From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-436796-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 25909 invoked by alias); 6 Dec 2013 01:45:59 -0000
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
Received: (qmail 25878 invoked by uid 48); 6 Dec 2013 01:45:56 -0000
From: "hjl.tools at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/59379] [4.9 Regression] gomp_init_num_threads is compiled into an infinite loop with --with-arch=corei7  --with-cpu=slm
Date: Fri, 06 Dec 2013 01:45:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 4.9.0
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: hjl.tools at gmail dot com
X-Bugzilla-Status: NEW
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 4.9.0
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields:
Message-ID: <bug-59379-4-HSx8Ajen6a@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-59379-4@http.gcc.gnu.org/bugzilla/>
References: <bug-59379-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-SW-Source: 2013-12/txt/msg00451.txt.bz2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59379

--- Comment #9 from H.J. Lu <hjl.tools at gmail dot com> ---
A small run-time testcase.  It went into an finite loop at -O.

---
[hjl@gnu-mic-2 pr59379]$ cat main.c 
#include <stdlib.h>
typedef unsigned long int __cpu_mask;
void *
__attribute__((malloc, noinline))
gomp_malloc (size_t s)
{
  return malloc (s);
}
typedef struct
{
  __cpu_mask __bits[1024 / (8 * sizeof (__cpu_mask))];
} cpu_set_t;
unsigned long gomp_cpuset_size __attribute__ ((visibility ("hidden")));
cpu_set_t *gomp_cpusetp __attribute__ ((visibility ("hidden")));
static unsigned long gomp_get_cpuset_size;
void
__attribute__ ((noinline))
gomp_init_num_threads (void)
{
  gomp_cpuset_size = 8;
  gomp_cpusetp = (cpu_set_t *) gomp_malloc (gomp_cpuset_size);
  do
    {
      gomp_get_cpuset_size = gomp_cpuset_size;
      unsigned long i;
      for (i = gomp_cpuset_size * 8; i; i--)
    if ((__extension__
         ({ size_t __cpu = (i - 1);
          __cpu < 8 * (gomp_cpuset_size)
          ? ((((const __cpu_mask *) ((gomp_cpusetp)->__bits))[((__cpu) / (8 *
sizeof (__cpu_mask)))] & ((__cpu_mask) 1 << ((__cpu) % (8 * sizeof
(__cpu_mask)))))) != 0
          : 0;
          })))
      break;
      gomp_cpuset_size = ((((i) + (8 * sizeof (__cpu_mask)) - 1) / (8 * sizeof
(__cpu_mask))) * sizeof (__cpu_mask));
      return;
    }
  while (1);
}
int
main ()
{
  gomp_init_num_threads ();
  return 0;
}
[hjl@gnu-mic-2 pr59379]$ make run
/export/build/gnu/gcc-lto-fdo/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc-lto-fdo/build-x86_64-linux/gcc/ -O -o x main.c
./x
make: *** wait: No child processes.  Stop.
make: *** Waiting for unfinished jobs....
make: *** wait: No child processes.  Stop.
---