re PR tree-optimization/33434 (inlining miscompilation)

	PR tree-optimization/33434
	* tree-inline.c (setup_one_parameter): If the value passed to
	a parameter is never used, don't set it up.

	* gcc.dg/pr33434-1.c: New test.
	* gcc.dg/pr33434-2.c: New test.
	* gcc.dg/pr33434-3.c: New test.
	* gcc.dg/pr33434-4.c: New test.

From-SVN: r130521

gcc/ChangeLog

+2007-11-29  Jan Hubicka  <jh@suse.cz>
+	    Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/33434
+	* tree-inline.c (setup_one_parameter): If the value passed to
+	a parameter is never used, don't set it up.
+
 2007-11-29  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/32130

gcc/testsuite/ChangeLog

 2007-11-29  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/33434
+	* gcc.dg/pr33434-1.c: New test.
+	* gcc.dg/pr33434-2.c: New test.
+	* gcc.dg/pr33434-3.c: New test.
+	* gcc.dg/pr33434-4.c: New test.
+
 	PR c++/34270
 	* g++.dg/template/cond7.C: New test.
 

gcc/testsuite/gcc.dg/pr33434-1.c

+/* PR tree-optimization/33434 */
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+int k;
+
+void f1 (int a, int b)
+{
+  a = 1;
+  b = 1;
+  if (a)
+    while (b --)
+      k = 1;
+  else
+    if (b != 1)
+      __builtin_abort ();
+}
+
+int main (void)
+{
+  f1 (1, 1);
+  if (k != 1)
+    __builtin_abort ();
+  return 0;
+}

gcc/testsuite/gcc.dg/pr33434-2.c

+/* PR tree-optimization/33434 */
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+int k;
+
+void f1 (int a)
+{
+  int b;
+  a = 1;
+  b = 1;
+  if (a)
+    while (b --)
+      k = 1;
+  else
+    if (b != 1)
+      __builtin_abort ();
+}
+
+int main (void)
+{
+  f1 (1);
+  if (k != 1)
+    __builtin_abort ();
+  return 0;
+}

gcc/testsuite/gcc.dg/pr33434-3.c

+/* PR tree-optimization/33434 */
+/* { dg-do run } */
+/* { dg-options "-O3" } */
+
+int k;
+
+void __attribute__((noinline)) f2 (int b)
+{
+  k = b - 1;
+}
+
+void f1 (int a, int b)
+{
+  f2 (b);
+  a = 1;
+  b = 1;
+  if (a)
+    while (b --)
+      k = 1;
+  else
+    if (b != 1)
+      __builtin_abort ();
+}
+
+int main (void)
+{
+  f1 (1, 1);
+  if (k != 1)
+    __builtin_abort ();
+  return 0;
+}

gcc/testsuite/gcc.dg/pr33434-4.c

+/* PR tree-optimization/33434 */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+void *baz (void);
+
+static void *
+bar (void *x)
+{
+  x = baz ();
+  return x;
+}
+
+void *
+foo (void *x)
+{
+  return bar (x);
+}

gcc/tree-inline.c

@@ -1508,6 +1508,14 @@ setup_one_parameter (copy_body_data *id, tree p, tree value, tree fn,
       return;
     }
 
+  /* If the value of argument is never used, don't care about initializing
+     it.  */
+  if (gimple_in_ssa_p (cfun) && !def && is_gimple_reg (p))
+    {
+      gcc_assert (!value || !TREE_SIDE_EFFECTS (value));
+      return;
+    }
+
   /* Initialize this VAR_DECL from the equivalent argument.  Convert
      the argument to the proper type in case it was promoted.  */
   if (value)