Mesa (master): st/mesa: add comment to explain _min(), _maxf(), etc. functions

[Brian Paul]

Module: Mesa
Branch: master
Commit: c88a0b6af318c02b2ffa6958187672da9b3838ce
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=c88a0b6af318c02b2ffa6958187672da9b3838ce

Author: Brian Paul <brianp at vmware.com>
Date:   Tue Feb 25 09:53:49 2014 -0700

st/mesa: add comment to explain _min(), _maxf(), etc. functions

Reviewed-by: Marek Olšák <marek.olsak at amd.com>

---

 src/mesa/state_tracker/st_extensions.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index d053efb..18ddd4e 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -39,6 +39,12 @@
 #include "st_extensions.h"
 #include "st_format.h"
 
+
+/*
+ * Note: we use these function rather than the MIN2, MAX2, CLAMP macros to
+ * avoid evaluating arguments (which are often function calls) more than once.
+ */
+
 static unsigned _min(unsigned a, unsigned b)
 {
    return (a < b) ? a : b;