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/*-

 * Copyright (c) 1991, 1998, 2001 The Regents of the University of California.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. [rescinded 22 July 1999]

 * 4. Neither the name of the University nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

#ifndef lint

static char sccsid[] = "@(#)gmon.c      5.3 (Berkeley) 5/22/91";

#endif /* not lint */

#include <fcntl.h>

#include <unistd.h>

#include <stdlib.h>

#include <stdio.h>

#define GMON_PTR_SIZE 4

struct phdr

  {

    char *lpc;                  /* base pc address of sample buffer */

    char *hpc;                  /* max pc address of sampled buffer */

    int ncnt;                   /* size of sample buffer (plus this header) */

    char version[4];            /* version number */

    char profrate[4];           /* profiling clock rate */

    char spare[3*4];            /* reserved */

  };

#define GMONVERSION     0x00051879

/*

 * Histogram counters are unsigned shorts:

 */

#define HISTCOUNTER unsigned short

/*

 * Fraction of text space to allocate for histogram counters here, 1/2:

 */

#define HISTFRACTION    2

/*

 * Fraction of text space to allocate for from hash buckets.  The

 * value of HASHFRACTION is based on the minimum number of bytes of

 * separation between two subroutine call points in the object code.

 * Given MIN_SUBR_SEPARATION bytes of separation the value of

 * HASHFRACTION is calculated as:

 *

 *      HASHFRACTION = MIN_SUBR_SEPARATION / (2 * sizeof(short) - 1);

 *

 * For the VAX, the shortest two call sequence is:

 *

 *      calls   $0,(r0)

 *      calls   $0,(r0)

 *

 * which is separated by only three bytes, thus HASHFRACTION is

 * calculated as:

 *

 *      HASHFRACTION = 3 / (2 * 2 - 1) = 1

 *

 * Note that the division above rounds down, thus if MIN_SUBR_FRACTION

 * is less than three, this algorithm will not work!

 */

#define HASHFRACTION 1

/*

 * Percent of text space to allocate for tostructs with a minimum:

 */

#define ARCDENSITY      2

#define MINARCS         50

struct tostruct

  {

    char *selfpc;

    int count;

    unsigned short link;

  };

/*

 * A raw arc, with pointers to the calling site and the called site

 * and a count.  Everything is defined in terms of characters so

 * as to get a packed representation (otherwise, different compilers

 * might introduce different padding):

 */

struct rawarc

  {

    unsigned long raw_frompc;

    unsigned long raw_selfpc;

    int raw_count;

  };

/*

 * General rounding functions:

 */

#define ROUNDDOWN(x,y)  (((x)/(y))*(y))

#define ROUNDUP(x,y)    ((((x)+(y)-1)/(y))*(y))

#ifdef __alpha

extern char *sbrk ();

#endif

    /*

     *  froms is actually a bunch of unsigned shorts indexing tos

     */

static int profiling = 3;

static unsigned short *froms;

static struct tostruct *tos = 0;

static long tolimit = 0;

static char *s_lowpc = 0;

static char *s_highpc = 0;

static unsigned long s_textsize = 0;

static int ssiz;

static char *sbuf;

static int s_scale;

    /* see profil(2) where this is describe (incorrectly) */

#define         SCALE_1_TO_1    0x10000L

#define MSG "No space for profiling buffer(s)\n"

#ifndef O_BINARY

#define O_BINARY 0

#endif

static void

moncleanup ()

{

  int fd;

  int fromindex;

  int endfrom;

  char *frompc;

  int toindex;

  struct rawarc rawarc;

  profiling = 1;

  fd = open ("gmon.out", O_WRONLY|O_TRUNC|O_CREAT|O_BINARY, 0666);

  if (fd < 0)

    {

      perror ("mcount: gmon.out");

      return;

    }

#ifdef DEBUG

  fprintf (stderr, "[mcleanup] sbuf 0x%x ssiz %d\n", sbuf, ssiz);

#endif /* DEBUG */

  write (fd, sbuf, ssiz);

  endfrom = s_textsize / (HASHFRACTION * sizeof (*froms));

  for (fromindex = 0; fromindex < endfrom; fromindex++)

    {

      if (froms[fromindex] == 0)

        {

          continue;

        }

      frompc = s_lowpc + (fromindex * HASHFRACTION * sizeof (*froms));

      for (toindex = froms[fromindex]; toindex != 0;

           toindex = tos[toindex].link)

        {

#ifdef DEBUG

          fprintf (stderr,

                   "[mcleanup] frompc 0x%x selfpc 0x%x count %d\n",

                   frompc, tos[toindex].selfpc, tos[toindex].count);

#endif /* DEBUG */

          rawarc.raw_frompc = (unsigned long) frompc;

          rawarc.raw_selfpc = (unsigned long) tos[toindex].selfpc;

          rawarc.raw_count = tos[toindex].count;

          write (fd, &rawarc, sizeof rawarc);

        }

    }

  close (fd);

}

static void

monstartup (lowpc, highpc)

     char *lowpc;

     char *highpc;

{

  int monsize;

  char *buffer;

  register int o;

  atexit (moncleanup);

  /*

   *    round lowpc and highpc to multiples of the density we're using

   *    so the rest of the scaling (here and in gprof) stays in ints.

   */

  lowpc = (char *)

    ROUNDDOWN ((unsigned) lowpc, HISTFRACTION * sizeof (HISTCOUNTER));

  s_lowpc = lowpc;

  highpc = (char *)

    ROUNDUP ((unsigned) highpc, HISTFRACTION * sizeof (HISTCOUNTER));

  s_highpc = highpc;

  s_textsize = highpc - lowpc;

  monsize = (s_textsize / HISTFRACTION) + sizeof (struct phdr);

  buffer = sbrk (monsize);

  if (buffer == (char *) -1)

    {

      write (2, MSG, sizeof (MSG));

      return;

    }

  froms = (unsigned short *) sbrk (s_textsize / HASHFRACTION);

  if (froms == (unsigned short *) -1)

    {

      write (2, MSG, sizeof (MSG));

      froms = 0;

      return;

    }

  tolimit = s_textsize * ARCDENSITY / 100;

  if (tolimit < MINARCS)

    {

      tolimit = MINARCS;

    }

  else if (tolimit > 65534)

    {

      tolimit = 65534;

    }

  tos = (struct tostruct *) sbrk (tolimit * sizeof (struct tostruct));

  if (tos == (struct tostruct *) -1)

    {

      write (2, MSG, sizeof (MSG));

      froms = 0;

      tos = 0;

      return;

    }

  tos[0].link = 0;

  sbuf = buffer;

  ssiz = monsize;

  ((struct phdr *) buffer)->lpc = lowpc;

  ((struct phdr *) buffer)->hpc = highpc;

  ((struct phdr *) buffer)->ncnt = ssiz;

  monsize -= sizeof (struct phdr);

  if (monsize <= 0)

    return;

  o = highpc - lowpc;

  if (monsize < o)

#if 0

    s_scale = ((float) monsize / o) * SCALE_1_TO_1;

#else /* avoid floating point */

    {

      int quot = o / monsize;

      if (quot >= 0x10000)

        s_scale = 1;

      else if (quot >= 0x100)

        s_scale = 0x10000 / quot;

      else if (o >= 0x800000)

        s_scale = 0x1000000 / (o / (monsize >> 8));

      else

        s_scale = 0x1000000 / ((o << 8) / monsize);

    }

#endif

  else

    s_scale = SCALE_1_TO_1;

  profiling = 0;

}

/* These happen to be in the right place because of how crt0 works */

extern char __attribute__((far)) _start;

extern char __attribute__((far)) _etext;

void

__mep_mcount_2 (selfpc, frompcindex)

     char *selfpc;

     unsigned short *frompcindex;

{

  struct tostruct *top;

  struct tostruct *prevtop;

  long toindex;

  static int initialized = 0;

  if (!initialized)

    {

      initialized = 1;

      monstartup (&_start, &_etext);

    }

  /*

   *    check that we are profiling

   *    and that we aren't recursively invoked.

   */

  if (profiling)

    {

      goto out;

    }

  profiling++;

  /*

   *    check that frompcindex is a reasonable pc value.

   *    for example:    signal catchers get called from the stack,

   *                    not from text space.  too bad.

   */

  frompcindex = (unsigned short *) ((long) frompcindex - (long) s_lowpc);

  if ((unsigned long) frompcindex > s_textsize)

    {

      goto done;

    }

  frompcindex =

    &froms[((long) frompcindex) / (HASHFRACTION * sizeof (*froms))];

  toindex = *frompcindex;

  if (toindex == 0)

    {

      /*

       *  first time traversing this arc

       */

      toindex = ++tos[0].link;

      if (toindex >= tolimit)

        {

          goto overflow;

        }

      *frompcindex = toindex;

      top = &tos[toindex];

      top->selfpc = selfpc;

      top->count = 1;

      top->link = 0;

      goto done;

    }

  top = &tos[toindex];

  if (top->selfpc == selfpc)

    {

      /*

       *  arc at front of chain; usual case.

       */

      top->count++;

      goto done;

    }

  /*

   *    have to go looking down chain for it.

   *    top points to what we are looking at,

   *    prevtop points to previous top.

   *    we know it is not at the head of the chain.

   */

  for (; /* goto done */ ;)

    {

      if (top->link == 0)

        {

          /*

           *        top is end of the chain and none of the chain

           *        had top->selfpc == selfpc.

           *        so we allocate a new tostruct

           *        and link it to the head of the chain.

           */

          toindex = ++tos[0].link;

          if (toindex >= tolimit)

            {

              goto overflow;

            }

          top = &tos[toindex];

          top->selfpc = selfpc;

          top->count = 1;

          top->link = *frompcindex;

          *frompcindex = toindex;

          goto done;

        }

      /*

       *  otherwise, check the next arc on the chain.

       */

      prevtop = top;

      top = &tos[top->link];

      if (top->selfpc == selfpc)

        {

          /*

           *        there it is.

           *        increment its count

           *        move it to the head of the chain.

           */

          top->count++;

          toindex = prevtop->link;

          prevtop->link = top->link;

          top->link = *frompcindex;

          *frompcindex = toindex;

          goto done;

        }

    }

done:

  profiling--;

  /* and fall through */

out:

  return;                       /* normal return restores saved registers */

overflow:

  profiling++;                  /* halt further profiling */

#   define      TOLIMIT "mcount: tos overflow\n"

  write (2, TOLIMIT, sizeof (TOLIMIT));

  goto out;

}