From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-107084-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 25071 invoked by alias); 17 Aug 2004 14:05:52 -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 25060 invoked by uid 48); 17 Aug 2004 14:05:51 -0000
Date: Tue, 17 Aug 2004 14:05:00 -0000
From: "pbrook at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Message-ID: <20040817140542.17064.pbrook@gcc.gnu.org>
Reply-To: gcc-bugzilla@gcc.gnu.org
Subject: [Bug tree-optimization/17064] New: -falias-noargument-global doesn't eliminate dead stores
X-Bugzilla-Reason: CC
X-SW-Source: 2004-08/txt/msg01664.txt.bz2
List-Id: <gcc-bugs.sourceware.org>

When the following example is compiled with -fargument-noalias-global, the 
store *p=1 is dead and should be removed. 
-fargument-noalias-global is the default for Fortran. 
 
#include <stdlib.h> 
int i; 
int j; 
 
void bar(void) 
{ 
  i = 42; 
} 
 
void foo(int * p) 
{ 
  *p = 1;/* This store is dead with -fargument-noalias-global.  */ 
  bar (); 
  *p = 2; 
} 
 
int main() 
{ 
  i = 0; 
  j = 0; 
  foo(&j); 
  if (i != 42 || j != 2) 
    abort(); 
  return 0; 
}

-- 
           Summary: -falias-noargument-global doesn't eliminate dead stores
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pbrook at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17064