Author: rminnich
Date: 2008-08-31 22:28:21 +0200 (Sun, 31 Aug 2008)
New Revision: 852
Modified:
coreboot-v3/lib/clog2.c
Log:
log2 is now log2f (floor) and log2c (ceiling) and users MUST pick one or
the other. It really matters for non-power-of-2 numbers.
This breaks k8 builds; fix is coming.
Signed-off-by: Ronald G. Minnich <[EMAIL PROTECTED]>
Acked-by: Carl-Daniel Hailfinger <[EMAIL PROTECTED]>
Modified: coreboot-v3/lib/clog2.c
===================================================================
--- coreboot-v3/lib/clog2.c 2008-08-31 02:46:37 UTC (rev 851)
+++ coreboot-v3/lib/clog2.c 2008-08-31 20:28:21 UTC (rev 852)
@@ -45,12 +45,15 @@
*
* ***** END LICENSE BLOCK ***** */
-int log2(unsigned int n)
+/**
+ * return the truncated log2 of the number.
+ * @param n number to take the log of
+ * @return log2 of the smallest integer that is a power of of 2
+ * and that is <= to the parameter. E.g. log2f(72) is 6.
+ */
+int log2f(unsigned int n)
{
int log2 = 0;
-
- if (n & (n - 1))
- log2++;
if (n >> 16)
log2 += 16, n >>= 16;
if (n >> 8)
@@ -63,3 +66,19 @@
log2++;
return log2;
}
+
+/**
+ * return the log2 of the number in integer form, rounded up as needed.
+ * @param n number to take the log of
+ * @return log2 of the smallest integer that is a power of 2
+ * that is >= to the parameter. E.g. log2(72) is 7.
+ */
+int log2c(unsigned int n)
+{
+ int log2 = 0;
+
+ if (n & (n - 1))
+ log2++;
+ return log2 + log2f(n);
+}
+
--
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