Index: head/lib/libpmc/libpmc.c
===================================================================
--- head/lib/libpmc/libpmc.c
+++ head/lib/libpmc/libpmc.c
@@ -423,9 +423,14 @@
 	__PMC_CAPS()
 };
 
-static const char * pmc_class_names[] = {
+struct pmc_class_map {
+	enum pmc_class	pm_class;
+	const char	*pm_name;
+};
+
+static const struct pmc_class_map pmc_class_names[] = {
 #undef	__PMC_CLASS
-#define __PMC_CLASS(C)	#C ,
+#define __PMC_CLASS(S,V,D) { .pm_class = PMC_CLASS_##S, .pm_name = #S } ,
 	__PMC_CLASSES()
 };
 
@@ -3362,9 +3367,11 @@
 const char *
 pmc_name_of_class(enum pmc_class pc)
 {
-	if ((int) pc >= PMC_CLASS_FIRST &&
-	    pc <= PMC_CLASS_LAST)
-		return (pmc_class_names[pc]);
+	size_t n;
+
+	for (n = 0; n < PMC_TABLE_SIZE(pmc_class_names); n++)
+		if (pc == pmc_class_names[n].pm_class)
+			return (pmc_class_names[n].pm_name);
 
 	errno = EINVAL;
 	return (NULL);
Index: head/sys/dev/hwpmc/hwpmc_mod.c
===================================================================
--- head/sys/dev/hwpmc/hwpmc_mod.c
+++ head/sys/dev/hwpmc/hwpmc_mod.c
@@ -4625,12 +4625,20 @@
 /*
  * initialization
  */
+static const char *
+pmc_name_of_pmcclass(enum pmc_class class)
+{
 
-static const char *pmc_name_of_pmcclass[] = {
+	switch (class) {
 #undef	__PMC_CLASS
-#define	__PMC_CLASS(N) #N ,
-	__PMC_CLASSES()
-};
+#define	__PMC_CLASS(S,V,D)						\
+	case PMC_CLASS_##S:						\
+		return #S;
+	__PMC_CLASSES();
+	default:
+		return ("<unknown>");
+	}
+}
 
 /*
  * Base class initializer: allocate structure and set default classes.
@@ -4909,7 +4917,7 @@
 		for (n = 0; n < (int) md->pmd_nclass; n++) {
 			pcd = &md->pmd_classdep[n];
 			printf(" %s/%d/%d/0x%b",
-			    pmc_name_of_pmcclass[pcd->pcd_class],
+			    pmc_name_of_pmcclass(pcd->pcd_class),
 			    pcd->pcd_num,
 			    pcd->pcd_width,
 			    pcd->pcd_caps,
Index: head/sys/sys/pmc.h
===================================================================
--- head/sys/sys/pmc.h
+++ head/sys/sys/pmc.h
@@ -123,30 +123,30 @@
  */
 
 #define	__PMC_CLASSES()							\
-	__PMC_CLASS(TSC)	/* CPU Timestamp counter */		\
-	__PMC_CLASS(K7)		/* AMD K7 performance counters */	\
-	__PMC_CLASS(K8)		/* AMD K8 performance counters */	\
-	__PMC_CLASS(P5)		/* Intel Pentium counters */		\
-	__PMC_CLASS(P6)		/* Intel Pentium Pro counters */	\
-	__PMC_CLASS(P4)		/* Intel Pentium-IV counters */		\
-	__PMC_CLASS(IAF)	/* Intel Core2/Atom, fixed function */	\
-	__PMC_CLASS(IAP)	/* Intel Core...Atom, programmable */	\
-	__PMC_CLASS(UCF)	/* Intel Uncore fixed function */	\
-	__PMC_CLASS(UCP)	/* Intel Uncore programmable */		\
-	__PMC_CLASS(XSCALE)	/* Intel XScale counters */		\
-	__PMC_CLASS(ARMV7)	/* ARMv7 */				\
-	__PMC_CLASS(ARMV8)	/* ARMv8 */				\
-	__PMC_CLASS(MIPS24K)	/* MIPS 24K */				\
-	__PMC_CLASS(OCTEON)	/* Cavium Octeon */			\
-	__PMC_CLASS(MIPS74K)	/* MIPS 74K */				\
-	__PMC_CLASS(PPC7450)	/* Motorola MPC7450 class */		\
-	__PMC_CLASS(PPC970)	/* IBM PowerPC 970 class */		\
-	__PMC_CLASS(E500)	/* Freescale e500 class */		\
-	__PMC_CLASS(SOFT)	/* Software events */
+	__PMC_CLASS(TSC,	0x000,	"CPU Timestamp counter")	\
+	__PMC_CLASS(K7,		0x100,	"AMD K7 performance counters")	\
+	__PMC_CLASS(K8,		0x101,	"AMD K8 performance counters")	\
+	__PMC_CLASS(P5,		0x102,	"Intel Pentium counters")	\
+	__PMC_CLASS(P6,		0x103,	"Intel Pentium Pro counters")	\
+	__PMC_CLASS(P4,		0x104,	"Intel Pentium-IV counters")	\
+	__PMC_CLASS(IAF,	0x105,	"Intel Core2/Atom, fixed function") \
+	__PMC_CLASS(IAP,	0x106,	"Intel Core...Atom, programmable") \
+	__PMC_CLASS(UCF,	0x107,	"Intel Uncore fixed function")	\
+	__PMC_CLASS(UCP,	0x108,	"Intel Uncore programmable")	\
+	__PMC_CLASS(XSCALE,	0x200,	"Intel XScale counters")	\
+	__PMC_CLASS(ARMV7,	0x201,	"ARMv7")			\
+	__PMC_CLASS(ARMV8,	0x202,	"ARMv8")			\
+	__PMC_CLASS(MIPS24K,	0x300,	"MIPS 24K")			\
+	__PMC_CLASS(OCTEON,	0x301,	"Cavium Octeon")		\
+	__PMC_CLASS(MIPS74K,	0x302,	"MIPS 74K")			\
+	__PMC_CLASS(PPC7450,	0x400,	"Motorola MPC7450 class")	\
+	__PMC_CLASS(PPC970,	0x401,	"IBM PowerPC 970 class")	\
+	__PMC_CLASS(E500,	0x402,	"Freescale e500 class")		\
+	__PMC_CLASS(SOFT,	0x8000,	"Software events")
 
 enum pmc_class {
 #undef  __PMC_CLASS
-#define	__PMC_CLASS(N)	PMC_CLASS_##N ,
+#define	__PMC_CLASS(S,V,D)	PMC_CLASS_##S = V,
 	__PMC_CLASSES()
 };