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authorPatrice Mandin <patmandin@gmail.com>2009-08-01 11:03:30 +0200
committerPatrice Mandin <patmandin@gmail.com>2009-08-01 11:03:30 +0200
commitc1785c19ca0716a7e85777242949a0c33e28988f (patch)
tree7d4441fd6685b86668431f8a975b32634972234c /src/gallium/auxiliary
parent801c3fcbca69a17f0696522b91cbfc378094974b (diff)
mesa st: Move logbase2 function to util/u_math.h
Diffstat (limited to 'src/gallium/auxiliary')
-rw-r--r--src/gallium/auxiliary/util/u_math.h23
1 files changed, 18 insertions, 5 deletions
diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h
index e5003af01d..30e6e2f6b3 100644
--- a/src/gallium/auxiliary/util/u_math.h
+++ b/src/gallium/auxiliary/util/u_math.h
@@ -216,23 +216,23 @@ util_fast_exp2(float x)
int32_t ipart;
float fpart, mpart;
union fi epart;
-
+
if(x > 129.00000f)
return 3.402823466e+38f;
-
+
if(x < -126.99999f)
return 0.0f;
ipart = (int32_t) x;
fpart = x - (float) ipart;
-
+
/* same as
* epart.f = (float) (1 << ipart)
* but faster and without integer overflow for ipart > 31 */
epart.i = (ipart + 127 ) << 23;
-
+
mpart = pow2_table[POW2_TABLE_OFFSET + (int)(fpart * POW2_TABLE_SCALE)];
-
+
return epart.f * mpart;
}
@@ -409,6 +409,19 @@ float_to_ubyte(float f)
}
+/**
+ * Calc log base 2
+ */
+static INLINE unsigned
+util_logbase2(unsigned n)
+{
+ unsigned log2 = 0;
+ while (n >>= 1)
+ ++log2;
+ return log2;
+}
+
+
#define CLAMP( X, MIN, MAX ) ( (X)<(MIN) ? (MIN) : ((X)>(MAX) ? (MAX) : (X)) )