zephyr/tests/unit/intmath/main.c

103 lines
2.4 KiB
C

/*
* Copyright (c) 2015 Wind River Systems, Inc.
* Copyright (c) 2018 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/ztest.h>
/* Built-time math test. Zephyr code depends on a standard C ABI with
* 2's complement signed math. As this isn't technically guaranteed
* by the compiler or language standard, validate it explicitly here.
*/
/* Recent GCC's can detect integer overflow in static expressions and
* will warn about it helpfully. But obviously integer overflow is
* the whole point here, so turn that warning off.
*/
#ifdef __GNUC__
#pragma GCC diagnostic ignored "-Woverflow"
#endif
/* Two's complement negation check: "-N" must equal "(~N)+1" */
#define NEG_CHECK(T, N) BUILD_ASSERT((-((T)N)) == (~((T)N)) + 1)
/* Checks that MAX+1==MIN in the given type */
#define ROLLOVER_CHECK(T, MAX, MIN) BUILD_ASSERT((T)((T)1 + (T)MAX) == (T)MIN)
#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Winteger-overflow"
#endif
ROLLOVER_CHECK(unsigned int, 0xffffffff, 0);
ROLLOVER_CHECK(unsigned short, 0xffff, 0);
ROLLOVER_CHECK(unsigned char, 0xff, 0);
NEG_CHECK(signed char, 1);
NEG_CHECK(signed char, 0);
NEG_CHECK(signed char, -1);
NEG_CHECK(signed char, 0x80);
NEG_CHECK(signed char, 0x7f);
ROLLOVER_CHECK(signed char, 127, -128);
NEG_CHECK(short, 1);
NEG_CHECK(short, 0);
NEG_CHECK(short, -1);
NEG_CHECK(short, 0x8000);
NEG_CHECK(short, 0x7fff);
ROLLOVER_CHECK(short, 32767, -32768);
NEG_CHECK(int, 1);
NEG_CHECK(int, 0);
NEG_CHECK(int, -1);
NEG_CHECK(int, 0x80000000);
NEG_CHECK(int, 0x7fffffff);
ROLLOVER_CHECK(int, 2147483647, -2147483648);
#ifdef __clang__
#pragma clang diagnostic pop
#endif
/**
* @addtogroup kernel_common_tests
* @{
*/
/**
* @brief Test integer arithmetic operations
*
* @details Test multiplication and division of two
* integers
*/
ZTEST(intmath, test_intmath)
{
/*
* Declaring volatile so the compiler doesn't try to optimize any
* of the math away at build time
*/
volatile uint64_t bignum, ba, bb;
volatile uint32_t num, a, b;
ba = 0x00000012ABCDEF12ULL;
bb = 0x0000001000000111ULL;
bignum = ba * bb;
zassert_true((bignum == 0xbcdf0509369bf232ULL), "64-bit multiplication failed");
a = 30000U;
b = 5872U;
num = a * b;
zassert_true((num == 176160000U), "32-bit multiplication failed");
a = 234424432U;
b = 98982U;
num = a / b;
zassert_true((num == 2368U), "32-bit division failed");
}
/**
* @}
*/
ZTEST_SUITE(intmath, NULL, NULL, NULL, NULL, NULL);