Hi!
Currently if a compiler is configured with enabled offloading, the 'devices'
array in libgomp is filled properly with a number of available devices.
However, if a program is compiled with -foffload=disable, the resolve_device
function returns a pointer to the device, and host-fallback is not happening.
The patch below fixes this issue.
make check-target-libgomp passed. OK for trunk?
libgomp/
* libgomp.h (struct gomp_device_descr): Add num_images.
* target.c (resolve_device): Call gomp_init_device. Return NULL if
there is no image loaded to the device.
(gomp_offload_image_to_device): Increase num_images.
(GOMP_offload_unregister): Decrease num_images.
(GOMP_target): Don't call gomp_init_device.
(GOMP_target_data): Ditto.
(GOMP_target_update): Ditto.
(gomp_target_init): Set num_images to 0.
* testsuite/libgomp.c/target-1-disable.c: New test.
diff --git a/libgomp/libgomp.h b/libgomp/libgomp.h
index 5272f01..47a064a 100644
--- a/libgomp/libgomp.h
+++ b/libgomp/libgomp.h
@@ -762,6 +762,9 @@ struct gomp_device_descr
/* Set to true when device is initialized. */
bool is_initialized;
+ /* Number of images offloaded to the device. */
+ int num_images;
+
/* OpenACC-specific data and functions. */
/* This is mutable because of its mutable data_environ and target_data
members. */
diff --git a/libgomp/target.c b/libgomp/target.c
index d8da783..f5126b9 100644
--- a/libgomp/target.c
+++ b/libgomp/target.c
@@ -132,6 +132,14 @@ resolve_device (int device_id)
if (device_id < 0 || device_id >= gomp_get_num_devices ())
return NULL;
+ gomp_mutex_lock (&devices[device_id].lock);
+ if (!devices[device_id].is_initialized)
+ gomp_init_device (&devices[device_id]);
+ gomp_mutex_unlock (&devices[device_id].lock);
+
+ if (devices[device_id].num_images <= 0)
+ return NULL;
+
return &devices[device_id];
}
@@ -697,6 +705,7 @@ gomp_offload_image_to_device (struct gomp_device_descr
*devicep,
struct addr_pair *target_table = NULL;
int i, num_target_entries
= devicep->load_image_func (devicep->target_id, target_data,
&target_table);
+ devicep->num_images++;
if (num_target_entries != num_funcs + num_vars)
{
@@ -831,6 +840,7 @@ GOMP_offload_unregister (void *host_table, enum
offload_target_type target_type,
}
devicep->unload_image_func (devicep->target_id, target_data);
+ devicep->num_images--;
/* Remove mapping from splay tree. */
struct splay_tree_key_s k;
@@ -966,11 +976,6 @@ GOMP_target (int device, void (*fn) (void *), const void
*unused,
return;
}
- gomp_mutex_lock (&devicep->lock);
- if (!devicep->is_initialized)
- gomp_init_device (devicep);
- gomp_mutex_unlock (&devicep->lock);
-
void *fn_addr;
if (devicep->capabilities & GOMP_OFFLOAD_CAP_NATIVE_EXEC)
@@ -1034,11 +1039,6 @@ GOMP_target_data (int device, const void *unused, size_t
mapnum,
return;
}
- gomp_mutex_lock (&devicep->lock);
- if (!devicep->is_initialized)
- gomp_init_device (devicep);
- gomp_mutex_unlock (&devicep->lock);
-
struct target_mem_desc *tgt
= gomp_map_vars (devicep, mapnum, hostaddrs, NULL, sizes, kinds, false,
false);
@@ -1069,11 +1069,6 @@ GOMP_target_update (int device, const void *unused,
size_t mapnum,
|| !(devicep->capabilities & GOMP_OFFLOAD_CAP_OPENMP_400))
return;
- gomp_mutex_lock (&devicep->lock);
- if (!devicep->is_initialized)
- gomp_init_device (devicep);
- gomp_mutex_unlock (&devicep->lock);
-
gomp_update (devicep, mapnum, hostaddrs, sizes, kinds, false);
}
@@ -1265,6 +1260,7 @@ gomp_target_init (void)
current_device.type = current_device.get_type_func ();
current_device.mem_map.root = NULL;
current_device.is_initialized = false;
+ current_device.num_images = 0;
current_device.openacc.data_environ = NULL;
for (i = 0; i < new_num_devices; i++)
{
diff --git a/libgomp/testsuite/libgomp.c/target-1-disable.c
b/libgomp/testsuite/libgomp.c/target-1-disable.c
new file mode 100644
index 0000000..00ea143
--- /dev/null
+++ b/libgomp/testsuite/libgomp.c/target-1-disable.c
@@ -0,0 +1,4 @@
+/* { dg-options "-foffload=disable" } */
+/* { dg-require-effective-target offload_device } */
+
+#include "target-1.c"
-- Ilya
