[U-Boot] [PATCH v2 03/51] dhry: Correct dhrystone calculation for fast machines

Simon Glass sjg at chromium.org
Sat Mar 12 06:06:48 CET 2016


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 at chromium.org>
---

Changes in v2: None

 lib/dhry/cmd_dhry.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/dhry/cmd_dhry.c b/lib/dhry/cmd_dhry.c
index 5dc191e..d7e1e6a 100644
--- a/lib/dhry/cmd_dhry.c
+++ b/lib/dhry/cmd_dhry.c
@@ -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;
 }
-- 
2.7.0.rc3.207.g0ac5344



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