dhry: Correct dhrystone calculation for fast machines
authorSimon Glass <sjg@chromium.org>
Wed, 16 Mar 2016 13:44:35 +0000 (07:44 -0600)
committerBin Meng <bmeng.cn@gmail.com>
Thu, 17 Mar 2016 02:27:27 +0000 (10:27 +0800)
At present samus reports about 5600 DMIPS. With the default iteration count
this is OK, but if 10 million runs are performed it overflows. Fix it.

Signed-off-by: Simon Glass <sjg@chromium.org>
lib/dhry/cmd_dhry.c

index 5dc191ea6263b839d0903e2335d0f0650c81bd60..d7e1e6a99ba9b7d0f63ece0f32dc7cb0213ad297 100644 (file)
@@ -6,11 +6,13 @@
 
 #include <common.h>
 #include <command.h>
+#include <div64.h>
 #include "dhry.h"
 
 static int do_dhry(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
-       ulong start, duration, dhry_per_sec, vax_mips;
+       ulong start, duration, vax_mips;
+       u64 dhry_per_sec;
        int iterations = 1000000;
 
        if (argc > 1)
@@ -19,10 +21,10 @@ static int do_dhry(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
        start = get_timer(0);
        dhry(iterations);
        duration = get_timer(start);
-       dhry_per_sec = iterations * 1000 / duration;
+       dhry_per_sec = lldiv(iterations * 1000ULL, duration);
        vax_mips = dhry_per_sec / 1757;
        printf("%d iterations in %lu ms: %lu/s, %lu DMIPS\n", iterations,
-              duration, dhry_per_sec, vax_mips);
+              duration, (ulong)dhry_per_sec, vax_mips);
 
        return 0;
 }