[gcc r15-2742] libgomp: Device load_image - improve minor num-funcs/vars check

[Tobias Burnus via Gcc-cvs]

https://gcc.gnu.org/g:0c56fd6a1fe086e038e61041b82df63e98958e9c

commit r15-2742-g0c56fd6a1fe086e038e61041b82df63e98958e9c
Author: Tobias Burnus <tbur...@baylibre.com>
Date:   Tue Aug 6 10:34:28 2024 +0200

    libgomp: Device load_image - improve minor num-funcs/vars check
    
    The run time library loads the offload functions and variable and optionally
    the ICV variable and returns the number of loaded items, which has to match
    the host side. The plugin returns "+1" (since GCC 12) for the ICV variable
    entry, independently whether it was loaded or not, but the var's value
    (start == end == 0) can be used to detect when this failed.
    
    Thus, we can tighten the assert check - which this commit does together with
    making the output less surprising - and simplify the condition further 
below.
    
    libgomp/ChangeLog:
    
            * target.c (gomp_load_image_to_device): Extend fatal-error message;
            simplify a condition.

Diff:
---
 libgomp/target.c | 78 +++++++++++++++++++++++++-------------------------------
 1 file changed, 35 insertions(+), 43 deletions(-)

diff --git a/libgomp/target.c b/libgomp/target.c
index efed6ad68ff4..fb9a6fb5c79e 100644
--- a/libgomp/target.c
+++ b/libgomp/target.c
@@ -2362,15 +2362,14 @@ gomp_load_image_to_device (struct gomp_device_descr 
*devicep, unsigned version,
                                num_ind_funcs
                                  ? (uint64_t *) host_ind_func_table : NULL);
 
-  if (num_target_entries != num_funcs + num_vars
-      /* "+1" due to the additional ICV struct.  */
-      && num_target_entries != num_funcs + num_vars + 1)
+  /* The "+1" is due to the additional ICV struct.  */
+  if (num_target_entries != num_funcs + num_vars + 1)
     {
       gomp_mutex_unlock (&devicep->lock);
       if (is_register_lock)
        gomp_mutex_unlock (&register_lock);
       gomp_fatal ("Cannot map target functions or variables"
-                 " (expected %u, have %u)", num_funcs + num_vars,
+                 " (expected %u + %u + 1, have %u)", num_funcs, num_vars,
                  num_target_entries);
     }
 
@@ -2454,48 +2453,41 @@ gomp_load_image_to_device (struct gomp_device_descr 
*devicep, unsigned version,
       array++;
     }
 
-  /* Last entry is for a ICVs variable.
-     Tolerate case where plugin does not return those entries.  */
-  if (num_funcs + num_vars < num_target_entries)
+  /* Last entry is for the ICV struct variable; if absent, start = end = 0.  */
+  struct addr_pair *icv_var = &target_table[num_funcs + num_vars];
+  if (icv_var->start != 0)
     {
-      struct addr_pair *var = &target_table[num_funcs + num_vars];
-
-      /* Start address will be non-zero for the ICVs variable if
-        the variable was found in this image.  */
-      if (var->start != 0)
+      /* The index of the devicep within devices[] is regarded as its
+        'device number', which is different from the per-device type
+        devicep->target_id.  */
+      int dev_num = (int) (devicep - &devices[0]);
+      struct gomp_offload_icvs *icvs = get_gomp_offload_icvs (dev_num);
+      size_t var_size = icv_var->end - icv_var->start;
+      if (var_size != sizeof (struct gomp_offload_icvs))
        {
-         /* The index of the devicep within devices[] is regarded as its
-            'device number', which is different from the per-device type
-            devicep->target_id.  */
-         int dev_num = (int) (devicep - &devices[0]);
-         struct gomp_offload_icvs *icvs = get_gomp_offload_icvs (dev_num);
-         size_t var_size = var->end - var->start;
-         if (var_size != sizeof (struct gomp_offload_icvs))
-           {
-             gomp_mutex_unlock (&devicep->lock);
-             if (is_register_lock)
-               gomp_mutex_unlock (&register_lock);
-             gomp_fatal ("offload plugin managed 'icv struct' not of expected "
-                         "format");
-           }
-         /* Copy the ICVs variable to place on device memory, hereby
-            actually designating its device number into effect.  */
-         gomp_copy_host2dev (devicep, NULL, (void *) var->start, icvs,
-                             var_size, false, NULL);
-         splay_tree_key k = &array->key;
-         k->host_start = (uintptr_t) icvs;
-         k->host_end =
-           k->host_start + (size_mask & sizeof (struct gomp_offload_icvs));
-         k->tgt = tgt;
-         k->tgt_offset = var->start;
-         k->refcount = REFCOUNT_INFINITY;
-         k->dynamic_refcount = 0;
-         k->aux = NULL;
-         array->left = NULL;
-         array->right = NULL;
-         splay_tree_insert (&devicep->mem_map, array);
-         array++;
+         gomp_mutex_unlock (&devicep->lock);
+         if (is_register_lock)
+           gomp_mutex_unlock (&register_lock);
+         gomp_fatal ("offload plugin managed 'icv struct' not of expected "
+                     "format");
        }
+      /* Copy the ICVs variable to place on device memory, hereby
+            actually designating its device number into effect.  */
+      gomp_copy_host2dev (devicep, NULL, (void *) icv_var->start, icvs,
+                         var_size, false, NULL);
+      splay_tree_key k = &array->key;
+      k->host_start = (uintptr_t) icvs;
+      k->host_end =
+      k->host_start + (size_mask & sizeof (struct gomp_offload_icvs));
+      k->tgt = tgt;
+      k->tgt_offset = icv_var->start;
+      k->refcount = REFCOUNT_INFINITY;
+      k->dynamic_refcount = 0;
+      k->aux = NULL;
+      array->left = NULL;
+      array->right = NULL;
+      splay_tree_insert (&devicep->mem_map, array);
+      array++;
     }
 
   free (target_table);