2010-05-02 Richard Guenther <rguenther@suse.de>

	PR tree-optimization/43879
	* tree-tailcall.c (find_tail_calls): Clobbers also prevent
	tail calls.

	* gcc.dg/torture/pr43879-3.c: New testcase.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@158977 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4cb8a34..88aa4b0 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2010-05-02  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/43879
+       * tree-tailcall.c (find_tail_calls): Clobbers also prevent
+       tail calls.
+
 2010-05-02  Bruno Haible  <bruno@clisp.org>
 
        * doc/extend.texi (Function Attributes): Fix a typo.

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 39a8d97..ff2b62c 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2010-05-02  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/43879
+       * gcc.dg/torture/pr43879-3.c: New testcase.
+
 2010-05-01  Richard Guenther  <rguenther@suse.de>
 
        PR tree-optimization/43949

diff --git a/gcc/testsuite/gcc.dg/torture/pr43879-3.c b/gcc/testsuite/gcc.dg/torture/pr43879-3.c
new file mode 100644 (file)
index 0000000..5ee80d5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr43879-3.c
@@ -0,0 +1,41 @@
+/* { dg-do run } */
+/* { dg-options "-fipa-pta" } */
+
+typedef unsigned long ulong;
+
+int __attribute__((noinline, noclone))
+f4 (int a, int b, int c, int d, int e)
+{
+  return a + b + c + d + e;
+}
+
+void __attribute__((noinline, noclone))
+f3 (int *p)
+{
+  *p = f4(1, 2, 3, 4, 5);
+}
+
+void __attribute__((noinline, noclone))
+f2 ()
+{
+  int unused;
+  f3 (&unused);
+}
+
+void __attribute__((noinline, noclone))
+f1 (ulong e, ulong f)
+{
+  if (e > 5 || f > 5) __builtin_abort();
+  f2 ();
+}
+
+
+int main()
+{
+ ulong e, f;
+ for (e = 5; e > 0; e--)
+   for (f = 5; f > 0; f--)
+     f1(e, f);
+ return 0;
+}
+

diff --git a/gcc/tree-tailcall.c b/gcc/tree-tailcall.c
index a9f0191..ec6d2fd 100644 (file)
--- a/gcc/tree-tailcall.c
+++ b/gcc/tree-tailcall.c
@@ -460,7 +460,8 @@ find_tail_calls (basic_block bb, struct tailcall **ret)
     {
       if (TREE_CODE (var) != PARM_DECL
          && auto_var_in_fn_p (var, cfun->decl)
-         && ref_maybe_used_by_stmt_p (call, var))
+         && (ref_maybe_used_by_stmt_p (call, var)
+             || call_may_clobber_ref_p (call, var)))
        return;
     }