| //===-- Implementation of 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/__support/common.h" |
| #include "src/stdlib/rand_util.h" |
| |
| namespace LIBC_NAMESPACE { |
| |
| // An implementation of the xorshift64star pseudo random number generator. This |
| // is a good general purpose generator for most non-cryptographics applications. |
| LLVM_LIBC_FUNCTION(int, rand, (void)) { |
| unsigned long x = rand_next; |
| x ^= x >> 12; |
| x ^= x << 25; |
| x ^= x >> 27; |
| rand_next = x; |
| return static_cast<int>((x * 0x2545F4914F6CDD1Dul) >> 32) & RAND_MAX; |
| } |
| |
| } // namespace LIBC_NAMESPACE |
