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| author | Jeff Epler <jepler@gmail.com> | 2018-05-19 11:25:03 -0500 |
|---|---|---|
| committer | Damien George <damien.p.george@gmail.com> | 2018-05-21 12:42:22 +1000 |
| commit | 60eb5305f637e21f7ec4006924c06518ca6de476 (patch) | |
| tree | e3ae16cfcbef19fc5c28d87dcc15b75bdd722852 /py/objfloat.c | |
| parent | 4f71a2a75a71b89dad2eed147d6e237b633b878e (diff) | |
py/objfloat: Fix undefined shifting behavior in high-quality float hash.
When computing e.g. hash(0.4e3) with ubsan enabled, a diagnostic like the
following would occur:
../../py/objfloat.c:91:30: runtime error: shift exponent 44 is too
large for 32-bit type 'int'
By casting constant "1" to the right type the intended value is preserved.
Diffstat (limited to 'py/objfloat.c')
| -rw-r--r-- | py/objfloat.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/py/objfloat.c b/py/objfloat.c index e4d5a6570..31c624778 100644 --- a/py/objfloat.c +++ b/py/objfloat.c @@ -88,7 +88,7 @@ typedef uint32_t mp_float_uint_t; if (adj_exp <= MP_FLOAT_FRAC_BITS) { // number may have a fraction; xor the integer part with the fractional part val = (frc >> (MP_FLOAT_FRAC_BITS - adj_exp)) - ^ (frc & ((1 << (MP_FLOAT_FRAC_BITS - adj_exp)) - 1)); + ^ (frc & (((mp_float_uint_t)1 << (MP_FLOAT_FRAC_BITS - adj_exp)) - 1)); } else if ((unsigned int)adj_exp < BITS_PER_BYTE * sizeof(mp_int_t) - 1) { // the number is a (big) whole integer and will fit in val's signed-width val = (mp_int_t)frc << (adj_exp - MP_FLOAT_FRAC_BITS); |