return util_fast_exp2(util_fast_log2(x) * y);
}
+/* Note that this counts zero as a power of two.
+ */
+static INLINE boolean
+util_is_power_of_two( unsigned v )
+{
+ return (v & (v-1)) == 0;
+}
+
/**
* Floor(x), returned as int.
}
+/**
+ * Test whether x is a power of two.
+ */
+static INLINE boolean
+util_is_pot(unsigned x)
+{
+ return (x & (x - 1)) == 0;
+}
+
+
/**
* Find first bit set in word. Least significant bit is 1.
* Return 0 if no bits set.
*/
-#if defined(_MSC_VER) && _MSC_VER >= 1300
+#if defined(_MSC_VER) && _MSC_VER >= 1300 && (_M_IX86 || _M_AMD64 || _M_IA64)
+unsigned char _BitScanForward(unsigned long* Index, unsigned long Mask);
+#pragma intrinsic(_BitScanForward)
static INLINE
unsigned long ffs( unsigned long u )
{
#define ffs __builtin_ffs
#endif
+#ifdef __MINGW32__
+#define ffs __builtin_ffs
+#endif
+
+
+/* Could also binary search for the highest bit.
+ */
+static INLINE unsigned
+util_unsigned_logbase2(unsigned n)
+{
+ unsigned log2 = 0;
+ while (n >>= 1)
+ ++log2;
+ return log2;
+}
+
/**
* Return float bits.
}
+/**
+ * Returns the smallest power of two >= x
+ */
+static INLINE unsigned
+util_next_power_of_two(unsigned x)
+{
+ unsigned i;
+
+ if (x == 0)
+ return 1;
+
+ --x;
+
+ for (i = 1; i < sizeof(unsigned) * 8; i <<= 1)
+ x |= x >> i;
+
+ return x + 1;
+}
+
+
+/**
+ * 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
+}
+
+
/**
* Clamp X to [MIN, MAX].
* This is a macro to allow float, int, uint, etc. types.
#define MIN2( A, B ) ( (A)<(B) ? (A) : (B) )
#define MAX2( A, B ) ( (A)>(B) ? (A) : (B) )
+#define MIN3( A, B, C ) MIN2( MIN2( A, B ), C )
+#define MAX3( A, B, C ) MAX2( MAX2( A, B ), C )
+
static INLINE int
align(int value, int alignment)
}
static INLINE unsigned
-minify(unsigned value)
+u_minify(unsigned value, unsigned levels)
{
- return MAX2(1, value >> 1);
+ return MAX2(1, value >> levels);
}
#ifndef COPY_4V