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 "config/gpu/app.h" 10 #include "src/__support/GPU/utils.h" 11 #include "src/__support/RPC/rpc_client.h" 12 #include "src/__support/macros/config.h" 13 #include "src/stdlib/atexit.h" 14 #include "src/stdlib/exit.h" 15 16 extern "C" int main(int argc, char **argv, char **envp); 17 18 namespace LIBC_NAMESPACE_DECL { 19 20 // FIXME: Factor this out into common logic so we don't need to stub it here. 21 void teardown_main_tls() {} 22 23 DataEnvironment app; 24 25 extern "C" uintptr_t __init_array_start[]; 26 extern "C" uintptr_t __init_array_end[]; 27 extern "C" uintptr_t __fini_array_start[]; 28 extern "C" uintptr_t __fini_array_end[]; 29 30 using InitCallback = void(int, char **, char **); 31 using FiniCallback = void(void); 32 33 static void call_init_array_callbacks(int argc, char **argv, char **env) { 34 size_t init_array_size = __init_array_end - __init_array_start; 35 for (size_t i = 0; i < init_array_size; ++i) 36 reinterpret_cast<InitCallback *>(__init_array_start[i])(argc, argv, env); 37 } 38 39 static void call_fini_array_callbacks() { 40 size_t fini_array_size = __fini_array_end - __fini_array_start; 41 for (size_t i = fini_array_size; i > 0; --i) 42 reinterpret_cast<FiniCallback *>(__fini_array_start[i - 1])(); 43 } 44 45 } // namespace LIBC_NAMESPACE_DECL 46 47 extern "C" [[gnu::visibility("protected"), clang::amdgpu_kernel, 48 clang::amdgpu_flat_work_group_size(1, 1), 49 clang::amdgpu_max_num_work_groups(1)]] void 50 _begin(int argc, char **argv, char **env) { 51 __atomic_store_n(&LIBC_NAMESPACE::app.env_ptr, 52 reinterpret_cast<uintptr_t *>(env), __ATOMIC_RELAXED); 53 // We want the fini array callbacks to be run after other atexit 54 // callbacks are run. So, we register them before running the init 55 // array callbacks as they can potentially register their own atexit 56 // callbacks. 57 LIBC_NAMESPACE::atexit(&LIBC_NAMESPACE::call_fini_array_callbacks); 58 LIBC_NAMESPACE::call_init_array_callbacks(argc, argv, env); 59 } 60 61 extern "C" [[gnu::visibility("protected"), clang::amdgpu_kernel]] void 62 _start(int argc, char **argv, char **envp, int *ret) { 63 // Invoke the 'main' function with every active thread that the user launched 64 // the _start kernel with. 65 __atomic_fetch_or(ret, main(argc, argv, envp), __ATOMIC_RELAXED); 66 } 67 68 extern "C" [[gnu::visibility("protected"), clang::amdgpu_kernel, 69 clang::amdgpu_flat_work_group_size(1, 1), 70 clang::amdgpu_max_num_work_groups(1)]] void 71 _end(int retval) { 72 // Only a single thread should call `exit` here, the rest should gracefully 73 // return from the kernel. This is so only one thread calls the destructors 74 // registred with 'atexit' above. 75 LIBC_NAMESPACE::exit(retval); 76 } 77