[patch] Fix assertion failure in compute_complex_ancestor_jump_func

[Eric Botcazou]

Hi,

this is a regression present on all active branches.  The following assertion 
triggers in compute_complex_ancestor_jump_func:

  index = ipa_get_param_decl_index (info, SSA_NAME_VAR (parm));
  gcc_assert (index >= 0);

because the PARM_DECL is the static_chain_decl so the returned index is -1.
It seems to me that this assertion is overzealous: in many other places, the 
code explicitly tests for the non-negativity of index and returns otherwise.

Hence the proposed fix, tested on x86_64-suse-linux, OK for all branches?


2014-02-17  Eric Botcazou  <ebotca...@adacore.com>

        * ipa-prop.c (compute_complex_ancestor_jump_func): Replace overzealous
        assertion with conditional return.


2014-02-17  Eric Botcazou  <ebotca...@adacore.com>

        * gnat.dg/opt32.adb: New test.


-- 
Eric Botcazou
Index: ipa-prop.c
===================================================================
--- ipa-prop.c	(revision 207796)
+++ ipa-prop.c	(working copy)
@@ -1211,7 +1211,8 @@ compute_complex_ancestor_jump_func (stru
     return;
   parm = TREE_OPERAND (expr, 0);
   index = ipa_get_param_decl_index (info, SSA_NAME_VAR (parm));
-  gcc_assert (index >= 0);
+  if (index < 0)
+    return;
 
   cond_bb = single_pred (assign_bb);
   cond = last_stmt (cond_bb);
-- { dg-do compile }
-- { dg-options "-O2" }

with Ada.Containers; use Ada.Containers;
with Ada.Containers.Vectors;

function Opt32 return Natural is

   package My_Vectors
      is new Vectors (Index_Type => Natural, Element_Type => Integer);
   use My_Vectors;

   V : Vector;

   function Sign_Changes return Natural is
      Cur      : Cursor := To_Cursor (V, 0);
      R        : Natural := 0;
      Negative : Boolean;
   begin
      Negative := Element (Cur) < 0;

      loop
         Cur := Next (Cur);
         exit when R > 100;

         if (Element (Cur) < 0) /= Negative then
            Negative := not Negative;
            R := R + 1;
         end if;
      end loop;

      return R;
   end;

begin
   return Sign_Changes;
end;