re PR tree-optimization/84739 (ICE in get_value_for_expr, at tree-ssa-ccp.c:649)

	PR tree-optimization/84739
	* tree-tailcall.c (find_tail_calls): Check call arguments against
	DECL_ARGUMENTS (current_function_decl) rather than
	DECL_ARGUMENTS (func) when checking for tail recursion.

	* gcc.dg/pr84739.c: New test.

From-SVN: r258351

gcc/ChangeLog

+2018-03-08  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/84739
+	* tree-tailcall.c (find_tail_calls): Check call arguments against
+	DECL_ARGUMENTS (current_function_decl) rather than
+	DECL_ARGUMENTS (func) when checking for tail recursion.
+
 2018-03-07  Jakub Jelinek  <jakub@redhat.com>
 
 	* doc/contrib.texi: Add entries for Martin Liska, David Malcolm,

gcc/testsuite/ChangeLog

+2018-03-08  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/84739
+	* gcc.dg/pr84739.c: New test.
+
 2018-03-07  Martin Sebor  <msebor@redhat.com>
 
 	PR tree-optimization/83519

gcc/testsuite/gcc.dg/pr84739.c

+/* PR tree-optimization/84739 */
+/* { dg-do compile } */
+/* { dg-require-weak "" } */
+/* { dg-options "-O2" } */
+
+static void baz (void) __attribute__((weakref("bar")));	/* { dg-warning "alias between functions of incompatible types" } */
+
+int
+foo (int x, int y)
+{
+  if (x)
+    y = 0;
+  if (y)
+    goto lab;
+  y = 0;
+lab:
+  return y;
+}
+
+void
+bar (int x, int y)	/* { dg-message "aliased declaration here" } */
+{
+  y = foo (x, y);
+  if (y != 0)
+    baz ();
+}

gcc/tree-tailcall.c

@@ -481,7 +481,7 @@ find_tail_calls (basic_block bb, struct tailcall **ret)
     {
       tree arg;
 
-      for (param = DECL_ARGUMENTS (func), idx = 0;
+      for (param = DECL_ARGUMENTS (current_function_decl), idx = 0;
 	   param && idx < gimple_call_num_args (call);
 	   param = DECL_CHAIN (param), idx ++)
 	{