util: add MIN4, MAX4

[mesa.git] / src / gallium / auxiliary / util / u_math.h

diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h
index 4c6c2bc00e1ed0993ac7de7c2fb612876ed0645f..6ba4e24f4ceddf4ec080c859d95128210e8699d0 100644 (file)
--- a/src/gallium/auxiliary/util/u_math.h
+++ b/src/gallium/auxiliary/util/u_math.h
@@ -168,6 +168,9 @@ static INLINE float logf( float f )
 #undef logf
 #define logf(x) ((float)log((double)(x)))
 #endif /* logf */
+
+#define isfinite(x) _finite((double)(x))
+#define isnan(x) _isnan((double)(x))
 #endif
 
 static INLINE double log2( double x )
@@ -283,6 +286,14 @@ util_fast_pow(float x, float y)
    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.
@@ -327,6 +338,15 @@ util_iround(float f)
 }
 
 
+/**
+ * Approximate floating point comparison
+ */
+static INLINE boolean
+util_is_approx(float a, float b, float tol)
+{
+   return fabs(b - a) <= tol;
+}
+
 
 /**
  * Test if x is NaN or +/- infinity.
@@ -340,11 +360,23 @@ util_is_inf_or_nan(float x)
 }
 
 
+/**
+ * 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 )
 {
@@ -450,6 +482,78 @@ util_logbase2(unsigned n)
 }
 
 
+/**
+ * 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
+}
+
+
+/**
+ * Reverse byte order of a 16 bit word.
+ */
+static INLINE uint16_t
+util_bswap16(uint16_t n)
+{
+   return (n >> 8) |
+          (n << 8);
+}
+
+
 /**
  * Clamp X to [MIN, MAX].
  * This is a macro to allow float, int, uint, etc. types.
@@ -459,17 +563,37 @@ util_logbase2(unsigned n)
 #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 )
+
+#define MIN4( A, B, C, D ) MIN2( MIN2( A, B ), MIN2(C, D) )
+#define MAX4( A, B, C, D ) MAX2( MAX2( A, B ), MIN2(C, D) )
+
 
+/**
+ * Align a value, only works pot alignemnts.
+ */
 static INLINE int
 align(int value, int alignment)
 {
    return (value + alignment - 1) & ~(alignment - 1);
 }
 
+/**
+ * Works like align but on npot alignments.
+ */
+static INLINE size_t
+util_align_npot(size_t value, size_t alignment)
+{
+   if (value % alignment)
+      return value + (alignment - (value % alignment));
+   return value;
+}
+
 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
@@ -499,6 +623,18 @@ do {                                     \
 #endif
 
 
+static INLINE uint32_t util_unsigned_fixed(float value, unsigned frac_bits)
+{
+   return value < 0 ? 0 : (uint32_t)(value * (1<<frac_bits));
+}
+
+static INLINE int32_t util_signed_fixed(float value, unsigned frac_bits)
+{
+   return (int32_t)(value * (1<<frac_bits));
+}
+
+
+
 #ifdef __cplusplus
 }
 #endif