avutil/softfloat: Fix overflow in av_div_sf()

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2017-05-06 21:31:49 +02:00
parent b9d2005ea5
commit 277e397eb5
1 changed files with 8 additions and 1 deletions

View File

@ -113,8 +113,15 @@ static inline av_const SoftFloat av_mul_sf(SoftFloat a, SoftFloat b){
* @return Will not be more denormalized than a.
*/
static inline av_const SoftFloat av_div_sf(SoftFloat a, SoftFloat b){
int64_t temp = (int64_t)a.mant * (1<<(ONE_BITS+1));
temp /= b.mant;
a.exp -= b.exp;
a.mant = ((int64_t)a.mant<<(ONE_BITS+1)) / b.mant;
a.mant = temp;
while (a.mant != temp) {
temp /= 2;
a.exp--;
a.mant = temp;
}
a = av_normalize1_sf(a);
if (!a.mant || a.exp < MIN_EXP)
return FLOAT_0;