From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-prs-return-22935-listarch-gcc-prs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 8515 invoked by alias); 14 Oct 2002 09:16:02 -0000
Mailing-List: contact gcc-prs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Archive: <http://gcc.gnu.org/ml/gcc-prs/>
List-Post: <mailto:gcc-prs@gcc.gnu.org>
List-Help: <mailto:gcc-prs-help@gcc.gnu.org>
Sender: gcc-prs-owner@gcc.gnu.org
Received: (qmail 8501 invoked by uid 71); 14 Oct 2002 09:16:02 -0000
Date: Mon, 14 Oct 2002 02:16:00 -0000
Message-ID: <20021014091602.8500.qmail@sources.redhat.com>
To: nobody@gcc.gnu.org
Cc: gcc-prs@gcc.gnu.org,
From: Andrew Pinski <pinskia@physics.uc.edu>
Subject: Re: c/8221: return value of a function is forgotten
Reply-To: Andrew Pinski <pinskia@physics.uc.edu>
X-SW-Source: 2002-10/txt/msg00542.txt.bz2
List-Id: <gcc-prs.sourceware.org>

The following reply was made to PR c/8221; it has been noted by GNATS.

From: Andrew Pinski <pinskia@physics.uc.edu>
To: c.kaliszyk@zodiac.mimuw.edu.pl
Cc: gcc-gnats@gcc.gnu.org, cek@wp.pl
Subject: Re: c/8221: return value of a function is forgotten
Date: Mon, 14 Oct 2002 02:12:23 -0700

 On Monday, Oct 14, 2002, at 01:44 US/Pacific, 
 c.kaliszyk@zodiac.mimuw.edu.pl wrote:
 > I call "gcc -O2" on this:
 > --cut--
 > inline int getcputime(void) {
 >   int i;
 >   __asm__(
 >     "rdtsc
 >     movl %%eax, %0"
 >     : :"g" (i) :"ax", "dx");
 >   return i;
 > }
 >
 > int main(void) {
 >   int x =3D getcputime();
 >   int y =3D getcputime();
 >   printf ("Time measure resolution: %i\n", y - x);
 >   return 0;
 > }
 
 
 I think you constraints are wrong, this works for me:
 inline int getcputime(void) {
    int i;
    __asm__ volatile(
      "rdtsc\n\
      movl %%eax, %0"
      : "=g" (i) : :"eax", "edx");
    return i;
 }
 
 int main(void) {
    int x = getcputime();
    int y = getcputime();
    printf ("Time measure resolution: %i\n", y - x);
    return 0;
 }
 
 
 read
 http://gcc.gnu.org/onlinedocs/gcc-3.2/gcc/Extended-Asm.html
 for information, this helped me get the correct result.
 
 Thanks,
 Andrew Pinski
 
 PS I think this bug is user error so can someone close it.