view src/strcmp.c @ 613:023b83f4e54b

[xemacs-hg @ 2001-06-10 10:42:16 by ben] ------ signal-code changes ------ data.c, device-tty.c, emacs.c, floatfns.c, linuxplay.c, nas.c, process-unix.c, signal.c, sunplay.c, sysdep.c, syssignal.h: use EMACS_SIGNAL everywhere instead of playing preprocessing games with signal(). s\windowsnt.h, s\mingw32.h, syssignal.h: Remove mswindows signal code from s+m headers and move to syssignal.h as one of the five ways of signal handling, instead of playing preprocessing games. fileio.c, sysdep.c: Rename sys_do_signal to qxe_reliable_signal. signal.c, process-unix.c, profile.c: Create set_timeout_signal(); use instead of just EMACS_SIGNAL to establish a signal handler on a timeout signal; this does special things under Cygwin. nt.c: Eliminate term_ntproc(), which is blank; used as a SIGABRT handler, which was wrong anyway. nt.c, win32.c: Move signal code from nt.c to win32.c, since Cygwin needs it too when dealing with timeout signals. s\cygwin32.h: Define CYGWIN_BROKEN_SIGNALS. ------ other changes ------ s\mingw32.h: Fix problems with NOT_C_CODE being in the wrong place and excluding defines needed when building Makefile.in.in. filelock.c, mule-canna.c, mule-ccl.c, mule-ccl.h, ralloc.c, unexalpha.c, unexapollo.c, unexcw.c, unexelfsgi.c, unexnt.c, unexsni.c, s\aix3-1.h, s\bsd4-1.h, s\bsd4-2.h, s\bsd4-3.h, s\cxux.h, s\cygwin32.h, s\dgux.h, s\dgux5-4r2.h, s\dgux5-4r3.h, s\dgux5-4r4.h, s\ewsux5r4.h, s\gnu.h, s\hpux.h, s\iris3-5.h, s\iris3-6.h, s\irix3-3.h, s\linux.h, s\mingw32.h, s\newsos5.h, s\nextstep.h, s\ptx.h, s\riscix1-1.h, s\riscix1-2.h, s\rtu.h, s\sco4.h, s\sco5.h, s\template.h, s\ultrix.h, s\umax.h, s\umips.h, s\unipl5-0.h, s\unipl5-2.h, s\usg5-0.h, s\usg5-2-2.h, s\usg5-2.h, s\usg5-3.h, s\usg5-4.h, s\windowsnt.h, s\xenix.h: Rename 'GNU Emacs' to XEmacs in the copyright and comments. nas.c: Stylistic cleanup. Avoid preprocessing games with names such as play_sound_file. ------ signal-code changes ------ data.c, device-tty.c, emacs.c, floatfns.c, linuxplay.c, nas.c, process-unix.c, signal.c, sunplay.c, sysdep.c, syssignal.h: use EMACS_SIGNAL everywhere instead of playing preprocessing games with signal(). s\windowsnt.h, s\mingw32.h, syssignal.h: Remove mswindows signal code from s+m headers and move to syssignal.h as one of the five ways of signal handling, instead of playing preprocessing games. fileio.c, sysdep.c: Rename sys_do_signal to qxe_reliable_signal. signal.c, process-unix.c, profile.c: Create set_timeout_signal(); use instead of just EMACS_SIGNAL to establish a signal handler on a timeout signal; this does special things under Cygwin. nt.c: Eliminate term_ntproc(), which is blank; used as a SIGABRT handler, which was wrong anyway. nt.c, win32.c: Move signal code from nt.c to win32.c, since Cygwin needs it too when dealing with timeout signals. s\cygwin32.h: Define CYGWIN_BROKEN_SIGNALS. ------ other changes ------ s\mingw32.h: Fix problems with NOT_C_CODE being in the wrong place and excluding defines needed when building Makefile.in.in. filelock.c, mule-canna.c, mule-ccl.c, mule-ccl.h, ralloc.c, unexalpha.c, unexapollo.c, unexcw.c, unexelfsgi.c, unexnt.c, unexsni.c, s\aix3-1.h, s\bsd4-1.h, s\bsd4-2.h, s\bsd4-3.h, s\cxux.h, s\cygwin32.h, s\dgux.h, s\dgux5-4r2.h, s\dgux5-4r3.h, s\dgux5-4r4.h, s\ewsux5r4.h, s\gnu.h, s\hpux.h, s\iris3-5.h, s\iris3-6.h, s\irix3-3.h, s\linux.h, s\mingw32.h, s\newsos5.h, s\nextstep.h, s\ptx.h, s\riscix1-1.h, s\riscix1-2.h, s\rtu.h, s\sco4.h, s\sco5.h, s\template.h, s\ultrix.h, s\umax.h, s\umips.h, s\unipl5-0.h, s\unipl5-2.h, s\usg5-0.h, s\usg5-2-2.h, s\usg5-2.h, s\usg5-3.h, s\usg5-4.h, s\windowsnt.h, s\xenix.h: Rename 'GNU Emacs' to XEmacs in the copyright and comments. nas.c: Stylistic cleanup. Avoid preprocessing games with names such as play_sound_file. xemacs-faq.texi: Update sections on Windows and MacOS availability. alist.el, apropos.el, autoload.el, bytecomp.el, cl-compat.el, cl-extra.el, cl-macs.el, cl-seq.el, cl.el, cmdloop.el, cus-edit.el, derived.el, gpm.el, itimer.el, lisp-mode.el, shadow.el, version.el, wid-browse.el: Rename 'GNU Emacs' to XEmacs in the copyright. Fix other references to GNU Emacs that should be XEmacs or just Emacs. files.el: Fix warning. simple.el: transpose-line-up/down will now move the region up or down by a line if active. cvtmail.c, fakemail.c, gnuserv.c, gnuserv.h, gnuslib.c, make-msgfile.c, make-path.c, pop.c, pop.h, profile.c, tcp.c: Rename 'GNU Emacs' to XEmacs in the copyright. Fix comments in similar ways. digest-doc.c, sorted-doc.c: Fix program and author name to reflect XEmacs.
author ben
date Sun, 10 Jun 2001 10:42:39 +0000
parents abe6d1db359e
children
line wrap: on
line source

/* This file is part of XEmacs.

XEmacs is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.

XEmacs is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with XEmacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* Synched up with: Not in FSF. */

/* In SunOS 4.1.1 the strcmp and strncmp functions reference memory
   past the last byte of the string! This will core dump if the memory 
   following the last byte is not mapped.

   Here are correct versions by hbs@lucid.com.
*/

# include <config.h>
# ifndef REGISTER	/* Strictly enforced in 20.3 */
# define REGISTER
# endif

#include <string.h>
#define ALIGNED(x) (!(((unsigned long) (x)) & (sizeof (unsigned long) - 1)))

#define MAGIC    0x7efefeff
#define HIGH_BIT_P(c) ((c) & hi_bit)
#define HAS_ZERO(c) (((((c) + magic) ^ (c)) & not_magic) != not_magic)

int
strcmp (const char *x, const char *y)
{
  if (x == y)
    return 0;
  else if (ALIGNED (x) && ALIGNED (y))
    {
      const unsigned long *x1 = (const unsigned long *) x;
      const unsigned long *y1 = (const unsigned long *) y;
      unsigned long c;
      unsigned long magic = MAGIC;
      unsigned long not_magic = ~magic;
      unsigned long hi_bit = 0x80000000;

      while ((c = *x1) == *y1)
        {
          if (HAS_ZERO(c)) 
            {
              if (!HIGH_BIT_P (c))
                return 0;
              else
                {
                  x = (const char *) x1;
                  y = (const char *) y1;
                  goto slow_loop;
                }
            }
              
          x1++; 
          y1++;
        }

      x = (const char *) x1;
      y = (const char *) y1;
      goto slow_loop;
    }
  else
    {
      char c;

    slow_loop:

      while ((c = *x) == *y)
        {
          if (c == (char) 0) return 0;
          x++; 
          y++;
        }
      return (*x - *y);
    }
}


int
strncmp (const char *x, const char *y, size_t n)
{
  if ((x == y) || (n <= 0))
    return 0;
  else if (ALIGNED (x) && ALIGNED (y))
    {
      const unsigned long *x1 = (const unsigned long *) x;
      const unsigned long *y1 = (const unsigned long *) y;
      unsigned long c;
      unsigned long magic = MAGIC;
      unsigned long not_magic = ~magic;
      unsigned long hi_bit = 0x80000000;

      while ((c = *x1) == *y1)
        {
          n -= sizeof (unsigned long);
          if (n <= 0)
            return 0;
          
          if (HAS_ZERO(c)) 
            {
              if (!HIGH_BIT_P (c))
                return 0;
              else
                {
                  x = (const char *) x1;
                  y = (const char *) y1;
                  goto slow_loop;
                }
            }
              
          x1++; 
          y1++;
        }

      x = (const char *) x1;
      y = (const char *) y1;
      goto slow_loop;
    }
  else
    {
      char c;

    slow_loop:

      while ((c = *x) == *y)
        {
          n--;
          if (n <= 0)
            return 0;
          if (c == (char) 0) 
            return 0;
          x++; 
          y++;
        }
      return (*x - *y);
    }
}