Create GCN-specific gthreads
2019-06-05 Kwok Cheung Yeung <kcy@codesourcery.com>
Andrew Stubbs <ams@codesourcery.com>
gcc/
* config.gcc (thread_file): Set to gcn for AMD GCN.
* config/gcn/gcn.c (gcn_emutls_var_init): New function.
(TARGET_EMUTLS_VAR_INIT): New hook.
config/
* gthr.m4 (GCC_AC_THREAD_HEADER): Add case for gcn.
libgcc/
* configure: Regenerate.
* config/gcn/gthr-gcn.h: New.
@@ -13,6 +13,7 @@ AC_DEFUN([GCC_AC_THREAD_HEADER],
case $1 in
aix) thread_header=config/rs6000/gthr-aix.h ;;
dce) thread_header=config/pa/gthr-dce.h ;;
+ gcn) thread_header=config/gcn/gthr-gcn.h ;;
lynx) thread_header=config/gthr-lynx.h ;;
mipssde) thread_header=config/mips/gthr-mipssde.h ;;
posix) thread_header=gthr-posix.h ;;
@@ -1428,6 +1428,7 @@ amdgcn-*-amdhsa)
fi
# Force .init_array support.
gcc_cv_initfini_array=yes
+ thread_file=gcn
;;
moxie-*-elf)
gas=yes
@@ -3163,6 +3163,16 @@ gcn_valid_cvt_p (machine_mode from, machine_mode to, enum gcn_cvt_t op)
|| (to == DFmode && (from == SImode || from == SFmode)));
}
+/* Implement TARGET_EMUTLS_VAR_INIT.
+
+ Disable emutls (gthr-gcn.h does not support it, yet). */
+
+tree
+gcn_emutls_var_init (tree, tree decl, tree)
+{
+ sorry_at (DECL_SOURCE_LOCATION (decl), "TLS is not implemented for GCN.");
+}
+
/* }}} */
/* {{{ Costs. */
@@ -6007,6 +6017,8 @@ print_operand (FILE *file, rtx x, int code)
#define TARGET_CONSTANT_ALIGNMENT gcn_constant_alignment
#undef TARGET_DEBUG_UNWIND_INFO
#define TARGET_DEBUG_UNWIND_INFO gcn_debug_unwind_info
+#undef TARGET_EMUTLS_VAR_INIT
+#define TARGET_EMUTLS_VAR_INIT gcn_emutls_var_init
#undef TARGET_EXPAND_BUILTIN
#define TARGET_EXPAND_BUILTIN gcn_expand_builtin
#undef TARGET_FUNCTION_ARG
new file mode 100644
@@ -0,0 +1,163 @@
+/* Threads compatibility routines for libgcc2 and libobjc. */
+/* Compile this one with gcc. */
+/* Copyright (C) 2019 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+<http://www.gnu.org/licenses/>. */
+
+/* AMD GCN does not support dynamic creation of threads. There may be many
+ hardware threads, but they're all created simultaneously at launch time.
+
+ This implementation is intended to provide mutexes for libgfortran, etc.
+ It is not intended to provide a TLS implementation at this time,
+ although that may be added later if needed.
+
+ __gthread_active_p returns "1" to ensure that mutexes are used, and that
+ programs attempting to use emutls will fail with the appropriate abort.
+ It is expected that the TLS tests will fail. */
+
+#ifndef GCC_GTHR_GCN_H
+#define GCC_GTHR_GCN_H
+
+#define __GTHREADS 1
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef _LIBOBJC
+#error "Objective C is not supported on AMD GCN"
+#else
+
+static inline int
+__gthread_active_p (void)
+{
+ return 1;
+}
+
+typedef int __gthread_key_t;
+typedef int __gthread_once_t;
+typedef int __gthread_mutex_t;
+typedef int __gthread_recursive_mutex_t;
+
+#define __GTHREAD_ONCE_INIT 0
+#define __GTHREAD_MUTEX_INIT 0
+#define __GTHREAD_RECURSIVE_MUTEX_INIT 0
+
+static inline int
+__gthread_once (__gthread_once_t *__once __attribute__((unused)),
+ void (*__func) (void) __attribute__((unused)))
+{
+ return 0;
+}
+
+static inline int
+__gthread_key_create (__gthread_key_t *__key __attribute__((unused)),
+ void (*__dtor) (void *) __attribute__((unused)))
+{
+ /* Operation is not supported. */
+ return -1;
+}
+
+static inline int
+__gthread_key_delete (__gthread_key_t __key __attribute__ ((__unused__)))
+{
+ /* Operation is not supported. */
+ return -1;
+}
+
+static inline void *
+__gthread_getspecific (__gthread_key_t __key __attribute__((unused)))
+{
+ return NULL;
+}
+
+static inline int
+__gthread_setspecific (__gthread_key_t __key __attribute__((unused)),
+ const void *__ptr __attribute__((unused)))
+{
+ /* Operation is not supported. */
+ return -1;
+}
+
+static inline int
+__gthread_mutex_destroy (__gthread_mutex_t *__mutex __attribute__((unused)))
+{
+ return 0;
+}
+
+static inline int
+__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *__mutex __attribute__((unused)))
+{
+ return 0;
+}
+
+
+static inline int
+__gthread_mutex_lock (__gthread_mutex_t *__mutex)
+{
+ while (__sync_lock_test_and_set (__mutex, 1))
+ asm volatile ("s_sleep\t1" ::: "memory");
+
+ return 0;
+}
+
+static inline int
+__gthread_mutex_trylock (__gthread_mutex_t *__mutex)
+{
+ return __sync_lock_test_and_set (__mutex, 1);
+}
+
+static inline int
+__gthread_mutex_unlock (__gthread_mutex_t *__mutex)
+{
+ __sync_lock_release (__mutex);
+
+ return 0;
+}
+
+static inline int
+__gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *__mutex __attribute__((unused)))
+{
+ /* Operation is not supported. */
+ return -1;
+}
+
+static inline int
+__gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *__mutex __attribute__((unused)))
+{
+ /* Operation is not supported. */
+ return -1;
+}
+
+static inline int
+__gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *__mutex __attribute__((unused)))
+{
+ /* Operation is not supported. */
+ return -1;
+}
+#endif /* _LIBOBJC */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ! GCC_GTHR_GCN_H */
@@ -5542,6 +5542,7 @@ tm_file="${tm_file_}"
case $target_thread_file in
aix) thread_header=config/rs6000/gthr-aix.h ;;
dce) thread_header=config/pa/gthr-dce.h ;;
+ gcn) thread_header=config/gcn/gthr-gcn.h ;;
lynx) thread_header=config/gthr-lynx.h ;;
mipssde) thread_header=config/mips/gthr-mipssde.h ;;
posix) thread_header=gthr-posix.h ;;
This patch creates a new gthread model for AMD GCN devices. For now, there's just enough support for libgfortran to use mutexes in its I/O routines. The rest can be added at a later time, if at all. Notes: * GCN GPUs do not support dynamic creation and deletion of threads, so there can be no implementation for those functions. (There may be many threads, of course, but they are hardware managed and must be launched all at once.) * It would be possible to implement support for EMUTLS, but I have no wish to do so at this time, and it isn't likely to be needed by OpenMP or OpenACC offload kernels, so those functions are also stub implementations. OK to commit?