From: Andres Freund <andres@anarazel.de>
Date: Sun, 1 Apr 2018 03:26:47 +0000 (-0700)
Subject: Fix non-portable use of round().
X-Git-Tag: REL_11_BETA1~405
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=686d399f2be6eea4b74d59cdadd427d09cb0e246;p=postgresql

Fix non-portable use of round().

round() is from C99.  Use rint() instead.  There are behavioral
differences between round() and rint(), but they should not matter to
the Bloom filter optimal_k() function.  We already assume POSIX
behavior for rint(), so there is no question of rint() not using
"rounds towards nearest" as its rounding mode.

Cleanup from commit 51bc271790eb234a1ba4d14d3e6530f70de92ab5.

Per buildfarm member thrips.

Author: Peter Geoghegan
Discussion: https://postgr.es/m/CAH2-Wzn76eCGUonARy-wrVtMHsf+4cvbK_oJAWTLfORTU5ki0w@mail.gmail.com
---

diff --git a/src/backend/lib/bloomfilter.c b/src/backend/lib/bloomfilter.c
index eb08f4a7b8..3565480d13 100644
--- a/src/backend/lib/bloomfilter.c
+++ b/src/backend/lib/bloomfilter.c
@@ -240,7 +240,7 @@ my_bloom_power(uint64 target_bitset_bits)
 static int
 optimal_k(uint64 bitset_bits, int64 total_elems)
 {
-	int			k = round(log(2.0) * bitset_bits / total_elems);
+	int			k = rint(log(2.0) * bitset_bits / total_elems);
 
 	return Max(1, Min(k, MAX_HASH_FUNCS));
 }