re PR tree-optimization/43367 (ice: in may_propagate_copy, at tree-ssa-copy.c:85)

2010-03-15  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/43367
	* tree-cfg.c (gimple_can_merge_blocks_p): Simplify PHI
	elimination check.

	* gcc.c-torture/compile/pr43367.c: New testcase.

From-SVN: r157458

gcc/ChangeLog

 2010-03-15  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/43367
+	* tree-cfg.c (gimple_can_merge_blocks_p): Simplify PHI
+	elimination check.
+
+2010-03-15  Richard Guenther  <rguenther@suse.de>
+
 	PR tree-optimization/43317
 	* ipa-struct-reorg.c (create_new_general_access): Update stmt.
 

gcc/testsuite/ChangeLog

 2010-03-15  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/43367
+	* gcc.c-torture/compile/pr43367.c: New testcase.
+
+2010-03-15  Richard Guenther  <rguenther@suse.de>
+
 	PR tree-optimization/43317
 	* gcc.dg/pr43317.c: New testcase.
 

gcc/testsuite/gcc.c-torture/compile/pr43367.c

+unsigned char g_17;
+
+const unsigned char func_39 (unsigned char p_40, unsigned char * p_41)
+{
+  return 0;
+}
+
+void int327 (const unsigned char p_48, unsigned char p_49)
+{
+  unsigned l_52;
+  unsigned char l_58[2];
+  int i, j;
+  if (func_39 (l_52, &p_49), p_48) {
+      unsigned char *l_60;
+      unsigned char *l = &l_58[1];
+      for (j; j; j++) {
+lbl_59:
+	  break;
+      }
+      for (l = 0; 1; l += 1) {
+	  for (p_49 = 1; p_49; p_49 += 0) {
+	      unsigned char **l_61[1][6];
+	      for (j = 0; j < 1; j++)
+		l_61[i][j] = &l_60;
+	      goto lbl_59;
+	  }
+      }
+  }
+}
+

gcc/tree-cfg.c

@@ -1438,27 +1438,12 @@ gimple_can_merge_blocks_p (basic_block a, basic_block b)
     return false;
 
   /* It must be possible to eliminate all phi nodes in B.  If ssa form
-     is not up-to-date, we cannot eliminate any phis; however, if only
-     some symbols as whole are marked for renaming, this is not a problem,
-     as phi nodes for those symbols are irrelevant in updating anyway.  */
+     is not up-to-date and a name-mapping is registered, we cannot eliminate
+     any phis.  Symbols marked for renaming are never a problem though.  */
   phis = phi_nodes (b);
-  if (!gimple_seq_empty_p (phis))
-    {
-      gimple_stmt_iterator i;
-
-      if (name_mappings_registered_p ())
-	return false;
-
-      for (i = gsi_start (phis); !gsi_end_p (i); gsi_next (&i))
-	{
-	  gimple phi = gsi_stmt (i);
-
-	  if (!is_gimple_reg (gimple_phi_result (phi))
-	      && !may_propagate_copy (gimple_phi_result (phi),
-				      gimple_phi_arg_def (phi, 0)))
-	    return false;
-	}
-    }
+  if (!gimple_seq_empty_p (phis)
+      && name_mappings_registered_p ())
+    return false;
 
   return true;
 }