From mboxrd@z Thu Jan  1 00:00:00 1970
From: Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>
To: egcs@cygnus.com
Subject: TREE_CST_RTL and CONSTRUCTORs
Date: Wed, 22 Apr 1998 04:19:00 -0000
Message-id: <199804220837.KAA16445@mira.isdn.cs.tu-berlin.de>
X-SW-Source: 1998-04/msg00902.html

The macro TREE_CST_RTL accesses the real_cst variant of the tree, so
I first required it to be a REAL_CST. Then I found that it is also used
to access STRING_CST nodes. This is fine, as both structures start
with

struct tree_*_cst
{
  char common[sizeof (struct tree_common)];
  struct rtx_def *rtl;

and the macro accesses rtl. Now, the comment says that it is also used
to access CONSTRUCTOR expressions, which has the lay-out

struct tree_exp
{
  char common[sizeof (struct tree_common)];
  int complexity;

So we really have the complexity field here. This problem is exposed in
gcc.c-torture/compile/920501-11.c, where output_constant_def is called
with a CONSTRUCTOR.

What is the story here? Is this intended, and gcc requires sizeof(int)
== sizeof(tree)? If so, I should relax the check to also accept
constructors in TREE_CST_RTL. If not, gcc should be changed.

Regards,
Martin