int4 range

Hi all,

I supposed the int4 range was from -2147483648 to +2147483647 but I
have the following message trying to update an int4 column:

prova=> update t set i=-2147483648;
NOTICE:  Integer input '2147483648' is out of range; promoted to float
UPDATE 1

The column was updated any way, but I don't understand the message.

prova=> update t set i=-2147483647;
UPDATE 1

PS: I'm using v6.4 on Linux.

-Jose'-