diff --git a/include/jemalloc/internal/arena_structs_a.h b/include/jemalloc/internal/arena_structs_a.h
index 07013a06..46aa77c8 100644
--- a/include/jemalloc/internal/arena_structs_a.h
+++ b/include/jemalloc/internal/arena_structs_a.h
@@ -1,6 +1,8 @@
 #ifndef JEMALLOC_INTERNAL_ARENA_STRUCTS_A_H
 #define JEMALLOC_INTERNAL_ARENA_STRUCTS_A_H
 
+#include "jemalloc/internal/bitmap.h"
+
 struct arena_slab_data_s {
 	/* Per region allocated/deallocated bitmap. */
 	bitmap_t	bitmap[BITMAP_GROUPS_MAX];
diff --git a/include/jemalloc/internal/arena_structs_b.h b/include/jemalloc/internal/arena_structs_b.h
index bef73aaf..ecc59d3b 100644
--- a/include/jemalloc/internal/arena_structs_b.h
+++ b/include/jemalloc/internal/arena_structs_b.h
@@ -2,6 +2,7 @@
 #define JEMALLOC_INTERNAL_ARENA_STRUCTS_B_H
 
 #include "jemalloc/internal/atomic.h"
+#include "jemalloc/internal/bitmap.h"
 #include "jemalloc/internal/jemalloc_internal_types.h"
 #include "jemalloc/internal/nstime.h"
 #include "jemalloc/internal/ql.h"
diff --git a/include/jemalloc/internal/bitmap.h b/include/jemalloc/internal/bitmap.h
new file mode 100644
index 00000000..f6374e14
--- /dev/null
+++ b/include/jemalloc/internal/bitmap.h
@@ -0,0 +1,369 @@
+#ifndef JEMALLOC_INTERNAL_BITMAP_H
+#define JEMALLOC_INTERNAL_BITMAP_H
+
+#include "jemalloc/internal/arena_types.h"
+#include "jemalloc/internal/bit_util.h"
+#include "jemalloc/internal/size_classes.h"
+
+typedef unsigned long bitmap_t;
+#define LG_SIZEOF_BITMAP	LG_SIZEOF_LONG
+
+/* Maximum bitmap bit count is 2^LG_BITMAP_MAXBITS. */
+#if LG_SLAB_MAXREGS > LG_CEIL_NSIZES
+/* Maximum bitmap bit count is determined by maximum regions per slab. */
+#  define LG_BITMAP_MAXBITS	LG_SLAB_MAXREGS
+#else
+/* Maximum bitmap bit count is determined by number of extent size classes. */
+#  define LG_BITMAP_MAXBITS	LG_CEIL_NSIZES
+#endif
+#define BITMAP_MAXBITS		(ZU(1) << LG_BITMAP_MAXBITS)
+
+/* Number of bits per group. */
+#define LG_BITMAP_GROUP_NBITS		(LG_SIZEOF_BITMAP + 3)
+#define BITMAP_GROUP_NBITS		(1U << LG_BITMAP_GROUP_NBITS)
+#define BITMAP_GROUP_NBITS_MASK		(BITMAP_GROUP_NBITS-1)
+
+/*
+ * Do some analysis on how big the bitmap is before we use a tree.  For a brute
+ * force linear search, if we would have to call ffs_lu() more than 2^3 times,
+ * use a tree instead.
+ */
+#if LG_BITMAP_MAXBITS - LG_BITMAP_GROUP_NBITS > 3
+#  define BITMAP_USE_TREE
+#endif
+
+/* Number of groups required to store a given number of bits. */
+#define BITMAP_BITS2GROUPS(nbits)					\
+    (((nbits) + BITMAP_GROUP_NBITS_MASK) >> LG_BITMAP_GROUP_NBITS)
+
+/*
+ * Number of groups required at a particular level for a given number of bits.
+ */
+#define BITMAP_GROUPS_L0(nbits)						\
+    BITMAP_BITS2GROUPS(nbits)
+#define BITMAP_GROUPS_L1(nbits)						\
+    BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(nbits))
+#define BITMAP_GROUPS_L2(nbits)						\
+    BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS((nbits))))
+#define BITMAP_GROUPS_L3(nbits)						\
+    BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(		\
+	BITMAP_BITS2GROUPS((nbits)))))
+#define BITMAP_GROUPS_L4(nbits)						\
+    BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(		\
+	BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS((nbits))))))
+
+/*
+ * Assuming the number of levels, number of groups required for a given number
+ * of bits.
+ */
+#define BITMAP_GROUPS_1_LEVEL(nbits)					\
+    BITMAP_GROUPS_L0(nbits)
+#define BITMAP_GROUPS_2_LEVEL(nbits)					\
+    (BITMAP_GROUPS_1_LEVEL(nbits) + BITMAP_GROUPS_L1(nbits))
+#define BITMAP_GROUPS_3_LEVEL(nbits)					\
+    (BITMAP_GROUPS_2_LEVEL(nbits) + BITMAP_GROUPS_L2(nbits))
+#define BITMAP_GROUPS_4_LEVEL(nbits)					\
+    (BITMAP_GROUPS_3_LEVEL(nbits) + BITMAP_GROUPS_L3(nbits))
+#define BITMAP_GROUPS_5_LEVEL(nbits)					\
+    (BITMAP_GROUPS_4_LEVEL(nbits) + BITMAP_GROUPS_L4(nbits))
+
+/*
+ * Maximum number of groups required to support LG_BITMAP_MAXBITS.
+ */
+#ifdef BITMAP_USE_TREE
+
+#if LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS
+#  define BITMAP_GROUPS(nbits)	BITMAP_GROUPS_1_LEVEL(nbits)
+#  define BITMAP_GROUPS_MAX	BITMAP_GROUPS_1_LEVEL(BITMAP_MAXBITS)
+#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 2
+#  define BITMAP_GROUPS(nbits)	BITMAP_GROUPS_2_LEVEL(nbits)
+#  define BITMAP_GROUPS_MAX	BITMAP_GROUPS_2_LEVEL(BITMAP_MAXBITS)
+#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 3
+#  define BITMAP_GROUPS(nbits)	BITMAP_GROUPS_3_LEVEL(nbits)
+#  define BITMAP_GROUPS_MAX	BITMAP_GROUPS_3_LEVEL(BITMAP_MAXBITS)
+#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 4
+#  define BITMAP_GROUPS(nbits)	BITMAP_GROUPS_4_LEVEL(nbits)
+#  define BITMAP_GROUPS_MAX	BITMAP_GROUPS_4_LEVEL(BITMAP_MAXBITS)
+#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 5
+#  define BITMAP_GROUPS(nbits)	BITMAP_GROUPS_5_LEVEL(nbits)
+#  define BITMAP_GROUPS_MAX	BITMAP_GROUPS_5_LEVEL(BITMAP_MAXBITS)
+#else
+#  error "Unsupported bitmap size"
+#endif
+
+/*
+ * Maximum number of levels possible.  This could be statically computed based
+ * on LG_BITMAP_MAXBITS:
+ *
+ * #define BITMAP_MAX_LEVELS \
+ *     (LG_BITMAP_MAXBITS / LG_SIZEOF_BITMAP) \
+ *     + !!(LG_BITMAP_MAXBITS % LG_SIZEOF_BITMAP)
+ *
+ * However, that would not allow the generic BITMAP_INFO_INITIALIZER() macro, so
+ * instead hardcode BITMAP_MAX_LEVELS to the largest number supported by the
+ * various cascading macros.  The only additional cost this incurs is some
+ * unused trailing entries in bitmap_info_t structures; the bitmaps themselves
+ * are not impacted.
+ */
+#define BITMAP_MAX_LEVELS	5
+
+#define BITMAP_INFO_INITIALIZER(nbits) {				\
+	/* nbits. */							\
+	nbits,								\
+	/* nlevels. */							\
+	(BITMAP_GROUPS_L0(nbits) > BITMAP_GROUPS_L1(nbits)) +		\
+	    (BITMAP_GROUPS_L1(nbits) > BITMAP_GROUPS_L2(nbits)) +	\
+	    (BITMAP_GROUPS_L2(nbits) > BITMAP_GROUPS_L3(nbits)) +	\
+	    (BITMAP_GROUPS_L3(nbits) > BITMAP_GROUPS_L4(nbits)) + 1,	\
+	/* levels. */							\
+	{								\
+		{0},							\
+		{BITMAP_GROUPS_L0(nbits)},				\
+		{BITMAP_GROUPS_L1(nbits) + BITMAP_GROUPS_L0(nbits)},	\
+		{BITMAP_GROUPS_L2(nbits) + BITMAP_GROUPS_L1(nbits) +	\
+		    BITMAP_GROUPS_L0(nbits)},				\
+		{BITMAP_GROUPS_L3(nbits) + BITMAP_GROUPS_L2(nbits) +	\
+		    BITMAP_GROUPS_L1(nbits) + BITMAP_GROUPS_L0(nbits)},	\
+		{BITMAP_GROUPS_L4(nbits) + BITMAP_GROUPS_L3(nbits) +	\
+		     BITMAP_GROUPS_L2(nbits) + BITMAP_GROUPS_L1(nbits)	\
+		     + BITMAP_GROUPS_L0(nbits)}				\
+	}								\
+}
+
+#else /* BITMAP_USE_TREE */
+
+#define BITMAP_GROUPS(nbits)	BITMAP_BITS2GROUPS(nbits)
+#define BITMAP_GROUPS_MAX	BITMAP_BITS2GROUPS(BITMAP_MAXBITS)
+
+#define BITMAP_INFO_INITIALIZER(nbits) {				\
+	/* nbits. */							\
+	nbits,								\
+	/* ngroups. */							\
+	BITMAP_BITS2GROUPS(nbits)					\
+}
+
+#endif /* BITMAP_USE_TREE */
+
+typedef struct bitmap_level_s {
+	/* Offset of this level's groups within the array of groups. */
+	size_t group_offset;
+} bitmap_level_t;
+
+typedef struct bitmap_info_s {
+	/* Logical number of bits in bitmap (stored at bottom level). */
+	size_t nbits;
+
+#ifdef BITMAP_USE_TREE
+	/* Number of levels necessary for nbits. */
+	unsigned nlevels;
+
+	/*
+	 * Only the first (nlevels+1) elements are used, and levels are ordered
+	 * bottom to top (e.g. the bottom level is stored in levels[0]).
+	 */
+	bitmap_level_t levels[BITMAP_MAX_LEVELS+1];
+#else /* BITMAP_USE_TREE */
+	/* Number of groups necessary for nbits. */
+	size_t ngroups;
+#endif /* BITMAP_USE_TREE */
+} bitmap_info_t;
+
+void bitmap_info_init(bitmap_info_t *binfo, size_t nbits);
+void bitmap_init(bitmap_t *bitmap, const bitmap_info_t *binfo, bool fill);
+size_t bitmap_size(const bitmap_info_t *binfo);
+
+static inline bool
+bitmap_full(bitmap_t *bitmap, const bitmap_info_t *binfo) {
+#ifdef BITMAP_USE_TREE
+	size_t rgoff = binfo->levels[binfo->nlevels].group_offset - 1;
+	bitmap_t rg = bitmap[rgoff];
+	/* The bitmap is full iff the root group is 0. */
+	return (rg == 0);
+#else
+	size_t i;
+
+	for (i = 0; i < binfo->ngroups; i++) {
+		if (bitmap[i] != 0) {
+			return false;
+		}
+	}
+	return true;
+#endif
+}
+
+static inline bool
+bitmap_get(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit) {
+	size_t goff;
+	bitmap_t g;
+
+	assert(bit < binfo->nbits);
+	goff = bit >> LG_BITMAP_GROUP_NBITS;
+	g = bitmap[goff];
+	return !(g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK)));
+}
+
+static inline void
+bitmap_set(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit) {
+	size_t goff;
+	bitmap_t *gp;
+	bitmap_t g;
+
+	assert(bit < binfo->nbits);
+	assert(!bitmap_get(bitmap, binfo, bit));
+	goff = bit >> LG_BITMAP_GROUP_NBITS;
+	gp = &bitmap[goff];
+	g = *gp;
+	assert(g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK)));
+	g ^= ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK);
+	*gp = g;
+	assert(bitmap_get(bitmap, binfo, bit));
+#ifdef BITMAP_USE_TREE
+	/* Propagate group state transitions up the tree. */
+	if (g == 0) {
+		unsigned i;
+		for (i = 1; i < binfo->nlevels; i++) {
+			bit = goff;
+			goff = bit >> LG_BITMAP_GROUP_NBITS;
+			gp = &bitmap[binfo->levels[i].group_offset + goff];
+			g = *gp;
+			assert(g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK)));
+			g ^= ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK);
+			*gp = g;
+			if (g != 0) {
+				break;
+			}
+		}
+	}
+#endif
+}
+
+/* ffu: find first unset >= bit. */
+static inline size_t
+bitmap_ffu(const bitmap_t *bitmap, const bitmap_info_t *binfo, size_t min_bit) {
+	assert(min_bit < binfo->nbits);
+
+#ifdef BITMAP_USE_TREE
+	size_t bit = 0;
+	for (unsigned level = binfo->nlevels; level--;) {
+		size_t lg_bits_per_group = (LG_BITMAP_GROUP_NBITS * (level +
+		    1));
+		bitmap_t group = bitmap[binfo->levels[level].group_offset + (bit
+		    >> lg_bits_per_group)];
+		unsigned group_nmask = ((min_bit > bit) ? (min_bit - bit) : 0)
+		    >> (lg_bits_per_group - LG_BITMAP_GROUP_NBITS);
+		assert(group_nmask <= BITMAP_GROUP_NBITS);
+		bitmap_t group_mask = ~((1LU << group_nmask) - 1);
+		bitmap_t group_masked = group & group_mask;
+		if (group_masked == 0LU) {
+			if (group == 0LU) {
+				return binfo->nbits;
+			}
+			/*
+			 * min_bit was preceded by one or more unset bits in
+			 * this group, but there are no other unset bits in this
+			 * group.  Try again starting at the first bit of the
+			 * next sibling.  This will recurse at most once per
+			 * non-root level.
+			 */
+			size_t sib_base = bit + (1U << lg_bits_per_group);
+			assert(sib_base > min_bit);
+			assert(sib_base > bit);
+			if (sib_base >= binfo->nbits) {
+				return binfo->nbits;
+			}
+			return bitmap_ffu(bitmap, binfo, sib_base);
+		}
+		bit += (ffs_lu(group_masked) - 1) << (lg_bits_per_group -
+		    LG_BITMAP_GROUP_NBITS);
+	}
+	assert(bit >= min_bit);
+	assert(bit < binfo->nbits);
+	return bit;
+#else
+	size_t i = min_bit >> LG_BITMAP_GROUP_NBITS;
+	bitmap_t g = bitmap[i] & ~((1LU << (min_bit & BITMAP_GROUP_NBITS_MASK))
+	    - 1);
+	size_t bit;
+	do {
+		bit = ffs_lu(g);
+		if (bit != 0) {
+			return (i << LG_BITMAP_GROUP_NBITS) + (bit - 1);
+		}
+		i++;
+		g = bitmap[i];
+	} while (i < binfo->ngroups);
+	return binfo->nbits;
+#endif
+}
+
+/* sfu: set first unset. */
+static inline size_t
+bitmap_sfu(bitmap_t *bitmap, const bitmap_info_t *binfo) {
+	size_t bit;
+	bitmap_t g;
+	unsigned i;
+
+	assert(!bitmap_full(bitmap, binfo));
+
+#ifdef BITMAP_USE_TREE
+	i = binfo->nlevels - 1;
+	g = bitmap[binfo->levels[i].group_offset];
+	bit = ffs_lu(g) - 1;
+	while (i > 0) {
+		i--;
+		g = bitmap[binfo->levels[i].group_offset + bit];
+		bit = (bit << LG_BITMAP_GROUP_NBITS) + (ffs_lu(g) - 1);
+	}
+#else
+	i = 0;
+	g = bitmap[0];
+	while ((bit = ffs_lu(g)) == 0) {
+		i++;
+		g = bitmap[i];
+	}
+	bit = (i << LG_BITMAP_GROUP_NBITS) + (bit - 1);
+#endif
+	bitmap_set(bitmap, binfo, bit);
+	return bit;
+}
+
+static inline void
+bitmap_unset(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit) {
+	size_t goff;
+	bitmap_t *gp;
+	bitmap_t g;
+	UNUSED bool propagate;
+
+	assert(bit < binfo->nbits);
+	assert(bitmap_get(bitmap, binfo, bit));
+	goff = bit >> LG_BITMAP_GROUP_NBITS;
+	gp = &bitmap[goff];
+	g = *gp;
+	propagate = (g == 0);
+	assert((g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK))) == 0);
+	g ^= ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK);
+	*gp = g;
+	assert(!bitmap_get(bitmap, binfo, bit));
+#ifdef BITMAP_USE_TREE
+	/* Propagate group state transitions up the tree. */
+	if (propagate) {
+		unsigned i;
+		for (i = 1; i < binfo->nlevels; i++) {
+			bit = goff;
+			goff = bit >> LG_BITMAP_GROUP_NBITS;
+			gp = &bitmap[binfo->levels[i].group_offset + goff];
+			g = *gp;
+			propagate = (g == 0);
+			assert((g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK)))
+			    == 0);
+			g ^= ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK);
+			*gp = g;
+			if (!propagate) {
+				break;
+			}
+		}
+	}
+#endif /* BITMAP_USE_TREE */
+}
+
+#endif /* JEMALLOC_INTERNAL_BITMAP_H */
diff --git a/include/jemalloc/internal/bitmap_externs.h b/include/jemalloc/internal/bitmap_externs.h
deleted file mode 100644
index 034a4e6b..00000000
--- a/include/jemalloc/internal/bitmap_externs.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef JEMALLOC_INTERNAL_BITMAP_EXTERNS_H
-#define JEMALLOC_INTERNAL_BITMAP_EXTERNS_H
-
-void	bitmap_info_init(bitmap_info_t *binfo, size_t nbits);
-void	bitmap_init(bitmap_t *bitmap, const bitmap_info_t *binfo, bool fill);
-size_t	bitmap_size(const bitmap_info_t *binfo);
-
-#endif /* JEMALLOC_INTERNAL_BITMAP_EXTERNS_H */
diff --git a/include/jemalloc/internal/bitmap_inlines.h b/include/jemalloc/internal/bitmap_inlines.h
deleted file mode 100644
index 84425b34..00000000
--- a/include/jemalloc/internal/bitmap_inlines.h
+++ /dev/null
@@ -1,200 +0,0 @@
-#ifndef JEMALLOC_INTERNAL_BITMAP_INLINES_H
-#define JEMALLOC_INTERNAL_BITMAP_INLINES_H
-
-#include "jemalloc/internal/bit_util.h"
-
-static inline bool
-bitmap_full(bitmap_t *bitmap, const bitmap_info_t *binfo) {
-#ifdef BITMAP_USE_TREE
-	size_t rgoff = binfo->levels[binfo->nlevels].group_offset - 1;
-	bitmap_t rg = bitmap[rgoff];
-	/* The bitmap is full iff the root group is 0. */
-	return (rg == 0);
-#else
-	size_t i;
-
-	for (i = 0; i < binfo->ngroups; i++) {
-		if (bitmap[i] != 0) {
-			return false;
-		}
-	}
-	return true;
-#endif
-}
-
-static inline bool
-bitmap_get(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit) {
-	size_t goff;
-	bitmap_t g;
-
-	assert(bit < binfo->nbits);
-	goff = bit >> LG_BITMAP_GROUP_NBITS;
-	g = bitmap[goff];
-	return !(g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK)));
-}
-
-static inline void
-bitmap_set(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit) {
-	size_t goff;
-	bitmap_t *gp;
-	bitmap_t g;
-
-	assert(bit < binfo->nbits);
-	assert(!bitmap_get(bitmap, binfo, bit));
-	goff = bit >> LG_BITMAP_GROUP_NBITS;
-	gp = &bitmap[goff];
-	g = *gp;
-	assert(g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK)));
-	g ^= ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK);
-	*gp = g;
-	assert(bitmap_get(bitmap, binfo, bit));
-#ifdef BITMAP_USE_TREE
-	/* Propagate group state transitions up the tree. */
-	if (g == 0) {
-		unsigned i;
-		for (i = 1; i < binfo->nlevels; i++) {
-			bit = goff;
-			goff = bit >> LG_BITMAP_GROUP_NBITS;
-			gp = &bitmap[binfo->levels[i].group_offset + goff];
-			g = *gp;
-			assert(g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK)));
-			g ^= ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK);
-			*gp = g;
-			if (g != 0) {
-				break;
-			}
-		}
-	}
-#endif
-}
-
-/* ffu: find first unset >= bit. */
-static inline size_t
-bitmap_ffu(const bitmap_t *bitmap, const bitmap_info_t *binfo, size_t min_bit) {
-	assert(min_bit < binfo->nbits);
-
-#ifdef BITMAP_USE_TREE
-	size_t bit = 0;
-	for (unsigned level = binfo->nlevels; level--;) {
-		size_t lg_bits_per_group = (LG_BITMAP_GROUP_NBITS * (level +
-		    1));
-		bitmap_t group = bitmap[binfo->levels[level].group_offset + (bit
-		    >> lg_bits_per_group)];
-		unsigned group_nmask = ((min_bit > bit) ? (min_bit - bit) : 0)
-		    >> (lg_bits_per_group - LG_BITMAP_GROUP_NBITS);
-		assert(group_nmask <= BITMAP_GROUP_NBITS);
-		bitmap_t group_mask = ~((1LU << group_nmask) - 1);
-		bitmap_t group_masked = group & group_mask;
-		if (group_masked == 0LU) {
-			if (group == 0LU) {
-				return binfo->nbits;
-			}
-			/*
-			 * min_bit was preceded by one or more unset bits in
-			 * this group, but there are no other unset bits in this
-			 * group.  Try again starting at the first bit of the
-			 * next sibling.  This will recurse at most once per
-			 * non-root level.
-			 */
-			size_t sib_base = bit + (1U << lg_bits_per_group);
-			assert(sib_base > min_bit);
-			assert(sib_base > bit);
-			if (sib_base >= binfo->nbits) {
-				return binfo->nbits;
-			}
-			return bitmap_ffu(bitmap, binfo, sib_base);
-		}
-		bit += (ffs_lu(group_masked) - 1) << (lg_bits_per_group -
-		    LG_BITMAP_GROUP_NBITS);
-	}
-	assert(bit >= min_bit);
-	assert(bit < binfo->nbits);
-	return bit;
-#else
-	size_t i = min_bit >> LG_BITMAP_GROUP_NBITS;
-	bitmap_t g = bitmap[i] & ~((1LU << (min_bit & BITMAP_GROUP_NBITS_MASK))
-	    - 1);
-	size_t bit;
-	do {
-		bit = ffs_lu(g);
-		if (bit != 0) {
-			return (i << LG_BITMAP_GROUP_NBITS) + (bit - 1);
-		}
-		i++;
-		g = bitmap[i];
-	} while (i < binfo->ngroups);
-	return binfo->nbits;
-#endif
-}
-
-/* sfu: set first unset. */
-static inline size_t
-bitmap_sfu(bitmap_t *bitmap, const bitmap_info_t *binfo) {
-	size_t bit;
-	bitmap_t g;
-	unsigned i;
-
-	assert(!bitmap_full(bitmap, binfo));
-
-#ifdef BITMAP_USE_TREE
-	i = binfo->nlevels - 1;
-	g = bitmap[binfo->levels[i].group_offset];
-	bit = ffs_lu(g) - 1;
-	while (i > 0) {
-		i--;
-		g = bitmap[binfo->levels[i].group_offset + bit];
-		bit = (bit << LG_BITMAP_GROUP_NBITS) + (ffs_lu(g) - 1);
-	}
-#else
-	i = 0;
-	g = bitmap[0];
-	while ((bit = ffs_lu(g)) == 0) {
-		i++;
-		g = bitmap[i];
-	}
-	bit = (i << LG_BITMAP_GROUP_NBITS) + (bit - 1);
-#endif
-	bitmap_set(bitmap, binfo, bit);
-	return bit;
-}
-
-static inline void
-bitmap_unset(bitmap_t *bitmap, const bitmap_info_t *binfo, size_t bit) {
-	size_t goff;
-	bitmap_t *gp;
-	bitmap_t g;
-	UNUSED bool propagate;
-
-	assert(bit < binfo->nbits);
-	assert(bitmap_get(bitmap, binfo, bit));
-	goff = bit >> LG_BITMAP_GROUP_NBITS;
-	gp = &bitmap[goff];
-	g = *gp;
-	propagate = (g == 0);
-	assert((g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK))) == 0);
-	g ^= ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK);
-	*gp = g;
-	assert(!bitmap_get(bitmap, binfo, bit));
-#ifdef BITMAP_USE_TREE
-	/* Propagate group state transitions up the tree. */
-	if (propagate) {
-		unsigned i;
-		for (i = 1; i < binfo->nlevels; i++) {
-			bit = goff;
-			goff = bit >> LG_BITMAP_GROUP_NBITS;
-			gp = &bitmap[binfo->levels[i].group_offset + goff];
-			g = *gp;
-			propagate = (g == 0);
-			assert((g & (ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK)))
-			    == 0);
-			g ^= ZU(1) << (bit & BITMAP_GROUP_NBITS_MASK);
-			*gp = g;
-			if (!propagate) {
-				break;
-			}
-		}
-	}
-#endif /* BITMAP_USE_TREE */
-}
-
-#endif /* JEMALLOC_INTERNAL_BITMAP_INLINES_H */
diff --git a/include/jemalloc/internal/bitmap_structs.h b/include/jemalloc/internal/bitmap_structs.h
deleted file mode 100644
index 297ae669..00000000
--- a/include/jemalloc/internal/bitmap_structs.h
+++ /dev/null
@@ -1,28 +0,0 @@
-#ifndef JEMALLOC_INTERNAL_BITMAP_STRUCTS_H
-#define JEMALLOC_INTERNAL_BITMAP_STRUCTS_H
-
-struct bitmap_level_s {
-	/* Offset of this level's groups within the array of groups. */
-	size_t group_offset;
-};
-
-struct bitmap_info_s {
-	/* Logical number of bits in bitmap (stored at bottom level). */
-	size_t nbits;
-
-#ifdef BITMAP_USE_TREE
-	/* Number of levels necessary for nbits. */
-	unsigned nlevels;
-
-	/*
-	 * Only the first (nlevels+1) elements are used, and levels are ordered
-	 * bottom to top (e.g. the bottom level is stored in levels[0]).
-	 */
-	bitmap_level_t levels[BITMAP_MAX_LEVELS+1];
-#else /* BITMAP_USE_TREE */
-	/* Number of groups necessary for nbits. */
-	size_t ngroups;
-#endif /* BITMAP_USE_TREE */
-};
-
-#endif /* JEMALLOC_INTERNAL_BITMAP_STRUCTS_H */
diff --git a/include/jemalloc/internal/bitmap_types.h b/include/jemalloc/internal/bitmap_types.h
deleted file mode 100644
index 95f0dd12..00000000
--- a/include/jemalloc/internal/bitmap_types.h
+++ /dev/null
@@ -1,147 +0,0 @@
-#ifndef JEMALLOC_INTERNAL_BITMAP_TYPES_H
-#define JEMALLOC_INTERNAL_BITMAP_TYPES_H
-
-#include "jemalloc/internal/size_classes.h"
-
-/* Maximum bitmap bit count is 2^LG_BITMAP_MAXBITS. */
-#if LG_SLAB_MAXREGS > LG_CEIL_NSIZES
-/* Maximum bitmap bit count is determined by maximum regions per slab. */
-#  define LG_BITMAP_MAXBITS	LG_SLAB_MAXREGS
-#else
-/* Maximum bitmap bit count is determined by number of extent size classes. */
-#  define LG_BITMAP_MAXBITS	LG_CEIL_NSIZES
-#endif
-#define BITMAP_MAXBITS		(ZU(1) << LG_BITMAP_MAXBITS)
-
-typedef struct bitmap_level_s bitmap_level_t;
-typedef struct bitmap_info_s bitmap_info_t;
-typedef unsigned long bitmap_t;
-#define LG_SIZEOF_BITMAP	LG_SIZEOF_LONG
-
-/* Number of bits per group. */
-#define LG_BITMAP_GROUP_NBITS		(LG_SIZEOF_BITMAP + 3)
-#define BITMAP_GROUP_NBITS		(1U << LG_BITMAP_GROUP_NBITS)
-#define BITMAP_GROUP_NBITS_MASK		(BITMAP_GROUP_NBITS-1)
-
-/*
- * Do some analysis on how big the bitmap is before we use a tree.  For a brute
- * force linear search, if we would have to call ffs_lu() more than 2^3 times,
- * use a tree instead.
- */
-#if LG_BITMAP_MAXBITS - LG_BITMAP_GROUP_NBITS > 3
-#  define BITMAP_USE_TREE
-#endif
-
-/* Number of groups required to store a given number of bits. */
-#define BITMAP_BITS2GROUPS(nbits)					\
-    (((nbits) + BITMAP_GROUP_NBITS_MASK) >> LG_BITMAP_GROUP_NBITS)
-
-/*
- * Number of groups required at a particular level for a given number of bits.
- */
-#define BITMAP_GROUPS_L0(nbits)						\
-    BITMAP_BITS2GROUPS(nbits)
-#define BITMAP_GROUPS_L1(nbits)						\
-    BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(nbits))
-#define BITMAP_GROUPS_L2(nbits)						\
-    BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS((nbits))))
-#define BITMAP_GROUPS_L3(nbits)						\
-    BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(		\
-	BITMAP_BITS2GROUPS((nbits)))))
-#define BITMAP_GROUPS_L4(nbits)						\
-    BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(		\
-	BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS((nbits))))))
-
-/*
- * Assuming the number of levels, number of groups required for a given number
- * of bits.
- */
-#define BITMAP_GROUPS_1_LEVEL(nbits)					\
-    BITMAP_GROUPS_L0(nbits)
-#define BITMAP_GROUPS_2_LEVEL(nbits)					\
-    (BITMAP_GROUPS_1_LEVEL(nbits) + BITMAP_GROUPS_L1(nbits))
-#define BITMAP_GROUPS_3_LEVEL(nbits)					\
-    (BITMAP_GROUPS_2_LEVEL(nbits) + BITMAP_GROUPS_L2(nbits))
-#define BITMAP_GROUPS_4_LEVEL(nbits)					\
-    (BITMAP_GROUPS_3_LEVEL(nbits) + BITMAP_GROUPS_L3(nbits))
-#define BITMAP_GROUPS_5_LEVEL(nbits)					\
-    (BITMAP_GROUPS_4_LEVEL(nbits) + BITMAP_GROUPS_L4(nbits))
-
-/*
- * Maximum number of groups required to support LG_BITMAP_MAXBITS.
- */
-#ifdef BITMAP_USE_TREE
-
-#if LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS
-#  define BITMAP_GROUPS(nbits)	BITMAP_GROUPS_1_LEVEL(nbits)
-#  define BITMAP_GROUPS_MAX	BITMAP_GROUPS_1_LEVEL(BITMAP_MAXBITS)
-#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 2
-#  define BITMAP_GROUPS(nbits)	BITMAP_GROUPS_2_LEVEL(nbits)
-#  define BITMAP_GROUPS_MAX	BITMAP_GROUPS_2_LEVEL(BITMAP_MAXBITS)
-#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 3
-#  define BITMAP_GROUPS(nbits)	BITMAP_GROUPS_3_LEVEL(nbits)
-#  define BITMAP_GROUPS_MAX	BITMAP_GROUPS_3_LEVEL(BITMAP_MAXBITS)
-#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 4
-#  define BITMAP_GROUPS(nbits)	BITMAP_GROUPS_4_LEVEL(nbits)
-#  define BITMAP_GROUPS_MAX	BITMAP_GROUPS_4_LEVEL(BITMAP_MAXBITS)
-#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 5
-#  define BITMAP_GROUPS(nbits)	BITMAP_GROUPS_5_LEVEL(nbits)
-#  define BITMAP_GROUPS_MAX	BITMAP_GROUPS_5_LEVEL(BITMAP_MAXBITS)
-#else
-#  error "Unsupported bitmap size"
-#endif
-
-/*
- * Maximum number of levels possible.  This could be statically computed based
- * on LG_BITMAP_MAXBITS:
- *
- * #define BITMAP_MAX_LEVELS \
- *     (LG_BITMAP_MAXBITS / LG_SIZEOF_BITMAP) \
- *     + !!(LG_BITMAP_MAXBITS % LG_SIZEOF_BITMAP)
- *
- * However, that would not allow the generic BITMAP_INFO_INITIALIZER() macro, so
- * instead hardcode BITMAP_MAX_LEVELS to the largest number supported by the
- * various cascading macros.  The only additional cost this incurs is some
- * unused trailing entries in bitmap_info_t structures; the bitmaps themselves
- * are not impacted.
- */
-#define BITMAP_MAX_LEVELS	5
-
-#define BITMAP_INFO_INITIALIZER(nbits) {				\
-	/* nbits. */							\
-	nbits,								\
-	/* nlevels. */							\
-	(BITMAP_GROUPS_L0(nbits) > BITMAP_GROUPS_L1(nbits)) +		\
-	    (BITMAP_GROUPS_L1(nbits) > BITMAP_GROUPS_L2(nbits)) +	\
-	    (BITMAP_GROUPS_L2(nbits) > BITMAP_GROUPS_L3(nbits)) +	\
-	    (BITMAP_GROUPS_L3(nbits) > BITMAP_GROUPS_L4(nbits)) + 1,	\
-	/* levels. */							\
-	{								\
-		{0},							\
-		{BITMAP_GROUPS_L0(nbits)},				\
-		{BITMAP_GROUPS_L1(nbits) + BITMAP_GROUPS_L0(nbits)},	\
-		{BITMAP_GROUPS_L2(nbits) + BITMAP_GROUPS_L1(nbits) +	\
-		    BITMAP_GROUPS_L0(nbits)},				\
-		{BITMAP_GROUPS_L3(nbits) + BITMAP_GROUPS_L2(nbits) +	\
-		    BITMAP_GROUPS_L1(nbits) + BITMAP_GROUPS_L0(nbits)},	\
-		{BITMAP_GROUPS_L4(nbits) + BITMAP_GROUPS_L3(nbits) +	\
-		     BITMAP_GROUPS_L2(nbits) + BITMAP_GROUPS_L1(nbits)	\
-		     + BITMAP_GROUPS_L0(nbits)}				\
-	}								\
-}
-
-#else /* BITMAP_USE_TREE */
-
-#define BITMAP_GROUPS(nbits)	BITMAP_BITS2GROUPS(nbits)
-#define BITMAP_GROUPS_MAX	BITMAP_BITS2GROUPS(BITMAP_MAXBITS)
-
-#define BITMAP_INFO_INITIALIZER(nbits) {				\
-	/* nbits. */							\
-	nbits,								\
-	/* ngroups. */							\
-	BITMAP_BITS2GROUPS(nbits)					\
-}
-
-#endif /* BITMAP_USE_TREE */
-
-#endif /* JEMALLOC_INTERNAL_BITMAP_TYPES_H */
diff --git a/include/jemalloc/internal/extent_structs.h b/include/jemalloc/internal/extent_structs.h
index aa0a3a75..5d8c3a20 100644
--- a/include/jemalloc/internal/extent_structs.h
+++ b/include/jemalloc/internal/extent_structs.h
@@ -2,6 +2,7 @@
 #define JEMALLOC_INTERNAL_EXTENT_STRUCTS_H
 
 #include "jemalloc/internal/atomic.h"
+#include "jemalloc/internal/bitmap.h"
 #include "jemalloc/internal/ql.h"
 #include "jemalloc/internal/rb.h"
 #include "jemalloc/internal/ph.h"
diff --git a/include/jemalloc/internal/jemalloc_internal_includes.h b/include/jemalloc/internal/jemalloc_internal_includes.h
index 0cb6183d..f98a1b27 100644
--- a/include/jemalloc/internal/jemalloc_internal_includes.h
+++ b/include/jemalloc/internal/jemalloc_internal_includes.h
@@ -48,7 +48,6 @@
 #include "jemalloc/internal/extent_dss_types.h"
 #include "jemalloc/internal/base_types.h"
 #include "jemalloc/internal/arena_types.h"
-#include "jemalloc/internal/bitmap_types.h"
 #include "jemalloc/internal/rtree_types.h"
 #include "jemalloc/internal/pages_types.h"
 #include "jemalloc/internal/tcache_types.h"
@@ -61,7 +60,6 @@
 #include "jemalloc/internal/witness_structs.h"
 #include "jemalloc/internal/mutex_structs.h"
 #include "jemalloc/internal/ctl_structs.h"
-#include "jemalloc/internal/bitmap_structs.h"
 #include "jemalloc/internal/arena_structs_a.h"
 #include "jemalloc/internal/extent_structs.h"
 #include "jemalloc/internal/extent_dss_structs.h"
@@ -80,7 +78,6 @@
 #include "jemalloc/internal/ctl_externs.h"
 #include "jemalloc/internal/witness_externs.h"
 #include "jemalloc/internal/mutex_externs.h"
-#include "jemalloc/internal/bitmap_externs.h"
 #include "jemalloc/internal/extent_externs.h"
 #include "jemalloc/internal/extent_dss_externs.h"
 #include "jemalloc/internal/extent_mmap_externs.h"
@@ -103,7 +100,6 @@
 #include "jemalloc/internal/jemalloc_internal_inlines_a.h"
 #include "jemalloc/internal/rtree_inlines.h"
 #include "jemalloc/internal/base_inlines.h"
-#include "jemalloc/internal/bitmap_inlines.h"
 /*
  * Include portions of arena code interleaved with tcache code in order to
  * resolve circular dependencies.