osprey/kgccfe/gnu/config/sparc/gmon-sol2.c

Go to the documentation of this file.

/*-
 * Copyright (c) 1991 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 [rescinded 22 July 1999]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.
 */

/* Mangled into a form that works on Sparc Solaris 2 by Mark Eichin
 * for Cygnus Support, July 1992.
 */

#include "config.h"
#include "system.h"

#if 0
#include "sparc/gmon.h"
#else
struct phdr {
  char *lpc;
  char *hpc;
  int ncnt;
};
#define HISTFRACTION 2
#define HISTCOUNTER unsigned short
#define HASHFRACTION 1
#define ARCDENSITY 2
#define MINARCS 50
struct tostruct {
  char *selfpc;
  long count;
  unsigned short link;
};
struct rawarc {
    unsigned long       raw_frompc;
    unsigned long       raw_selfpc;
    long                raw_count;
};
#define ROUNDDOWN(x,y)  (((x)/(y))*(y))
#define ROUNDUP(x,y)    ((((x)+(y)-1)/(y))*(y))

#endif

/* extern mcount() asm ("mcount"); */
/*extern*/ char *minbrk /* asm ("minbrk") */;

    /*
     *  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"

static void moncontrol  PARAMS ((int));
extern void monstartup  PARAMS ((char *, char *));
extern void _mcleanup PARAMS ((void));

void monstartup(lowpc, highpc)
    char  *lowpc;
    char  *highpc;
{
    int     monsize;
    char    *buffer;
    register int  o;

  /*
   *  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 long)lowpc, HISTFRACTION*sizeof(HISTCOUNTER));
    s_lowpc = lowpc;
    highpc = (char *)
      ROUNDUP((unsigned long)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;
    }
    minbrk = sbrk(0);
    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 )
#ifndef hp300
  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;
    moncontrol(1);
}

void
_mcleanup()
{
    int     fd;
    int     fromindex;
    int     endfrom;
    char    *frompc;
    int     toindex;
    struct rawarc rawarc;
    char    *profdir;
    const char    *proffile;
    char    *progname;
    char     buf[PATH_MAX];
    extern char        **___Argv;

    moncontrol(0);

    if ((profdir = getenv("PROFDIR")) != NULL) {
  /* If PROFDIR contains a null value, no profiling output is produced */
  if (*profdir == '\0') {
      return;
  }

  progname=strrchr(___Argv[0], '/');
  if (progname == NULL)
      progname=___Argv[0];
  else
      progname++;

  sprintf(buf, "%s/%ld.%s", profdir, (long) getpid(), progname);
  proffile = buf;
    } else {
  proffile = "gmon.out";
    }

    fd = creat( proffile, 0666 );
    if ( fd < 0 ) {
  perror( proffile );
  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 );
}

/*
 * The Sparc stack frame is only held together by the frame pointers
 * in the register windows. According to the SVR4 SPARC ABI
 * Supplement, Low Level System Information/Operating System
 * Interface/Software Trap Types, a type 3 trap will flush all of the
 * register windows to the stack, which will make it possible to walk
 * the frames and find the return addresses.
 *  However, it seems awfully expensive to incur a trap (system
 * call) for every function call. It turns out that "call" simply puts
 * the return address in %o7 expecting the "save" in the procedure to
 * shift it into %i7; this means that before the "save" occurs, %o7
 * contains the address of the call to mcount, and %i7 still contains
 * the caller above that. The asm mcount here simply saves those
 * registers in argument registers and branches to internal_mcount,
 * simulating a call with arguments.
 *  Kludges:
 *  1) the branch to internal_mcount is hard coded; it should be
 * possible to tell asm to use the assembler-name of a symbol.
 *  2) in theory, the function calling mcount could have saved %i7
 * somewhere and reused the register; in practice, I *think* this will
 * break longjmp (and maybe the debugger) but I'm not certain. (I take
 * some comfort in the knowledge that it will break the native mcount
 * as well.)
 *  3) if builtin_return_address worked, this could be portable.
 * However, it would really have to be optimized for arguments of 0
 * and 1 and do something like what we have here in order to avoid the
 * trap per function call performance hit. 
 *  4) the atexit and monsetup calls prevent this from simply
 * being a leaf routine that doesn't do a "save" (and would thus have
 * access to %o7 and %i7 directly) but the call to write() at the end
 * would have also prevented this.
 *
 * -- [eichin:19920702.1107EST]
 */

static void internal_mcount PARAMS ((char *, unsigned short *)) ATTRIBUTE_UNUSED;

/* i7 == last ret, -> frompcindex */
/* o7 == current ret, -> selfpc */
/* Solaris 2 libraries use _mcount.  */
asm(".global _mcount; _mcount: mov %i7,%o1; mov %o7,%o0;b,a internal_mcount");
/* This is for compatibility with old versions of gcc which used mcount.  */
asm(".global mcount; mcount: mov %i7,%o1; mov %o7,%o0;b,a internal_mcount");

static void internal_mcount(selfpc, frompcindex)
  register char     *selfpc;
  register unsigned short   *frompcindex;
{
  register struct tostruct  *top;
  register struct tostruct  *prevtop;
  register long     toindex;
  static char already_setup;

  /*
   *  find the return address for mcount,
   *  and the return address for mcount's caller.
   */

  if(!already_setup) {
          extern char etext[];
    extern char _start[];
    extern char _init[];
    already_setup = 1;
    monstartup(_start < _init ? _start : _init, etext);
#ifdef USE_ONEXIT
    on_exit(_mcleanup, 0);
#else
    atexit(_mcleanup);
#endif
  }
  /*
   *  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;
}

/*
 * Control profiling
 *  profiling is what mcount checks to see if
 *  all the data structures are ready.
 */
static void moncontrol(mode)
    int mode;
{
    if (mode) {
  /* start */
  profil((unsigned short *)(sbuf + sizeof(struct phdr)),
         ssiz - sizeof(struct phdr),
         (long)s_lowpc, s_scale);
  profiling = 0;
    } else {
  /* stop */
  profil((unsigned short *)0, 0, 0, 0);
  profiling = 3;
    }
}

---