re PR middle-end/59330 (Crash in is_gimple_reg_type)

2013-11-28  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/59330
	* tree-ssa-dce.c (eliminate_unnecessary_stmts): Simplify
	and fix delayed marking of free calls not necessary.

	* gcc.dg/torture/pr59330.c: New testcase.

From-SVN: r205486

gcc/ChangeLog

+2013-11-28  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/59330
+	* tree-ssa-dce.c (eliminate_unnecessary_stmts): Simplify
+	and fix delayed marking of free calls not necessary.
+
 2013-11-28  Andrew MacLeod  <amacleod@redhat.com>
 
 	* tree-ssa-propagate.c (valid_gimple_call_p): Pass TREE_TYPE to

gcc/testsuite/ChangeLog

 2013-11-28  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/59330
+	* gcc.dg/torture/pr59330.c: New testcase.
+
+2013-11-28  Richard Biener  <rguenther@suse.de>
+
 	PR lto/59323
 	* gcc.dg/lto/pr59323_0.c: New testcase.
 

gcc/testsuite/gcc.dg/torture/pr59330.c

+/* { dg-do run } */
+
+void free(void *ptr)
+{
+}
+
+void *foo(void)
+{
+  return 0;
+}
+
+int main(void)
+{
+  void *p = foo();
+  free(p);
+  return 0;
+}

gcc/tree-ssa-dce.c

@@ -1191,26 +1191,18 @@ eliminate_unnecessary_stmts (void)
 	  stats.total++;
 
 	  /* We can mark a call to free as not necessary if the
-	     defining statement of its argument is an allocation
-	     function and that is not necessary itself.  */
-	  if (gimple_call_builtin_p (stmt, BUILT_IN_FREE))
+	     defining statement of its argument is not necessary
+	     (and thus is getting removed).  */
+	  if (gimple_plf (stmt, STMT_NECESSARY)
+	      && gimple_call_builtin_p (stmt, BUILT_IN_FREE))
 	    {
 	      tree ptr = gimple_call_arg (stmt, 0);
-	      tree callee2;
-	      gimple def_stmt;
-	      if (TREE_CODE (ptr) != SSA_NAME)
-		continue;
-	      def_stmt = SSA_NAME_DEF_STMT (ptr);
-	      if (!is_gimple_call (def_stmt)
-		  || gimple_plf (def_stmt, STMT_NECESSARY))
-		continue;
-	      callee2 = gimple_call_fndecl (def_stmt);
-	      if (callee2 == NULL_TREE
-		  || DECL_BUILT_IN_CLASS (callee2) != BUILT_IN_NORMAL
-		  || (DECL_FUNCTION_CODE (callee2) != BUILT_IN_MALLOC
-		      && DECL_FUNCTION_CODE (callee2) != BUILT_IN_CALLOC))
-		continue;
-	      gimple_set_plf (stmt, STMT_NECESSARY, false);
+	      if (TREE_CODE (ptr) == SSA_NAME)
+		{
+		  gimple def_stmt = SSA_NAME_DEF_STMT (ptr);
+		  if (!gimple_plf (def_stmt, STMT_NECESSARY))
+		    gimple_set_plf (stmt, STMT_NECESSARY, false);
+		}
 	    }
 
 	  /* If GSI is not necessary then remove it.  */