diff options
Diffstat (limited to 'src/backend/utils/adt/int8.c')
| -rw-r--r-- | src/backend/utils/adt/int8.c | 53 |
1 files changed, 30 insertions, 23 deletions
diff --git a/src/backend/utils/adt/int8.c b/src/backend/utils/adt/int8.c index 17d2973280b..62f54c12d50 100644 --- a/src/backend/utils/adt/int8.c +++ b/src/backend/utils/adt/int8.c @@ -1342,25 +1342,29 @@ i8tod(PG_FUNCTION_ARGS) Datum dtoi8(PG_FUNCTION_ARGS) { - float8 arg = PG_GETARG_FLOAT8(0); - int64 result; - - /* Round arg to nearest integer (but it's still in float form) */ - arg = rint(arg); + float8 num = PG_GETARG_FLOAT8(0); /* - * Does it fit in an int64? Avoid assuming that we have handy constants - * defined for the range boundaries, instead test for overflow by - * reverse-conversion. + * Get rid of any fractional part in the input. This is so we don't fail + * on just-out-of-range values that would round into range. Note + * assumption that rint() will pass through a NaN or Inf unchanged. */ - result = (int64) arg; + num = rint(num); - if ((float8) result != arg) + /* + * Range check. We must be careful here that the boundary values are + * expressed exactly in the float domain. We expect PG_INT64_MIN to be an + * exact power of 2, so it will be represented exactly; but PG_INT64_MAX + * isn't, and might get rounded off, so avoid using it. + */ + if (num < (float8) PG_INT64_MIN || + num >= -((float8) PG_INT64_MIN) || + isnan(num)) ereport(ERROR, (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), errmsg("bigint out of range"))); - PG_RETURN_INT64(result); + PG_RETURN_INT64((int64) num); } Datum @@ -1380,26 +1384,29 @@ i8tof(PG_FUNCTION_ARGS) Datum ftoi8(PG_FUNCTION_ARGS) { - float4 arg = PG_GETARG_FLOAT4(0); - int64 result; - float8 darg; - - /* Round arg to nearest integer (but it's still in float form) */ - darg = rint(arg); + float4 num = PG_GETARG_FLOAT4(0); /* - * Does it fit in an int64? Avoid assuming that we have handy constants - * defined for the range boundaries, instead test for overflow by - * reverse-conversion. + * Get rid of any fractional part in the input. This is so we don't fail + * on just-out-of-range values that would round into range. Note + * assumption that rint() will pass through a NaN or Inf unchanged. */ - result = (int64) darg; + num = rint(num); - if ((float8) result != darg) + /* + * Range check. We must be careful here that the boundary values are + * expressed exactly in the float domain. We expect PG_INT64_MIN to be an + * exact power of 2, so it will be represented exactly; but PG_INT64_MAX + * isn't, and might get rounded off, so avoid using it. + */ + if (num < (float4) PG_INT64_MIN || + num >= -((float4) PG_INT64_MIN) || + isnan(num)) ereport(ERROR, (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), errmsg("bigint out of range"))); - PG_RETURN_INT64(result); + PG_RETURN_INT64((int64) num); } Datum |