From e94c1a55dada49772622d2be2d17a2a9973b2661 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sun, 26 Sep 2021 14:24:03 -0400 Subject: [PATCH] Avoid unnecessary division in interval_cmp_value(). Splitting the time field into days and microseconds is pretty useless when we're just going to recombine those values. It's unclear if anyone will notice the speedup in real-world cases, but a cycle shaved is a cycle earned. Discussion: https://postgr.es/m/2629129.1632675713@sss.pgh.pa.us --- src/backend/utils/adt/timestamp.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c index 1c0bf0aa5c..cb9faff0bb 100644 --- a/src/backend/utils/adt/timestamp.c +++ b/src/backend/utils/adt/timestamp.c @@ -2352,20 +2352,17 @@ static inline INT128 interval_cmp_value(const Interval *interval) { INT128 span; - int64 dayfraction; int64 days; /* - * Separate time field into days and dayfraction, then add the month and - * day fields to the days part. We cannot overflow int64 days here. + * Combine the month and day fields into an integral number of days. + * Because the inputs are int32, int64 arithmetic suffices here. */ - dayfraction = interval->time % USECS_PER_DAY; - days = interval->time / USECS_PER_DAY; - days += interval->month * INT64CONST(30); + days = interval->month * INT64CONST(30); days += interval->day; - /* Widen dayfraction to 128 bits */ - span = int64_to_int128(dayfraction); + /* Widen time field to 128 bits */ + span = int64_to_int128(interval->time); /* Scale up days to microseconds, forming a 128-bit product */ int128_add_int64_mul_int64(&span, days, USECS_PER_DAY);