Read OMP_TARGET_OFFLOAD and provide API to access ICV

Added settings code to read OMP_TARGET_OFFLOAD environment variable. Added
target-offload-var ICV as __kmp_target_offload, set via OMP_TARGET_OFFLOAD,
if available, otherwise defaulting to DEFAULT. Valid values for the ICV are
specified as enum values {0,1,2} for disabled, default, and mandatory. An
internal API access function __kmpc_get_target_offload is provided.

Patch by Terry Wilmarth

Differential Revision: https://reviews.llvm.org/D44577

llvm-svn: 328046

5 files changed, 64 insertions, 0 deletions

diff --git a/openmp/runtime/src/dllexports b/openmp/runtime/src/dllexports
index 32dec094bd3..4fc48f40766 100644
--- a/openmp/runtime/src/dllexports
+++ b/openmp/runtime/src/dllexports
@@ -403,6 +403,7 @@ kmpc_set_disp_num_buffers                   267
     %ifdef OMP_45
         __kmpc_task_reduction_init          268
         __kmpc_task_reduction_get_th_data   269
+        __kmpc_get_target_offload           271
     %endif
 %endif
 
diff --git a/openmp/runtime/src/kmp.h b/openmp/runtime/src/kmp.h
index c7e2965119d..2ca8500165e 100644
--- a/openmp/runtime/src/kmp.h
+++ b/openmp/runtime/src/kmp.h
@@ -3813,6 +3813,18 @@ KMP_EXPORT void KMPC_CONVENTION kmpc_set_library(int);
 KMP_EXPORT void KMPC_CONVENTION kmpc_set_defaults(char const *);
 KMP_EXPORT void KMPC_CONVENTION kmpc_set_disp_num_buffers(int);
 
+#if OMP_50_ENABLED
+enum kmp_target_offload_kind {
+  tgt_disabled = 0,
+  tgt_default = 1,
+  tgt_mandatory = 2
+};
+typedef enum kmp_target_offload_kind kmp_target_offload_kind_t;
+// Set via OMP_TARGET_OFFLOAD if specified, defaults to tgt_default otherwise
+extern kmp_target_offload_kind_t __kmp_target_offload;
+extern int __kmpc_get_target_offload();
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/openmp/runtime/src/kmp_csupport.cpp b/openmp/runtime/src/kmp_csupport.cpp
index 702b65076e1..dbf2f995a78 100644
--- a/openmp/runtime/src/kmp_csupport.cpp
+++ b/openmp/runtime/src/kmp_csupport.cpp
@@ -4065,4 +4065,8 @@ void __kmpc_doacross_fini(ident_t *loc, int gtid) {
 }
 #endif
 
+#if OMP_50_ENABLED
+int __kmpc_get_target_offload(void) { return __kmp_target_offload; }
+#endif // OMP_50_ENABLED
+
 // end of file //
diff --git a/openmp/runtime/src/kmp_global.cpp b/openmp/runtime/src/kmp_global.cpp
index ab14ddb1889..3ba0ec9fafe 100644
--- a/openmp/runtime/src/kmp_global.cpp
+++ b/openmp/runtime/src/kmp_global.cpp
@@ -502,4 +502,7 @@ int _You_must_link_with_Intel_OpenMP_library = 1;
 int _You_must_link_with_Microsoft_OpenMP_library = 1;
 #endif
 
+#if OMP_50_ENABLED
+kmp_target_offload_kind_t __kmp_target_offload = tgt_default;
+#endif
 // end of file //
diff --git a/openmp/runtime/src/kmp_settings.cpp b/openmp/runtime/src/kmp_settings.cpp
index 0a05e7c6b75..ee3923cad83 100644
--- a/openmp/runtime/src/kmp_settings.cpp
+++ b/openmp/runtime/src/kmp_settings.cpp
@@ -1179,6 +1179,46 @@ static void __kmp_stg_print_default_device(kmp_str_buf_t *buffer,
 } // __kmp_stg_print_default_device
 #endif
 
+#if OMP_50_ENABLED
+// -----------------------------------------------------------------------------
+// OpenMP 5.0: OMP_TARGET_OFFLOAD
+static void __kmp_stg_parse_target_offload(char const *name, char const *value,
+                                           void *data) {
+  const char *next = value;
+  const char *scan = next;
+
+  __kmp_target_offload = tgt_default;
+  SKIP_WS(next);
+  if (*next == '\0')
+    return;
+  scan = next;
+  if (__kmp_match_str("MANDATORY", scan, &next)) {
+    __kmp_target_offload = tgt_mandatory;
+  } else if (__kmp_match_str("DISABLED", scan, &next)) {
+    __kmp_target_offload = tgt_disabled;
+  } else if (__kmp_match_str("DEFAULT", scan, &next)) {
+    __kmp_target_offload = tgt_default;
+  } else {
+    KMP_WARNING(SyntaxErrorUsing, name, "DEFAULT");
+  }
+
+} // __kmp_stg_parse_target_offload
+
+static void __kmp_stg_print_target_offload(kmp_str_buf_t *buffer,
+                                           char const *name, void *data) {
+  const char *value = NULL;
+  if (__kmp_target_offload == tgt_default)
+    value = "DEFAULT";
+  else if (__kmp_target_offload == tgt_mandatory)
+    value = "MANDATORY";
+  else if (__kmp_target_offload == tgt_disabled)
+    value = "DISABLED";
+  if (value) {
+    __kmp_str_buf_print(buffer, "   %s=%s\n", name, value);
+  }
+} // __kmp_stg_print_target_offload
+#endif
+
 #if OMP_45_ENABLED
 // -----------------------------------------------------------------------------
 // OpenMP 4.5: OMP_MAX_TASK_PRIORITY
@@ -4443,6 +4483,10 @@ static kmp_setting_t __kmp_stg_table[] = {
     {"OMP_DEFAULT_DEVICE", __kmp_stg_parse_default_device,
      __kmp_stg_print_default_device, NULL, 0, 0},
 #endif
+#if OMP_50_ENABLED
+    {"OMP_TARGET_OFFLOAD", __kmp_stg_parse_target_offload,
+     __kmp_stg_print_target_offload, NULL, 0, 0},
+#endif
 #if OMP_45_ENABLED
     {"OMP_MAX_TASK_PRIORITY", __kmp_stg_parse_max_task_priority,
      __kmp_stg_print_max_task_priority, NULL, 0, 0},