[PATCH (updated)] Avoid annoying build warning on 32-bit platforms

[Chris Wedgwood <cw@f00f.org>]

On Wed, Oct 20, 2004 at 11:56:45AM +0200, Mikael Pettersson wrote:

> There's a coding idiom for doing this: just break up
> the ">> 32" in two steps, like: ((time >> 31) >> 1).

i assumed gcc would complain there too but it doesn't and it does
optimize this away (i checked)

> Definitely preferable over #ifdef:s.

indeed



Avoid annoying gcc warning on 32-bit platforms.

Signed-off-by: cw@f00f.org

===== drivers/char/random.c 1.57 vs edited =====
--- 1.57/drivers/char/random.c	2004-10-05 14:21:53 -07:00
+++ edited/drivers/char/random.c	2004-10-20 03:19:17 -07:00
@@ -818,12 +818,10 @@ static void add_timer_randomness(struct 
 	 * jiffies.
 	 */
 	time = get_cycles();
-	if (time != 0) {
-		if (sizeof(time) > 4)
-			num ^= (u32)(time >> 32);
-	} else {
+	if (time)
+		num ^= (u32)((time >> 32) >> 1);
+	else
 		time = jiffies;
-	}
 
 	/*
 	 * Calculate number of bits of randomness we probably added.