diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ac3f3fb3af05dcebc21ea53c3ca7cd3d6e3f7410..90f93eac12cf33c37ae86012769122767af0c455 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2009-03-07  Jan Hubicka  <jh@suse.cz>
+
+	PR target/39361
+	* tree-inline.c (setup_one_parameter): Do replacement of const argument
+	by constant in SSA form.
+
 2009-03-07  Ulrich Weigand  <Ulrich.Weigand@de.ibm.com>
 
 	PR middle-end/38028
diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index 917b5267434fcc16a8f44853e38868038690cd5a..15419c38a67eadd9d5a9604fe6cf1577c2e582e9 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -2110,6 +2110,10 @@ setup_one_parameter (copy_body_data *id, tree p, tree value, tree fn,
      We need to construct map for the variable anyway as it might be used
      in different SSA names when parameter is set in function.
 
+     Do replacement at -O0 for const arguments replaced by constant.
+     This is important for builtin_constant_p and other construct requiring
+     constant argument to be visible in inlined function body.
+
      FIXME: This usually kills the last connection in between inlined
      function parameter and the actual value in debug info.  Can we do
      better here?  If we just inserted the statement, copy propagation
@@ -2118,7 +2122,9 @@ setup_one_parameter (copy_body_data *id, tree p, tree value, tree fn,
      We might want to introduce a notion that single SSA_NAME might
      represent multiple variables for purposes of debugging. */
   if (gimple_in_ssa_p (cfun) && rhs && def && is_gimple_reg (p)
-      && optimize
+      && (optimize
+          || (TREE_READONLY (p)
+	      && is_gimple_min_invariant (rhs)))
       && (TREE_CODE (rhs) == SSA_NAME
 	  || is_gimple_min_invariant (rhs))
       && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (def))