#include <fcntl.h>

typedef struct {
  long low;
  long high;
  long nbytes;
} header;

typedef struct {
    unsigned long from;
    unsigned long to;
    unsigned long count;
} MTABE;

typedef struct MTAB {
  MTABE calls[341];
  struct MTAB *prev;
} MTAB;

static header h;
short *histogram asm("mcount_histogram");
short mcount_skip asm("mcount_skip");
static int histlen;
static MTAB *mtab=0;

void mcount(_to)
{
  MTAB *m;
  int i;
  int to;
  int ebp;
  int from;
  int mtabi;
  MTABE **cache;

  mcount_skip = 1;
  asm("movl %%edx,%0" : "=g" (cache));
  to = *((&_to)-1) - 13;
  ebp = *((&_to)-2);
  from = ((int *)ebp)[1];
  if (*cache && ((*cache)->from == from) && ((*cache)->to == to))
  {
    (*cache)->count++;
    mcount_skip = 0;
    return;
  }
  mtabi = -1;
  for (m=mtab; m; m=m->prev)
  {
    for (i=0; i<341; i++)
    {
      if (m->calls[i].from == 0)
      {
        mtabi = i;
        break;
      }
      if ((m->calls[i].from == from) &&
          (m->calls[i].to == to))
        {
          m->calls[i].count ++;
          *cache = m->calls + i;
          mcount_skip = 0;
          return;
        }
    }
  }
  if (mtabi != -1)
  {
    mtab->calls[mtabi].from = from;
    mtab->calls[mtabi].to = to;
    mtab->calls[mtabi].count = 1;
    *cache = mtab->calls + mtabi;
    mcount_skip = 0;
    return;
  }
  m = (MTAB *)sbrk(sizeof(MTAB));
  m->prev = mtab;
  mtab = m;
  memset(m, 0, sizeof(MTAB));
  m->calls[0].from = from;
  m->calls[0].to = to;
  m->calls[0].count = 1;
  *cache = m->calls;
  mcount_skip = 0;
}

extern int etext;

extern void mcount_isr_init() asm("mcount_isr_init");
extern void mcount_init() asm("mcount_init");
void mcount_init()
{
  int hs;
  h.low = 0x1020;
  h.high = (int)&etext;
  histlen = (h.high-h.low)/4*sizeof(short);
  h.nbytes = sizeof(header) + histlen;
  histogram = (short *)sbrk(histlen);
  memset(histogram, 0, histlen);
  mcount_isr_init();
}

extern void mcount_write() asm("mcount_write");
void mcount_write()
{
  MTAB *m;
  int i, f;

  f = open("gmon.out", O_WRONLY|O_CREAT|O_TRUNC|O_BINARY, 0666);
  write(f, &h, sizeof(header));
  write(f, histogram, histlen);
  for (m=mtab; m; m=m->prev)
  {
    for (i=0; i<341; i++)
      if (m->calls[i].from == 0)
        break;
    write(f, m->calls, i*12);
  }
  close(f);
}