[PATCH 5/5] app/test: add tests for portable versions of __builtin_add_overflow

[Andre Muezerie <andremue@linux.microsoft.com>]

__builtin_add_overflow is gcc specific. There's a need for a portable
version that can also be used with other compilers.

This patch adds tests for these new portable functions, to confirm
they behave the same way across different compilers.

Signed-off-by: Andre Muezerie <andremue@linux.microsoft.com>
---
 app/test/meson.build |   1 +
 app/test/test_math.c | 125 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 126 insertions(+)
 create mode 100644 app/test/test_math.c

diff --git a/app/test/meson.build b/app/test/meson.build
index 22b3291fa6..ab23f8dc79 100644
--- a/app/test/meson.build
+++ b/app/test/meson.build
@@ -118,6 +118,7 @@ source_file_deps = {
     'test_lpm_perf.c': ['net', 'lpm'],
     'test_malloc.c': [],
     'test_malloc_perf.c': [],
+    'test_math.c': [],
     'test_mbuf.c': ['net'],
     'test_mcslock.c': [],
     'test_member.c': ['member', 'net'],
diff --git a/app/test/test_math.c b/app/test/test_math.c
new file mode 100644
index 0000000000..55fb11f22c
--- /dev/null
+++ b/app/test/test_math.c
@@ -0,0 +1,125 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright (C) 2025 Microsoft Corporation
+ */
+
+#include <rte_math.h>
+#include <rte_debug.h>
+
+#include "test.h"
+
+/* Check condition and return if true. */
+#define TEST_MATH_RETURN_IF_ERROR(X) \
+do { \
+	if (X) { \
+		return -1; \
+	} \
+} while (0)
+
+RTE_LOG_REGISTER(math_logtype_test, test.math, INFO);
+
+static int
+verify_add_overflow_u8(uint8_t a, uint8_t b,
+		uint8_t expected_res, uint8_t expected_overflow)
+{
+	uint8_t res;
+	uint8_t overflow = __rte_add_overflow_u8(a, b, &res);
+	RTE_TEST_ASSERT_EQUAL(res, expected_res,
+			"ERROR: __rte_add_overflow_u8(0x%x, 0x%x) returned result 0x%x,"
+			" but 0x%x was expected.", a, b, res, expected_res);
+	RTE_TEST_ASSERT_EQUAL(overflow, expected_overflow,
+			"ERROR: __rte_add_overflow_u8(0x%x, 0x%x) returned overflow 0x%x,"
+			" but 0x%x was expected.", a, b, overflow, expected_overflow);
+
+	return 0;
+}
+
+static int
+verify_add_overflow_u16(uint16_t a, uint16_t b,
+		uint16_t expected_res, uint16_t expected_overflow)
+{
+	uint16_t res;
+	uint8_t overflow = __rte_add_overflow_u16(a, b, &res);
+	RTE_TEST_ASSERT_EQUAL(res, expected_res,
+			"ERROR: __rte_add_overflow_u16(0x%x, 0x%x) returned result 0x%x,"
+			" but 0x%x was expected.", a, b, res, expected_res);
+	RTE_TEST_ASSERT_EQUAL(overflow, expected_overflow,
+			"ERROR: __rte_add_overflow_u16(0x%x, 0x%x) returned overflow 0x%x,"
+			" but 0x%x was expected.", a, b, overflow, expected_overflow);
+
+	return 0;
+}
+
+static int
+verify_add_overflow_u32(uint32_t a, uint32_t b,
+		uint32_t expected_res, uint32_t expected_overflow)
+{
+	uint32_t res;
+	uint8_t overflow = __rte_add_overflow_u32(a, b, &res);
+	RTE_TEST_ASSERT_EQUAL(res, expected_res,
+			"ERROR: __rte_add_overflow_u32(0x%x, 0x%x) returned result 0x%x,"
+			" but 0x%x was expected.", a, b, res, expected_res);
+	RTE_TEST_ASSERT_EQUAL(overflow, expected_overflow,
+			"ERROR: __rte_add_overflow_u32(0x%x, 0x%x) returned overflow 0x%x,"
+			" but 0x%x was expected.", a, b, overflow, expected_overflow);
+
+	return 0;
+}
+
+static int
+test_add_overflow_u8(void)
+{
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u8(0, 0, 0, 0));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u8(0, 1, 1, 0));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u8(0, 0xFF, 0xFF, 0));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u8(1, 0xFF, 0, 1));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u8(2, 0xFF, 1, 1));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u8(4, 0xFE, 2, 1));
+
+	return 0;
+}
+
+static int
+test_add_overflow_u16(void)
+{
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u16(0, 0, 0, 0));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u16(0, 1, 1, 0));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u16(0, 0xFFFF, 0xFFFF, 0));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u16(1, 0xFFFF, 0, 1));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u16(2, 0xFFFF, 1, 1));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u16(4, 0xFFFE, 2, 1));
+
+	return 0;
+}
+
+static int
+test_add_overflow_u32(void)
+{
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u32(0, 0, 0, 0));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u32(0, 1, 1, 0));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u32(0, 0xFFFFFFFF, 0xFFFFFFFF, 0));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u32(1, 0xFFFFFFFF, 0, 1));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u32(2, 0xFFFFFFFF, 1, 1));
+	TEST_MATH_RETURN_IF_ERROR(verify_add_overflow_u32(4, 0xFFFFFFFE, 2, 1));
+
+	return 0;
+}
+
+static struct unit_test_suite math_test_suite = {
+	.suite_name = "math autotest",
+	.setup = NULL,
+	.teardown = NULL,
+	.unit_test_cases = {
+		TEST_CASE(test_add_overflow_u8),
+		TEST_CASE(test_add_overflow_u16),
+		TEST_CASE(test_add_overflow_u32),
+		TEST_CASES_END()
+	}
+};
+
+static int
+test_math(void)
+{
+	return unit_test_suite_runner(&math_test_suite);
+}
+
+REGISTER_FAST_TEST(math_autotest, true, true, test_math);
-- 
2.47.0.vfs.0.3