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.

diff --git a/config/gthr.m4 b/config/gthr.m4
index 7b29f1f3327..4b937306ad0 100644
--- a/config/gthr.m4
+++ b/config/gthr.m4
@@ -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 ;;
diff --git a/gcc/config.gcc b/gcc/config.gcc
index 6b00c387247..b450098aa09 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -1428,6 +1428,7 @@ amdgcn-*-amdhsa)
 	fi
 	# Force .init_array support.
 	gcc_cv_initfini_array=yes
+	thread_file=gcn
 	;;
 moxie-*-elf)
 	gas=yes
diff --git a/gcc/config/gcn/gcn.c b/gcc/config/gcn/gcn.c
index 71f4b4ce35a..e528b649cce 100644
--- a/gcc/config/gcn/gcn.c
+++ b/gcc/config/gcn/gcn.c
@@ -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
diff --git a/libgcc/config/gcn/gthr-gcn.h b/libgcc/config/gcn/gthr-gcn.h
new file mode 100644
index 00000000000..4227b515f01
--- /dev/null
+++ b/libgcc/config/gcn/gthr-gcn.h
@@ -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 */
diff --git a/libgcc/configure b/libgcc/configure
index b2914de0629..af910b62931 100644
--- a/libgcc/configure
+++ b/libgcc/configure
@@ -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 ;;
