10809 Performance optimization of AVL tree comparator functions

Portions contributed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Richard Elling <richard.elling@gmail.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

25 files changed, 163 insertions, 260 deletions

diff --git a/usr/src/lib/libzfs/common/libzfs_dataset.c b/usr/src/lib/libzfs/common/libzfs_dataset.c
index 662e207eea..1b2bf860e2 100644
--- a/usr/src/lib/libzfs/common/libzfs_dataset.c
+++ b/usr/src/lib/libzfs/common/libzfs_dataset.c
@@ -774,15 +774,13 @@ typedef struct mnttab_node {
 static int
 libzfs_mnttab_cache_compare(const void *arg1, const void *arg2)
 {
-	const mnttab_node_t *mtn1 = arg1;
-	const mnttab_node_t *mtn2 = arg2;
+	const mnttab_node_t *mtn1 = (const mnttab_node_t *)arg1;
+	const mnttab_node_t *mtn2 = (const mnttab_node_t *)arg2;
 	int rv;
 
 	rv = strcmp(mtn1->mtn_mt.mnt_special, mtn2->mtn_mt.mnt_special);
 
-	if (rv == 0)
-		return (0);
-	return (rv > 0 ? 1 : -1);
+	return (AVL_ISIGN(rv));
 }
 
 void
diff --git a/usr/src/lib/libzfs/common/libzfs_iter.c b/usr/src/lib/libzfs/common/libzfs_iter.c
index b0cb1ff186..bdef9757ef 100644
--- a/usr/src/lib/libzfs/common/libzfs_iter.c
+++ b/usr/src/lib/libzfs/common/libzfs_iter.c
@@ -272,12 +272,7 @@ zfs_snapshot_compare(const void *larg, const void *rarg)
 	lcreate = zfs_prop_get_int(l, ZFS_PROP_CREATETXG);
 	rcreate = zfs_prop_get_int(r, ZFS_PROP_CREATETXG);
 
-	if (lcreate < rcreate)
-		return (-1);
-	else if (lcreate > rcreate)
-		return (+1);
-	else
-		return (0);
+	return (AVL_CMP(lcreate, rcreate));
 }
 
 int
diff --git a/usr/src/lib/libzfs/common/libzfs_sendrecv.c b/usr/src/lib/libzfs/common/libzfs_sendrecv.c
index e56aa7f7c1..7ed81fd0d1 100644
--- a/usr/src/lib/libzfs/common/libzfs_sendrecv.c
+++ b/usr/src/lib/libzfs/common/libzfs_sendrecv.c
@@ -482,15 +482,10 @@ typedef struct fsavl_node {
 static int
 fsavl_compare(const void *arg1, const void *arg2)
 {
-	const fsavl_node_t *fn1 = arg1;
-	const fsavl_node_t *fn2 = arg2;
+	const fsavl_node_t *fn1 = (const fsavl_node_t *)arg1;
+	const fsavl_node_t *fn2 = (const fsavl_node_t *)arg2;
 
-	if (fn1->fn_guid > fn2->fn_guid)
-		return (+1);
-	else if (fn1->fn_guid < fn2->fn_guid)
-		return (-1);
-	else
-		return (0);
+	return (AVL_CMP(fn1->fn_guid, fn2->fn_guid));
 }
 
 /*
diff --git a/usr/src/lib/libzpool/common/sys/zfs_context.h b/usr/src/lib/libzpool/common/sys/zfs_context.h
index d1dce80196..8612aefb0f 100644
--- a/usr/src/lib/libzpool/common/sys/zfs_context.h
+++ b/usr/src/lib/libzpool/common/sys/zfs_context.h
@@ -285,6 +285,14 @@ extern vnode_t *rootdir;
 #define	minclsyspri	60
 #define	maxclsyspri	99
 
+#if (GCC_VERSION >= 302) || (__INTEL_COMPILER >= 800) || defined(__clang__)
+#define	_zfs_expect(expr, value)    (__builtin_expect((expr), (value)))
+#else
+#define	_zfs_expect(expr, value)    (expr)
+#endif
+
+#define	likely(x)	_zfs_expect((x) != 0, 1)
+
 #define	CPU_SEQID	(thr_self() & (max_ncpus - 1))
 
 extern void kernel_init(int);
diff --git a/usr/src/uts/common/fs/zfs/ddt.c b/usr/src/uts/common/fs/zfs/ddt.c
index 06c51fe05b..963ecbd58f 100644
--- a/usr/src/uts/common/fs/zfs/ddt.c
+++ b/usr/src/uts/common/fs/zfs/ddt.c
@@ -755,22 +755,31 @@ ddt_prefetch(spa_t *spa, const blkptr_t *bp)
 	}
 }
 
+/*
+ * Opaque struct used for ddt_key comparison
+ */
+#define	DDT_KEY_CMP_LEN	(sizeof (ddt_key_t) / sizeof (uint16_t))
+
+typedef struct ddt_key_cmp {
+	uint16_t	u16[DDT_KEY_CMP_LEN];
+} ddt_key_cmp_t;
+
 int
 ddt_entry_compare(const void *x1, const void *x2)
 {
 	const ddt_entry_t *dde1 = x1;
 	const ddt_entry_t *dde2 = x2;
-	const uint64_t *u1 = (const uint64_t *)&dde1->dde_key;
-	const uint64_t *u2 = (const uint64_t *)&dde2->dde_key;
-
-	for (int i = 0; i < DDT_KEY_WORDS; i++) {
-		if (u1[i] < u2[i])
-			return (-1);
-		if (u1[i] > u2[i])
-			return (1);
+	const ddt_key_cmp_t *k1 = (const ddt_key_cmp_t *)&dde1->dde_key;
+	const ddt_key_cmp_t *k2 = (const ddt_key_cmp_t *)&dde2->dde_key;
+	int32_t cmp = 0;
+
+	for (int i = 0; i < DDT_KEY_CMP_LEN; i++) {
+		cmp = (int32_t)k1->u16[i] - (int32_t)k2->u16[i];
+		if (likely(cmp))
+			break;
 	}
 
-	return (0);
+	return (AVL_ISIGN(cmp));
 }
 
 static ddt_t *
diff --git a/usr/src/uts/common/fs/zfs/dnode.c b/usr/src/uts/common/fs/zfs/dnode.c
index 2f9e188454..f360eb997e 100644
--- a/usr/src/uts/common/fs/zfs/dnode.c
+++ b/usr/src/uts/common/fs/zfs/dnode.c
@@ -90,19 +90,13 @@ dbuf_compare(const void *x1, const void *x2)
 	const dmu_buf_impl_t *d1 = x1;
 	const dmu_buf_impl_t *d2 = x2;
 
-	if (d1->db_level < d2->db_level) {
-		return (-1);
-	}
-	if (d1->db_level > d2->db_level) {
-		return (1);
-	}
+	int cmp = AVL_CMP(d1->db_level, d2->db_level);
+	if (likely(cmp))
+		return (cmp);
 
-	if (d1->db_blkid < d2->db_blkid) {
-		return (-1);
-	}
-	if (d1->db_blkid > d2->db_blkid) {
-		return (1);
-	}
+	cmp = AVL_CMP(d1->db_blkid, d2->db_blkid);
+	if (likely(cmp))
+		return (cmp);
 
 	if (d1->db_state == DB_SEARCH) {
 		ASSERT3S(d2->db_state, !=, DB_SEARCH);
@@ -112,13 +106,7 @@ dbuf_compare(const void *x1, const void *x2)
 		return (1);
 	}
 
-	if ((uintptr_t)d1 < (uintptr_t)d2) {
-		return (-1);
-	}
-	if ((uintptr_t)d1 > (uintptr_t)d2) {
-		return (1);
-	}
-	return (0);
+	return (AVL_PCMP(d1, d2));
 }
 
 /* ARGSUSED */
diff --git a/usr/src/uts/common/fs/zfs/dsl_deadlist.c b/usr/src/uts/common/fs/zfs/dsl_deadlist.c
index 356e5b51c3..2f3647bc8e 100644
--- a/usr/src/uts/common/fs/zfs/dsl_deadlist.c
+++ b/usr/src/uts/common/fs/zfs/dsl_deadlist.c
@@ -55,15 +55,10 @@
 static int
 dsl_deadlist_compare(const void *arg1, const void *arg2)
 {
-	const dsl_deadlist_entry_t *dle1 = arg1;
-	const dsl_deadlist_entry_t *dle2 = arg2;
+	const dsl_deadlist_entry_t *dle1 = (const dsl_deadlist_entry_t *)arg1;
+	const dsl_deadlist_entry_t *dle2 = (const dsl_deadlist_entry_t *)arg2;
 
-	if (dle1->dle_mintxg < dle2->dle_mintxg)
-		return (-1);
-	else if (dle1->dle_mintxg > dle2->dle_mintxg)
-		return (+1);
-	else
-		return (0);
+	return (AVL_CMP(dle1->dle_mintxg, dle2->dle_mintxg));
 }
 
 static void
diff --git a/usr/src/uts/common/fs/zfs/dsl_deleg.c b/usr/src/uts/common/fs/zfs/dsl_deleg.c
index b2f69045a6..e72c66ade6 100644
--- a/usr/src/uts/common/fs/zfs/dsl_deleg.c
+++ b/usr/src/uts/common/fs/zfs/dsl_deleg.c
@@ -384,14 +384,13 @@ typedef struct perm_set {
 static int
 perm_set_compare(const void *arg1, const void *arg2)
 {
-	const perm_set_t *node1 = arg1;
-	const perm_set_t *node2 = arg2;
+	const perm_set_t *node1 = (const perm_set_t *)arg1;
+	const perm_set_t *node2 = (const perm_set_t *)arg2;
 	int val;
 
 	val = strcmp(node1->p_setname, node2->p_setname);
-	if (val == 0)
-		return (0);
-	return (val > 0 ? 1 : -1);
+
+	return (AVL_ISIGN(val));
 }
 
 /*
diff --git a/usr/src/uts/common/fs/zfs/lz4.c b/usr/src/uts/common/fs/zfs/lz4.c
index 82a08939dc..6426ba67b2 100644
--- a/usr/src/uts/common/fs/zfs/lz4.c
+++ b/usr/src/uts/common/fs/zfs/lz4.c
@@ -284,8 +284,13 @@ lz4_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
 #define	expect(expr, value)    (expr)
 #endif
 
+#ifndef likely
 #define	likely(expr)	expect((expr) != 0, 1)
+#endif
+
+#ifndef unlikely
 #define	unlikely(expr)	expect((expr) != 0, 0)
+#endif
 
 /* Basic types */
 #if defined(_MSC_VER)
diff --git a/usr/src/uts/common/fs/zfs/metaslab.c b/usr/src/uts/common/fs/zfs/metaslab.c
index 1bd057de0c..0044f37964 100644
--- a/usr/src/uts/common/fs/zfs/metaslab.c
+++ b/usr/src/uts/common/fs/zfs/metaslab.c
@@ -453,8 +453,8 @@ metaslab_class_expandable_space(metaslab_class_t *mc)
 static int
 metaslab_compare(const void *x1, const void *x2)
 {
-	const metaslab_t *m1 = x1;
-	const metaslab_t *m2 = x2;
+	const metaslab_t *m1 = (const metaslab_t *)x1;
+	const metaslab_t *m2 = (const metaslab_t *)x2;
 
 	int sort1 = 0;
 	int sort2 = 0;
@@ -480,22 +480,13 @@ metaslab_compare(const void *x1, const void *x2)
 	if (sort1 > sort2)
 		return (1);
 
-	if (m1->ms_weight < m2->ms_weight)
-		return (1);
-	if (m1->ms_weight > m2->ms_weight)
-		return (-1);
-
-	/*
-	 * If the weights are identical, use the offset to force uniqueness.
-	 */
-	if (m1->ms_start < m2->ms_start)
-		return (-1);
-	if (m1->ms_start > m2->ms_start)
-		return (1);
+	int cmp = AVL_CMP(m2->ms_weight, m1->ms_weight);
+	if (likely(cmp))
+		return (cmp);
 
-	ASSERT3P(m1, ==, m2);
+	IMPLY(AVL_CMP(m1->ms_start, m2->ms_start) == 0, m1 == m2);
 
-	return (0);
+	return (AVL_CMP(m1->ms_start, m2->ms_start));
 }
 
 uint64_t
@@ -1130,18 +1121,11 @@ metaslab_rangesize_compare(const void *x1, const void *x2)
 	uint64_t rs_size1 = r1->rs_end - r1->rs_start;
 	uint64_t rs_size2 = r2->rs_end - r2->rs_start;
 
-	if (rs_size1 < rs_size2)
-		return (-1);
-	if (rs_size1 > rs_size2)
-		return (1);
-
-	if (r1->rs_start < r2->rs_start)
-		return (-1);
+	int cmp = AVL_CMP(rs_size1, rs_size2);
+	if (likely(cmp))
+		return (cmp);
 
-	if (r1->rs_start > r2->rs_start)
-		return (1);
-
-	return (0);
+	return (AVL_CMP(r1->rs_start, r2->rs_start));
 }
 
 /*
diff --git a/usr/src/uts/common/fs/zfs/range_tree.c b/usr/src/uts/common/fs/zfs/range_tree.c
index c99d0e68fc..0a852a9c8d 100644
--- a/usr/src/uts/common/fs/zfs/range_tree.c
+++ b/usr/src/uts/common/fs/zfs/range_tree.c
@@ -109,20 +109,13 @@ range_tree_stat_decr(range_tree_t *rt, range_seg_t *rs)
 static int
 range_tree_seg_compare(const void *x1, const void *x2)
 {
-	const range_seg_t *r1 = x1;
-	const range_seg_t *r2 = x2;
+	const range_seg_t *r1 = (const range_seg_t *)x1;
+	const range_seg_t *r2 = (const range_seg_t *)x2;
 
-	if (r1->rs_start < r2->rs_start) {
-		if (r1->rs_end > r2->rs_start)
-			return (0);
-		return (-1);
-	}
-	if (r1->rs_start > r2->rs_start) {
-		if (r1->rs_start < r2->rs_end)
-			return (0);
-		return (1);
-	}
-	return (0);
+	ASSERT3U(r1->rs_start, <=, r1->rs_end);
+	ASSERT3U(r2->rs_start, <=, r2->rs_end);
+
+	return ((r1->rs_start >= r2->rs_end) - (r1->rs_end <= r2->rs_start));
 }
 
 range_tree_t *
diff --git a/usr/src/uts/common/fs/zfs/sa.c b/usr/src/uts/common/fs/zfs/sa.c
index d8cf42db5f..d3c0a3e8ef 100644
--- a/usr/src/uts/common/fs/zfs/sa.c
+++ b/usr/src/uts/common/fs/zfs/sa.c
@@ -243,31 +243,23 @@ sa_cache_fini(void)
 static int
 layout_num_compare(const void *arg1, const void *arg2)
 {
-	const sa_lot_t *node1 = arg1;
-	const sa_lot_t *node2 = arg2;
+	const sa_lot_t *node1 = (const sa_lot_t *)arg1;
+	const sa_lot_t *node2 = (const sa_lot_t *)arg2;
 
-	if (node1->lot_num > node2->lot_num)
-		return (1);
-	else if (node1->lot_num < node2->lot_num)
-		return (-1);
-	return (0);
+	return (AVL_CMP(node1->lot_num, node2->lot_num));
 }
 
 static int
 layout_hash_compare(const void *arg1, const void *arg2)
 {
-	const sa_lot_t *node1 = arg1;
-	const sa_lot_t *node2 = arg2;
+	const sa_lot_t *node1 = (const sa_lot_t *)arg1;
+	const sa_lot_t *node2 = (const sa_lot_t *)arg2;
 
-	if (node1->lot_hash > node2->lot_hash)
-		return (1);
-	if (node1->lot_hash < node2->lot_hash)
-		return (-1);
-	if (node1->lot_instance > node2->lot_instance)
-		return (1);
-	if (node1->lot_instance < node2->lot_instance)
-		return (-1);
-	return (0);
+	int cmp = AVL_CMP(node1->lot_hash, node2->lot_hash);
+	if (likely(cmp))
+		return (cmp);
+
+	return (AVL_CMP(node1->lot_instance, node2->lot_instance));
 }
 
 boolean_t
diff --git a/usr/src/uts/common/fs/zfs/spa.c b/usr/src/uts/common/fs/zfs/spa.c
index 96fc30bf75..6348d133a9 100644
--- a/usr/src/uts/common/fs/zfs/spa.c
+++ b/usr/src/uts/common/fs/zfs/spa.c
@@ -900,19 +900,14 @@ spa_change_guid(spa_t *spa)
 static int
 spa_error_entry_compare(const void *a, const void *b)
 {
-	spa_error_entry_t *sa = (spa_error_entry_t *)a;
-	spa_error_entry_t *sb = (spa_error_entry_t *)b;
+	const spa_error_entry_t *sa = (const spa_error_entry_t *)a;
+	const spa_error_entry_t *sb = (const spa_error_entry_t *)b;
 	int ret;
 
-	ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
+	ret = memcmp(&sa->se_bookmark, &sb->se_bookmark,
 	    sizeof (zbookmark_phys_t));
 
-	if (ret < 0)
-		return (-1);
-	else if (ret > 0)
-		return (1);
-	else
-		return (0);
+	return (AVL_ISIGN(ret));
 }
 
 /*
diff --git a/usr/src/uts/common/fs/zfs/spa_misc.c b/usr/src/uts/common/fs/zfs/spa_misc.c
index 45948c2a7a..9a80f89a8a 100644
--- a/usr/src/uts/common/fs/zfs/spa_misc.c
+++ b/usr/src/uts/common/fs/zfs/spa_misc.c
@@ -915,18 +915,13 @@ typedef struct spa_aux {
 	int		aux_count;
 } spa_aux_t;
 
-static int
+static inline int
 spa_aux_compare(const void *a, const void *b)
 {
-	const spa_aux_t *sa = a;
-	const spa_aux_t *sb = b;
+	const spa_aux_t *sa = (const spa_aux_t *)a;
+	const spa_aux_t *sb = (const spa_aux_t *)b;
 
-	if (sa->aux_guid < sb->aux_guid)
-		return (-1);
-	else if (sa->aux_guid > sb->aux_guid)
-		return (1);
-	else
-		return (0);
+	return (AVL_CMP(sa->aux_guid, sb->aux_guid));
 }
 
 void
@@ -1984,11 +1979,8 @@ spa_name_compare(const void *a1, const void *a2)
 	int s;
 
 	s = strcmp(s1->spa_name, s2->spa_name);
-	if (s > 0)
-		return (1);
-	if (s < 0)
-		return (-1);
-	return (0);
+
+	return (AVL_ISIGN(s));
 }
 
 int
diff --git a/usr/src/uts/common/fs/zfs/space_reftree.c b/usr/src/uts/common/fs/zfs/space_reftree.c
index a866e65d54..aa289ba106 100644
--- a/usr/src/uts/common/fs/zfs/space_reftree.c
+++ b/usr/src/uts/common/fs/zfs/space_reftree.c
@@ -54,20 +54,14 @@
 static int
 space_reftree_compare(const void *x1, const void *x2)
 {
-	const space_ref_t *sr1 = x1;
-	const space_ref_t *sr2 = x2;
+	const space_ref_t *sr1 = (const space_ref_t *)x1;
+	const space_ref_t *sr2 = (const space_ref_t *)x2;
 
-	if (sr1->sr_offset < sr2->sr_offset)
-		return (-1);
-	if (sr1->sr_offset > sr2->sr_offset)
-		return (1);
+	int cmp = AVL_CMP(sr1->sr_offset, sr2->sr_offset);
+	if (likely(cmp))
+		return (cmp);
 
-	if (sr1 < sr2)
-		return (-1);
-	if (sr1 > sr2)
-		return (1);
-
-	return (0);
+	return (AVL_PCMP(sr1, sr2));
 }
 
 void
diff --git a/usr/src/uts/common/fs/zfs/sys/zfs_context.h b/usr/src/uts/common/fs/zfs/sys/zfs_context.h
index 37de17b4a4..ebcdc7f111 100644
--- a/usr/src/uts/common/fs/zfs/sys/zfs_context.h
+++ b/usr/src/uts/common/fs/zfs/sys/zfs_context.h
@@ -73,6 +73,14 @@ extern "C" {
 #include <sys/disp.h>
 #include <sys/callo.h>
 
+#if (GCC_VERSION >= 302) || (__INTEL_COMPILER >= 800) || defined(__clang__)
+#define	_zfs_expect(expr, value)    (__builtin_expect((expr), (value)))
+#else
+#define	_zfs_expect(expr, value)    (expr)
+#endif
+
+#define	likely(x)	_zfs_expect((x) != 0, 1)
+
 #define	CPU_SEQID	(CPU->cpu_seqid)
 
 #ifdef	__cplusplus
diff --git a/usr/src/uts/common/fs/zfs/unique.c b/usr/src/uts/common/fs/zfs/unique.c
index fbe7b619a2..d33f451938 100644
--- a/usr/src/uts/common/fs/zfs/unique.c
+++ b/usr/src/uts/common/fs/zfs/unique.c
@@ -42,14 +42,10 @@ typedef struct unique {
 static int
 unique_compare(const void *a, const void *b)
 {
-	const unique_t *una = a;
-	const unique_t *unb = b;
-
-	if (una->un_value < unb->un_value)
-		return (-1);
-	if (una->un_value > unb->un_value)
-		return (+1);
-	return (0);
+	const unique_t *una = (const unique_t *)a;
+	const unique_t *unb = (const unique_t *)b;
+
+	return (AVL_CMP(una->un_value, unb->un_value));
 }
 
 void
diff --git a/usr/src/uts/common/fs/zfs/vdev_cache.c b/usr/src/uts/common/fs/zfs/vdev_cache.c
index 9b4755321d..34ae6d5270 100644
--- a/usr/src/uts/common/fs/zfs/vdev_cache.c
+++ b/usr/src/uts/common/fs/zfs/vdev_cache.c
@@ -105,29 +105,24 @@ static vdc_stats_t vdc_stats = {
 
 #define	VDCSTAT_BUMP(stat)	atomic_inc_64(&vdc_stats.stat.value.ui64);
 
-static int
+static inline int
 vdev_cache_offset_compare(const void *a1, const void *a2)
 {
-	const vdev_cache_entry_t *ve1 = a1;
-	const vdev_cache_entry_t *ve2 = a2;
-
-	if (ve1->ve_offset < ve2->ve_offset)
-		return (-1);
-	if (ve1->ve_offset > ve2->ve_offset)
-		return (1);
-	return (0);
+	const vdev_cache_entry_t *ve1 = (const vdev_cache_entry_t *)a1;
+	const vdev_cache_entry_t *ve2 = (const vdev_cache_entry_t *)a2;
+
+	return (AVL_CMP(ve1->ve_offset, ve2->ve_offset));
 }
 
 static int
 vdev_cache_lastused_compare(const void *a1, const void *a2)
 {
-	const vdev_cache_entry_t *ve1 = a1;
-	const vdev_cache_entry_t *ve2 = a2;
+	const vdev_cache_entry_t *ve1 = (const vdev_cache_entry_t *)a1;
+	const vdev_cache_entry_t *ve2 = (const vdev_cache_entry_t *)a2;
 
-	if (ve1->ve_lastused < ve2->ve_lastused)
-		return (-1);
-	if (ve1->ve_lastused > ve2->ve_lastused)
-		return (1);
+	int cmp = AVL_CMP(ve1->ve_lastused, ve2->ve_lastused);
+	if (likely(cmp))
+		return (cmp);
 
 	/*
 	 * Among equally old entries, sort by offset to ensure uniqueness.
diff --git a/usr/src/uts/common/fs/zfs/vdev_label.c b/usr/src/uts/common/fs/zfs/vdev_label.c
index b11c528348..3c469ffe43 100644
--- a/usr/src/uts/common/fs/zfs/vdev_label.c
+++ b/usr/src/uts/common/fs/zfs/vdev_label.c
@@ -1013,19 +1013,13 @@ retry:
  * among uberblocks with equal txg, choose the one with the latest timestamp.
  */
 static int
-vdev_uberblock_compare(uberblock_t *ub1, uberblock_t *ub2)
+vdev_uberblock_compare(const uberblock_t *ub1, const uberblock_t *ub2)
 {
-	if (ub1->ub_txg < ub2->ub_txg)
-		return (-1);
-	if (ub1->ub_txg > ub2->ub_txg)
-		return (1);
+	int cmp = AVL_CMP(ub1->ub_txg, ub2->ub_txg);
+	if (likely(cmp))
+		return (cmp);
 
-	if (ub1->ub_timestamp < ub2->ub_timestamp)
-		return (-1);
-	if (ub1->ub_timestamp > ub2->ub_timestamp)
-		return (1);
-
-	return (0);
+	return (AVL_CMP(ub1->ub_timestamp, ub2->ub_timestamp));
 }
 
 struct ubl_cbdata {
diff --git a/usr/src/uts/common/fs/zfs/vdev_queue.c b/usr/src/uts/common/fs/zfs/vdev_queue.c
index f29f4eeb9d..dff83e3108 100644
--- a/usr/src/uts/common/fs/zfs/vdev_queue.c
+++ b/usr/src/uts/common/fs/zfs/vdev_queue.c
@@ -202,20 +202,15 @@ int zfs_vdev_def_queue_depth = 32;
 int
 vdev_queue_offset_compare(const void *x1, const void *x2)
 {
-	const zio_t *z1 = x1;
-	const zio_t *z2 = x2;
+	const zio_t *z1 = (const zio_t *)x1;
+	const zio_t *z2 = (const zio_t *)x2;
 
-	if (z1->io_offset < z2->io_offset)
-		return (-1);
-	if (z1->io_offset > z2->io_offset)
-		return (1);
+	int cmp = AVL_CMP(z1->io_offset, z2->io_offset);
 
-	if (z1 < z2)
-		return (-1);
-	if (z1 > z2)
-		return (1);
+	if (likely(cmp))
+		return (cmp);
 
-	return (0);
+	return (AVL_PCMP(z1, z2));
 }
 
 static inline avl_tree_t *
@@ -237,20 +232,15 @@ vdev_queue_type_tree(vdev_queue_t *vq, zio_type_t t)
 int
 vdev_queue_timestamp_compare(const void *x1, const void *x2)
 {
-	const zio_t *z1 = x1;
-	const zio_t *z2 = x2;
+	const zio_t *z1 = (const zio_t *)x1;
+	const zio_t *z2 = (const zio_t *)x2;
 
-	if (z1->io_timestamp < z2->io_timestamp)
-		return (-1);
-	if (z1->io_timestamp > z2->io_timestamp)
-		return (1);
+	int cmp = AVL_CMP(z1->io_timestamp, z2->io_timestamp);
 
-	if (z1 < z2)
-		return (-1);
-	if (z1 > z2)
-		return (1);
+	if (likely(cmp))
+		return (cmp);
 
-	return (0);
+	return (AVL_PCMP(z1, z2));
 }
 
 void
diff --git a/usr/src/uts/common/fs/zfs/zap_micro.c b/usr/src/uts/common/fs/zfs/zap_micro.c
index bb5da13ba1..48b0be6665 100644
--- a/usr/src/uts/common/fs/zfs/zap_micro.c
+++ b/usr/src/uts/common/fs/zfs/zap_micro.c
@@ -281,15 +281,11 @@ mze_compare(const void *arg1, const void *arg2)
 	const mzap_ent_t *mze1 = arg1;
 	const mzap_ent_t *mze2 = arg2;
 
-	if (mze1->mze_hash > mze2->mze_hash)
-		return (+1);
-	if (mze1->mze_hash < mze2->mze_hash)
-		return (-1);
-	if (mze1->mze_cd > mze2->mze_cd)
-		return (+1);
-	if (mze1->mze_cd < mze2->mze_cd)
-		return (-1);
-	return (0);
+	int cmp = AVL_CMP(mze1->mze_hash, mze2->mze_hash);
+	if (likely(cmp))
+		return (cmp);
+
+	return (AVL_CMP(mze1->mze_cd, mze2->mze_cd));
 }
 
 static void
diff --git a/usr/src/uts/common/fs/zfs/zfs_fuid.c b/usr/src/uts/common/fs/zfs/zfs_fuid.c
index 6eb03c2c18..7877a97b49 100644
--- a/usr/src/uts/common/fs/zfs/zfs_fuid.c
+++ b/usr/src/uts/common/fs/zfs/zfs_fuid.c
@@ -71,14 +71,10 @@ static char *nulldomain = "";
 static int
 idx_compare(const void *arg1, const void *arg2)
 {
-	const fuid_domain_t *node1 = arg1;
-	const fuid_domain_t *node2 = arg2;
+	const fuid_domain_t *node1 = (const fuid_domain_t *)arg1;
+	const fuid_domain_t *node2 = (const fuid_domain_t *)arg2;
 
-	if (node1->f_idx < node2->f_idx)
-		return (-1);
-	else if (node1->f_idx > node2->f_idx)
-		return (1);
-	return (0);
+	return (AVL_CMP(node1->f_idx, node2->f_idx));
 }
 
 /*
@@ -87,14 +83,13 @@ idx_compare(const void *arg1, const void *arg2)
 static int
 domain_compare(const void *arg1, const void *arg2)
 {
-	const fuid_domain_t *node1 = arg1;
-	const fuid_domain_t *node2 = arg2;
+	const fuid_domain_t *node1 = (const fuid_domain_t *)arg1;
+	const fuid_domain_t *node2 = (const fuid_domain_t *)arg2;
 	int val;
 
 	val = strcmp(node1->f_ksid->kd_name, node2->f_ksid->kd_name);
-	if (val == 0)
-		return (0);
-	return (val > 0 ? 1 : -1);
+
+	return (AVL_ISIGN(val));
 }
 
 void
diff --git a/usr/src/uts/common/fs/zfs/zfs_rlock.c b/usr/src/uts/common/fs/zfs/zfs_rlock.c
index 4e80ab27cc..6c2f39bca3 100644
--- a/usr/src/uts/common/fs/zfs/zfs_rlock.c
+++ b/usr/src/uts/common/fs/zfs/zfs_rlock.c
@@ -106,14 +106,10 @@
 static int
 rangelock_compare(const void *arg1, const void *arg2)
 {
-	const locked_range_t *rl1 = arg1;
-	const locked_range_t *rl2 = arg2;
-
-	if (rl1->lr_offset > rl2->lr_offset)
-		return (1);
-	if (rl1->lr_offset < rl2->lr_offset)
-		return (-1);
-	return (0);
+	const locked_range_t *rl1 = (const locked_range_t *)arg1;
+	const locked_range_t *rl2 = (const locked_range_t *)arg2;
+
+	return (AVL_CMP(rl1->lr_offset, rl2->lr_offset));
 }
 
 /*
diff --git a/usr/src/uts/common/fs/zfs/zil.c b/usr/src/uts/common/fs/zfs/zil.c
index 64b2c5944b..546e4f3d1e 100644
--- a/usr/src/uts/common/fs/zfs/zil.c
+++ b/usr/src/uts/common/fs/zfs/zil.c
@@ -123,17 +123,11 @@ zil_bp_compare(const void *x1, const void *x2)
 	const dva_t *dva1 = &((zil_bp_node_t *)x1)->zn_dva;
 	const dva_t *dva2 = &((zil_bp_node_t *)x2)->zn_dva;
 
-	if (DVA_GET_VDEV(dva1) < DVA_GET_VDEV(dva2))
-		return (-1);
-	if (DVA_GET_VDEV(dva1) > DVA_GET_VDEV(dva2))
-		return (1);
-
-	if (DVA_GET_OFFSET(dva1) < DVA_GET_OFFSET(dva2))
-		return (-1);
-	if (DVA_GET_OFFSET(dva1) > DVA_GET_OFFSET(dva2))
-		return (1);
+	int cmp = AVL_CMP(DVA_GET_VDEV(dva1), DVA_GET_VDEV(dva2));
+	if (likely(cmp))
+		return (cmp);
 
-	return (0);
+	return (AVL_CMP(DVA_GET_OFFSET(dva1), DVA_GET_OFFSET(dva2)));
 }
 
 static void
@@ -495,12 +489,7 @@ zil_lwb_vdev_compare(const void *x1, const void *x2)
 	const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev;
 	const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev;
 
-	if (v1 < v2)
-		return (-1);
-	if (v1 > v2)
-		return (1);
-
-	return (0);
+	return (AVL_CMP(v1, v2));
 }
 
 static lwb_t *
@@ -1729,12 +1718,7 @@ zil_aitx_compare(const void *x1, const void *x2)
 	const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid;
 	const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid;
 
-	if (o1 < o2)
-		return (-1);
-	if (o1 > o2)
-		return (1);
-
-	return (0);
+	return (AVL_CMP(o1, o2));
 }
 
 /*
diff --git a/usr/src/uts/common/sys/avl.h b/usr/src/uts/common/sys/avl.h
index cc4af828e6..ec2647a8bc 100644
--- a/usr/src/uts/common/sys/avl.h
+++ b/usr/src/uts/common/sys/avl.h
@@ -100,6 +100,13 @@ extern "C" {
  * as is needed for any linked list implementation.
  */
 
+/*
+ * AVL comparator helpers
+ */
+#define	AVL_ISIGN(a)	(((a) > 0) - ((a) < 0))
+#define	AVL_CMP(a, b)	(((a) > (b)) - ((a) < (b)))
+#define	AVL_PCMP(a, b)	\
+	(((uintptr_t)(a) > (uintptr_t)(b)) - ((uintptr_t)(a) < (uintptr_t)(b)))
 
 /*
  * Type used for the root of the AVL tree.