On Wed, Dec 14, 2011 at 12:36 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > AFAICS it's really impractical to do that. The code Andrew is having > problems with is essentially > > double a,b,c; > ... > a = b * c; > if (isinf(a)) throw error; > > and the problem is that the multiplication result overflows in double > precision, but not in the wider-than-double register precision. > Therefore, if a is in a register and the isinf() primitive inspects the > register, it will return false, even though when the value gets stored > to memory it will become an infinity.
Uh, wow. That really is pretty insane. How is anyone supposed to write sensible code around that non-API? -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
