Peter Eisentraut <peter.eisentr...@2ndquadrant.com> writes: > On 4/12/17 00:12, Tom Lane wrote: >> Now a human can see that saved_timeval.tv_usec must be 0..999999, so >> that the %d format item must always emit exactly 3 characters, which >> means that really 5 bytes would be enough. I wouldn't expect a >> compiler to know that, but if it's making a generic assumption about >> the worst-case width of %d, shouldn't it conclude that we might need >> as many as 13 bytes for the buffer? Why does msbuf[10] satisfy it >> if msbuf[8] doesn't?
> Because the /1000 takes off three digits? Huh ... I would not really have expected it to figure that out, but this makes it pretty clear that it did: > test.c:11:15: note: directive argument in the range [-2147483, 2147483] > (This is with -O2. With -O0 it only asks for 5 bytes.) But that reinforces my suspicion that the intelligence brought to bear here will be variable. I'd still go for msbuf[16]; it's not like anybody's going to notice the extra stack consumption. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers