[PATCH] bitops: fix issue in parallel atomic tests

Mattias Rönnblom mattias.ronnblom at ericsson.com
Sun Oct 13 13:57:19 CEST 2024


The macros generating the parallel test for atomic test-and-
[set|clear|flip] functions used a 64-bit reference word when assuring
no neighbouring bits were modified, even when generating code for the
32-bit version of the test.

This issue causes spurious test failures on GCC 12.2.0 (the default
compiler on for example Debian 12 "bookworm"), when optimization level
2 or higher are used.

The test failures do not occur with GCC 11, 12.3 and 13.2.

To the author, this looks like a promotion-related compiler bug in GCC
12.2.

Fixes: 35326b61aecb ("bitops: add atomic bit operations in new API")

Signed-off-by: Mattias Rönnblom <mattias.ronnblom at ericsson.com>
---
 app/test/test_bitops.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/app/test/test_bitops.c b/app/test/test_bitops.c
index 4200073ae4..681e984037 100644
--- a/app/test/test_bitops.c
+++ b/app/test/test_bitops.c
@@ -227,7 +227,7 @@ test_bit_atomic_parallel_test_and_modify ## size(void) \
 	bool expected_value = total_flips % 2; \
 	TEST_ASSERT(expected_value == rte_bit_test(&word, bit), \
 		"After %"PRId64" flips, the bit value should be %d", total_flips, expected_value); \
-	uint64_t expected_word = 0; \
+	uint ## size ## _t expected_word = 0; \
 	rte_bit_assign(&expected_word, bit, expected_value); \
 	TEST_ASSERT(expected_word == word, "Untouched bits have changed value"); \
 	return TEST_SUCCESS; \
@@ -275,7 +275,7 @@ test_bit_atomic_parallel_flip ## size(void) \
 	bool expected_value = total_flips % 2; \
 	TEST_ASSERT(expected_value == rte_bit_test(&word, bit), \
 		"After %"PRId64" flips, the bit value should be %d", total_flips, expected_value); \
-	uint64_t expected_word = 0; \
+	uint ## size ## _t expected_word = 0; \
 	rte_bit_assign(&expected_word, bit, expected_value); \
 	TEST_ASSERT(expected_word == word, "Untouched bits have changed value"); \
 	return TEST_SUCCESS; \
-- 
2.43.0



More information about the dev mailing list