+/**
+ * Return number of bits set in n.
+ */
+static INLINE unsigned
+util_bitcount(unsigned n)
+{
+#if defined(PIPE_CC_GCC)
+ return __builtin_popcount(n);
+#else
+ /* K&R classic bitcount.
+ *
+ * For each iteration, clear the LSB from the bitfield.
+ * Requires only one iteration per set bit, instead of
+ * one iteration per bit less than highest set bit.
+ */
+ unsigned bits = 0;
+ for (bits; n; bits++) {
+ n &= n - 1;
+ }
+ return bits;
+#endif
+}
+
+
+/**
+ * Reverse byte order of a 32 bit word.
+ */
+static INLINE uint32_t
+util_bswap32(uint32_t n)
+{
+#if defined(PIPE_CC_GCC) && (PIPE_CC_GCC_VERSION >= 403)
+ return __builtin_bswap32(n);
+#else
+ return (n >> 24) |
+ ((n >> 8) & 0x0000ff00) |
+ ((n << 8) & 0x00ff0000) |
+ (n << 24);
+#endif
+}
+
+
+/**
+ * Reverse byte order of a 16 bit word.
+ */
+static INLINE uint16_t
+util_bswap16(uint16_t n)
+{
+ return (n >> 8) |
+ (n << 8);
+}
+
+