| //===-- Unittests for rand ------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "src/stdlib/rand.h" |
| #include "src/stdlib/srand.h" |
| #include "test/UnitTest/Test.h" |
| |
| #include <stddef.h> |
| #include <stdlib.h> |
| |
| TEST(LlvmLibcRandTest, UnsetSeed) { |
| static int vals[1000]; |
| |
| for (size_t i = 0; i < 1000; ++i) { |
| int val = LIBC_NAMESPACE::rand(); |
| ASSERT_GE(val, 0); |
| ASSERT_LE(val, RAND_MAX); |
| vals[i] = val; |
| } |
| |
| // FIXME: The GPU implementation cannot initialize the seed correctly. |
| #ifndef LIBC_TARGET_ARCH_IS_GPU |
| // The C standard specifies that if 'srand' is never called it should behave |
| // as if 'srand' was called with a value of 1. If we seed the value with 1 we |
| // should get the same sequence as the unseeded version. |
| LIBC_NAMESPACE::srand(1); |
| for (size_t i = 0; i < 1000; ++i) |
| ASSERT_EQ(LIBC_NAMESPACE::rand(), vals[i]); |
| #endif |
| } |
| |
| TEST(LlvmLibcRandTest, SetSeed) { |
| const unsigned int SEED = 12344321; |
| LIBC_NAMESPACE::srand(SEED); |
| const size_t NUM_RESULTS = 10; |
| int results[NUM_RESULTS]; |
| for (size_t i = 0; i < NUM_RESULTS; ++i) { |
| results[i] = LIBC_NAMESPACE::rand(); |
| ASSERT_GE(results[i], 0); |
| ASSERT_LE(results[i], RAND_MAX); |
| } |
| |
| // If the seed is set to the same value, it should give the same sequence. |
| LIBC_NAMESPACE::srand(SEED); |
| |
| for (size_t i = 0; i < NUM_RESULTS; ++i) { |
| int val = LIBC_NAMESPACE::rand(); |
| EXPECT_EQ(results[i], val); |
| } |
| } |