From 8c183806a6b0f95ab53db4b029bc82823785c363 Mon Sep 17 00:00:00 2001
From: Mats Kindahl <mats@timescale.com>
Date: Tue, 6 Feb 2024 14:53:53 +0100
Subject: Standardize integer comparison for qsort()

Introduce a macro INT_CMP() that will standardize integer comparison
for implementing comparison function for qsort(). The macro will ensure
that the function returns -1, 0, or 1 without risking overflow as a
result of subtracting the two integers, which is otherwise a common
pattern for implementing this.
---
 contrib/hstore/hstore_gist.c                    |  2 +-
 contrib/intarray/_intbig_gist.c                 |  2 +-
 contrib/pg_stat_statements/pg_stat_statements.c |  7 +------
 contrib/pg_trgm/trgm_op.c                       |  7 +------
 contrib/seg/seg.c                               |  7 +------
 src/backend/access/nbtree/nbtinsert.c           |  7 +------
 src/backend/access/nbtree/nbtpage.c             |  9 ++-------
 src/backend/access/nbtree/nbtsplitloc.c         |  7 +------
 src/backend/access/spgist/spgdoinsert.c         |  4 +---
 src/backend/access/spgist/spgkdtreeproc.c       |  8 ++------
 src/backend/access/spgist/spgtextproc.c         |  2 +-
 src/backend/backup/basebackup_incremental.c     |  7 +------
 src/backend/backup/walsummary.c                 |  6 +-----
 src/backend/catalog/heap.c                      |  7 +------
 src/backend/nodes/list.c                        | 12 ++----------
 src/backend/nodes/tidbitmap.c                   |  6 +-----
 src/backend/optimizer/geqo/geqo_pool.c          |  7 +------
 src/backend/parser/parse_agg.c                  |  2 +-
 src/backend/postmaster/autovacuum.c             |  5 +----
 src/backend/replication/logical/reorderbuffer.c |  6 +-----
 src/backend/replication/syncrep.c               |  7 +------
 src/backend/utils/adt/oid.c                     |  6 +-----
 src/backend/utils/adt/tsgistidx.c               |  9 ++-------
 src/backend/utils/adt/tsquery_gist.c            |  5 +----
 src/backend/utils/adt/tsvector.c                |  4 +---
 src/backend/utils/adt/tsvector_op.c             |  4 +---
 src/backend/utils/adt/xid.c                     |  6 +-----
 src/backend/utils/cache/relcache.c              |  2 +-
 src/backend/utils/cache/syscache.c              |  4 +---
 src/backend/utils/cache/typcache.c              |  7 +------
 src/backend/utils/resowner/resowner.c           |  9 +--------
 src/bin/pg_dump/pg_dump_sort.c                  |  6 +-----
 src/bin/pg_upgrade/function.c                   |  8 ++++----
 src/bin/pg_walsummary/pg_walsummary.c           |  7 +------
 src/bin/psql/crosstabview.c                     |  2 +-
 src/include/access/gin_private.h                |  7 +------
 src/include/c.h                                 |  8 ++++++++
 37 files changed, 51 insertions(+), 170 deletions(-)

diff --git a/contrib/hstore/hstore_gist.c b/contrib/hstore/hstore_gist.c
index fe343739eb..e125b76290 100644
--- a/contrib/hstore/hstore_gist.c
+++ b/contrib/hstore/hstore_gist.c
@@ -356,7 +356,7 @@ typedef struct
 static int
 comparecost(const void *a, const void *b)
 {
-	return ((const SPLITCOST *) a)->cost - ((const SPLITCOST *) b)->cost;
+	return INT_CMP(((const SPLITCOST *) a)->cost, ((const SPLITCOST *) b)->cost);
 }
 
 
diff --git a/contrib/intarray/_intbig_gist.c b/contrib/intarray/_intbig_gist.c
index 8c6c4b5d05..7f0deda34d 100644
--- a/contrib/intarray/_intbig_gist.c
+++ b/contrib/intarray/_intbig_gist.c
@@ -312,7 +312,7 @@ typedef struct
 static int
 comparecost(const void *a, const void *b)
 {
-	return ((const SPLITCOST *) a)->cost - ((const SPLITCOST *) b)->cost;
+	return INT_CMP(((const SPLITCOST *) a)->cost,  ((const SPLITCOST *) b)->cost);
 }
 
 
diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c
index 8c6a3a2d08..f32e6868ed 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.c
+++ b/contrib/pg_stat_statements/pg_stat_statements.c
@@ -3007,10 +3007,5 @@ comp_location(const void *a, const void *b)
 	int			l = ((const LocationLen *) a)->location;
 	int			r = ((const LocationLen *) b)->location;
 
-	if (l < r)
-		return -1;
-	else if (l > r)
-		return +1;
-	else
-		return 0;
+	return INT_CMP(l, r);
 }
diff --git a/contrib/pg_trgm/trgm_op.c b/contrib/pg_trgm/trgm_op.c
index 49d4497b4f..f6020141a2 100644
--- a/contrib/pg_trgm/trgm_op.c
+++ b/contrib/pg_trgm/trgm_op.c
@@ -433,12 +433,7 @@ comp_ptrgm(const void *v1, const void *v2)
 	if (cmp != 0)
 		return cmp;
 
-	if (p1->index < p2->index)
-		return -1;
-	else if (p1->index == p2->index)
-		return 0;
-	else
-		return 1;
+	return INT_CMP(p1->index, p2->index);
 }
 
 /*
diff --git a/contrib/seg/seg.c b/contrib/seg/seg.c
index 7f9fc24eb4..ff2ffaf8c7 100644
--- a/contrib/seg/seg.c
+++ b/contrib/seg/seg.c
@@ -300,12 +300,7 @@ gseg_picksplit_item_cmp(const void *a, const void *b)
 	const gseg_picksplit_item *i1 = (const gseg_picksplit_item *) a;
 	const gseg_picksplit_item *i2 = (const gseg_picksplit_item *) b;
 
-	if (i1->center < i2->center)
-		return -1;
-	else if (i1->center == i2->center)
-		return 0;
-	else
-		return 1;
+	return INT_CMP(i1->center, i2->center);
 }
 
 /*
diff --git a/src/backend/access/nbtree/nbtinsert.c b/src/backend/access/nbtree/nbtinsert.c
index 709edd1c17..1aeaf19efd 100644
--- a/src/backend/access/nbtree/nbtinsert.c
+++ b/src/backend/access/nbtree/nbtinsert.c
@@ -3013,10 +3013,5 @@ _bt_blk_cmp(const void *arg1, const void *arg2)
 	BlockNumber b1 = *((BlockNumber *) arg1);
 	BlockNumber b2 = *((BlockNumber *) arg2);
 
-	if (b1 < b2)
-		return -1;
-	else if (b1 > b2)
-		return 1;
-
-	return 0;
+	return INT_CMP(b1, b2);
 }
diff --git a/src/backend/access/nbtree/nbtpage.c b/src/backend/access/nbtree/nbtpage.c
index 567bade9f4..bb31cda542 100644
--- a/src/backend/access/nbtree/nbtpage.c
+++ b/src/backend/access/nbtree/nbtpage.c
@@ -1466,14 +1466,9 @@ _bt_delitems_cmp(const void *a, const void *b)
 	TM_IndexDelete *indexdelete1 = (TM_IndexDelete *) a;
 	TM_IndexDelete *indexdelete2 = (TM_IndexDelete *) b;
 
-	if (indexdelete1->id > indexdelete2->id)
-		return 1;
-	if (indexdelete1->id < indexdelete2->id)
-		return -1;
+	Assert(INT_CMP(indexdelete1->id, indexdelete2->id) != 0);
 
-	Assert(false);
-
-	return 0;
+	return INT_CMP(indexdelete1->id, indexdelete2->id);
 }
 
 /*
diff --git a/src/backend/access/nbtree/nbtsplitloc.c b/src/backend/access/nbtree/nbtsplitloc.c
index d0b1d82578..f33f1f9d51 100644
--- a/src/backend/access/nbtree/nbtsplitloc.c
+++ b/src/backend/access/nbtree/nbtsplitloc.c
@@ -596,12 +596,7 @@ _bt_splitcmp(const void *arg1, const void *arg2)
 	SplitPoint *split1 = (SplitPoint *) arg1;
 	SplitPoint *split2 = (SplitPoint *) arg2;
 
-	if (split1->curdelta > split2->curdelta)
-		return 1;
-	if (split1->curdelta < split2->curdelta)
-		return -1;
-
-	return 0;
+	return INT_CMP(split1->curdelta,  split2->curdelta);
 }
 
 /*
diff --git a/src/backend/access/spgist/spgdoinsert.c b/src/backend/access/spgist/spgdoinsert.c
index bb063c858d..995392d480 100644
--- a/src/backend/access/spgist/spgdoinsert.c
+++ b/src/backend/access/spgist/spgdoinsert.c
@@ -110,9 +110,7 @@ addNode(SpGistState *state, SpGistInnerTuple tuple, Datum label, int offset)
 static int
 cmpOffsetNumbers(const void *a, const void *b)
 {
-	if (*(const OffsetNumber *) a == *(const OffsetNumber *) b)
-		return 0;
-	return (*(const OffsetNumber *) a > *(const OffsetNumber *) b) ? 1 : -1;
+	return INT_CMP(*(const OffsetNumber *) a, *(const OffsetNumber *) b);
 }
 
 /*
diff --git a/src/backend/access/spgist/spgkdtreeproc.c b/src/backend/access/spgist/spgkdtreeproc.c
index 900fe0d2af..a1a2598a3f 100644
--- a/src/backend/access/spgist/spgkdtreeproc.c
+++ b/src/backend/access/spgist/spgkdtreeproc.c
@@ -87,9 +87,7 @@ x_cmp(const void *a, const void *b)
 	SortedPoint *pa = (SortedPoint *) a;
 	SortedPoint *pb = (SortedPoint *) b;
 
-	if (pa->p->x == pb->p->x)
-		return 0;
-	return (pa->p->x > pb->p->x) ? 1 : -1;
+	return INT_CMP(pa->p->x, pb->p->x);
 }
 
 static int
@@ -98,9 +96,7 @@ y_cmp(const void *a, const void *b)
 	SortedPoint *pa = (SortedPoint *) a;
 	SortedPoint *pb = (SortedPoint *) b;
 
-	if (pa->p->y == pb->p->y)
-		return 0;
-	return (pa->p->y > pb->p->y) ? 1 : -1;
+	return INT_CMP(pa->p->y, pb->p->y);
 }
 
 
diff --git a/src/backend/access/spgist/spgtextproc.c b/src/backend/access/spgist/spgtextproc.c
index b8fd0c2ad8..4855f1f1de 100644
--- a/src/backend/access/spgist/spgtextproc.c
+++ b/src/backend/access/spgist/spgtextproc.c
@@ -325,7 +325,7 @@ cmpNodePtr(const void *a, const void *b)
 	const spgNodePtr *aa = (const spgNodePtr *) a;
 	const spgNodePtr *bb = (const spgNodePtr *) b;
 
-	return aa->c - bb->c;
+	return INT_CMP(aa->c, bb->c);
 }
 
 Datum
diff --git a/src/backend/backup/basebackup_incremental.c b/src/backend/backup/basebackup_incremental.c
index 0504c465db..c45c015f3c 100644
--- a/src/backend/backup/basebackup_incremental.c
+++ b/src/backend/backup/basebackup_incremental.c
@@ -994,10 +994,5 @@ compare_block_numbers(const void *a, const void *b)
 	BlockNumber aa = *(BlockNumber *) a;
 	BlockNumber bb = *(BlockNumber *) b;
 
-	if (aa > bb)
-		return 1;
-	else if (aa == bb)
-		return 0;
-	else
-		return -1;
+	return INT_CMP(aa,bb);
 }
diff --git a/src/backend/backup/walsummary.c b/src/backend/backup/walsummary.c
index 867870aaad..41e34fcb8b 100644
--- a/src/backend/backup/walsummary.c
+++ b/src/backend/backup/walsummary.c
@@ -355,9 +355,5 @@ ListComparatorForWalSummaryFiles(const ListCell *a, const ListCell *b)
 	WalSummaryFile *ws1 = lfirst(a);
 	WalSummaryFile *ws2 = lfirst(b);
 
-	if (ws1->start_lsn < ws2->start_lsn)
-		return -1;
-	if (ws1->start_lsn > ws2->start_lsn)
-		return 1;
-	return 0;
+	return INT_CMP(ws1->start_lsn, ws2->start_lsn);
 }
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index c73f7bcd01..b26d2bf04a 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -2758,12 +2758,7 @@ list_cookedconstr_attnum_cmp(const ListCell *p1, const ListCell *p2)
 {
 	AttrNumber	v1 = ((CookedConstraint *) lfirst(p1))->attnum;
 	AttrNumber	v2 = ((CookedConstraint *) lfirst(p2))->attnum;
-
-	if (v1 < v2)
-		return -1;
-	if (v1 > v2)
-		return 1;
-	return 0;
+	return INT_CMP(v1, v2);
 }
 
 /*
diff --git a/src/backend/nodes/list.c b/src/backend/nodes/list.c
index 957186bef5..769c97ee83 100644
--- a/src/backend/nodes/list.c
+++ b/src/backend/nodes/list.c
@@ -1692,11 +1692,7 @@ list_int_cmp(const ListCell *p1, const ListCell *p2)
 	int			v1 = lfirst_int(p1);
 	int			v2 = lfirst_int(p2);
 
-	if (v1 < v2)
-		return -1;
-	if (v1 > v2)
-		return 1;
-	return 0;
+	return INT_CMP(v1, v2);
 }
 
 /*
@@ -1708,9 +1704,5 @@ list_oid_cmp(const ListCell *p1, const ListCell *p2)
 	Oid			v1 = lfirst_oid(p1);
 	Oid			v2 = lfirst_oid(p2);
 
-	if (v1 < v2)
-		return -1;
-	if (v1 > v2)
-		return 1;
-	return 0;
+	return INT_CMP(v1, v2);
 }
diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index 0f4850065f..944f261e38 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -1425,11 +1425,7 @@ tbm_comparator(const void *left, const void *right)
 	BlockNumber l = (*((PagetableEntry *const *) left))->blockno;
 	BlockNumber r = (*((PagetableEntry *const *) right))->blockno;
 
-	if (l < r)
-		return -1;
-	else if (l > r)
-		return 1;
-	return 0;
+	return INT_CMP(l,r);
 }
 
 /*
diff --git a/src/backend/optimizer/geqo/geqo_pool.c b/src/backend/optimizer/geqo/geqo_pool.c
index 0ec97d5a3f..165ff7a380 100644
--- a/src/backend/optimizer/geqo/geqo_pool.c
+++ b/src/backend/optimizer/geqo/geqo_pool.c
@@ -147,12 +147,7 @@ compare(const void *arg1, const void *arg2)
 	const Chromosome *chromo1 = (const Chromosome *) arg1;
 	const Chromosome *chromo2 = (const Chromosome *) arg2;
 
-	if (chromo1->worth == chromo2->worth)
-		return 0;
-	else if (chromo1->worth > chromo2->worth)
-		return 1;
-	else
-		return -1;
+	return INT_CMP(chromo1->worth, chromo2->worth);
 }
 
 /* alloc_chromo
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 7b211a7743..af3c4da463 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -1760,7 +1760,7 @@ cmp_list_len_asc(const ListCell *a, const ListCell *b)
 	int			la = list_length((const List *) lfirst(a));
 	int			lb = list_length((const List *) lfirst(b));
 
-	return (la > lb) ? 1 : (la == lb) ? 0 : -1;
+	return INT_CMP(la, lb);
 }
 
 /* list_sort comparator to sort sub-lists by length and contents */
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 2c3099f76f..82a6f4a2f0 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -1119,10 +1119,7 @@ rebuild_database_list(Oid newdb)
 static int
 db_comparator(const void *a, const void *b)
 {
-	if (((const avl_dbase *) a)->adl_score == ((const avl_dbase *) b)->adl_score)
-		return 0;
-	else
-		return (((const avl_dbase *) a)->adl_score < ((const avl_dbase *) b)->adl_score) ? 1 : -1;
+	return INT_CMP(((const avl_dbase *) a)->adl_score, ((const avl_dbase *) b)->adl_score);
 }
 
 /*
diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
index bbf0966182..5d61a2227e 100644
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -5119,11 +5119,7 @@ file_sort_by_lsn(const ListCell *a_p, const ListCell *b_p)
 	RewriteMappingFile *a = (RewriteMappingFile *) lfirst(a_p);
 	RewriteMappingFile *b = (RewriteMappingFile *) lfirst(b_p);
 
-	if (a->lsn < b->lsn)
-		return -1;
-	else if (a->lsn > b->lsn)
-		return 1;
-	return 0;
+	return INT_CMP(a->lsn, b->lsn);
 }
 
 /*
diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c
index 2e6493aaaa..6aecce074d 100644
--- a/src/backend/replication/syncrep.c
+++ b/src/backend/replication/syncrep.c
@@ -698,12 +698,7 @@ cmp_lsn(const void *a, const void *b)
 	XLogRecPtr	lsn1 = *((const XLogRecPtr *) a);
 	XLogRecPtr	lsn2 = *((const XLogRecPtr *) b);
 
-	if (lsn1 > lsn2)
-		return -1;
-	else if (lsn1 == lsn2)
-		return 0;
-	else
-		return 1;
+	return INT_CMP(lsn2, lsn1);
 }
 
 /*
diff --git a/src/backend/utils/adt/oid.c b/src/backend/utils/adt/oid.c
index 62bcfc5b56..a46adfe764 100644
--- a/src/backend/utils/adt/oid.c
+++ b/src/backend/utils/adt/oid.c
@@ -259,11 +259,7 @@ 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 INT_CMP(v1, v2);
 }
 
 
diff --git a/src/backend/utils/adt/tsgistidx.c b/src/backend/utils/adt/tsgistidx.c
index a62b285365..bd6eac3ea4 100644
--- a/src/backend/utils/adt/tsgistidx.c
+++ b/src/backend/utils/adt/tsgistidx.c
@@ -136,9 +136,7 @@ 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 INT_CMP(a,b);
 }
 
 static void
@@ -598,10 +596,7 @@ 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 INT_CMP(a->cost, b->cost);
 }
 
 
diff --git a/src/backend/utils/adt/tsquery_gist.c b/src/backend/utils/adt/tsquery_gist.c
index f0b1c81c81..29d49f45dc 100644
--- a/src/backend/utils/adt/tsquery_gist.c
+++ b/src/backend/utils/adt/tsquery_gist.c
@@ -156,10 +156,7 @@ 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 INT_CMP(((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 fb7b7c712a..1875612019 100644
--- a/src/backend/utils/adt/tsvector.c
+++ b/src/backend/utils/adt/tsvector.c
@@ -37,9 +37,7 @@ 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 INT_CMP(apos, bpos);
 }
 
 /*
diff --git a/src/backend/utils/adt/tsvector_op.c b/src/backend/utils/adt/tsvector_op.c
index 71386d0a1f..c17d0599e3 100644
--- a/src/backend/utils/adt/tsvector_op.c
+++ b/src/backend/utils/adt/tsvector_op.c
@@ -435,9 +435,7 @@ 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 INT_CMP(a,b);
 }
 
 static int
diff --git a/src/backend/utils/adt/xid.c b/src/backend/utils/adt/xid.c
index 63adf5668b..79b35cbd7b 100644
--- a/src/backend/utils/adt/xid.c
+++ b/src/backend/utils/adt/xid.c
@@ -140,11 +140,7 @@ 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 INT_CMP(xid1, xid2);
 }
 
 /*
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index ac106b40e3..fd3a56349e 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -4520,7 +4520,7 @@ AttrDefaultCmp(const void *a, const void *b)
 	const AttrDefault *ada = (const AttrDefault *) a;
 	const AttrDefault *adb = (const AttrDefault *) b;
 
-	return ada->adnum - adb->adnum;
+	return INT_CMP(ada->adnum, adb->adnum);
 }
 
 /*
diff --git a/src/backend/utils/cache/syscache.c b/src/backend/utils/cache/syscache.c
index 162855b158..2bfc7e7fe0 100644
--- a/src/backend/utils/cache/syscache.c
+++ b/src/backend/utils/cache/syscache.c
@@ -676,7 +676,5 @@ oid_compare(const void *a, const void *b)
 	Oid			oa = *((const Oid *) a);
 	Oid			ob = *((const Oid *) b);
 
-	if (oa == ob)
-		return 0;
-	return (oa > ob) ? 1 : -1;
+	return INT_CMP(oa, ob);
 }
diff --git a/src/backend/utils/cache/typcache.c b/src/backend/utils/cache/typcache.c
index 84fc83cb11..b689471e53 100644
--- a/src/backend/utils/cache/typcache.c
+++ b/src/backend/utils/cache/typcache.c
@@ -2722,12 +2722,7 @@ enum_oid_cmp(const void *left, const void *right)
 	const EnumItem *l = (const EnumItem *) left;
 	const EnumItem *r = (const EnumItem *) right;
 
-	if (l->enum_oid < r->enum_oid)
-		return -1;
-	else if (l->enum_oid > r->enum_oid)
-		return 1;
-	else
-		return 0;
+	return INT_CMP(l->enum_oid, r->enum_oid);
 }
 
 /*
diff --git a/src/backend/utils/resowner/resowner.c b/src/backend/utils/resowner/resowner.c
index aa199b23ff..4cda8dde7f 100644
--- a/src/backend/utils/resowner/resowner.c
+++ b/src/backend/utils/resowner/resowner.c
@@ -264,14 +264,7 @@ resource_priority_cmp(const void *a, const void *b)
 
 	/* Note: reverse order */
 	if (ra->kind->release_phase == rb->kind->release_phase)
-	{
-		if (ra->kind->release_priority == rb->kind->release_priority)
-			return 0;
-		else if (ra->kind->release_priority > rb->kind->release_priority)
-			return -1;
-		else
-			return 1;
-	}
+		return INT_CMP(ra->kind->release_priority, rb->kind->release_priority);
 	else if (ra->kind->release_phase > rb->kind->release_phase)
 		return -1;
 	else
diff --git a/src/bin/pg_dump/pg_dump_sort.c b/src/bin/pg_dump/pg_dump_sort.c
index f358dd22b9..72937622ac 100644
--- a/src/bin/pg_dump/pg_dump_sort.c
+++ b/src/bin/pg_dump/pg_dump_sort.c
@@ -1504,9 +1504,5 @@ int_cmp(void *a, void *b, void *arg)
 	int			ai = (int) (intptr_t) a;
 	int			bi = (int) (intptr_t) b;
 
-	if (ai < bi)
-		return -1;
-	if (ai > bi)
-		return 1;
-	return 0;
+	return INT_CMP(ai, bi);
 }
diff --git a/src/bin/pg_upgrade/function.c b/src/bin/pg_upgrade/function.c
index af998f74d3..d21c534d7c 100644
--- a/src/bin/pg_upgrade/function.c
+++ b/src/bin/pg_upgrade/function.c
@@ -32,14 +32,14 @@ library_name_compare(const void *p1, const void *p2)
 	int			slen1 = strlen(str1);
 	int			slen2 = strlen(str2);
 	int			cmp = strcmp(str1, str2);
+	int lhsdb = ((const LibraryInfo *) p1)->dbnum;
+	int rhsdb = ((const LibraryInfo *) p2)->dbnum;
 
 	if (slen1 != slen2)
-		return slen1 - slen2;
+		return INT_CMP(slen1, slen2);
 	if (cmp != 0)
 		return cmp;
-	else
-		return ((const LibraryInfo *) p1)->dbnum -
-			((const LibraryInfo *) p2)->dbnum;
+	return INT_CMP(lhsdb, rhsdb);
 }
 
 
diff --git a/src/bin/pg_walsummary/pg_walsummary.c b/src/bin/pg_walsummary/pg_walsummary.c
index 1341c83c69..2de4547279 100644
--- a/src/bin/pg_walsummary/pg_walsummary.c
+++ b/src/bin/pg_walsummary/pg_walsummary.c
@@ -219,12 +219,7 @@ compare_block_numbers(const void *a, const void *b)
 	BlockNumber aa = *(BlockNumber *) a;
 	BlockNumber bb = *(BlockNumber *) b;
 
-	if (aa > bb)
-		return 1;
-	else if (aa == bb)
-		return 0;
-	else
-		return -1;
+	return INT_CMP(aa, bb);
 }
 
 /*
diff --git a/src/bin/psql/crosstabview.c b/src/bin/psql/crosstabview.c
index c6116b7238..50f24055b6 100644
--- a/src/bin/psql/crosstabview.c
+++ b/src/bin/psql/crosstabview.c
@@ -709,5 +709,5 @@ pivotFieldCompare(const void *a, const void *b)
 static int
 rankCompare(const void *a, const void *b)
 {
-	return *((const int *) a) - *((const int *) b);
+	return INT_CMP(*(const int *) a, *(const int *) b);
 }
diff --git a/src/include/access/gin_private.h b/src/include/access/gin_private.h
index 51d0c74a6b..da5646ab41 100644
--- a/src/include/access/gin_private.h
+++ b/src/include/access/gin_private.h
@@ -489,12 +489,7 @@ ginCompareItemPointers(ItemPointer a, ItemPointer b)
 	uint64		ia = (uint64) GinItemPointerGetBlockNumber(a) << 32 | GinItemPointerGetOffsetNumber(a);
 	uint64		ib = (uint64) GinItemPointerGetBlockNumber(b) << 32 | GinItemPointerGetOffsetNumber(b);
 
-	if (ia == ib)
-		return 0;
-	else if (ia > ib)
-		return 1;
-	else
-		return -1;
+	return INT_CMP(ia, ib);
 }
 
 extern int	ginTraverseLock(Buffer buffer, bool searchMode);
diff --git a/src/include/c.h b/src/include/c.h
index 2e3ea206e1..114c3373ca 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -1090,6 +1090,14 @@ extern void ExceptionalCondition(const char *conditionName,
  * ----------------------------------------------------------------
  */
 
+/*
+ * Compare two integers and return -1, 0, or 1 without risking overflow.
+ *
+ * This macro is used to avoid running into overflow issues because a simple
+ * subtraction of the two values when implementing a cmp function for qsort().
+*/
+#define INT_CMP(lhs,rhs) (((lhs) > (rhs)) - ((lhs) < (rhs)))
+
 /*
  * Invert the sign of a qsort-style comparison result, ie, exchange negative
  * and positive integer values, being careful not to get the wrong answer
-- 
2.34.1