From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-153257-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 31305 invoked by alias); 5 Aug 2005 06:08:47 -0000
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
Received: (qmail 31083 invoked by uid 48); 5 Aug 2005 06:08:42 -0000
Date: Fri, 05 Aug 2005 06:08:00 -0000
Message-ID: <20050805060842.31082.qmail@sourceware.org>
From: "pault at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
In-Reply-To: <20050705050725.22304.albertm@uphs.upenn.edu>
References: <20050705050725.22304.albertm@uphs.upenn.edu>
Reply-To: gcc-bugzilla@gcc.gnu.org
Subject: [Bug fortran/22304] gfortran silently changes values in equilvanence'd variables
X-Bugzilla-Reason: CC
X-SW-Source: 2005-08/txt/msg00536.txt.bz2
List-Id: <gcc-bugs.sourceware.org>


------- Additional Comments From pault at gcc dot gnu dot org  2005-08-05 06:08 -------
This is amusing.....

      integer o(4), b, c
      COMMON /IBM/ o
      EQUIVALENCE (o(1),b),(C,o(4))
      o(3)=1
      CALL MYSUB1
      CALL MYSUB2
      END 
 
      subroutine MYSUB1 
      integer o (4), b, c
      COMMON /IBM/ o 
      EQUIVALENCE (o(1), b), (o(4), c) 
      WRITE (6,*) "IN MYSUB1: o(3)= ", o(3) 
      RETURN 
      END

      subroutine MYSUB2
      integer o (4), b, c
      COMMON /IBM/ o 
      EQUIVALENCE (o(1), b), (c, o(4)) 
      WRITE (6,*) "IN MYSUB2: o(3)= ", o(3) 
      RETURN 
      END 
 
 IN MYSUB1: o(3)=            0
 IN MYSUB2: o(3)=    134519416

The code shows that SUB1 references the common block, whereas SUB2 goes for a
home grown equivalence.  This is a good clue as to where things are failing.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22304