+\f
+/* Bitwise tests. */
+
+int log_2_floor(uint32_t);
+int log_2_ceil(uint32_t);
+unsigned int count_1bits(uint64_t);
+
+/* Returns the number of trailing 0-bits in 'n'. Undefined if 'n' == 0. */
+#if __GNUC__ >= 4
+static inline int
+raw_ctz(uint64_t n)
+{
+ /* With GCC 4.7 on 32-bit x86, if a 32-bit integer is passed as 'n', using
+ * a plain __builtin_ctzll() here always generates an out-of-line function
+ * call. The test below helps it to emit a single 'bsf' instruction. */
+ return (__builtin_constant_p(n <= UINT32_MAX) && n <= UINT32_MAX
+ ? __builtin_ctz(n)
+ : __builtin_ctzll(n));
+}
+#else
+/* Defined in util.c. */
+int raw_ctz(uint64_t n);
+#endif
+
+/* Returns the number of trailing 0-bits in 'n', or 32 if 'n' is 0. */
+static inline int
+ctz(uint32_t n)
+{
+ return n ? raw_ctz(n) : 32;
+}
+
+/* Returns the number of trailing 0-bits in 'n', or 64 if 'n' is 0. */
+static inline int
+ctz64(uint64_t n)
+{
+ return n ? raw_ctz(n) : 64;
+}
+
+/* Returns the rightmost 1-bit in 'x' (e.g. 01011000 => 00001000), or 0 if 'x'
+ * is 0. */
+static inline uintmax_t
+rightmost_1bit(uintmax_t x)
+{
+ return x & -x;
+}
+
+/* Returns 'x' with its rightmost 1-bit changed to a zero (e.g. 01011000 =>
+ * 01010000), or 0 if 'x' is 0. */
+static inline uintmax_t
+zero_rightmost_1bit(uintmax_t x)
+{
+ return x & (x - 1);
+}
+
+/* Returns the index of the rightmost 1-bit in 'x' (e.g. 01011000 => 3), or 32
+ * if 'x' is 0.
+ *
+ * Unlike the other functions for rightmost 1-bits, this function only works
+ * with 32-bit integers. */
+static inline uint32_t
+rightmost_1bit_idx(uint32_t x)
+{
+ return x ? ctz(x) : 32;
+}
+
+/* Returns the index of the rightmost 1-bit in 'x' (e.g. 01011000 => 6), or 32
+ * if 'x' is 0.
+ *
+ * This function only works with 32-bit integers. */
+static inline uint32_t
+leftmost_1bit_idx(uint32_t x)
+{
+ return x ? log_2_floor(x) : 32;
+}
+\f
+bool is_all_zeros(const uint8_t *, size_t);
+bool is_all_ones(const uint8_t *, size_t);
+void bitwise_copy(const void *src, unsigned int src_len, unsigned int src_ofs,
+ void *dst, unsigned int dst_len, unsigned int dst_ofs,
+ unsigned int n_bits);
+void bitwise_zero(void *dst_, unsigned int dst_len, unsigned dst_ofs,
+ unsigned int n_bits);
+void bitwise_one(void *dst_, unsigned int dst_len, unsigned dst_ofs,
+ unsigned int n_bits);
+bool bitwise_is_all_zeros(const void *, unsigned int len, unsigned int ofs,
+ unsigned int n_bits);
+void bitwise_put(uint64_t value,
+ void *dst, unsigned int dst_len, unsigned int dst_ofs,
+ unsigned int n_bits);
+uint64_t bitwise_get(const void *src, unsigned int src_len,
+ unsigned int src_ofs, unsigned int n_bits);