diff --git a/include/os/freebsd/spl/sys/debug.h b/include/os/freebsd/spl/sys/debug.h
index 2751f57801f7..1f820bc3345f 100644
--- a/include/os/freebsd/spl/sys/debug.h
+++ b/include/os/freebsd/spl/sys/debug.h
@@ -1,168 +1,168 @@
 /*
  * Copyright (c) 2020 iXsystems, Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
  * $FreeBSD$
  */
 
 /*
  * Available Solaris debug functions.  All of the ASSERT() macros will be
  * compiled out when NDEBUG is defined, this is the default behavior for
  * the SPL.  To enable assertions use the --enable-debug with configure.
  * The VERIFY() functions are never compiled out and cannot be disabled.
  *
  * PANIC()	- Panic the node and print message.
  * ASSERT()	- Assert X is true, if not panic.
  * ASSERT3B()	- Assert boolean X OP Y is true, if not panic.
  * ASSERT3S()	- Assert signed X OP Y is true, if not panic.
  * ASSERT3U()	- Assert unsigned X OP Y is true, if not panic.
  * ASSERT3P()	- Assert pointer X OP Y is true, if not panic.
  * ASSERT0()	- Assert value is zero, if not panic.
  * VERIFY()	- Verify X is true, if not panic.
  * VERIFY3B()	- Verify boolean X OP Y is true, if not panic.
  * VERIFY3S()	- Verify signed X OP Y is true, if not panic.
  * VERIFY3U()	- Verify unsigned X OP Y is true, if not panic.
  * VERIFY3P()	- Verify pointer X OP Y is true, if not panic.
  * VERIFY0()	- Verify value is zero, if not panic.
  */
 
 #ifndef _SPL_DEBUG_H
 #define	_SPL_DEBUG_H
 
 
 /*
  * Common DEBUG functionality.
  */
 int spl_panic(const char *file, const char *func, int line,
     const char *fmt, ...);
 void spl_dumpstack(void);
 
 #ifndef expect
 #define	expect(expr, value) (__builtin_expect((expr), (value)))
 #endif
 #define	likely(expr)   expect((expr) != 0, 1)
 #define	unlikely(expr) expect((expr) != 0, 0)
 
 /* BEGIN CSTYLED */
 #define	PANIC(fmt, a...)						\
 	spl_panic(__FILE__, __FUNCTION__, __LINE__, fmt, ## a)
 
-#define	VERIFY(cond)							\
-	(void) (unlikely(!(cond)) &&					\
+#define	VERIFY(cond)										\
+	(void) (unlikely(!(cond)) &&							\
 	    spl_panic(__FILE__, __FUNCTION__, __LINE__,			\
 	    "%s", "VERIFY(" #cond ") failed\n"))
 
-#define	VERIFY3B(LEFT, OP, RIGHT)	do {				\
-		boolean_t _verify3_left = (boolean_t)(LEFT);		\
-		boolean_t _verify3_right = (boolean_t)(RIGHT);		\
-		if (!(_verify3_left OP _verify3_right))			\
+#define	VERIFY3B(LEFT, OP, RIGHT)	do {					\
+		const boolean_t _verify3_left = (boolean_t)(LEFT);	\
+		const boolean_t _verify3_right = (boolean_t)(RIGHT);\
+		if (unlikely(!(_verify3_left OP _verify3_right)))	\
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
-		    "failed (%d " #OP " %d)\n",				\
-		    (boolean_t) (_verify3_left),			\
-		    (boolean_t) (_verify3_right));			\
+		    "failed (%d " #OP " %d)\n",						\
+		    (boolean_t) (_verify3_left),					\
+		    (boolean_t) (_verify3_right));					\
 	} while (0)
 
-#define	VERIFY3S(LEFT, OP, RIGHT)	do {				\
-		int64_t _verify3_left = (int64_t)(LEFT);		\
-		int64_t _verify3_right = (int64_t)(RIGHT);		\
-		if (!(_verify3_left OP _verify3_right))			\
+#define	VERIFY3S(LEFT, OP, RIGHT)	do {					\
+		const int64_t _verify3_left = (int64_t)(LEFT);		\
+		const int64_t _verify3_right = (int64_t)(RIGHT);	\
+		if (unlikely(!(_verify3_left OP _verify3_right)))	\
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
-		    "failed (%lld " #OP " %lld)\n",			\
-		    (long long) (_verify3_left),			\
-		    (long long) (_verify3_right));			\
+		    "failed (%lld " #OP " %lld)\n",					\
+		    (long long) (_verify3_left),					\
+		    (long long) (_verify3_right));					\
 	} while (0)
 
-#define	VERIFY3U(LEFT, OP, RIGHT)	do {				\
-		uint64_t _verify3_left = (uint64_t)(LEFT);		\
-		uint64_t _verify3_right = (uint64_t)(RIGHT);		\
-		if (!(_verify3_left OP _verify3_right))			\
+#define	VERIFY3U(LEFT, OP, RIGHT)	do {					\
+		const uint64_t _verify3_left = (uint64_t)(LEFT);	\
+		const uint64_t _verify3_right = (uint64_t)(RIGHT);	\
+		if (unlikely(!(_verify3_left OP _verify3_right)))	\
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
-		    "failed (%llu " #OP " %llu)\n",			\
-		    (unsigned long long) (_verify3_left),		\
-		    (unsigned long long) (_verify3_right));		\
+		    "failed (%llu " #OP " %llu)\n",					\
+		    (unsigned long long) (_verify3_left),			\
+		    (unsigned long long) (_verify3_right));			\
 	} while (0)
 
-#define	VERIFY3P(LEFT, OP, RIGHT)	do {				\
-		uintptr_t _verify3_left = (uintptr_t)(LEFT);		\
-		uintptr_t _verify3_right = (uintptr_t)(RIGHT);		\
-		if (!(_verify3_left OP _verify3_right))			\
+#define	VERIFY3P(LEFT, OP, RIGHT)	do {					\
+		const uintptr_t _verify3_left = (uintptr_t)(LEFT);	\
+		const uintptr_t _verify3_right = (uintptr_t)(RIGHT);\
+		if (unlikely(!(_verify3_left OP _verify3_right)))	\
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
-		    "failed (%px " #OP " %px)\n",			\
-		    (void *) (_verify3_left),				\
-		    (void *) (_verify3_right));				\
+		    "failed (%px " #OP " %px)\n",					\
+		    (void *) (_verify3_left),						\
+		    (void *) (_verify3_right));						\
 	} while (0)
 
-#define	VERIFY0(RIGHT)	do {				\
-		int64_t _verify3_left = (int64_t)(0);		\
-		int64_t _verify3_right = (int64_t)(RIGHT);		\
-		if (!(_verify3_left == _verify3_right))			\
+#define	VERIFY0(RIGHT)	do {								\
+		const int64_t _verify3_left = (int64_t)(0);			\
+		const int64_t _verify3_right = (int64_t)(RIGHT);	\
+		if (unlikely(!(_verify3_left == _verify3_right)))	\
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
-		    "VERIFY3(0 == " #RIGHT ") "				\
-		    "failed (0 == %lld)\n",				\
-		    (long long) (_verify3_right));			\
+		    "VERIFY3(0 == " #RIGHT ") "						\
+		    "failed (0 == %lld)\n",							\
+		    (long long) (_verify3_right));					\
 	} while (0)
-#define	CTASSERT_GLOBAL(x)		CTASSERT(x)
+#define        CTASSERT_GLOBAL(x)              CTASSERT(x)
 
 /*
  * Debugging disabled (--disable-debug)
  */
 #ifdef NDEBUG
 
 #define	ASSERT(x)		((void)0)
 #define	ASSERT3B(x,y,z)		((void)0)
 #define	ASSERT3S(x,y,z)		((void)0)
 #define	ASSERT3U(x,y,z)		((void)0)
 #define	ASSERT3P(x,y,z)		((void)0)
 #define	ASSERT0(x)		((void)0)
 #define	IMPLY(A, B)		((void)0)
 #define	EQUIV(A, B)		((void)0)
 
 /*
  * Debugging enabled (--enable-debug)
  */
 #else
 
 #define	ASSERT3B	VERIFY3B
 #define	ASSERT3S	VERIFY3S
 #define	ASSERT3U	VERIFY3U
 #define	ASSERT3P	VERIFY3P
 #define	ASSERT0		VERIFY0
 #define	ASSERT		VERIFY
 #define	IMPLY(A, B) \
-	((void)(((!(A)) || (B)) || \
+	((void)(likely((!(A)) || (B)) || \
 	    spl_panic(__FILE__, __FUNCTION__, __LINE__, \
 	    "(" #A ") implies (" #B ")")))
 #define	EQUIV(A, B) \
-	((void)((!!(A) == !!(B)) || \
+	((void)(likely(!!(A) == !!(B)) || \
 	    spl_panic(__FILE__, __FUNCTION__, __LINE__, \
 	    "(" #A ") is equivalent to (" #B ")")))
 /* END CSTYLED */
 
 #endif /* NDEBUG */
 
 #endif /* SPL_DEBUG_H */
diff --git a/include/os/linux/spl/sys/debug.h b/include/os/linux/spl/sys/debug.h
index 46da5c783397..dc6b85eebff7 100644
--- a/include/os/linux/spl/sys/debug.h
+++ b/include/os/linux/spl/sys/debug.h
@@ -1,168 +1,168 @@
 /*
  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
  *  Copyright (C) 2007 The Regents of the University of California.
  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
  *  UCRL-CODE-235197
  *
  *  This file is part of the SPL, Solaris Porting Layer.
  *
  *  The SPL is free software; you can redistribute it and/or modify it
  *  under the terms of the GNU General Public License as published by the
  *  Free Software Foundation; either version 2 of the License, or (at your
  *  option) any later version.
  *
  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  *  for more details.
  *
  *  You should have received a copy of the GNU General Public License along
  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 /*
  * Available Solaris debug functions.  All of the ASSERT() macros will be
  * compiled out when NDEBUG is defined, this is the default behavior for
  * the SPL.  To enable assertions use the --enable-debug with configure.
  * The VERIFY() functions are never compiled out and cannot be disabled.
  *
  * PANIC()	- Panic the node and print message.
  * ASSERT()	- Assert X is true, if not panic.
  * ASSERT3B()	- Assert boolean X OP Y is true, if not panic.
  * ASSERT3S()	- Assert signed X OP Y is true, if not panic.
  * ASSERT3U()	- Assert unsigned X OP Y is true, if not panic.
  * ASSERT3P()	- Assert pointer X OP Y is true, if not panic.
  * ASSERT0()	- Assert value is zero, if not panic.
  * VERIFY()	- Verify X is true, if not panic.
  * VERIFY3B()	- Verify boolean X OP Y is true, if not panic.
  * VERIFY3S()	- Verify signed X OP Y is true, if not panic.
  * VERIFY3U()	- Verify unsigned X OP Y is true, if not panic.
  * VERIFY3P()	- Verify pointer X OP Y is true, if not panic.
  * VERIFY0()	- Verify value is zero, if not panic.
  */
 
 #ifndef _SPL_DEBUG_H
 #define	_SPL_DEBUG_H
 
 /*
  * Common DEBUG functionality.
  */
 #define	__printflike(a, b)	__printf(a, b)
 
 #ifndef __maybe_unused
 #define	__maybe_unused __attribute__((unused))
 #endif
 
 int spl_panic(const char *file, const char *func, int line,
     const char *fmt, ...);
 void spl_dumpstack(void);
 
 /* BEGIN CSTYLED */
 #define	PANIC(fmt, a...)						\
 	spl_panic(__FILE__, __FUNCTION__, __LINE__, fmt, ## a)
 
-#define	VERIFY(cond)							\
-	(void) (unlikely(!(cond)) &&					\
+#define	VERIFY(cond)										\
+	(void) (unlikely(!(cond)) &&							\
 	    spl_panic(__FILE__, __FUNCTION__, __LINE__,			\
 	    "%s", "VERIFY(" #cond ") failed\n"))
 
-#define	VERIFY3B(LEFT, OP, RIGHT)	do {				\
-		boolean_t _verify3_left = (boolean_t)(LEFT);		\
-		boolean_t _verify3_right = (boolean_t)(RIGHT);		\
-		if (!(_verify3_left OP _verify3_right))			\
+#define	VERIFY3B(LEFT, OP, RIGHT)	do {					\
+		const boolean_t _verify3_left = (boolean_t)(LEFT);	\
+		const boolean_t _verify3_right = (boolean_t)(RIGHT);\
+		if (unlikely(!(_verify3_left OP _verify3_right)))	\
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
-		    "failed (%d " #OP " %d)\n",				\
-		    (boolean_t) (_verify3_left),			\
-		    (boolean_t) (_verify3_right));			\
+		    "failed (%d " #OP " %d)\n",						\
+		    (boolean_t) (_verify3_left),					\
+		    (boolean_t) (_verify3_right));					\
 	} while (0)
 
-#define	VERIFY3S(LEFT, OP, RIGHT)	do {				\
-		int64_t _verify3_left = (int64_t)(LEFT);		\
-		int64_t _verify3_right = (int64_t)(RIGHT);		\
-		if (!(_verify3_left OP _verify3_right))			\
+#define	VERIFY3S(LEFT, OP, RIGHT)	do {					\
+		const int64_t _verify3_left = (int64_t)(LEFT);		\
+		const int64_t _verify3_right = (int64_t)(RIGHT);	\
+		if (unlikely(!(_verify3_left OP _verify3_right)))	\
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
-		    "failed (%lld " #OP " %lld)\n",			\
-		    (long long) (_verify3_left),			\
-		    (long long) (_verify3_right));			\
+		    "failed (%lld " #OP " %lld)\n",					\
+		    (long long) (_verify3_left),					\
+		    (long long) (_verify3_right));					\
 	} while (0)
 
-#define	VERIFY3U(LEFT, OP, RIGHT)	do {				\
-		uint64_t _verify3_left = (uint64_t)(LEFT);		\
-		uint64_t _verify3_right = (uint64_t)(RIGHT);		\
-		if (!(_verify3_left OP _verify3_right))			\
+#define	VERIFY3U(LEFT, OP, RIGHT)	do {					\
+		const uint64_t _verify3_left = (uint64_t)(LEFT);	\
+		const uint64_t _verify3_right = (uint64_t)(RIGHT);	\
+		if (unlikely(!(_verify3_left OP _verify3_right)))	\
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
-		    "failed (%llu " #OP " %llu)\n",			\
-		    (unsigned long long) (_verify3_left),		\
-		    (unsigned long long) (_verify3_right));		\
+		    "failed (%llu " #OP " %llu)\n",					\
+		    (unsigned long long) (_verify3_left),			\
+		    (unsigned long long) (_verify3_right));			\
 	} while (0)
 
-#define	VERIFY3P(LEFT, OP, RIGHT)	do {				\
-		uintptr_t _verify3_left = (uintptr_t)(LEFT);		\
-		uintptr_t _verify3_right = (uintptr_t)(RIGHT);		\
-		if (!(_verify3_left OP _verify3_right))			\
+#define	VERIFY3P(LEFT, OP, RIGHT)	do {					\
+		const uintptr_t _verify3_left = (uintptr_t)(LEFT);	\
+		const uintptr_t _verify3_right = (uintptr_t)(RIGHT);\
+		if (unlikely(!(_verify3_left OP _verify3_right)))	\
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
-		    "failed (%px " #OP " %px)\n",			\
-		    (void *) (_verify3_left),				\
-		    (void *) (_verify3_right));				\
+		    "failed (%px " #OP " %px)\n",					\
+		    (void *) (_verify3_left),						\
+		    (void *) (_verify3_right));						\
 	} while (0)
 
-#define	VERIFY0(RIGHT)	do {				\
-		int64_t _verify3_left = (int64_t)(0);		\
-		int64_t _verify3_right = (int64_t)(RIGHT);		\
-		if (!(_verify3_left == _verify3_right))			\
+#define	VERIFY0(RIGHT)	do {								\
+		const int64_t _verify3_left = (int64_t)(0);			\
+		const int64_t _verify3_right = (int64_t)(RIGHT);	\
+		if (unlikely(!(_verify3_left == _verify3_right)))	\
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
-		    "VERIFY3(0 == " #RIGHT ") "				\
-		    "failed (0 == %lld)\n",				\
-		    (long long) (_verify3_right));			\
+		    "VERIFY3(0 == " #RIGHT ") "						\
+		    "failed (0 == %lld)\n",							\
+		    (long long) (_verify3_right));					\
 	} while (0)
 
 #define	CTASSERT_GLOBAL(x)		_CTASSERT(x, __LINE__)
 #define	CTASSERT(x)			{ _CTASSERT(x, __LINE__); }
 #define	_CTASSERT(x, y)			__CTASSERT(x, y)
 #define	__CTASSERT(x, y)						\
 	typedef char __attribute__ ((unused))				\
 	__compile_time_assertion__ ## y[(x) ? 1 : -1]
 
 /*
  * Debugging disabled (--disable-debug)
  */
 #ifdef NDEBUG
 
 #define	ASSERT(x)		((void)0)
 #define	ASSERT3B(x,y,z)		((void)0)
 #define	ASSERT3S(x,y,z)		((void)0)
 #define	ASSERT3U(x,y,z)		((void)0)
 #define	ASSERT3P(x,y,z)		((void)0)
 #define	ASSERT0(x)		((void)0)
 #define	IMPLY(A, B)		((void)0)
 #define	EQUIV(A, B)		((void)0)
 
 /*
  * Debugging enabled (--enable-debug)
  */
 #else
 
 #define	ASSERT3B	VERIFY3B
 #define	ASSERT3S	VERIFY3S
 #define	ASSERT3U	VERIFY3U
 #define	ASSERT3P	VERIFY3P
 #define	ASSERT0		VERIFY0
 #define	ASSERT		VERIFY
 #define	IMPLY(A, B) \
-	((void)(((!(A)) || (B)) || \
+	((void)(likely((!(A)) || (B)) || \
 	    spl_panic(__FILE__, __FUNCTION__, __LINE__, \
 	    "(" #A ") implies (" #B ")")))
 #define	EQUIV(A, B) \
-	((void)((!!(A) == !!(B)) || \
+	((void)(likely(!!(A) == !!(B)) || \
 	    spl_panic(__FILE__, __FUNCTION__, __LINE__, \
 	    "(" #A ") is equivalent to (" #B ")")))
 /* END CSTYLED */
 
 #endif /* NDEBUG */
 
 #endif /* SPL_DEBUG_H */