1//===-- Implementation of crt for amdgpu ----------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "src/__support/GPU/utils.h"
10#include "src/__support/RPC/rpc_client.h"
11#include "src/stdlib/atexit.h"
12#include "src/stdlib/exit.h"
13
14extern "C" int main(int argc, char **argv, char **envp);
15
16namespace LIBC_NAMESPACE {
17
18extern "C" uintptr_t __init_array_start[];
19extern "C" uintptr_t __init_array_end[];
20extern "C" uintptr_t __fini_array_start[];
21extern "C" uintptr_t __fini_array_end[];
22
23using InitCallback = void(int, char **, char **);
24using FiniCallback = void(void);
25
26static void call_init_array_callbacks(int argc, char **argv, char **env) {
27 size_t init_array_size = __init_array_end - __init_array_start;
28 for (size_t i = 0; i < init_array_size; ++i)
29 reinterpret_cast<InitCallback *>(__init_array_start[i])(argc, argv, env);
30}
31
32static void call_fini_array_callbacks() {
33 size_t fini_array_size = __fini_array_end - __fini_array_start;
34 for (size_t i = fini_array_size; i > 0; --i)
35 reinterpret_cast<FiniCallback *>(__fini_array_start[i - 1])();
36}
37
38} // namespace LIBC_NAMESPACE
39
40extern "C" [[gnu::visibility("protected"), clang::amdgpu_kernel]] void
41_begin(int argc, char **argv, char **env) {
42 // We want the fini array callbacks to be run after other atexit
43 // callbacks are run. So, we register them before running the init
44 // array callbacks as they can potentially register their own atexit
45 // callbacks.
46 LIBC_NAMESPACE::atexit(&LIBC_NAMESPACE::call_fini_array_callbacks);
47 LIBC_NAMESPACE::call_init_array_callbacks(argc, argv, env);
48}
49
50extern "C" [[gnu::visibility("protected"), clang::amdgpu_kernel]] void
51_start(int argc, char **argv, char **envp, int *ret) {
52 // Invoke the 'main' function with every active thread that the user launched
53 // the _start kernel with.
54 __atomic_fetch_or(ret, main(argc, argv, envp), __ATOMIC_RELAXED);
55}
56
57extern "C" [[gnu::visibility("protected"), clang::amdgpu_kernel]] void
58_end(int retval) {
59 // Only a single thread should call `exit` here, the rest should gracefully
60 // return from the kernel. This is so only one thread calls the destructors
61 // registred with 'atexit' above.
62 LIBC_NAMESPACE::exit(retval);
63}
64

source code of libc/startup/gpu/amdgpu/start.cpp