libc/libgloss/mep/mep-gmon.c

412 lines
10 KiB
C

/*-
* 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 [rescinded 22 July 1999]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;
}