From: R. Steve McKown <rsmckown@gmail.com>
Date: Thu, 8 Dec 2011 03:05:19 +0000 (-0700)
Subject: Ensure proper behavior in timer_cwait
X-Git-Tag: 1.0~41
X-Git-Url: https://oss.titaniummirror.com/gitweb?p=rgblamp.git;a=commitdiff_plain;h=250129a53a803f2c5c1359f89f1e9a834e8c37a7

Ensure proper behavior in timer_cwait

Ah, the Hi-Tech compiler's lovely interpretation of promotions.  See
3.6.1, Integral Promotion.  This may affect the conditional in
timer_cwait(), so force a cast of the result to be sure it is correct.
---

diff --git a/timer.h b/timer.h
index c28ed0b..20e0c8b 100644
--- a/timer.h
+++ b/timer.h
@@ -44,7 +44,7 @@
 #define timer_cwait(c) \
   { \
     unsigned t0 = TMR0; \
-    while ((TMR0 - t0) <= c); \
+    while ((unsigned)(TMR0 - t0) <= c); /* cast prevents integral promotion */ \
   } while (0)
 
 void timer_uwait(unsigned us);