Re: [PATCH] Fix overflow and underflow in regr_r2()
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Dean Rasheed <dean.a.rasheed@gmail.com>
Cc: Chengpeng Yan <chengpeng_yan@outlook.com>,
PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2026-05-16T21:18:43Z
Lists: pgsql-hackers
Dean Rasheed <dean.a.rasheed@gmail.com> writes: > I just had a thought: a simpler (and probably faster and more > accurate) solution would be to use frexp() and ldexp(), which are both > part of C99, so ought to be OK. Seems like a plan. We're already relying on ldexp() in pg_prng.c, so I doubt there's a portability issue. Reading the man page for frexp(), we might want to special-case Inf and NaN inputs to avoid assuming what it will do with those. But that would only be needed in the slow path where we're recovering from overflow/underflow. regards, tom lane