From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-231582-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 9132 invoked by alias); 6 Oct 2007 02:31:25 -0000
Received: (qmail 9026 invoked by uid 48); 6 Oct 2007 02:31:15 -0000
Date: Sat, 06 Oct 2007 02:31:00 -0000
Message-ID: <20071006023115.9025.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/msg00497.txt.bz2



------- Comment #6 from hjl at lucon dot org  2007-10-06 02:31 -------
A smaller testcase:

bash-3.2$ cat x.c
extern void abort (void);

typedef struct foo_t
{ 
  unsigned int blksz;
  unsigned int bf_cnt; 
} 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, unsigned int extent)
{
  long long blkoffset = _RNDDOWN(offset, (long long )pxp->blksz);
  unsigned int diff = (unsigned int)(offset - blkoffset);
  unsigned int blkextent = _RNDUP(diff + extent, pxp->blksz);

  if (pxp->blksz < blkextent)
    return -1LL;

  if (pxp->bf_cnt > pxp->blksz)
    pxp->bf_cnt = pxp->blksz;

  return blkoffset;
}

int
main ()
{
  foo_t x;
  long long xx;

  x.blksz = 8192;
  x.bf_cnt = 0;
  xx = foo (&x, 0, 4096);
  if (xx != 0LL)
    abort ();
  return 0;
}
bash-3.2$ ./xgcc -B./ -m32 -O x.c
bash-3.2$ ./a.out 
Aborted
bash-3.2$ 


-- 


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