time: move the CONFIG_SYS_TIMER_RATE handling to the compiler
CONFIG_SYS_TIMER_RATE might be a dynamic value, i.e. a function call
instead of a static value, thus it has to be evaluated at runtime. If it
is a static value, the compiler should be able to optimize the unused
branches out.
This will be needed for kirkwoods dynamic CONFIG_SYS_TCLK setting.
Cc: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/lib/time.c b/lib/time.c
index 96074b8..bbf191f 100644
--- a/lib/time.c
+++ b/lib/time.c
@@ -47,12 +47,15 @@
{
ulong count = timer_read_counter();
-#if CONFIG_SYS_TIMER_RATE == 1000000
- return count;
-#elif CONFIG_SYS_TIMER_RATE > 1000000
- return lldiv(count, CONFIG_SYS_TIMER_RATE / 1000000);
-#elif defined(CONFIG_SYS_TIMER_RATE)
- return (unsigned long long)count * 1000000 / CONFIG_SYS_TIMER_RATE;
+#ifdef CONFIG_SYS_TIMER_RATE
+ const ulong timer_rate = CONFIG_SYS_TIMER_RATE;
+
+ if (timer_rate == 1000000)
+ return count;
+ else if (timer_rate > 1000000)
+ return lldiv(count, timer_rate / 1000000);
+ else
+ return (unsigned long long)count * 1000000 / timer_rate;
#else
/* Assume the counter is in microseconds */
return count;