Changeset 1181Tweet

Timestamp:

Mar 30, 2012, 10:48:45 AM (11 years ago)

Author:

sam

Message:

math: add a few comments.

File:

• trunk/src/math/half.cpp (modified) (3 diffs)

trunk/src/math/half.cpp

@@ -2 +2 @@
 // Lol Engine
 //
-// Copyright: (c) 2010-2011 Sam Hocevar <sam@hocevar.net>
+// Copyright: (c) 2010-2012 Sam Hocevar <sam@hocevar.net>
 //   This program is free software; you can redistribute it and/or
 //   modify it under the terms of the Do What The Fuck You Want To
@@ -41 +41 @@
 /* Lookup table-based algorithm from “Fast Half Float Conversions”
  * by Jeroen van der Zijp, November 2008. No rounding is performed,
- * and some NaN values may be incorrectly converted to Inf. */
+ * and some NaN values may be incorrectly converted to Inf (because
+ * the lowest order bits in the mantissa are ignored). */
 static inline uint16_t float_to_half_nobranch(uint32_t x)
 {
@@ -158 +159 @@
 #endif
 
+/* We use this De Bruijn sequence to compute a branchless integer log2 */
 static int const shifttable[32] =
 {