Fix for PR44932

Fix for PR44932

[Xinliang David Li]

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Hi, this patch fixes the problem reported in 44932. The bogus warning
is emitted because the predicate set for the definitions are not
properly computed as a result of the bug in collecting the edge set
for phi operands that are defined.

Bootstrapped and tested on x86-64/linux.

Ok to checkin?

Thanks,

David

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Index: gcc/tree-ssa-uninit.c
===================================================================
--- gcc/tree-ssa-uninit.c	(revision 162159)
+++ gcc/tree-ssa-uninit.c	(working copy)
@@ -490,17 +490,33 @@ collect_phi_def_edges (gimple phi, basic
       opnd_edge = gimple_phi_arg_edge (phi, i);
       opnd = gimple_phi_arg_def (phi, i);
 
-      if (TREE_CODE (opnd) != SSA_NAME
-          || !ssa_undefined_value_p (opnd))
-        VEC_safe_push (edge, heap, *edges, opnd_edge);
+      if (TREE_CODE (opnd) != SSA_NAME)
+        {
+          if (dump_file)
+            {
+              fprintf (dump_file, "\n[CHECK] Found def edge %d in ", (int)i);
+              print_gimple_stmt (dump_file, phi, 0, 0);
+            }
+          VEC_safe_push (edge, heap, *edges, opnd_edge);
+        }
       else
         {
           gimple def = SSA_NAME_DEF_STMT (opnd);
+
           if (gimple_code (def) == GIMPLE_PHI
               && dominated_by_p (CDI_DOMINATORS,
                                  gimple_bb (def), cd_root))
             collect_phi_def_edges (def, cd_root, edges,
                                    visited_phis);
+          else if (!ssa_undefined_value_p (opnd))
+            {
+              if (dump_file)
+                {
+                  fprintf (dump_file, "\n[CHECK] Found def edge %d in ", (int)i);
+                  print_gimple_stmt (dump_file, phi, 0, 0);
+                }
+              VEC_safe_push (edge, heap, *edges, opnd_edge);
+            }
         }
     }
 }
@@ -1530,7 +1546,7 @@ is_use_properly_guarded (gimple use_stmt
 
   if (dump_file)
     dump_predicates (use_stmt, num_preds, preds,
-                     "Use in stmt ");
+                     "\nUse in stmt ");
 
   has_valid_preds = find_def_preds (&def_preds,
                                     &num_def_preds, phi);
@@ -1615,15 +1631,26 @@ find_uninit_use (gimple phi, unsigned un
         }
       pointer_set_destroy (visited_phis);
 
+      if (dump_file)
+        {
+          fprintf (dump_file, "[CHECK]: Found unguarded use: ");
+          print_gimple_stmt (dump_file, use_stmt, 0, 0);
+        }
       /* Found one real use, return.  */
       if (gimple_code (use_stmt) != GIMPLE_PHI)
-         return use_stmt;
+        return use_stmt;
 
       /* Found a phi use that is not guarded,
          add the phi to the worklist.  */
       if (!pointer_set_insert (added_to_worklist,
                                use_stmt))
         {
+          if (dump_file)
+            {
+              fprintf (dump_file, "[WORKLIST]: Update worklist with phi: ");
+              print_gimple_stmt (dump_file, use_stmt, 0, 0);
+            }
+
           VEC_safe_push (gimple, heap, *worklist, use_stmt);
           pointer_set_insert (possibly_undefined_names,
 	                      phi_result);
@@ -1658,6 +1685,12 @@ warn_uninitialized_phi (gimple phi, VEC(
   if  (MASK_EMPTY (uninit_opnds))
     return;
 
+  if (dump_file)
+    {
+      fprintf (dump_file, "[CHECK]: examining phi: ");
+      print_gimple_stmt (dump_file, phi, 0, 0);
+    }
+
   /* Now check if we have any use of the value without proper guard.  */
   uninit_use_stmt = find_uninit_use (phi, uninit_opnds,
                                      worklist, added_to_worklist);
@@ -1717,6 +1750,11 @@ execute_late_warn_uninitialized (void)
               {
                 VEC_safe_push (gimple, heap, worklist, phi);
 		pointer_set_insert (added_to_worklist, phi);
+                if (dump_file)
+                  {
+                    fprintf (dump_file, "[WORKLIST]: add to initial list: ");
+                    print_gimple_stmt (dump_file, phi, 0, 0);
+                  }
                 break;
               }
           }
@@ -1728,7 +1766,7 @@ execute_late_warn_uninitialized (void)
       cur_phi = VEC_pop (gimple, worklist);
       warn_uninitialized_phi (cur_phi, &worklist, added_to_worklist);
     }
-  
+
   VEC_free (gimple, heap, worklist);
   pointer_set_destroy (added_to_worklist);
   pointer_set_destroy (possibly_undefined_names);

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2010-07-16  Xinliang David Li  <davidxl@google.com>

	PR testsuite/44932
	* tree-ssa-uninit.c (collect_phi_def_edges): Fix bug collecting def edges.
	(find_uninit_use): Add dump.
	(is_use_properly_guarded): Ditto.
	(warn_uninitialized_phi): Ditto.
	(execute_late_warn_uninitialized): Ditto.

Re: Fix for PR44932

[Richard Guenther]

On Sun, Jul 18, 2010 at 8:38 AM, Xinliang David Li <davidxl@google.com> wrote:
> Hi, this patch fixes the problem reported in 44932. The bogus warning
> is emitted because the predicate set for the definitions are not
> properly computed as a result of the bug in collecting the edge set
> for phi operands that are defined.
>
> Bootstrapped and tested on x86-64/linux.
>
> Ok to checkin?

Ok if you guard the extra dump_file printing by && (dump_flags & TDF_DETAILS).

Thanks,
Richard.

> Thanks,
>
> David
>

Re: Fix for PR44932

[Xinliang David Li]

 Made the suggested change and submitted it.

Thanks,

David

On Sun, Jul 18, 2010 at 11:22 AM, Richard Guenther
<richard.guenther@gmail.com> wrote:
> On Sun, Jul 18, 2010 at 8:38 AM, Xinliang David Li <davidxl@google.com> wrote:
>> Hi, this patch fixes the problem reported in 44932. The bogus warning
>> is emitted because the predicate set for the definitions are not
>> properly computed as a result of the bug in collecting the edge set
>> for phi operands that are defined.
>>
>> Bootstrapped and tested on x86-64/linux.
>>
>> Ok to checkin?
>
> Ok if you guard the extra dump_file printing by && (dump_flags & TDF_DETAILS).
>
> Thanks,
> Richard.
>
>> Thanks,
>>
>> David
>>
>