Use new overflow-safe integer comparison functions.

Commit 6b80394781 introduced integer comparison functions designed
to be as efficient as possible while avoiding overflow.  This
commit makes use of these functions in many of the in-tree qsort()
comparators to help ensure transitivity.  Many of these comparator
functions should also see a small performance boost.

Author: Mats Kindahl
Reviewed-by: Andres Freund, Fabrízio de Royes Mello
Discussion: https://postgr.es/m/CA%2B14426g2Wa9QuUpmakwPxXFWG_1FaY0AsApkvcTBy-YfS6uaw%40mail.gmail.com

6 files changed, 14 insertions, 27 deletions

diff --git a/src/backend/utils/adt/oid.c b/src/backend/utils/adt/oid.c
index 62bcfc5b566..56fb1fd77ce 100644
--- a/src/backend/utils/adt/oid.c
+++ b/src/backend/utils/adt/oid.c
@@ -18,6 +18,7 @@
 #include <limits.h>
 
 #include "catalog/pg_type.h"
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "nodes/miscnodes.h"
 #include "nodes/value.h"
@@ -259,11 +260,7 @@ oid_cmp(const void *p1, const void *p2)
 	Oid			v1 = *((const Oid *) p1);
 	Oid			v2 = *((const Oid *) p2);
 
-	if (v1 < v2)
-		return -1;
-	if (v1 > v2)
-		return 1;
-	return 0;
+	return pg_cmp_u32(v1, v2);
 }
 
 
diff --git a/src/backend/utils/adt/tsgistidx.c b/src/backend/utils/adt/tsgistidx.c
index a62b285365a..3fb76964343 100644
--- a/src/backend/utils/adt/tsgistidx.c
+++ b/src/backend/utils/adt/tsgistidx.c
@@ -17,6 +17,7 @@
 #include "access/gist.h"
 #include "access/heaptoast.h"
 #include "access/reloptions.h"
+#include "common/int.h"
 #include "lib/qunique.h"
 #include "port/pg_bitutils.h"
 #include "tsearch/ts_utils.h"
@@ -136,9 +137,7 @@ compareint(const void *va, const void *vb)
 	int32		a = *((const int32 *) va);
 	int32		b = *((const int32 *) vb);
 
-	if (a == b)
-		return 0;
-	return (a > b) ? 1 : -1;
+	return pg_cmp_s32(a, b);
 }
 
 static void
@@ -598,10 +597,7 @@ comparecost(const void *va, const void *vb)
 	const SPLITCOST *a = (const SPLITCOST *) va;
 	const SPLITCOST *b = (const SPLITCOST *) vb;
 
-	if (a->cost == b->cost)
-		return 0;
-	else
-		return (a->cost > b->cost) ? 1 : -1;
+	return pg_cmp_s32(a->cost, b->cost);
 }
 
 
diff --git a/src/backend/utils/adt/tsquery_gist.c b/src/backend/utils/adt/tsquery_gist.c
index f0b1c81c816..2db304b10bd 100644
--- a/src/backend/utils/adt/tsquery_gist.c
+++ b/src/backend/utils/adt/tsquery_gist.c
@@ -16,6 +16,7 @@
 
 #include "access/gist.h"
 #include "access/stratnum.h"
+#include "common/int.h"
 #include "tsearch/ts_utils.h"
 #include "utils/builtins.h"
 
@@ -156,10 +157,8 @@ typedef struct
 static int
 comparecost(const void *a, const void *b)
 {
-	if (((const SPLITCOST *) a)->cost == ((const SPLITCOST *) b)->cost)
-		return 0;
-	else
-		return (((const SPLITCOST *) a)->cost > ((const SPLITCOST *) b)->cost) ? 1 : -1;
+	return pg_cmp_s32(((const SPLITCOST *) a)->cost,
+					  ((const SPLITCOST *) b)->cost);
 }
 
 #define WISH_F(a,b,c) (double)( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )
diff --git a/src/backend/utils/adt/tsvector.c b/src/backend/utils/adt/tsvector.c
index fb7b7c712a4..10bc4f2234f 100644
--- a/src/backend/utils/adt/tsvector.c
+++ b/src/backend/utils/adt/tsvector.c
@@ -14,6 +14,7 @@
 
 #include "postgres.h"
 
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "nodes/miscnodes.h"
 #include "tsearch/ts_locale.h"
@@ -37,9 +38,7 @@ compareWordEntryPos(const void *a, const void *b)
 	int			apos = WEP_GETPOS(*(const WordEntryPos *) a);
 	int			bpos = WEP_GETPOS(*(const WordEntryPos *) b);
 
-	if (apos == bpos)
-		return 0;
-	return (apos > bpos) ? 1 : -1;
+	return pg_cmp_s32(apos, bpos);
 }
 
 /*
diff --git a/src/backend/utils/adt/tsvector_op.c b/src/backend/utils/adt/tsvector_op.c
index 71386d0a1ff..947a592ed28 100644
--- a/src/backend/utils/adt/tsvector_op.c
+++ b/src/backend/utils/adt/tsvector_op.c
@@ -19,6 +19,7 @@
 #include "catalog/namespace.h"
 #include "catalog/pg_type.h"
 #include "commands/trigger.h"
+#include "common/int.h"
 #include "executor/spi.h"
 #include "funcapi.h"
 #include "lib/qunique.h"
@@ -435,9 +436,7 @@ compare_int(const void *va, const void *vb)
 	int			a = *((const int *) va);
 	int			b = *((const int *) vb);
 
-	if (a == b)
-		return 0;
-	return (a > b) ? 1 : -1;
+	return pg_cmp_s32(a, b);
 }
 
 static int
diff --git a/src/backend/utils/adt/xid.c b/src/backend/utils/adt/xid.c
index 63adf5668b5..ae273b19610 100644
--- a/src/backend/utils/adt/xid.c
+++ b/src/backend/utils/adt/xid.c
@@ -19,6 +19,7 @@
 #include "access/multixact.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "utils/builtins.h"
 #include "utils/xid8.h"
@@ -140,11 +141,7 @@ xidComparator(const void *arg1, const void *arg2)
 	TransactionId xid1 = *(const TransactionId *) arg1;
 	TransactionId xid2 = *(const TransactionId *) arg2;
 
-	if (xid1 > xid2)
-		return 1;
-	if (xid1 < xid2)
-		return -1;
-	return 0;
+	return pg_cmp_u32(xid1, xid2);
 }
 
 /*