[PATCH v2 06/10] app/test: fix operator precedence bug
Stephen Hemminger
stephen at networkplumber.org
Thu Nov 14 20:25:04 CET 2024
The test loop was much shorter than desired because when
MAX_NUM is defined with out paren's the divide operator /
takes precedence over shift.
But when MAX_NUM is fixed, some tests take too long
and have to modified to avoid running over full N^2
space of 1<<20.
Note: this is a very old bug, goes back to 2013.
Link: https://pvs-studio.com/en/blog/posts/cpp/1179/
Fixes: 1fb8b07ee511 ("app: add some tests")
Cc: stable at dpdk.org
Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
---
app/test/test_common.c | 31 +++++++++++++++++--------------
1 file changed, 17 insertions(+), 14 deletions(-)
diff --git a/app/test/test_common.c b/app/test/test_common.c
index 21eb2285e1..6dbd7fc9a9 100644
--- a/app/test/test_common.c
+++ b/app/test/test_common.c
@@ -9,11 +9,12 @@
#include <rte_common.h>
#include <rte_bitops.h>
#include <rte_hexdump.h>
+#include <rte_random.h>
#include <rte_pause.h>
#include "test.h"
-#define MAX_NUM 1 << 20
+#define MAX_NUM (1 << 20)
#define FAIL(x)\
{printf(x "() test failed!\n");\
@@ -218,19 +219,21 @@ test_align(void)
}
}
- for (p = 1; p <= MAX_NUM / 2; p++) {
- for (i = 1; i <= MAX_NUM / 2; i++) {
- val = RTE_ALIGN_MUL_CEIL(i, p);
- if (val % p != 0 || val < i)
- FAIL_ALIGN("RTE_ALIGN_MUL_CEIL", i, p);
- val = RTE_ALIGN_MUL_FLOOR(i, p);
- if (val % p != 0 || val > i)
- FAIL_ALIGN("RTE_ALIGN_MUL_FLOOR", i, p);
- val = RTE_ALIGN_MUL_NEAR(i, p);
- if (val % p != 0 || ((val != RTE_ALIGN_MUL_CEIL(i, p))
- & (val != RTE_ALIGN_MUL_FLOOR(i, p))))
- FAIL_ALIGN("RTE_ALIGN_MUL_NEAR", i, p);
- }
+ /* testing the whole space of 2^20^2 takes too long. */
+ for (j = 1; j <= MAX_NUM ; j++) {
+ i = rte_rand_max(MAX_NUM - 1) + 1;
+ p = rte_rand_max(MAX_NUM - 1) + 1;
+
+ val = RTE_ALIGN_MUL_CEIL(i, p);
+ if (val % p != 0 || val < i)
+ FAIL_ALIGN("RTE_ALIGN_MUL_CEIL", i, p);
+ val = RTE_ALIGN_MUL_FLOOR(i, p);
+ if (val % p != 0 || val > i)
+ FAIL_ALIGN("RTE_ALIGN_MUL_FLOOR", i, p);
+ val = RTE_ALIGN_MUL_NEAR(i, p);
+ if (val % p != 0 || ((val != RTE_ALIGN_MUL_CEIL(i, p))
+ & (val != RTE_ALIGN_MUL_FLOOR(i, p))))
+ FAIL_ALIGN("RTE_ALIGN_MUL_NEAR", i, p);
}
return 0;
--
2.45.2
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