From: Ben Pfaff <blp@cs.stanford.edu>
Date: Tue, 20 Jan 2009 06:32:57 +0000 (-0800)
Subject: Remove unnecessary optimization barrier.
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?p=pintos-anon;a=commitdiff_plain;h=3b458804e1d0a460fb1c90f06f495b9f7a972424

Remove unnecessary optimization barrier.

The compiler can't optimize out the load of "ticks" here because
it can't look into intr_disable() and intr_set_level() and know that
they don't modify "ticks".

Thanks to Martin <mfleener@stanford.edu> for pointing this out.
---

diff --git a/src/devices/timer.c b/src/devices/timer.c
index c97667f..befaaae 100644
--- a/src/devices/timer.c
+++ b/src/devices/timer.c
@@ -73,7 +73,6 @@ timer_ticks (void)
   enum intr_level old_level = intr_disable ();
   int64_t t = ticks;
   intr_set_level (old_level);
-  barrier ();
   return t;
 }