALL_NORMAL_EXP (-37) #elif MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_DOUBLE #define DEC_VAL_MAX 1e200 +#define SMALL_NORMAL_VAL (1e-307) +#define SMALL_NORMAL_EXP (-307) #endif const char *top = str + len; @@ -275,8 +280,13 @@ mp_obj_t mp_parse_num_decimal(const char *str, size_t len, bool allow_imag, bool exp_val = -exp_val; } - // apply the exponent - dec_val *= MICROPY_FLOAT_C_FUN(pow)(10, exp_val + exp_extra); + // apply the exponent, making sure it's not a subnormal value + exp_val += exp_extra; + if (exp_val < SMALL_NORMAL_EXP) { + exp_val -= SMALL_NORMAL_EXP; + dec_val *= SMALL_NORMAL_VAL; + } + dec_val *= MICROPY_FLOAT_C_FUN(pow)(10, exp_val); } // negate value if needed |