llvmpipe: added comment about lookup-tables vs. computation

2010-01-15 11:26:35 -07:00
parent 4bef3575e6
commit 12ba9e99db
1 changed files with 3 additions and 0 deletions
@@ -40,6 +40,9 @@
 * Map an index in [0,15] to an x,y position, multiplied by 4.
 * This is used to get the position of each subtile in a 4x4
 * grid of edge step values.
+ * Note: we can use some bit twiddling to compute these values instead
+ * of using a look-up table, but there's no measurable performance
+ * difference.
 */
 static const int pos_table4[16][2] = {
   { 0, 0 },