From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-231574-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 19914 invoked by alias); 5 Oct 2007 23:14:40 -0000
Received: (qmail 19842 invoked by uid 48); 5 Oct 2007 23:14:31 -0000
Date: Fri, 05 Oct 2007 23:14:00 -0000
Message-ID: <20071005231431.19841.qmail@sourceware.org>
X-Bugzilla-Reason: CC
References: <bug-33669-682@http.gcc.gnu.org/bugzilla/>
Subject: [Bug rtl-optimization/33669] [4.3 Regression]  Revision 128957 miscompiles 481.wrf
In-Reply-To: <bug-33669-682@http.gcc.gnu.org/bugzilla/>
Reply-To: gcc-bugzilla@gcc.gnu.org
To: gcc-bugs@gcc.gnu.org
From: "hjl at lucon dot org" <gcc-bugzilla@gcc.gnu.org>
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
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
X-SW-Source: 2007-10/txt/msg00489.txt.bz2



------- Comment #4 from hjl at lucon dot org  2007-10-05 23:14 -------
#include <string.h>
#include <stdlib.h>

typedef struct foo_t { 
          size_t blksz;
          size_t  bf_extent;
         size_t  bf_cnt; 
          void    *bf_base;
} foo_t;


#define _RNDUP(x, unit)  ((((x) + (unit) - 1) / (unit)) \
        * (unit))
#define _RNDDOWN(x, unit)  ((x) - ((x)%(unit)))

long long
foo(foo_t *const pxp,  long long offset, size_t extent)
{
        const long long blkoffset = _RNDDOWN(offset,
                                             (long long )pxp->blksz);
        size_t diff = (size_t)(offset - blkoffset);
        size_t blkextent = _RNDUP(diff + extent, pxp->blksz);

        if(pxp->blksz < blkextent)
                return -1;
        {
                void *const middle = pxp->bf_base;
                if(pxp->bf_cnt > pxp->blksz)
                {
                        pxp->bf_extent = pxp->blksz;
                }
                if(pxp->bf_cnt > 0)
                {
                        /* copy lower half into upper half */
                        (void) memcpy(middle, pxp->bf_base, pxp->blksz);
                }
        }

        return  blkoffset;
}

int
main ()
{
  foo_t x;
  char buffer [8192];
  long long xx;

  x.blksz = 8192;
  x.bf_extent = 0;
  x.bf_cnt = 0;
  x.bf_base = buffer;
  xx = foo (&x, 0, 4096);
  if (xx != 0LL)
    abort ();
  return 0;
}
[hjl@gnu-27 pr33669]$ /export/gnu/import/rrs/128957/usr/bin/gcc  foo.c -m32 -O
[hjl@gnu-27 pr33669]$ ./a.out 
Aborted
[hjl@gnu-27 pr33669]$ 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33669