[gomp4 8/8] libgomp: provide ICVs via env.c on nvptx

[Alexander Monakov <amonakov at ispras dot ru>]

This patch ports env.c to NVPTX.  It drops all environment parsing routines
since there's no "environment" on the device.  For now, the useful effect of
the patch is providing 'omp_is_initial_device' to distinguish host execution
from target execution in user code.

Several functions use gomp_icv, which is not adjusted for NVPTX and thus will
try to use EMUTLS.  The intended way forward is to provide a custom
implementation of gomp_icv on NVPTX, likely via pre-allocating storage prior
to spawning a team.

	* config/nvptx/env.c: New file.
---
 libgomp/config/nvptx/env.c | 219 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 219 insertions(+)

diff --git a/libgomp/config/nvptx/env.c b/libgomp/config/nvptx/env.c
index e69de29..f964b29 100644
--- a/libgomp/config/nvptx/env.c
+++ b/libgomp/config/nvptx/env.c
@@ -0,0 +1,219 @@
+/* Copyright (C) 2015 Free Software Foundation, Inc.
+
+   This file is part of the GNU Offloading and Multi Processing Library
+   (libgomp).
+
+   Libgomp 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.
+
+   Libgomp 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/>.  */
+
+/* This file defines the OpenMP internal control variables.  There is
+   no environment on the accelerator, so the variables can be changed
+   only via OpenMP API in target regions.  */
+
+#include "libgomp.h"
+#include "libgomp_f.h"
+
+#include <limits.h>
+
+struct gomp_task_icv gomp_global_icv = {
+  .nthreads_var = 1,
+  .thread_limit_var = UINT_MAX,
+  .run_sched_var = GFS_DYNAMIC,
+  .run_sched_modifier = 1,
+  .default_device_var = 0,
+  .dyn_var = false,
+  .nest_var = false,
+  .bind_var = omp_proc_bind_false,
+  .target_data = NULL
+};
+
+unsigned long gomp_max_active_levels_var = INT_MAX;
+unsigned long gomp_available_cpus = 1, gomp_managed_threads = 1;
+unsigned long long gomp_spin_count_var, gomp_throttled_spin_count_var;
+unsigned long *gomp_nthreads_var_list, gomp_nthreads_var_list_len;
+char *gomp_bind_var_list;
+unsigned long gomp_bind_var_list_len;
+void **gomp_places_list;
+unsigned long gomp_places_list_len;
+int gomp_debug_var;
+
+void
+omp_set_num_threads (int n)
+{
+  struct gomp_task_icv *icv = gomp_icv (true);
+  icv->nthreads_var = (n > 0 ? n : 1);
+}
+
+void
+omp_set_dynamic (int val)
+{
+  struct gomp_task_icv *icv = gomp_icv (true);
+  icv->dyn_var = val;
+}
+
+int
+omp_get_dynamic (void)
+{
+  struct gomp_task_icv *icv = gomp_icv (false);
+  return icv->dyn_var;
+}
+
+void
+omp_set_nested (int val)
+{
+  struct gomp_task_icv *icv = gomp_icv (true);
+  icv->nest_var = val;
+}
+
+int
+omp_get_nested (void)
+{
+  struct gomp_task_icv *icv = gomp_icv (false);
+  return icv->nest_var;
+}
+
+void
+omp_set_schedule (omp_sched_t kind, int modifier)
+{
+  struct gomp_task_icv *icv = gomp_icv (true);
+  switch (kind)
+    {
+    case omp_sched_static:
+      if (modifier < 1)
+	modifier = 0;
+      icv->run_sched_modifier = modifier;
+      break;
+    case omp_sched_dynamic:
+    case omp_sched_guided:
+      if (modifier < 1)
+	modifier = 1;
+      icv->run_sched_modifier = modifier;
+      break;
+    case omp_sched_auto:
+      break;
+    default:
+      return;
+    }
+  icv->run_sched_var = kind;
+}
+
+void
+omp_get_schedule (omp_sched_t *kind, int *modifier)
+{
+  struct gomp_task_icv *icv = gomp_icv (false);
+  *kind = icv->run_sched_var;
+  *modifier = icv->run_sched_modifier;
+}
+
+int
+omp_get_max_threads (void)
+{
+  struct gomp_task_icv *icv = gomp_icv (false);
+  return icv->nthreads_var;
+}
+
+int
+omp_get_thread_limit (void)
+{
+  struct gomp_task_icv *icv = gomp_icv (false);
+  return icv->thread_limit_var > INT_MAX ? INT_MAX : icv->thread_limit_var;
+}
+
+void
+omp_set_max_active_levels (int max_levels)
+{
+  if (max_levels >= 0)
+    gomp_max_active_levels_var = max_levels;
+}
+
+int
+omp_get_max_active_levels (void)
+{
+  return gomp_max_active_levels_var;
+}
+
+int
+omp_get_cancellation (void)
+{
+  return 0;
+}
+
+omp_proc_bind_t
+omp_get_proc_bind (void)
+{
+  return omp_proc_bind_false;
+}
+
+void
+omp_set_default_device (int device_num __attribute__((unused)))
+{
+}
+
+int
+omp_get_default_device (void)
+{
+  return 0;
+}
+
+int
+omp_get_num_devices (void)
+{
+  return 0;
+}
+
+int
+omp_get_num_teams (void)
+{
+  /* FORNOW.  */
+  return 1;
+}
+
+int
+omp_get_team_num (void)
+{
+  /* FORNOW.  */
+  return 0;
+}
+
+int
+omp_is_initial_device (void)
+{
+  /* PTX is an accelerator-only target.  */
+  return 0;
+}
+
+ialias (omp_set_dynamic)
+ialias (omp_set_nested)
+ialias (omp_set_num_threads)
+ialias (omp_get_dynamic)
+ialias (omp_get_nested)
+ialias (omp_set_schedule)
+ialias (omp_get_schedule)
+ialias (omp_get_max_threads)
+ialias (omp_get_thread_limit)
+ialias (omp_set_max_active_levels)
+ialias (omp_get_max_active_levels)
+ialias (omp_get_cancellation)
+ialias (omp_get_proc_bind)
+ialias (omp_set_default_device)
+ialias (omp_get_default_device)
+ialias (omp_get_num_devices)
+ialias (omp_get_num_teams)
+ialias (omp_get_team_num)
+ialias (omp_is_initial_device)