diff options
Diffstat (limited to 'src/backend/utils/adt/timestamp.c')
| -rw-r--r-- | src/backend/utils/adt/timestamp.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c index da73796eac8..552b631ba78 100644 --- a/src/backend/utils/adt/timestamp.c +++ b/src/backend/utils/adt/timestamp.c @@ -5308,10 +5308,16 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric) int64 secs_from_day_month; int64 val; - /* this always fits into int64 */ - secs_from_day_month = ((int64) DAYS_PER_YEAR * (interval->month / MONTHS_PER_YEAR) + - (int64) DAYS_PER_MONTH * (interval->month % MONTHS_PER_YEAR) + - interval->day) * SECS_PER_DAY; + /* + * To do this calculation in integer arithmetic even though + * DAYS_PER_YEAR is fractional, multiply everything by 4 and then + * divide by 4 again at the end. This relies on DAYS_PER_YEAR + * being a multiple of 0.25 and on SECS_PER_DAY being a multiple + * of 4. + */ + secs_from_day_month = ((int64) (4 * DAYS_PER_YEAR) * (interval->month / MONTHS_PER_YEAR) + + (int64) (4 * DAYS_PER_MONTH) * (interval->month % MONTHS_PER_YEAR) + + (int64) 4 * interval->day) * (SECS_PER_DAY / 4); /*--- * result = secs_from_day_month + interval->time / 1'000'000 |