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[sdcc.git] / sdcc / src / SDCCpeeph.c

/*-------------------------------------------------------------------------
  SDCCpeeph.c - The peep hole optimizer: for interpreting the
                peep hole rules

  Copyright (C) 1999, Sandeep Dutta . sandeep.dutta@usa.net

  This program 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.

  This program 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 this program; if not, write to the Free Software
  Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
-------------------------------------------------------------------------*/

#include "common.h"
#include "dbuf_string.h"

#define ISCHARDIGIT(c) isdigit((unsigned char)c)
#define ISCHARSPACE(c) isspace((unsigned char)c)
#define ISCHARALNUM(c) isalnum((unsigned char)c)

#define ISINST(l, i) (!STRNCASECMP((l), (i), sizeof(i) - 1) && (!(l)[sizeof(i) - 1] || isspace((unsigned char)((l)[sizeof(i) - 1]))))

static peepRule *rootRules = NULL;
static peepRule *currRule = NULL;

#define HTAB_SIZE 53

hTab *labelHash = NULL;

static struct
{
  allocTrace values;
  allocTrace labels;
} _G;

static int hashSymbolName (const char *name);
static void buildLabelRefCountHash (lineNode * head);
static void bindVar (int key, char **s, hTab ** vtab);

static bool matchLine (char *, const char *, hTab **);

#define FBYNAME(x) static int x (hTab *vars, lineNode *currPl, lineNode *endPl, \
        lineNode *head, char *cmdLine)

#if !OPT_DISABLE_PIC14
void peepRules2pCode(peepRule *);
#endif

#if !OPT_DISABLE_PIC16
void pic16_peepRules2pCode(peepRule *);
#endif

/*-----------------------------------------------------------------*/
/* getPatternVar - finds a pattern variable                        */
/*-----------------------------------------------------------------*/

static char*
getPatternVar (hTab *vars, char **cmdLine)
{
  int varNumber;
  char *digitend;

  if (!cmdLine || !*cmdLine || !**cmdLine)
    return NULL; /* no parameters given */

  while (**cmdLine && ISCHARSPACE(**cmdLine))
    (*cmdLine)++; /* skip whitespace */

  if (**cmdLine != '%')
    goto error;
  (*cmdLine)++;
  if (!ISCHARDIGIT (**cmdLine))
    goto error;
  varNumber = strtol (*cmdLine, &digitend, 10);
  *cmdLine = digitend;
  return hTabItemWithKey (vars, varNumber);

error:
  fprintf (stderr,
           "*** internal error: peephole restriction malformed: %s\n", *cmdLine);
  return NULL;
}

/*-----------------------------------------------------------------*/
/* interpreteLine - interpret general ASxxxx syntax                */
/* Returns distance                                                */
/* Can recurse to interpret some simple macros                     */
/*-----------------------------------------------------------------*/

static int
interpretLine (lineNode **pl, char *buff, bool back)
{
  int dist = 0;
  if ((*pl)->line &&
      !(*pl)->isComment &&
      !(*pl)->isLabel &&
      !(*pl)->isDebug)
    {
      // handle general ASxxxx syntax
      // this can be a lot bigger than 4B due to macros
      if(ISINST((*pl)->line, ".db") || ISINST((*pl)->line, ".byte") || ISINST((*pl)->line, ".fcb"))
        {
          int i, j;
          for(i = 1, j = 0; (*pl)->line[j]; i += (*pl)->line[j] == ',', j++);
          dist += i;
        }
      else if(ISINST((*pl)->line, ".dw") || ISINST((*pl)->line, ".word") || ISINST((*pl)->line, ".fdb"))
        {
          int i, j;
          for(i = 1, j = 0; (*pl)->line[j]; i += (*pl)->line[j] == ',', j++);
          dist += i * 2;
        }
      else if(ISINST((*pl)->line, ".3byte") || ISINST((*pl)->line, ".triple"))
        {
          int i, j;
          for(i = 1, j = 0; (*pl)->line[j]; i += (*pl)->line[j] == ',', j++);
          dist += i * 3;
        }
      else if(ISINST((*pl)->line, ".4byte") || ISINST((*pl)->line, ".quad"))
        {
          int i, j;
          for(i = 1, j = 0; (*pl)->line[j]; i += (*pl)->line[j] == ',', j++);
          dist += i * 4;
        }
      else if(ISINST((*pl)->line, ".str") || ISINST((*pl)->line, ".ascii") || ISINST((*pl)->line, ".fcc")
          || ISINST((*pl)->line, ".strz") || ISINST((*pl)->line, ".asciz")
          || ISINST((*pl)->line, ".strs") || ISINST((*pl)->line, ".ascis"))
        {
          const char *value;
          // skip directive
          for (value = (*pl)->line; *value && !isspace (*value); ++value);
          // skip space
          for (; *value && isspace (*value); ++value);
          // just part of the syntax
          if(*value == '^')
            ++value;
          // delimiter can be freely chosen
          char delimiter = *(value++);
          for (;*value && *value != delimiter; ++value, ++dist);
          // \0 terminated string
          if (ISINST((*pl)->line, ".strz") || ISINST((*pl)->line, ".asciz"))
            ++dist;
          // it doesn't end with delimiter
          if (*value != delimiter)
            {
              werrorfl("delimitererror", 0, W_UNRECOGNIZED_ASM, __func__, 999, (*pl)->line);
              return 999;
            }
        }
      else if(!back && ISINST((*pl)->line, ".rept"))
        {
          // we can ignore the label for now
          // rept doesn't allow duplicate labels
          const char *op1start;
          int times;

          // skip directive
          for (op1start = (*pl)->line; *op1start && !isspace (*op1start); ++op1start);
          // skip space
          for (; *op1start && isspace (*op1start); ++op1start);
          times = atoi(op1start);
          // 0 times is probably an error with atoi
          if(times == 0)
            {
              werrorfl("atoierror", 0, W_UNRECOGNIZED_ASM, __func__, 999, (*pl)->line);
              return 999;
            }
          (*pl) = (*pl)->next;
          while((*pl) && !ISINST((*pl)->line, ".endm"))
            {
              dist += interpretLine(pl, buff, back);
              if(!pl)
                break;
              (*pl) = (*pl)->next;
            }
          // we reached the end, not .endm
          if(!(*pl))
            return 999;
          dist *= times;
        }
      else if(back && ISINST((*pl)->line, ".endm"))
        {
          // parse rept backwards
          const char *op1start;
          int times;

          (*pl) = (*pl)->prev;
          while((*pl) && !ISINST((*pl)->line, ".rept"))
            {
              dist += interpretLine(pl, buff, back);
              if(!(*pl))
                break;
              (*pl) = (*pl)->prev;
            }
          // we reached the end, not .rept
          if(!(*pl))
            return 999;
          // skip directive
          for (op1start = (*pl)->line; *op1start && !isspace (*op1start); ++op1start);
          // skip space
          for (; *op1start && isspace (*op1start); ++op1start);
          times = atoi(op1start);
          // 0 times is probably an error with atoi
          if(times == 0)
            {
              werrorfl("atoierror", 0, W_UNRECOGNIZED_ASM, __func__, 999, (*pl)->line);
              return 999;
            }
          dist *= times;
        }
      else if (ISINST((*pl)->line, ".incbin"))
        {
          // .incbin /string/ [,offset [,count]]
          // if count is given, we can work with it
          const char *op1start = (*pl)->line;
          int count;
          // skip first comma
          while (*op1start && *(op1start++) != ',');
          if (!*op1start)
            {
              werrorfl("unsupported", 0, W_UNRECOGNIZED_ASM, __func__, 999, (*pl)->line);
              return(999);
            }
          // skip first comma
          while (*op1start && *(op1start++) != ',');
          if (!*op1start)
            {
              werrorfl("unsupported", 0, W_UNRECOGNIZED_ASM, __func__, 999, (*pl)->line);
              return(999);
            }
          // skip space
          for (; *op1start && isspace (*op1start); ++op1start);
          if (!*op1start)
            {
              werrorfl("unsupported", 0, W_UNRECOGNIZED_ASM, __func__, 999, (*pl)->line);
              return(999);
            }
          count = atoi(op1start);
          // probably an error with atoi
          if (count == 0)
            {
              werrorfl("atoierror", 0, W_UNRECOGNIZED_ASM, __func__, 999, (*pl)->line);
              return 999;
            }
          dist += count;
        }
      else if (ISINST((*pl)->line, ".odd") || ISINST((*pl)->line, ".even"))
        {
          // 0 or 1, assume worst
          dist += 1;
        }
      else if(ISINST((*pl)->line, ".bndry") || ISINST((*pl)->line, ".ds") || ISINST((*pl)->line, ".rmb")
          || ISINST((*pl)->line, ".rs") || ISINST((*pl)->line, ".blkb") || ISINST((*pl)->line, ".blkw")
          || ISINST((*pl)->line, ".blk3") || ISINST((*pl)->line, ".blk4"))
        {
          const char *op1start;
          int offset;

          // skip directive
          for (op1start = (*pl)->line; *op1start && !isspace (*op1start); ++op1start);
          // skip space
          for (; *op1start && isspace (*op1start); ++op1start);
          offset = atoi(op1start);
          // 0 times is probably an error with atoi
          if (offset == 0)
            {
              werrorfl("atoierror", 0, W_UNRECOGNIZED_ASM, __func__, 999, (*pl)->line);
              return 999;
            }
          if (ISINST((*pl)->line, ".blkw"))
            offset *= 2;
          if (ISINST((*pl)->line, ".blk3"))
            offset *= 2;
          if (ISINST((*pl)->line, ".blk4"))
            offset *= 2;
          // bndry: assume the worst
          dist += offset;
        }
      else if ( ISINST((*pl)->line, ".iift") || ISINST((*pl)->line, ".iiff") || ISINST((*pl)->line, ".iiftf")
          || ISINST((*pl)->line, ".iifne") || ISINST((*pl)->line, ".iifeq") || ISINST((*pl)->line, ".iifgt")
          || ISINST((*pl)->line, ".iiflt") || ISINST((*pl)->line, ".iifge") || ISINST((*pl)->line, ".iifle")
          || ISINST((*pl)->line, ".iifdef") || ISINST((*pl)->line, ".iifndef") || ISINST((*pl)->line, ".iifb")
          || ISINST((*pl)->line, ".iifnb") || ISINST((*pl)->line, ".iifidn") || ISINST((*pl)->line, ".iifdif")
          || ISINST((*pl)->line, ".iif"))
        {
          // the line ends with real operations and directives
          werrorfl("unsupported", 0, W_UNRECOGNIZED_ASM, __func__, 999, (*pl)->line);
          dist += 999;
        }
      else if (ISINST((*pl)->line, ".msg") || ISINST((*pl)->line, ".error") || ISINST((*pl)->line, ".assume")
          || ISINST((*pl)->line, ".radix") || ISINST((*pl)->line, ".local") || ISINST((*pl)->line, ".globl")
          || ISINST((*pl)->line, ".equ") || ISINST((*pl)->line, ".gblequ") || ISINST((*pl)->line, ".lclequ")
          || ISINST((*pl)->line, ".if") || ISINST((*pl)->line, ".else") || ISINST((*pl)->line, ".endif")
          || ISINST((*pl)->line, ".ift") || ISINST((*pl)->line, ".iff") || ISINST((*pl)->line, ".iftf")
          || ISINST((*pl)->line, ".ifne") || ISINST((*pl)->line, ".ifeq") || ISINST((*pl)->line, ".ifgt")
          || ISINST((*pl)->line, ".iflt") || ISINST((*pl)->line, ".ifge") || ISINST((*pl)->line, ".ifle")
          || ISINST((*pl)->line, ".ifdef") || ISINST((*pl)->line, ".ifndef") || ISINST((*pl)->line, ".ifb")
          || ISINST((*pl)->line, ".ifnb") || ISINST((*pl)->line, ".ifidn") || ISINST((*pl)->line, ".ifdif")
          || ISINST((*pl)->line, ".define") || ISINST((*pl)->line, ".undefine"))
        {
          // ignore these, makes it longer at worst
          dist += 0;
        }
      else if (ISINST((*pl)->line, ".macro") || ISINST((*pl)->line, ".irp") || ISINST((*pl)->line, ".irpc")
          || ISINST((*pl)->line, ".include") || ISINST((*pl)->line, ".rept") || ISINST((*pl)->line, ".endm"))
        {
          // catch some unsupported long or complex directives
          werrorfl("unsupported", 0, W_UNRECOGNIZED_ASM, __func__, 999, (*pl)->line);
          dist += 999;
        }
      // get port specific size
      else
        {
          const char *op1start;
          // skip directive
          for (op1start = (*pl)->line; *op1start && !isspace (*op1start); ++op1start);
          // skip space
          for (; *op1start && isspace (*op1start); ++op1start);
          // catch "sym1 .equ expr" "sym1 = expr" "sym1 =: expr" etc
          // ".equ sym1 expr" got already handled
          if (ISINST(op1start, ".equ") || ISINST(op1start, ".gblequ") || ISINST(op1start, ".lclequ")
            || *op1start == '=')
            {
              // ignored
              dist += 0;
            }
          else if (port->peep.getSize)
            {
              dist += port->peep.getSize((*pl));
#if 0
              fprintf(stderr, "Line: %s, dist: %i, total: %i\n", pl->line, port->peep.getSize(pl), dist);
#endif
            }
          else
            {
              // could be a macro call
              dist += 999;
            }
        }
    }
  return dist;
}

/*-----------------------------------------------------------------*/
/* pcDistance - finds a label backward or forward                  */
/*-----------------------------------------------------------------*/

static int
pcDistance (lineNode *cpos, char *lbl, bool back)
{
  lineNode *pl = cpos;
  char buff[MAX_PATTERN_LEN];
  int dist = 0;

  SNPRINTF (buff, sizeof(buff) - 1, "%s:", lbl);
  while (pl)
    {
      dist += interpretLine(&pl, buff, back);
      // interpretLine changes pl
      if (!pl)
        break;

      if (strncmp (pl->line, buff, strlen (buff)) == 0)
        return dist;
      if (back)
        pl = pl->prev;
      else
        pl = pl->next;
    }
  return 0;
}

/*-----------------------------------------------------------------*/
/* flat24bitMode - will check to see if we are in flat24 mode      */
/*-----------------------------------------------------------------*/
FBYNAME (flat24bitMode)
{
  return (options.model == MODEL_FLAT24);
}

/*-----------------------------------------------------------------*/
/* xramMovcOption - check if using movc to read xram               */
/*-----------------------------------------------------------------*/
FBYNAME (xramMovcOption)
{
  return (options.xram_movc && (strcmp(port->target,"mcs51") == 0));
}

/*-----------------------------------------------------------------*/
/* useAcallAjmp - Enable replacement of lcall/ljmp with acall/ajmp */
/*-----------------------------------------------------------------*/
FBYNAME (useAcallAjmp)
{
  return (options.acall_ajmp && (strcmp(port->target,"mcs51") == 0));
}

/*-----------------------------------------------------------------*/
/* labelInRange - will check to see if label is within range       */
/*-----------------------------------------------------------------*/
FBYNAME (labelInRange)
{
  int dist = 0;
  char *lbl = getPatternVar (vars, &cmdLine);

  if (!lbl)
    {
      fprintf (stderr,
             "*** internal error: labelInRange peephole restriction"
             " malformed: %s\n", cmdLine);

      /* If no parameters given, assume that %5 pattern variable
         has the label name for backward compatibility */
      lbl = hTabItemWithKey (vars, 5);
    }

  if (!lbl)
    return FALSE;

  do
    {
      /* Don't optimize jumps in a jump table; a more generic test */
      if (currPl->ic && currPl->ic->op == JUMPTABLE)
        return FALSE;

      /* if the previous two instructions are "ljmp"s then don't
         do it since it can be part of a jump table */
      if (currPl->prev && currPl->prev->prev &&
          strstr (currPl->prev->line, "ljmp") &&
          strstr (currPl->prev->prev->line, "ljmp"))
        return FALSE;

      /* Calculate the label distance. For mcs51 the jump can be
         -127 to + 127 bytes, for Z80 -126 to +129 bytes.*/
      dist = (pcDistance (currPl, lbl, TRUE) +
              pcDistance (currPl, lbl, FALSE));

      /* Use 125 for now. Could be made more exact using port and
         exact jump location instead of currPl. */
      if (!dist || dist > 127)
        return FALSE;

      lbl = getPatternVar (vars, &cmdLine);
    }
  while (lbl);

  return TRUE;
}

/*-----------------------------------------------------------------*/
/* labelJTInRange - will check to see if label %5 and up are       */
/* within range.                                                   */
/* Specifically meant to optimize long (3-byte) jumps to short     */
/* (2-byte) jumps in jumptables                                    */
/*-----------------------------------------------------------------*/
FBYNAME (labelJTInRange)
{
  char *lbl;
  int dist, count, i;

  /* Only optimize within a jump table */
  if (currPl->ic && currPl->ic->op != JUMPTABLE)
    return FALSE;

  count = elementsInSet( IC_JTLABELS (currPl->ic) );

  /* check all labels (this is needed if the case statements are unsorted) */
  for (i=0; i<count; i++)
    {
      /* assumes that the %5 pattern variable has the first ljmp label */
      lbl = hTabItemWithKey (vars, 5+i);
      if (!lbl)
        return FALSE;

      dist = (pcDistance (currPl, lbl, TRUE) +
              pcDistance (currPl, lbl, FALSE));

      /* three terms used to calculate allowable distance */
      /* Could be made more exact and port-specific. */
      if (!dist ||
          dist > 127+           /* range of sjmp */
                 (3+3*i)+       /* offset between this jump and currPl,
                                   should use pcDistance instead? */
                 (count-i-1)    /* if peephole applies distance is shortened */
         )
        return FALSE;
    }
  return TRUE;
}

/*-----------------------------------------------------------------*/
/* optimizeReturn - is it allowed to optimize RET instructions     */
/*-----------------------------------------------------------------*/
FBYNAME (optimizeReturn)
{
  return (options.peepReturn >= 0);
}

/*-----------------------------------------------------------------*/
/* labelIsReturnOnly - Check if label is followed by ret           */
/*-----------------------------------------------------------------*/
FBYNAME (labelIsReturnOnly)
{
  /* assumes that %5 pattern variable has the label name */
  const char *label, *p;
  const lineNode *pl;
  int len;
  char * retInst;

  /* Don't optimize jumps in a jump table; a more generic test */
  if (currPl->ic && currPl->ic->op == JUMPTABLE)
    return FALSE;

  if (!(label = getPatternVar (vars, &cmdLine)))
    {
      fprintf (stderr,
             "*** internal error: labelIsReturnOnly peephole restriction"
             " malformed: %s\n", cmdLine);

      /* If no parameters given, assume that %5 pattern variable
         has the label name for backward compatibility */
      label = hTabItemWithKey (vars, 5);
    }

  if (!label)
    return FALSE;
  len = strlen(label);

  for(pl = currPl; pl; pl = pl->next)
    {
      if (pl->line && !pl->isDebug && !pl->isComment && pl->isLabel)
        {
          if (strncmp(pl->line, label, len) == 0)
            break; /* Found Label */
          if (strlen(pl->line) != 7       || !ISCHARDIGIT(*(pl->line))   ||
              !ISCHARDIGIT(*(pl->line+1)) || !ISCHARDIGIT(*(pl->line+2)) ||
              !ISCHARDIGIT(*(pl->line+3)) || !ISCHARDIGIT(*(pl->line+4)) ||
              *(pl->line+5) != '$')
            {
              return FALSE; /* non-local label encountered */
            }
        }
    }
  if (!pl)
    return FALSE; /* did not find the label */
  pl = pl->next;
  while (pl && (pl->isDebug || pl->isComment || pl->isLabel))
    pl = pl->next;
  if (!pl || !pl->line || pl->isDebug)
    return FALSE; /* next line not valid */
  for (p = pl->line; *p && ISCHARSPACE(*p); p++)
    ;

  retInst = "ret";
  if (TARGET_HC08_LIKE || TARGET_MOS6502_LIKE)
    retInst = "rts";

  if (strncmp(p, retInst,strlen(retInst)) != 0)
    return FALSE;

  p+=strlen(retInst);
  while(*p && ISCHARSPACE(*p))
    p++;

  if(*p==0 || *p==';')
    return TRUE;

  return FALSE;
}

/*-----------------------------------------------------------------*/
/* labelIsUncondJump - Check if label %5 is followed by an         */
/* unconditional jump and put the destination of that jump in %6   */
/*-----------------------------------------------------------------*/
FBYNAME (labelIsUncondJump)
{
  /* assumes that %5 pattern variable has the label name */
  const char *label;
  char *p, *q;
  const lineNode *pl;
  bool found = FALSE;
  int len;
  char * jpInst = NULL;
  char * jpInst2 = NULL;

  label = hTabItemWithKey (vars, 5);
  if (!label)
    return FALSE;
  len = strlen(label);

  for (pl = currPl; pl; pl = pl->prev)
    {
      if (pl->line && !pl->isDebug && !pl->isComment && pl->isLabel)
        {
          if (strncmp(pl->line, label, len) == 0 && pl->line[len] == ':')
            {
              found = true;
              break; /* Found Label */
            }
          if (strlen(pl->line) != 7       || !ISCHARDIGIT(*(pl->line))   ||
              !ISCHARDIGIT(*(pl->line+1)) || !ISCHARDIGIT(*(pl->line+2)) ||
              !ISCHARDIGIT(*(pl->line+3)) || !ISCHARDIGIT(*(pl->line+4)) ||
              *(pl->line+5) != '$')
            {
              break; /* non-local label encountered */
            }
        }
    }

  if (!found)
    {
      for (pl = currPl; pl; pl = pl->next)
        {
          if (pl->line && !pl->isDebug && !pl->isComment && pl->isLabel)
            {
              if (strncmp(pl->line, label, len) == 0 && pl->line[len] == ':')
                {
                  found = true;
                  break; /* Found Label */
                }
              if (strlen(pl->line) != 7       || !ISCHARDIGIT(*(pl->line))   ||
                  !ISCHARDIGIT(*(pl->line+1)) || !ISCHARDIGIT(*(pl->line+2)) ||
                  !ISCHARDIGIT(*(pl->line+3)) || !ISCHARDIGIT(*(pl->line+4)) ||
                  *(pl->line+5) != '$')
                {
                  return FALSE; /* non-local label encountered */
                }
            }
        }
    }

  if (!pl || !found)
    return FALSE; /* did not find the label */
  pl = pl->next;
  while (pl && (pl->isDebug || pl->isComment))
    pl = pl->next;
  if (!pl || !pl->line)
    return FALSE; /* next line not valid */
  p = pl->line;
  while (*p && ISCHARSPACE(*p))
    p++;

  if (TARGET_MCS51_LIKE)
    {
      jpInst = "ljmp";
      jpInst2 = "sjmp";
    }
  else if (TARGET_HC08_LIKE || TARGET_MOS6502_LIKE)
    {
      jpInst = "jmp";
      jpInst2 = "bra";
    }
  else if (TARGET_Z80_LIKE || TARGET_IS_F8)
    {
      jpInst = "jp";
      jpInst2 = "jr";
    }
  else if (TARGET_IS_STM8)
    {
      jpInst = (options.model == MODEL_LARGE ? "jpf" : "jp");
      jpInst2 = "jra";
    }
  else if (TARGET_PDK_LIKE)
    {
      jpInst = "goto";
    }
  len = strlen(jpInst);
  if (strncmp(p, jpInst, len))
    {
      len = jpInst2 ? strlen(jpInst2) : 0;
      if(!jpInst2 || strncmp(p, jpInst2, len))
        return FALSE; /* next line is no jump */
    }

  p += len;
  while (*p && ISCHARSPACE(*p))
    p++;

  q = p;
  while (*q && *q!=';')
    q++;
  while (q>p && ISCHARSPACE(*q))
    q--;
  len = q-p;
  if (len == 0)
    return false; /* no destination? */

  if (TARGET_Z80_LIKE)
    {
      while (q>p && *q!=',')
        q--;
      if (*q==',')
        return false; /* conditional jump */
    }

  if (TARGET_IS_F8 && p[0] == '#')
    p++;

  /* now put the destination in %6 */
  bindVar (6, &p, &vars);

  return true;
}

/*-----------------------------------------------------------------*/
/* okToRemoveSLOC - Check if label %1 is a SLOC and not other      */
/* usage of it in the code depends on a value from this section    */
/*-----------------------------------------------------------------*/
FBYNAME (okToRemoveSLOC)
{
  const lineNode *pl;
  const char *sloc, *p;
  int dummy1, dummy2, dummy3;

  /* assumes that %1 as the SLOC name */
  sloc = hTabItemWithKey (vars, 1);
  if (sloc == NULL) return FALSE;
  p = strstr(sloc, "sloc");
  if (p == NULL) return FALSE;
  p += 4;
  if (sscanf(p, "%d_%d_%d", &dummy1, &dummy2, &dummy3) != 3) return FALSE;
  /*TODO: ultra-paranoid: get function name from "head" and check that */
  /* the sloc name begins with that.  Probably not really necessary */

  /* Look for any occurrence of this SLOC before the peephole match */
  for (pl = currPl->prev; pl; pl = pl->prev) {
        if (pl->line && !pl->isDebug && !pl->isComment
          && *pl->line != ';' && strstr(pl->line, sloc))
                return FALSE;
  }
  /* Look for any occurrence of this SLOC after the peephole match */
  for (pl = endPl->next; pl; pl = pl->next) {
        if (pl->line && !pl->isDebug && !pl->isComment
          && *pl->line != ';' && strstr(pl->line, sloc))
                return FALSE;
  }
  return TRUE; /* safe for a peephole to remove it :) */
}

/*-----------------------------------------------------------------*/
/* deadMove - Check, if a pop/push pair can be removed             */
/*-----------------------------------------------------------------*/
FBYNAME (deadMove)
{
  const char *reg = hTabItemWithKey (vars, 1);

  if (port->peep.deadMove)
    return port->peep.deadMove (reg, currPl, head);

  fprintf (stderr, "Function deadMove not initialized in port structure\n");
  return FALSE;
}

/*-----------------------------------------------------------------*/
/* labelHashEntry- searches for a label in the list labelHash      */
/* Builds labelHash, if it does not yet exist.                     */
/* Returns the labelHashEntry or NULL                              */
/*-----------------------------------------------------------------*/
labelHashEntry *
getLabelRef (const char *label, lineNode *head)
{
  labelHashEntry *entry;

  /* If we don't have the label hash table yet, build it. */
  if (!labelHash)
    {
      buildLabelRefCountHash (head);
    }

  entry = hTabFirstItemWK (labelHash, hashSymbolName (label));

  while (entry)
    {
      if (!strcmp (label, entry->name))
        {
          break;
        }
      entry = hTabNextItemWK (labelHash);
    }
  return entry;
}

/* labelRefCount:

 * takes two parameters: a variable (bound to a label name)
 * and an expected reference count.
 *
 * Returns TRUE if that label is defined and referenced exactly
 * the given number of times.
 */
FBYNAME (labelRefCount)
{
  int varNumber, expectedRefCount;
  bool rc = FALSE;

  if (sscanf (cmdLine, "%*[ \t%]%d %d", &varNumber, &expectedRefCount) == 2)
    {
      char *label = hTabItemWithKey (vars, varNumber);

      if (label)
        {
          labelHashEntry *entry = getLabelRef (label, head);

          if (entry)
            {
#if 0
              /* debug spew. */
              fprintf (stderr, "labelRefCount: %s has refCount %d, want %d\n",
                       label, entry->refCount, expectedRefCount);
#endif

              rc = (expectedRefCount == entry->refCount);
            }
          else
            {
              // Not a local label. We do not know how often it might be referenced.
              rc = FALSE;
            }
        }
      else
        {
          fprintf (stderr, "*** internal error: var %d not bound"
                   " in peephole labelRefCount rule.\n",
                   varNumber);
        }
    }
  else
    {
      fprintf (stderr,
               "*** internal error: labelRefCount peephole restriction"
               " malformed: %s\n", cmdLine);
    }
  return rc;
}

/* labelRefCountChange:
 * takes two parameters: a variable (bound to a label name)
 * and a signed int for changing the reference count.
 *
 * Please note, this function is not a conditional. It unconditionally
 * changes the label. It should be passed as the 'last' function
 * so it only is applied if all other conditions have been met.
 *
 * should always return TRUE
 */
FBYNAME (labelRefCountChange)
{
  int varNumber, RefCountDelta;
  bool rc = FALSE;

  /* If we don't have the label hash table yet, build it. */
  if (!labelHash)
    {
      buildLabelRefCountHash (head);
    }

  if (sscanf (cmdLine, "%*[ \t%]%d %i", &varNumber, &RefCountDelta) == 2)
    {
      char *label = hTabItemWithKey (vars, varNumber);

      if (label)
        {
          labelHashEntry *entry;

          entry = hTabFirstItemWK (labelHash, hashSymbolName (label));

          while (entry)
            {
              if (!strcmp (label, entry->name))
                {
                  break;
                }
              entry = hTabNextItemWK (labelHash);
            }
          if (entry)
            {
              if (0 <= entry->refCount + RefCountDelta)
                {
                  entry->refCount += RefCountDelta;
                  rc = TRUE;
                }
              else
                {
                  fprintf (stderr, "*** internal error: label %s may not get"
                          " negative refCount in %s peephole.\n",
                           label, __func__);
                }
            }
            else
            {
              // Not a local label. We do not know how often it might be referenced.
              return TRUE;
            }
        }
      else
        {
          fprintf (stderr, "*** internal error: var %d not bound"
                   " in peephole %s rule.\n",
                   varNumber, __func__);
        }
    }
  else
    {
      fprintf (stderr,
               "*** internal error: labelRefCountChange peephole restriction"
               " malformed: %s\n", cmdLine);
    }
  return rc;
}

/* newLabel creates new dollar-label and returns it in the specified container.
 * Optional second operand may specify initial reference count, by default 1.
 * return TRUE if no errors detected
 */
FBYNAME (newLabel)
{
  int varNumber;
  unsigned refCount;
  switch (sscanf (cmdLine, " %%%d %u", &varNumber, &refCount))
    {
    case 1:
      refCount = 1;
      break;
    case 2:
      break;
    default:
      fprintf (stderr,
               "*** internal error: newLabel peephole restriction"
               " malformed: %s\n", cmdLine);
      return FALSE;
    }

  if (varNumber <= 0)
    {
      fprintf (stderr, "*** internal error: invalid container %%%d"
               " in peephole %s rule.\n",
               varNumber, __func__);
      return FALSE;
    }

  if (labelHash == NULL)
    buildLabelRefCountHash (head);

  labelHashEntry *entry;
  int key;
  unsigned maxLabel = 100; // do not use labels below than 00100$
  for (entry = hTabFirstItem (labelHash, &key); entry;
       entry = hTabNextItem (labelHash, &key))
    {
      const char *name = entry->name;
      wassert (name);
      if (!ISCHARDIGIT (name[0]))
        continue;
      if (name[strlen (name)-1] != '$')
        continue;
      unsigned n;
      if (sscanf (name, "%u$", &n) != 1)
        continue;
      if (maxLabel < n)
        maxLabel = n;
    }
  ++maxLabel;
  entry = traceAlloc (&_G.labels, Safe_alloc (sizeof (*entry)));
  int len = snprintf (entry->name, SDCC_NAME_MAX, "%05u$", maxLabel);
  entry->name[len] = 0;
  entry->refCount = refCount;
  hTabAddItem (&labelHash, hashSymbolName (entry->name), entry);

  char *value = traceAlloc (&_G.values, Safe_strdup(entry->name));
  hTabAddItem (&vars, varNumber, value);

  return TRUE;
}

/* Within the context of the lines currPl through endPl, determine
** if the variable var contains a symbol that is volatile. Returns
** TRUE only if it is certain that this was not volatile (the symbol
** was found and not volatile, or var was a constant or CPU register).
** Returns FALSE if the symbol was found and volatile, the symbol was
** not found, or var was a indirect/pointer addressing mode.
*/
static bool
notVolatileVariable(const char *var, lineNode *currPl, lineNode *endPl)
{
  char symname[SDCC_NAME_MAX + 1];
  char *p = symname;
  const char *vp = var;
  lineNode *cl;
  operand *op;
  iCode *last_ic;

  const bool global_not_volatile = currFunc ? !currFunc->funcUsesVolatile : false;

  /* Can't tell if indirect accesses are volatile or not, so
  ** assume they are (if there is a volatile access in the function at all), just to be safe.
  */
  if (TARGET_IS_MCS51 || TARGET_IS_DS390 || TARGET_IS_DS400)
    {
      if (*var=='@')
        return global_not_volatile;
    }
  if (TARGET_Z80_LIKE)
    {
      if (var[0] == '#')
        return true;
      if (var[0] == '(')
        return global_not_volatile;
      if (strstr (var, "(bc)"))
        return global_not_volatile;
      if (strstr (var, "(de)"))
        return global_not_volatile;
      if (strstr (var, "(hl"))
        return global_not_volatile;
      if (strstr (var, "(ix"))
        return global_not_volatile;
      if (strstr (var, "(iy"))
        return global_not_volatile;
      // sm83-specific ldh can be volatile
      // but HRAM doesn't have to be volatile
      if (TARGET_ID_SM83 && strstr (var, "(c)"))
        return global_not_volatile;
    }

  if (TARGET_IS_STM8)
    {
      if (var[0] == '#')
        return true;
      if (var[0] == '(')
        return global_not_volatile;
      if (strstr (var, "(x)"))
        return global_not_volatile;
      if (strstr (var, "(y)"))
        return global_not_volatile;
      if (strstr (var, ", x)"))
        return global_not_volatile;
      if (strstr (var, ", y)"))
        return global_not_volatile;
      if (strstr (var, ", sp)"))
        return global_not_volatile;
      if (strchr (var, '[') && strchr (var, ']'))
        return global_not_volatile;
      if (strstr(var, "0x") || strstr(var, "0X") || isdigit(var[0]))
        return global_not_volatile;
    }

  if (TARGET_PDK_LIKE)
    {
      if (var[0] == '#')
        return true;
      if (!strcmp (var, "a") || !strcmp (var, "p"))
        return true;
    }

  if (TARGET_HC08_LIKE || TARGET_IS_MOS6502)
    {
      if (var[0] == '#')
        return true;
      if (strstr(var, "0x") || strstr(var, "0X") || isdigit(var[0]))
        return global_not_volatile;
    }

  /* Extract a symbol name from the variable */
  while (*vp && (*vp!='_'))
    vp++;
  while (*vp && (ISCHARALNUM(*vp) || *vp=='_'))
    *p++ = *vp++;
  *p='\0';

  if (!symname[0])
    {
      /* Nothing resembling a symbol name was found, so it can't
         be volatile
      */
      return true;
    }

  last_ic = NULL;
  for (cl = currPl; cl!=endPl->next; cl = cl->next)
  {
    if (cl->ic && (cl->ic!=last_ic))
      {
        last_ic = cl->ic;
        switch (cl->ic->op)
          {
          case IFX:
            op = IC_COND (cl->ic);
            if (IS_SYMOP (op) &&
                ( !strcmp(OP_SYMBOL (op)->rname, symname) ||
                  (OP_SYMBOL (op)->isspilt &&
                   SPIL_LOC (op) &&
                   !strcmp(SPIL_LOC (op)->rname, symname)) ))
              {
                return !op->isvolatile;
              }
          case JUMPTABLE:
            op = IC_JTCOND (cl->ic);
            if (IS_SYMOP (op) &&
                ( !strcmp(OP_SYMBOL (op)->rname, symname) ||
                  (OP_SYMBOL (op)->isspilt &&
                   SPIL_LOC (op) &&
                   !strcmp(SPIL_LOC (op)->rname, symname)) ))
              {
                return !op->isvolatile;
              }
          default:
            op = IC_LEFT (cl->ic);
            if (IS_SYMOP (op) &&
                ( !strcmp(OP_SYMBOL (op)->rname, symname) ||
                  (OP_SYMBOL (op)->isspilt &&
                   SPIL_LOC (op) &&
                   !strcmp(SPIL_LOC (op)->rname, symname)) ))
              {
                return !op->isvolatile;
              }
            op = IC_RIGHT (cl->ic);
            if (IS_SYMOP (op) &&
                ( !strcmp(OP_SYMBOL (op)->rname, symname) ||
                  (OP_SYMBOL (op)->isspilt &&
                   SPIL_LOC (op) &&
                   !strcmp(SPIL_LOC (op)->rname, symname)) ))
              {
                return !op->isvolatile;
              }
            op = IC_RESULT (cl->ic);
            if (IS_SYMOP (op) &&
                ( !strcmp(OP_SYMBOL (op)->rname, symname) ||
                  (OP_SYMBOL (op)->isspilt &&
                   SPIL_LOC (op) &&
                   !strcmp(SPIL_LOC (op)->rname, symname)) ))
              {
                return !op->isvolatile;
              }
          }
      }
  }

  /* Couldn't find the symbol for some reason. Assume volatile if the current function touches anything volatile. */
  return global_not_volatile;
}

/*  notVolatile:
 *
 *  This rule restriction has two different behaviours depending on
 *  the number of parameters given.
 *
 *    if notVolatile                 (no parameters given)
 *       The rule is applied only if none of the iCodes originating
 *       the matched pattern reference a volatile operand.
 *
 *    if notVolatile %1 ...          (one or more parameters given)
 *       The rule is applied if the parameters are not expressions
 *       containing volatile symbols and are not pointer accesses.
 *
 */
FBYNAME (notVolatile)
{
  int varNumber;
  char *var;
  char *digitend;
  lineNode *cl;
  operand *op;

  if (!cmdLine)
    {
      /* If no parameters given, just scan the iCodes for volatile operands */
      for (cl = currPl; cl!=endPl->next; cl = cl->next)
      {
        if (cl->ic)
          {
            switch (cl->ic->op)
              {
              case IFX:
                op = IC_COND (cl->ic);
                if (IS_SYMOP (op) && op->isvolatile)
                  return FALSE;
              case JUMPTABLE:
                op = IC_JTCOND (cl->ic);
                if (IS_SYMOP (op) && op->isvolatile)
                  return FALSE;
              default:
                op = IC_LEFT (cl->ic);
                if (IS_SYMOP (op) && op->isvolatile)
                  return FALSE;
                op = IC_RIGHT (cl->ic);
                if (IS_SYMOP (op) && op->isvolatile)
                  return FALSE;
                op = IC_RESULT (cl->ic);
                if (IS_SYMOP (op) && op->isvolatile)
                  return FALSE;
              }
          }
      }
      return TRUE;
    }

  /* There were parameters; check the volatility of each */
  while (*cmdLine && ISCHARSPACE(*cmdLine))
    cmdLine++;
  while (*cmdLine)
    {
      if (*cmdLine!='%')
        goto error;
      cmdLine++;
      if (!ISCHARDIGIT(*cmdLine))
        goto error;
      varNumber = strtol(cmdLine, &digitend, 10);
      cmdLine = digitend;
      while (*cmdLine && ISCHARSPACE(*cmdLine))
        cmdLine++;

      var = hTabItemWithKey (vars, varNumber);

      if (var)
        {
          if (!notVolatileVariable (var, currPl, endPl))
            return false;
        }
      else
        {
          fprintf (stderr, "*** internal error: var %d not bound"
                   " in peephole notVolatile rule.\n",
                   varNumber);
          return FALSE;
        }
    }

  return TRUE;

error:
  fprintf (stderr,
           "*** internal error: notVolatile peephole restriction"
           " malformed: %s\n", cmdLine);
  return FALSE;
}

/*------------------------------------------------------------------*/
/* setFromConditionArgs - parse a peephole condition's arguments    */
/* to produce a set of strings, one per argument. Variables %x will */
/* be replaced with their values. String literals (in single quotes)*/
/* are accepted and return in unquoted form.                        */
/*------------------------------------------------------------------*/
static set *
setFromConditionArgs (char *cmdLine, hTab * vars)
{
  int varNumber;
  char *var;
  char *digitend;
  set *operands = NULL;

  if (!cmdLine)
    return NULL;

  while (*cmdLine && ISCHARSPACE(*cmdLine))
    cmdLine++;

  while (*cmdLine)
    {
      if (*cmdLine == '%')
        {
          cmdLine++;
          if (!ISCHARDIGIT(*cmdLine))
            goto error;
          varNumber = strtol(cmdLine, &digitend, 10);
          cmdLine = digitend;

          var = hTabItemWithKey (vars, varNumber);

          if (var)
            {
              addSetHead (&operands, var);
            }
          else
            goto error;
        }
      else if (*cmdLine == '\'' )
        {
          char quote = *cmdLine;

          var = ++cmdLine;
          while (*cmdLine && *cmdLine != quote)
            cmdLine++;
          if (*cmdLine == quote)
            *cmdLine++ = '\0';
          else
            goto error;
          addSetHead (&operands, var);
        }
      else
        goto error;

      while (*cmdLine && ISCHARSPACE(*cmdLine))
        cmdLine++;
    }

  return operands;

error:
  deleteSet (&operands);
  return NULL;
}

static const char *
operandBaseName (const char *op)
{
  if (TARGET_IS_MCS51 || TARGET_IS_DS390 || TARGET_IS_DS400)
    {
      if (!strncmp (op, "ar", 2) && ISCHARDIGIT(*(op+2)) && !*(op+3))
        return op+1;
      if (!strcmp (op, "ab"))
        return "ab";
      if (!strcmp (op, "acc") || !strncmp (op, "acc.", 4) || *op == 'a')
        return "a";
      // bug 1739475, temp fix
      if (op[0] == '@')
        return operandBaseName(op+1);
    }
  if (TARGET_Z80_LIKE)
    {
      if (!strcmp (op, "d") || !strcmp (op, "e") || !strcmp (op, "(de)"))
        return "de";
      if (!strcmp (op, "b") || !strcmp (op, "c") || !strcmp (op, "(bc)"))
        return "bc";
      if (!strcmp (op, "h") || !strcmp (op, "l") || !strcmp (op, "(hl)") || !strcmp (op, "(hl+)")  || !strcmp (op, "(hl-)"))
        return "hl";
      if (!strcmp (op, "iyh") || !strcmp (op, "iyl") || strstr (op, "iy"))
        return "iy";
      if (!strcmp (op, "ixh") || !strcmp (op, "ixl") || strstr (op, "ix"))
        return "ix";
      if (!strcmp (op, "a"))
        return "af";
    }

  return op;
}

/*------------------------------------------------------------------*/
/* optimizeFor - check optimization conditions                      */
/* valid parameters:                                                */
/*  code-size  -> checks for optimize.codeSize > 0                  */
/*  code-speed -> checks for optimize.codeSpeed > 0                 */
/*  add the ! symbol before each parameter to negate the condition  */
/* combinations with multiple parameters                            */
/*  '!code-speed' '!code-size': apply for balanced opt.             */
/*  '!code-size': apply for balanced and when optimizing for speed  */
/*  '!code-speed': apply unless optimizing for code speed           */
/*------------------------------------------------------------------*/
FBYNAME (optimizeFor)
{
  const char *cond;
  int speed = 0, size = 0; // 0: nothing requested, >0 optimization requested, <0 negated optimization requested
  
  bool ret = false, error = false;

  set *operands = setFromConditionArgs (cmdLine, vars);

  if (!operands)
  {
    fprintf (stderr,
             "*** internal error: optimizeFor peephole restriction"
             " requires operand(s): %s\n", cmdLine);
    return false;
  }

  // Loop through all conditions to check requested optimizations
  for (cond = setFirstItem (operands); !error && cond != NULL; cond = setNextItem (operands))
    {
      const char *condTextSpeed = strstr (cond, "code-speed");
      const char *condTextSize  = strstr (cond, "code-size");
      const char *condNegated = strstr (cond, "!");
      const char *condText = condTextSpeed ? condTextSpeed : condTextSize;
      
      // Check for invalid conditions or invalid combinations in the same string
      if (!condText || condTextSpeed && condTextSize || condNegated && (condNegated + 1 != condText))
        {
          error = true;
          break;
        }
      if (condTextSize)
        {
          if (size == 0)
            size = condNegated ? -1 : 1;
          else
            error = true;
        }
      else
        {
          if (speed == 0)
            speed = condNegated ? -1 : 1;
          else
            error = true;
        }
    }
  // check error, invalid combination of both speed and size or nothing
  if (error || (speed != -1) && (speed == size) )
    {
      fprintf (stderr,
             "*** internal error: optimizeFor peephole restriction"
             " malformed: %s\n", cmdLine);
      error = true;
    }
  else
    { // Check conditions and generate return value
      ret = true;
      if (speed != 0)
        ret &= (speed < 0) ^ (optimize.codeSpeed > 0);
        
      if (size != 0)
        ret &= (size < 0) ^ (optimize.codeSize > 0);
    }
    
  deleteSet(&operands);
  return (ret);
}

/*-----------------------------------------------------------------*/
/* notUsed - Check, if values in all registers are not read again  */
/*-----------------------------------------------------------------*/
FBYNAME (notUsed)
{
  const char *what;
  bool ret;

  if (!port->peep.notUsed)
    {
      fprintf (stderr, "Function notUsed not initialized in port structure\n");
      return FALSE;
    }

  set *operands = setFromConditionArgs (cmdLine, vars);

  if (!operands)
    {
      fprintf (stderr,
             "*** internal error: notUsed peephole restriction"
             " requires operand(s): %s\n", cmdLine);
      return FALSE;
    }

  what = setFirstItem (operands);
  for (ret = TRUE; ret && what != NULL; what = setNextItem (operands))
    ret = port->peep.notUsed (what, endPl, head);

  deleteSet(&operands);

  return (ret);
}

/*-----------------------------------------------------------------*/
/* notUsedFrom - Check, if values in registers are not read again  */
/*           starting from label                                   */
/*           Registers are checked from left to right              */
/*-----------------------------------------------------------------*/
FBYNAME (notUsedFrom)
{
  const char *what, *label;
  bool ret;
  
  if (!port->peep.notUsedFrom)
    {
      fprintf (stderr, "Function notUsedFrom not initialized in port structure\n");
      return false;
    }
  
  set *operands = setFromConditionArgs (cmdLine, vars);

  if (!operands)
  {
    fprintf (stderr,
             "*** internal error: notUsedFrom peephole restriction"
             " requires operand(s): %s\n", cmdLine);
    return false;
  }
  if (elementsInSet(operands) < 2)
  {
    fprintf (stderr,
             "*** internal error: notUsedFrom peephole restriction"
             " malformed: %s\n", cmdLine);
    deleteSet(&operands);
    return false;
  }

  operands = reverseSet(operands);

  label = setFirstItem (operands);
  what = setNextItem (operands);

  for (ret = true; ret && what; what = setNextItem (operands))
      ret = port->peep.notUsedFrom (what, label, head);
  
  deleteSet(&operands);

  return (ret);
}

/*-----------------------------------------------------------------*/
/* unusedReg - find first unused register from specified list and  */
/* assign to container specified as first argument. Fails if all   */
/* of specified registers are accessed for reading.                */
/*-----------------------------------------------------------------*/
FBYNAME (unusedReg)
{
  int dst;
  int n;
  if (sscanf (cmdLine, " %%%d%n", &dst, &n) != 1 || dst <= 0)
    {
      fprintf (stderr,
               "*** internal error: unusedReg peephole restriction"
               " malformed: %s\n", cmdLine);
      return FALSE;
    }

  set *operands = setFromConditionArgs (&cmdLine[n], vars);
  if (!operands || elementsInSet (operands) < 2 || elementsInSet (operands) > 3)
    {
      fprintf (stderr,
               "*** internal error: unusedReg peephole restriction"
               " malformed: %s\n", cmdLine);
      return FALSE;
    }

  char *what = setFirstItem (operands);
  for (; what != NULL; what = setNextItem (operands))
    if (port->peep.notUsed (what, endPl, head))
      break;

  bool ret = (what != NULL);
  if (ret)
    {
      char *s[] = {what, NULL};
      bindVar (dst, s, &vars);
    }

  deleteSet (&operands);

  return ret;
}

/*-----------------------------------------------------------------*/
/* canAssign - Check, if we can do ld dst, src.                    */
/*-----------------------------------------------------------------*/
FBYNAME (canAssign)
{
  set *operands;
  const char *dst, *src, *exotic;

  operands = setFromConditionArgs (cmdLine, vars);

  if (!operands || elementsInSet(operands) < 2 || elementsInSet(operands) > 3)
    {
      fprintf (stderr,
               "*** internal error: canAssign peephole restriction"
               " malformed: %s\n", cmdLine);
      return FALSE;
    }

  if(elementsInSet(operands) == 3)
    {
      exotic = setFirstItem (operands);
      src = setNextItem (operands);
      dst = setNextItem (operands);
    }
  else
    {
      exotic = 0;
      src = setFirstItem (operands);
      dst = setNextItem (operands);
    }

  if (port->peep.canAssign)
    {
      bool ret = port->peep.canAssign (dst, src, exotic);
      deleteSet (&operands);
      return (ret);
    }

  deleteSet (&operands);

  fprintf (stderr, "Function canAssign not initialized in port structure\n");
  return FALSE;
}

/*-----------------------------------------------------------------*/
/* canJoinRegs - joins set of registers to combined one, returns   */
/* true, if result register is valid. First operand can be         */
/* 'unordered' if order of registers is not sufficient. Last       */
/* operand should be wildcard. If result is not required, then     */
/* wildcard should be %0. If some of source registers is not       */
/* sufficient then empty string can be passed.                     */
/*-----------------------------------------------------------------*/
FBYNAME (canJoinRegs)
{
  // Must be specified at least 3 parameters: reg_hi reg_lo and dst
  // If destination is not required, then %0 should be specified
  if (!port->peep.canJoinRegs)
    {
      fprintf (stderr, "Function canJoinRegs not supported by the port\n");
      return FALSE;
    }

  int dstKey;
  int i;
  for (i = strlen (cmdLine)-1; i >= 0 && ISCHARSPACE (cmdLine[i]); --i)
    ;
  for (; i >= 0 && !ISCHARSPACE (cmdLine[i]); --i)
    ;
  if (i < 0 || cmdLine[i+1] != '%' || (cmdLine[i+1] && (sscanf (&cmdLine[i+2], "%d", &dstKey) != 1 || dstKey < 0)))
    {
      fprintf (stderr,
           "*** internal error: canJoinRegs peephole restriction"
           " has bad result container: %s\n", &cmdLine[i+1]);
      return FALSE;
    }
  //parse cmd line without last operand
  cmdLine[i] = '\0';
  set *operands = setFromConditionArgs (cmdLine, vars);
  cmdLine[i] = ' ';

  if (operands == NULL)
    {
      fprintf (stderr,
               "*** internal error: canJoinRegs peephole restriction"
               " malformed: %s\n", cmdLine);
      return FALSE;
    }

  bool unordered = false;
  const char *first = setFirstItem (operands);
  if (first && !strcmp (first, "unordered"))
    {
      unordered = true;
      deleteSetItem (&operands, (void*)first);
    }

  int size = elementsInSet (operands);
  if (size < 2)
    {
      fprintf (stderr,
               "*** internal error: canJoinRegs peephole restriction"
               " requires at least 3 operands: %s\n", cmdLine);
      return FALSE;
    }

  const char **regs = (const char**) Safe_alloc ( (size + 1) * sizeof (*regs));
  i = size;
  regs[size] = NULL; /* end of registers */
  //fill regs reversing order (operands have reversed order)
  for (set *it = operands; it; it = it->next)
    regs[--i] = (const char*)it->item;

  //if unordered specified, then sort elements by ascending order
  if (unordered)
    qsort (regs, size, sizeof (*regs), (int (*)(const void*,const void*))&strcmp);

  char dst[20];
  bool result;
  for (;;)
    {
      result = port->peep.canJoinRegs (regs, dst);
      if (result || !unordered)
        break;

      //do next registers permutation
      int i;
      //find last regs[i] < regs[i+1]
      for (i = size-2; i >= 0; --i)
        if (strcmp (regs[i+1], regs[i]) > 0)
          break;
      if (i < 0)
        break; /* was last permutation */

      int j;
      //find last regs[j] > regs[i], where j > i
      for (j = size-1; j > i; --j)
        if (strcmp (regs[j], regs[i]) > 0)
          break;

      //swap regs[j] and regs[i]
      const char *t = regs[i];
      regs[i] = regs[j];
      regs[j] = t;
      //reverse order from j+1 to end
      for (j = j+1, i = size - 1; j < i; ++j, --i)
        {
          t = regs[j];
          regs[j] = regs[i];
          regs[i] = t;
        }
    }

  Safe_free (regs);

  if (result && dstKey > 0)
    {
      char *s[] = { dst, NULL };
      bindVar (dstKey, s, &vars);
    }

  deleteSet (&operands);
  return result;
}

/*-----------------------------------------------------------------*/
/* canSplitReg - returns true, if register can be splitted. First  */
/* operand contains complex register name and is required. Other   */
/* operands should be wildcards. If result is not sufficient then  */
/* they can be omited.                                             */
/*-----------------------------------------------------------------*/
FBYNAME (canSplitReg)
{
  if (!port->peep.canSplitReg)
    {
      fprintf (stderr, "Function canSplitReg not supported by the port\n");
      return FALSE;
    }

  int i;
  //find start of first operand
  for (i = 0; cmdLine[i] && ISCHARSPACE (cmdLine[i]); ++i)
    ;
  if (cmdLine[i] == '\0')
    {
      fprintf (stderr,
               "*** internal error: canSplitReg peephole restriction"
               " malformed: %s\n", cmdLine);
      return FALSE;
    }

  //find end of first operand
  for (; cmdLine[i] && !ISCHARSPACE (cmdLine[i]); ++i)
    ;

  //parse first operand
  char t = cmdLine[i];
  cmdLine[i] = '\0';
  set *operands = setFromConditionArgs (cmdLine, vars);
  cmdLine[i] = t;
  if (cmdLine[i] == '\0')
    {
      fprintf (stderr,
               "*** internal error: canSplitReg peephole restriction"
               " malformed: %s\n", cmdLine);
      return FALSE;
    }

  //scan remaining operands
  int size = 2;
  int *varIds = (int*)Safe_alloc (size * sizeof(*varIds));
  const char *cl = &cmdLine[i+1];
  for (i = 0;; ++i)
    {
      if (i >= size)
        {
          size *= 2;
          varIds = (int*)Safe_realloc (varIds, size * sizeof(*varIds));
        }
      int len;
      if (sscanf (cl, " %%%d%n", &varIds[i], &len) != 1)
        break;
      if (varIds[i] < 0)
        {
          fprintf (stderr,
                   "*** internal error: canSplitReg peephole restriction"
                   " has invalid destination container: %s\n", cmdLine);
          return FALSE;
        }
      cl += len;
    }
  size = i;
  char (*dst)[16];
  dst = Safe_alloc (size * sizeof (*dst));
  bool ret = port->peep.canSplitReg ((char*)setFirstItem (operands), dst, size);
  for (i = 0; ret && i < size; ++i)
    {
      if (varIds[i] <= 0)
        continue;
      char *s[] = { dst[i], NULL };
      bindVar (varIds[i], s, &vars);
    }
  Safe_free (dst);
  Safe_free (varIds);
  deleteSet (&operands);
  return ret;
}

/*-----------------------------------------------------------------*/
/* operandsNotRelated - returns true if the condition's operands   */
/* are not related (taking into account register name aliases).    */
/* N-way comparison performed between all operands.                */
/*-----------------------------------------------------------------*/
FBYNAME (operandsNotRelated)
{
  set *operands;
  const char *op1, *op2;

  operands = setFromConditionArgs (cmdLine, vars);

  if (!operands)
    {
      fprintf (stderr,
               "*** internal error: operandsNotRelated peephole restriction"
               " malformed: %s\n", cmdLine);
      return FALSE;
    }

  bool ret = true;
  while ((op1 = setFirstItem (operands)))
    {
      deleteSetItem (&operands, (void*)op1);
      op1 = operandBaseName (op1);

      for (op2 = setFirstItem (operands); op2; op2 = setNextItem (operands))
        {
          if ((strchr(op1, '(') || strchr(op1, '[')) && (strchr(op2, '(') || strchr(op2, '['))) // Might be the same or overlapping memory locations; err on the safe side.
            {
              ret = false;
              goto done;
            }

          op2 = operandBaseName (op2);
          if (strcmp (op1, op2) == 0)
            {
              ret = false;
              goto done;
            }

          if (TARGET_IS_MCS51 || TARGET_IS_DS390 || TARGET_IS_DS400)
            {
              /* handle overlapping 'dptr' vs. { 'dpl', 'dph' }  */
              if (!strcmp (op1, "dptr") && (!strcmp (op2, "dpl") || !strcmp (op2, "dph")) ||
                !strcmp (op2, "dptr") && (!strcmp (op1, "dpl") || !strcmp (op1, "dph")) || 
                !strcmp (op1, "ab") && (!strcmp (op2, "a") || !strcmp (op2, "b")) ||
                !strcmp (op2, "ab") && (!strcmp (op1, "a") || !strcmp (op1, "b")))
                  {
                    ret = false;
                    goto done;
                  }
            }
        }
    }

done:
  deleteSet (&operands);
  return ret;
}

/*-----------------------------------------------------------------*/
/* notSimilar - Check, if one is another's substring               */
/*-----------------------------------------------------------------*/
FBYNAME (notSimilar)
{
  set *operands;
  const char *op1, *op2;

  operands = setFromConditionArgs (cmdLine, vars);

  if (!operands)
    {
      fprintf (stderr,
               "*** internal error: notSimilar peephole restriction"
               " malformed: %s\n", cmdLine);
      return FALSE;
    }

  while ((op1 = setFirstItem (operands)))
    {
      deleteSetItem (&operands, (void*)op1);

      for (op2 = setFirstItem (operands); op2; op2 = setNextItem (operands))
        {
          if (strstr (op1, op2) || strstr (op2, op1))
            {
              deleteSet (&operands);
              return FALSE;
            }
        }
    }

  deleteSet (&operands);
  return TRUE;
}

/*-----------------------------------------------------------------*/
/* symmParmStack - Caller readjusts stack by the number of bytes
   that were pushed in all calls to this function                  */
/*-----------------------------------------------------------------*/
FBYNAME (symmParmStack)
{
  set *operands = setFromConditionArgs (cmdLine, vars);

  if (!operands)
  {
    fprintf (stderr,
             "*** internal error: symmParmStack peephole restriction"
             " requires operand: %s\n", cmdLine);
    return FALSE;
  }

  const char *name = setFirstItem (operands);

  bool ret = false;

  if (port->peep.symmParmStack)
    return port->peep.symmParmStack (name);
  deleteSet(&operands);

  return ret;
}

/*-----------------------------------------------------------------*/
/* notSame - Check, that arguments are pairwise not the same       */
/*-----------------------------------------------------------------*/
FBYNAME (notSame)
{
  set *operands;
  const char *op1, *op2;

  operands = setFromConditionArgs (cmdLine, vars);

  if (!operands)
    {
      fprintf (stderr,
               "*** internal error: notSame peephole restriction"
               " malformed: %s\n", cmdLine);
      return FALSE;
    }

  while ((op1 = setFirstItem (operands)))
    {
      deleteSetItem (&operands, (void*)op1);

      for (op2 = setFirstItem (operands); op2; op2 = setNextItem (operands))
        {
          if (strcmp (op1, op2) == 0)
            {
              deleteSet (&operands);
              return FALSE;
            }
        }
    }

  deleteSet (&operands);
  return TRUE;
}

/*-----------------------------------------------------------------*/
/* same - Check if first operand matches any of the remaining      */
/*-----------------------------------------------------------------*/
FBYNAME (same)
{
    set *operands;
    const char *match, *op;

    operands = setFromConditionArgs(cmdLine, vars);

    if (!operands)
    {
        fprintf(stderr,
            "*** internal error: same peephole restriction"
            " malformed: %s\n", cmdLine);
        return FALSE;
    }

    operands = reverseSet(operands);

    match = setFirstItem(operands);
    for (op = setNextItem(operands); op; op = setNextItem(operands))
    {
        if (strcmp(match, op) == 0)
        {
            deleteSet(&operands);
            return TRUE;
        }
    }

    deleteSet(&operands);
    return FALSE;
}

/*-----------------------------------------------------------------*/
/* strIsSymbol - returns true if the parameter is a symbol         */
/* That is: an underscore followed by one or more chars            */
/*-----------------------------------------------------------------*/
static bool
strIsSymbol(const char *str)
{
  return *str == '_' && str[1] != '\0';
}

/*-----------------------------------------------------------------*/
/* strIsLiteral - returns true if the parameter is a literal       */
/* Checks these formats: binary, octal, decimal, hexadecimal       */
/* Skips preceding signs.                                          */
/*-----------------------------------------------------------------*/
static bool
strIsLiteral(const char *str)
{
  const char digits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'}; 
  unsigned char base = 10;
  unsigned char validDigits = 0;
  
  // has to start with a number or a sign
  if(!isdigit( (unsigned char)(*str) ) && (*str) != '-' && (*str) != '+')
    return false;
  // skip sign
  if ((*str) == '-' || (*str) == '+')
    str++;

  // handle 0b 0o 0d 0x
  if((*str) == '0')
    {
      const char nextChar = tolower((unsigned char)(str[1]));
      validDigits = 0;
      if (nextChar == 'b')
        {
          base = 2;
          ++str;
        }
      else if(nextChar == 'o')
        {
          base = 8;
          ++str;
        }
      else if(nextChar == 'd')
        {
          base = 10;
          ++str;
        }
      else if(nextChar == 'x')
        {
          base = 16;
          ++str;
        }
      else
        validDigits = 1; // the first '0' is a valid digit
      
      ++str;
    }
  
  while((unsigned char)(*str) != '\0'){
    unsigned char i;
    for(i = 0; i < base; ++i){
      if(tolower((unsigned char)(*str)) == digits[i])
        break;
    }
    // number was too big or not valid
    if(i >= base)
      return false;
    ++validDigits;
    ++str;
  }
  return validDigits > 0;
}

/*-----------------------------------------------------------------*/
/* operandsLiteral - returns true if the condition's operands are  */
/* literals.                                                       */
/*-----------------------------------------------------------------*/
FBYNAME (operandsLiteral)
{
  set *operands = setFromConditionArgs (cmdLine, vars);
  const char *op;

  if (!operands)
    {
      fprintf (stderr,
               "*** internal error: operandsLiteral peephole restriction"
               " malformed: %s\n", cmdLine);
      return FALSE;
    }

  for (op = setFirstItem (operands); op; op = setNextItem (operands))
    {
      if (!strIsLiteral(op))
        {
          deleteSet (&operands);
          return false;
        }
    }

  deleteSet (&operands);
  return true;
}

/*-----------------------------------------------------------------*/
/* strIsLiteralOrSymbol - returns true if the parameter is a       */
/* literal or compiler symbol                                      */
/*-----------------------------------------------------------------*/
static bool
strIsLiteralOrSymbol(const char *str)
{
  return strIsSymbol(str) || strIsLiteral(str);
}

/*-----------------------------------------------------------------*/
/* operandsLitOrSym - returns true if the condition's operands are */
/* literals or compiler symbols.                                   */
/*-----------------------------------------------------------------*/
FBYNAME (operandsLitOrSym)
{
  set *operands;
  const char *op;

  operands = setFromConditionArgs (cmdLine, vars);

  if (!operands)
    {
      fprintf (stderr,
               "*** internal error: operandsLitOrSym peephole restriction"
               " malformed: %s\n", cmdLine);
      return false;
    }

  for (op = setFirstItem (operands); op; op = setNextItem (operands))
    {
      if (!strIsLiteralOrSymbol(op))
        {
          deleteSet (&operands);
          return false;
        }
    }

  deleteSet (&operands);
  return true;
}

/*-----------------------------------------------------------------*/
/* removeParentheses                                               */
/* First operand: parameter to be parsed                           */
/* Second operand: result of conversion                            */
/* The function removes the input parameter parentheses if present,*/
/* else it copies the input directly to the output.                */
/* returns true if the input has not parentheses.                  */
/* returns true if it has parametheses at first and last chars     */
/*              and there was no other error                       */
/*-----------------------------------------------------------------*/
FBYNAME (removeParentheses)
{
  int dstKey;
  int i;
  
  // Find space previous to last operand
  for (i = strlen (cmdLine)-1; i >= 0 && ISCHARSPACE (cmdLine[i]); --i)
    ;
  for (; i >= 0 && !ISCHARSPACE (cmdLine[i]); --i)
    ;
  if (i < 0 || cmdLine[i+1] != '%' || (cmdLine[i+1] && (sscanf (&cmdLine[i+2], "%d", &dstKey) != 1 || dstKey < 0)))
    {
      fprintf (stderr,
           "*** internal error: removeParentheses peephole restriction"
           " has bad result container: %s\n", &cmdLine[i+1]);
      return false;
    }
  //Parse cmd line without last operand
  cmdLine[i] = '\0';
  set *operands = setFromConditionArgs (cmdLine, vars);
  cmdLine[i] = ' '; // Restore space
    
  if (!operands || elementsInSet(operands) > 1)
    {
      fprintf (stderr,
               "*** internal error: removeParentheses peephole restriction"
               " malformed: %s\n", cmdLine);
      return false;
    }
  
  // Parse the operand and remove the parenthesis
  char r[128];  
  const char *op = setFirstItem (operands);
  
  if (*op == '(')
  {
    if(op[strlen(op)-1] == ')')
      op++; // Skip start parenthesis
    else
      {
        // Abort if no matching closing parenthesis
        deleteSet (&operands);
        return false;
      }
  }
  if (strlen(op) > 127) // Abort if string does not fit in buffer
    {
      deleteSet (&operands);
      return false;
    }
  
  // Do the copy and skip ending parenthesis
  i = 0;
  while (*op)
  {
    if (*op != ')')
      {
        r[i++] = *op++;
      }
    else
      {
        op++;
        break;
      }
  }
  r[i] = '\0';
  
  // Abort if remaining chars in source or no chars copied into result string
  if ((*op) || (i == 0))
    {
      deleteSet (&operands);
      return false;
    }
     
  char *p[] = {r, NULL};  
  bindVar (dstKey, p, &vars);

  deleteSet (&operands);
  return true;
}

static long *
immdGet (const char *pc, long *pl)
{
  long s = 1;

  if (!pc || !pl)
    return NULL;

  // omit space
  for (; ISCHARSPACE (*pc); pc++);
  // parse sign
  for (; !ISCHARDIGIT (*pc); pc++)
    if (*pc == '-')
      s *= -1;
  else if (*pc == '+')
      s *= +1;
  else
    return NULL;

  if (pc[0] == '0' && (pc[1] == 'x' || pc[1] == 'X'))
    {
      if (sscanf (pc + 2, "%lx", pl) != 1)
        return NULL;
    }
  else
    {
      if (sscanf (pc, "%ld", pl) != 1)
        return NULL;
    }

  *pl *= s;
  return pl;
}

static bool
immdError (const char *info, const char *param, const char *cmd)
{
  fprintf (stderr, "*** internal error: immdInRange gets "
           "%s: \"%s\" in \"%s\"\n", info, param, cmd);
  return FALSE;
}

/*-----------------------------------------------------------------*/
/* isPowerOfTwo - true if n is a power of 2                        */
/*-----------------------------------------------------------------*/
static bool
isPowerOfTwo(unsigned long n)
{  
  return (n != 0) && ((n & (n - 1)) == 0);
}  

/*-----------------------------------------------------------------*/
/* findBitPosition - Returns the bit position set or cleared in n  */
/* Parameters:                                                     */
/*  n: value to be tested.                                         */
/*  bits: number of positions to test.                             */
/*  complement: when true, the number must be bitwise complemented */
/* Returns:                                                        */
/*  -2 if bits is out of valid range (1..32)                       */
/*  -1 if n has more than one bit set or cleared                   */
/*  -1 if n has bits in positions over the bits param              */
/*  bit position (starting at 0) when only 1 bit set or clear      */
/* Examples:                                                       */
/*  n=0x02, bits=8, complemented=false -> 1                        */
/*  n=0x7F, bits=8, complemented=true  -> 7                        */
/*-----------------------------------------------------------------*/
static int
findBitPosition(unsigned long n, unsigned long bits, bool complement)
{
  unsigned long mask;
  int bitPos;
  
  if ((bits < 1) || (bits > 32)) //bits out of range?
    return -2;
  mask = (1ULL << bits) -1;
  if (n != (n & mask)) // bits outside mask?
    return -1;
  
  if (complement)
    n = (~n) & mask;
  if (!isPowerOfTwo (n)) // Not valid if more than one bit is set
    return -1;
  
  bitPos = -1;
  // One by one move the only set bit to right till it reaches end  
  while (n)
    {  
      n >>= 1;
      bitPos++; //count number of shifts
    }
  
  return bitPos;
}

/*-----------------------------------------------------------------*/
/* swapOperation - Calculates a swap operation with given params   */
/* Parameters:                                                     */
/*  n: value to be swapped.                                        */
/*  bits: length of value to be swapped, in bits.                  */
/* Returns 0 if no error:                                          */
/*  -2 if bits is out of valid range: even numbers (2..32)         */
/*  -1 if n has bits in positions over the bits param              */
/*-----------------------------------------------------------------*/
static int
swapOperation (unsigned long n, unsigned long bits, unsigned long * result)
{
  unsigned long mask = (1ULL << bits) -1;
  unsigned int shift = bits / 2;
  
  if ((bits < 1) || (bits > 32) || (bits & 0x01)) // bits out of range or odd
    return -2;
  if (n != (n & mask)) // bits outside mask?
    return -1;
  
  *result = (((n << shift) | (n >> shift)) & mask);
  return 0; // no error.
}

/*-----------------------------------------------------------------*/ 
/* stringMatchesOperator - returns true if 'str' matches 'op'      */
/* 'str' matches 'op' if they contain the same string              */
/* 'str' also matches if surrounded by quotes or double quotes     */
/*-----------------------------------------------------------------*/
static bool 
stringMatchesOperator (const char * str, const char *op)
{
  if (str && op)
    {
      if (strcmp(str, op) == 0)
        {
          return true;
        }
      else
        {
          size_t length = strlen(str);
          // Check if quotes are present and they are the same at start and end.
          if ((length >= 2) && ((str[0] == '\'') || (str[0] == '\"')) && (str[0] == str[length-1]))
            return strncmp(&str[1], op, length-2) == 0;
        }
    }
  return false;
}
/*-----------------------------------------------------------------*/ 
/* immdInRange - returns true if the result of a given operation   */
/* of two immediates is in a give range.                           */
/*-----------------------------------------------------------------*/
FBYNAME (immdInRange)
{
  char r[64], operator[24];
  const char *op;
  long i, j, k, h, low, high, left_l, right_l, order;

  for (i = order = 0; order < 6;)
    {
      // pick up one parameter in the temp buffer r[64]
      for (; ISCHARSPACE (cmdLine[i]) && cmdLine[i]; i++);
      for (j = i; !ISCHARSPACE (cmdLine[j]) && cmdLine[j]; j++);
      if (!cmdLine[i]) // unexpected end
        return immdError ("no enough input", "", cmdLine);
      else if(j >= 64)
        return immdError ("buffer overflow", "", cmdLine);
      else
        {
          for (k = i; k < j; k++)
            r[k - i] = cmdLine[k];
          r[j - i] = 0;
        }
      // parse the string by order
      switch (order)
        {
          case 0: // lower bound
            if (!immdGet (r, &low))
              return immdError ("bad lower bound", r, cmdLine);
            break;
          case 1: // upper bound
            if (!immdGet (r, &high))
              return immdError ("bad upper bound", r, cmdLine);
            break;
          case 2: // operator
            if (sscanf (r, "%23s", operator) != 1)
              return immdError ("bad operator", r, cmdLine);
            break;
          case 3: // left operand
            if (immdGet (r, &left_l)) // the left operand is given directly
              {
              }
            else if (r[0] == '%') // the left operand is passed via pattern match
              {
                if (!immdGet (r + 1, &k) || !(op = hTabItemWithKey (vars, (int) k)))
                  return immdError ("bad left operand", r, cmdLine);
                else if (!immdGet (op, &left_l))
                  return FALSE;
              }
            else
              return immdError ("bad left operand", r, cmdLine);
            break;
          case 4: // right operand
            if (immdGet (r, &right_l)) // the right operand is given directly
              {
              }
            else if (r[0] == '%') // the right operand is passed via pattern match
              {
                if (!immdGet (r + 1, &k) || !(op = hTabItemWithKey (vars, (int) k)))
                  return immdError ("bad right operand", r, cmdLine);
                else if (!immdGet (op, &right_l))
                  return immdError ("bad right operand", op, r);
              }
            else
              return immdError ("bad right operand", r, cmdLine);
            break;
          case 5: // result
            if (r[0] != '%' || !(immdGet (r + 1, &h) || (r[1] == 'x' && immdGet (r + 2, &h))))
              return immdError ("bad result container", r, cmdLine);
            break;
          default: // should not reach
            return immdError ("unexpected input", "", cmdLine);
            break;
        }
      order++;
      i = j;
    }

  // calculate
  if (stringMatchesOperator (operator, "+")) // add
    {
      i = left_l + right_l;
    }
  else if (stringMatchesOperator (operator, "-")) // sub
    {
      i = left_l - right_l;
    }
  else if (stringMatchesOperator (operator, "*")) // mul
    {
      i = left_l * right_l;
    }
  else if (stringMatchesOperator (operator, "/")) // div
    {
      if (right_l == 0)
        return immdError ("division by zero", "", cmdLine);
      i = left_l / right_l;
    }
  else if (stringMatchesOperator (operator, "%")) // mod
    {
      if (right_l == 0)
        return immdError ("division by zero", "", cmdLine);
      i = left_l % right_l;
    }
  else if (stringMatchesOperator (operator, "&")) // and
    {
      i = left_l & right_l;
    }
  else if (stringMatchesOperator (operator, "^")) // xor
    {
      i = left_l ^ right_l;
    }
  else if (stringMatchesOperator (operator, "|")) // or
    {
      i = left_l | right_l;
    }
  else if (stringMatchesOperator (operator, "singleSetBit") || stringMatchesOperator (operator, "singleResetBit")) // singleSetBit - singleResetBit
    {
      i = findBitPosition(left_l, right_l, stringMatchesOperator (operator, "singleResetBit"));
      if(i < -1 )
        return immdError ("bad right operand", operator, cmdLine);
      if(i < 0)
        return false;
    }
  else if (stringMatchesOperator (operator, "swap")) // swap
    {
      if (swapOperation(left_l, right_l, (unsigned long *)&i) != 0)
        return immdError ("bad right operand", operator, cmdLine);
    }
  else
    return immdError ("bad operator", operator, cmdLine);

  // bind the result
  if ((low <= i && i <= high) || (high <= i && i <= low))
    {
      bool hex = false;
      if(r[1] == 'x'){
        hex = true;
        r[1] = '0';
      }
      char *p[] = {r, NULL};
      if(!hex)
        sprintf (r, "%ld", i);
      else
        sprintf (r, "0x%lx", i);
      bindVar ((int) h, p, &vars);
      return TRUE;
    }
  else
    {
      return FALSE;
    }
}

/*-----------------------------------------------------------------*/
/* inSequence - Check that numerical constants are in sequence     */
/*-----------------------------------------------------------------*/
FBYNAME (inSequence)
{
  set *operands;
  const char *op;
  long seq, val, stride;

  if ((operands = setFromConditionArgs(cmdLine, vars)) == NULL)
    {
      fprintf (stderr,
               "*** internal error: inSequence peephole restriction"
               " malformed: %s\n", cmdLine);
      return FALSE;
    }

  operands = reverseSet(operands);

  op = setFirstItem(operands);
  if ((immdGet(op, &stride) == NULL) || ((op = setNextItem(operands)) == NULL))
    {
      fprintf (stderr,
               "*** internal error: inSequence peephole restriction"
               " malformed: %s\n", cmdLine);
      return FALSE;
    }

  for (seq = LONG_MIN; op; op = setNextItem(operands))
    {
      if ((immdGet(op, &val) == NULL) || ((seq != LONG_MIN) && (val != seq+stride)))
        {
          deleteSet(&operands);
          return FALSE;
        }
      seq = val;
    }

  deleteSet(&operands);
  return TRUE;
}

/*-----------------------------------------------------------------*/
/* isPort - return true if port name matches one of args           */
/*-----------------------------------------------------------------*/
FBYNAME (isPort)
{
  const char *name;
  bool ret = false;

  set *operands = setFromConditionArgs(cmdLine, vars);

  if (!operands)
    {
      fprintf(stderr,
        "*** internal error: isPort peephole restriction"
        " malformed: %s\n", cmdLine);
      return false;
    }

  while (name = setFirstItem(operands))
    {
      deleteSetItem(&operands, (void *)name);

      if (strcmp(port->target, name) == 0)
        {
          ret = true;
          break;
        }
    }

  deleteSet(&operands);

  return ret;
}

/*-----------------------------------------------------------------*/
/* notInJumpTable - check that we are not in a jump table          */
/*-----------------------------------------------------------------*/
FBYNAME (notInJumpTable)
{
  return (currPl->ic && currPl->ic->op != JUMPTABLE);
}

static const struct ftab
{
  char *fname;
  int (*func) (hTab *, lineNode *, lineNode *, lineNode *, char *);
}
ftab[] =                                            // sorted on the number of times used
{                                                   // in the peephole rules on 2010-06-12
  {
    "labelRefCount", labelRefCount                  // 161
  },
  {
    "notVolatile", notVolatile                      // 118
  },
  {
    "notUsed", notUsed                              // 96
  },
  {
    "labelRefCountChange", labelRefCountChange      // 86
  },
  {
    "labelInRange", labelInRange                    // 51
  },
  {
    "notSame", notSame                              // 28
  },
  {
    "operandsNotRelated", operandsNotRelated        // 28
  },
  {
    "same", same                                    // z88dk z80
  },
  {
    "labelJTInRange", labelJTInRange                // 13
  },
  {
    "24bitMode", flat24bitMode                      // 9
  },
  {
    "canAssign", canAssign                          // 8
  },
  {
    "inSequence", inSequence                        // z88dk z80
  },
  {
    "optimizeFor", optimizeFor
  },
  {
    "optimizeReturn", optimizeReturn                // ? just a guess
  },
  {
    "notUsedFrom", notUsedFrom                      // ? just a guess
  },
  {
    "labelIsReturnOnly", labelIsReturnOnly          // 6
  },
  {
    "operandsLiteral", operandsLiteral              // 6
  },
  {
    "operandsLitOrSym", operandsLitOrSym
  },
  {
    "removeParentheses", removeParentheses
  },
  {
    "labelIsUncondJump", labelIsUncondJump          // 4
  },
  {
    "deadMove", deadMove                            // 2
  },
  {
    "useAcallAjmp", useAcallAjmp                    // 2
  },
  {
    "xramMovcOption", xramMovcOption                // 2
  },
  {
    "okToRemoveSLOC", okToRemoveSLOC                // 0
  },
  {
    "immdInRange", immdInRange
  },
  {
    "notSimilar", notSimilar
  },
  {
    "symmParmStack", symmParmStack
  },
  {
    "isPort", isPort
  },
  {
    "canJoinRegs", canJoinRegs
  },
  {
    "canSplitReg", canSplitReg
  },
  {
    "unusedReg", unusedReg
  },
  {
    "newLabel", newLabel
  },
  {
    "notInJumpTable", notInJumpTable
  },
};

/*-----------------------------------------------------------------*/
/* callFuncByName - calls a function as defined in the table       */
/*-----------------------------------------------------------------*/
static int
callFuncByName (char *fname,
                hTab *vars,
                lineNode *currPl, /* first source line matched */
                lineNode *endPl,  /* last source line matched */
                lineNode *head)
{
  int   i;
  char  *cmdCopy, *funcName, *funcArgs, *cmdTerm;
  char  c;
  int   rc;

  /* Isolate the function name part (we are passed the full condition
   * string including arguments)
   */
  cmdTerm = cmdCopy = Safe_strdup(fname);

  do
    {
      funcArgs = funcName = cmdTerm;
      while ((c = *funcArgs) && c != ' ' && c != '\t' && c != '(')
        funcArgs++;
      *funcArgs = '\0';  /* terminate the function name */
      if (c)
        funcArgs++;

      /* Find the start of the arguments */
      if (c == ' ' || c == '\t')
        while ((c = *funcArgs) && (c == ' ' || c == '\t'))
          funcArgs++;

      /* If the arguments started with an opening parenthesis,  */
      /* use the closing parenthesis for the end of the         */
      /* arguments and look for the start of another condition  */
      /* that can optionally follow. If there was no opening    */
      /* parethesis, then everything that follows are arguments */
      /* and there can be no additional conditions.             */
      if (c == '(')
        {

          int num_parenthesis = 0;
          cmdTerm = funcArgs;          

          while ((c = *cmdTerm) && (c != ')' || num_parenthesis))
            {
              if (c == '(')
                num_parenthesis++;
              else if (c == ')')
                num_parenthesis--;
              cmdTerm++;
            }
          *cmdTerm = '\0';  /* terminate the arguments */
          if (c == ')')
            {
              cmdTerm++;
              while ((c = *cmdTerm) && (c == ' ' || c == '\t' || c == ','))
                cmdTerm++;
              if (!*cmdTerm)
                cmdTerm = NULL;
            }
          else
            cmdTerm = NULL; /* closing parenthesis missing */
        }
      else
        cmdTerm = NULL;

      if (!*funcArgs)
        funcArgs = NULL;

      rc = -1;
      for (i = 0; i < ((sizeof (ftab)) / (sizeof (struct ftab))); i++)
        {
          if (strcmp (ftab[i].fname, funcName) == 0)
            {
              rc = (*ftab[i].func) (vars, currPl, endPl, head, funcArgs);
              break;
            }
        }

      if (rc == -1)
        {
          fprintf (stderr,
                   "could not find named function \"%s\" in "
                   "peephole function table\n",
                   funcName);
          // If the function couldn't be found, let's assume it's
          // a bad rule and refuse it.
          rc = FALSE;
          break;
        }
    }
  while (rc && cmdTerm);

  Safe_free(cmdCopy);

  return rc;
}

/*-----------------------------------------------------------------*/
/* newPeepRule - creates a new peeprule and attach it to the root  */
/*-----------------------------------------------------------------*/
static peepRule *
newPeepRule (lineNode * match,
             lineNode * replace,
             char *cond,
             int restart,
             int barrier)
{
  peepRule *pr;

  pr = Safe_alloc ( sizeof (peepRule));
  pr->match = match;
  pr->replace = replace;
  pr->restart = restart;
  pr->barrier = barrier;

  if (cond && *cond)
    {
      pr->cond = Safe_strdup (cond);
    }
  else
    pr->cond = NULL;

  pr->vars = newHashTable (16);

  /* if root is empty */
  if (!rootRules)
    rootRules = currRule = pr;
  else
    currRule = currRule->next = pr;

  return pr;
}

#define SKIP_SPACE(x,y) { while (*x && (ISCHARSPACE(*x) || *x == '\n')) x++; \
                         if (!*x) { fprintf(stderr,y); return ; } }

#define EXPECT_STR(x,y,z) { while (*x && strncmp(x,y,strlen(y))) x++ ;   \
                           if (!*x) { fprintf(stderr,z); return ; } }
#define EXPECT_CHR(x,y,z) { while (*x && *x != y) x++ ;   \
                           if (!*x) { fprintf(stderr,z); return ; } }

/*-----------------------------------------------------------------*/
/* getPeepLine - parses the peep lines                             */
/*-----------------------------------------------------------------*/
static void
getPeepLine (lineNode ** head, const char **bpp)
{
  char lines[MAX_PATTERN_LEN];
  char *lp;
  int isComment;

  lineNode *currL = NULL;
  const char *bp = *bpp;
  while (1)
    {

      if (!*bp)
        {
          fprintf (stderr, "unexpected end of match pattern\n");
          return;
        }

      if (*bp == '\n')
        {
          bp++;
          while (ISCHARSPACE (*bp) ||
                 *bp == '\n')
            bp++;
        }

      if (*bp == '}')
        {
          bp++;
          break;
        }

      /* read till end of line */
      lp = lines;
      while ((*bp != '\n' && *bp != '}') && *bp)
        *lp++ = *bp++;
      *lp = '\0';

      lp = lines;
      while (*lp && ISCHARSPACE(*lp))
        lp++;
      isComment = (*lp == ';');

      if (!isComment || (isComment && !options.noPeepComments))
        {
          const char *dummy1;
          int dummy2;

          if (!currL)
            *head = currL = newLineNode (lines);
          else
            currL = connectLine (currL, newLineNode (lines));
          currL->isComment = isComment;
          currL->isLabel = isLabelDefinition (currL->line, &dummy1, &dummy2,
                                              TRUE);
        }

    }

  *bpp = bp;
}

/*-----------------------------------------------------------------*/
/* readRules - reads the rules from a string buffer                */
/*-----------------------------------------------------------------*/
static void
readRules (const char *bp)
{
  char restart = 0, barrier = 0;
  char lines[MAX_PATTERN_LEN];
  size_t safetycounter;
  char *lp;
  const char *rp;
  lineNode *match;
  lineNode *replace;
  lineNode *currL = NULL;

  if (!bp)
    return;
top:
  restart = 0;
  barrier = 0;

  /* look for the token "replace" that is the
     start of a rule */
  while (*bp && strncmp (bp, "replace", 7))
    {
      if (!strncmp (bp, "barrier", 7))
        barrier = 1;
      bp++;
    }

  /* if not found */
  if (!*bp)
    return;

  /* then look for either "restart" or '{' */
  while (strncmp (bp, "restart", 7) && *bp != '{' && bp)
    bp++;

  /* not found */
  if (!*bp)
    {
      fprintf (stderr, "expected 'restart' or '{'\n");
      return;
    }

  /* if brace */
  if (*bp == '{')
    bp++;
  else
    {                           /* must be restart */
      restart++;
      bp += strlen ("restart");
      /* look for '{' */
      EXPECT_CHR (bp, '{', "expected '{'\n");
      bp++;
    }

  /* skip thru all the blank space */
  SKIP_SPACE (bp, "unexpected end of rule\n");

  match = replace = currL = NULL;
  /* we are the start of a rule */
  getPeepLine (&match, &bp);

  /* now look for by */
  EXPECT_STR (bp, "by", "expected 'by'\n");

  /* then look for a '{' */
  EXPECT_CHR (bp, '{', "expected '{'\n");
  bp++;

  /* save char position (needed for generating error msg) */
  rp = bp;

  SKIP_SPACE (bp, "unexpected end of rule\n");
  getPeepLine (&replace, &bp);

  /* look for a 'if' */
  while ((ISCHARSPACE (*bp) || *bp == '\n' || (*bp == '/' && *(bp+1) == '/')) && *bp)
    {
      ++bp;
      if (*bp == '/') while (*bp && *bp != '\n') ++bp;
    }

  if (strncmp (bp, "if", 2) == 0)
    {
      bp += 2;
      while ((ISCHARSPACE (*bp) || *bp == '\n' || (*bp == '/' && *(bp+1) == '/')) && *bp)
      {
        bp++;
        if (*bp == '/')
          while (*bp && *bp != '\n')
            bp++;
      }
      if (!*bp)
        {
          fprintf (stderr, "expected condition name\n");
          return;
        }

      /* look for the condition */
      lp = lines;
      for (safetycounter = 0; *bp && (*bp != '\n'); safetycounter++)
        {
          wassertl(safetycounter < MAX_PATTERN_LEN, "Peephole line too long.\n");
          *lp++ = *bp++;
        }
      *lp = '\0';

      newPeepRule (match, replace, lines, restart, barrier);
    }
  else
    {
      if (*bp && strncmp (bp, "replace", 7) && strncmp (bp, "barrier", 7))
        {
          /* not the start of a new peeprule, so "if" should be here */

          char strbuff[1000];
          char *cp;

          /* go to the start of the line following "{" of the "by" token */
          while (*rp && (*rp == '\n'))
            rp++;

          /* copy text of rule starting with line after "by {" */
          cp = strbuff;
          while (*rp && (rp < bp) && ((cp - strbuff) < sizeof(strbuff)))
              *cp++ = *rp++;

          /* and now the rest of the line */
          while (*rp && (*rp != '\n') && ((cp - strbuff) < sizeof(strbuff)))
            *cp++ = *rp++;

          *cp = '\0';
          fprintf (stderr, "%s\nexpected '} if ...'\n", strbuff);
          return;
        }
      newPeepRule (match, replace, NULL, restart, barrier);
    }
  goto top;

}

/*-----------------------------------------------------------------*/
/* keyForVar - returns the numeric key for a var                   */
/*-----------------------------------------------------------------*/
static int
keyForVar (const char *d)
{
  int i = 0;

  while (ISCHARDIGIT (*d))
    {
      i *= 10;
      i += (*d++ - '0');
    }

  return i;
}

/*-----------------------------------------------------------------*/
/* bindVar - binds a value to a variable in the given hashtable    */
/*-----------------------------------------------------------------*/
static void
bindVar (int key, char **s, hTab ** vtab)
{
  char vval[MAX_PATTERN_LEN];
  char *vvx;
  char *vv = vval;

  /* first get the value of the variable */
  vvx = *s;
  /* the value is ended by a ',' or space or newline or null or ) */
  while (*vvx &&
         *vvx != ',' &&
         !ISCHARSPACE (*vvx) &&
         *vvx != '\n' &&
         *vvx != ':' &&
         *vvx != ';' &&
         *vvx != ')')
    {
      char ubb = 0;
      /* if we find a '(' then we need to balance it */
      if (*vvx == '(')
        {
          ubb++;
          while (ubb)
            {
              *vv++ = *vvx++;
              if (*vvx == '(')
                ubb++;
              if (*vvx == ')')
                ubb--;
            }
          // include the trailing ')'
          *vv++ = *vvx++;
        }
      else
        *vv++ = *vvx++;
    }
  *s = vvx;
  *vv = '\0';
  /* got value */
  vvx = traceAlloc (&_G.values, Safe_strdup(vval));

  hTabAddItem (vtab, key, vvx);
}

/*-----------------------------------------------------------------*/
/* matchLine - matches one line                                    */
/*-----------------------------------------------------------------*/
static bool
matchLine (char *s, const char *d, hTab ** vars)
{
  if (!s || !(*s))
    return FALSE;

  /* skip leading white spaces */
  while (ISCHARSPACE (*s))
    s++;
  while (ISCHARSPACE (*d))
    d++;

  while (*s && *d)
    {
      /* skip white space in both */
      while (ISCHARSPACE(*s))
          s++;
      if(*s==';') break;
      
      while (ISCHARSPACE(*d))
          d++;

      /* if the destination is a var */
      if (*d == '%' && ISCHARDIGIT (*(d + 1)) && vars)
        {
          const char *v = hTabItemWithKey (*vars, keyForVar (d + 1));
          /* if the variable is already bound
             then it MUST match with dest */
          if (v)
            {
              while (*v)
                if (*v++ != *s++)
                  return FALSE;
            }
          else
            /* variable not bound we need to bind it */
            bindVar (keyForVar (d + 1), &s, vars);

          /* in either case go past the variable */
          d++;
          while (ISCHARDIGIT (*d))
            d++;
        }
      else if (*s == ',' && *d == ',') /* Allow comma to match comma */
        {
          s++, d++;
        }
      else if (*s && *d) /* they should be an exact match otherwise */
        {
          if (*s++ != *d++)
            return FALSE;
        }
    }

  /* skip trailing whitespaces */
  if (*s)
    while (ISCHARSPACE (*s))
      s++;

  /* skip trailing comments as well*/
  if(*s==';')
   while (*s)
     s++;

  if (*d)
    while (ISCHARSPACE (*d))
      d++;

  /* after all this if only one of them
     has something left over then no match */
  if (*s || *d)
    return FALSE;

  return TRUE;
}

/*-----------------------------------------------------------------*/
/* matchRule - matches a all the rule lines                        */
/*-----------------------------------------------------------------*/
static bool
matchRule (lineNode * pl,
           lineNode ** mtail,
           peepRule * pr,
           lineNode * head)
{
  lineNode *spl;                /* source pl */
  lineNode *rpl;                /* rule peep line */

/*     setToNull((void *) &pr->vars);    */
/*     pr->vars = newHashTable(100); */

  /* for all the lines defined in the rule */
  rpl = pr->match;
  spl = pl;
  while (spl && rpl)
    {

      /* if the source line starts with a ';' then
         comment line don't process or the source line
         contains == . debugger information skip it */
      if (spl->line &&
          (*spl->line == ';' || spl->isDebug))
        {
          spl = spl->next;
          continue;
        }

      if (!matchLine (spl->line, rpl->line, &pr->vars))
        return FALSE;

      rpl = rpl->next;
      if (rpl)
        spl = spl->next;
    }

  /* if rules ended */
  if (!rpl)
    {
      /* if this rule has additional conditions */
      if (pr->cond)
        {
          /* constraints which uses variables as destination container
             requires to vars table to be defined */
          if (!pr->vars)
            pr->vars = newHashTable (128);

          if (callFuncByName (pr->cond, pr->vars, pl, spl, head))
            {
              *mtail = spl;
              return TRUE;
            }
          else
            return FALSE;
        }
      else
        {
          *mtail = spl;
          return TRUE;
        }
    }
  else
    return FALSE;
}

static void
reassociate_ic_down (lineNode *shead, lineNode *stail,
                     lineNode *rhead, lineNode *rtail)
{
  lineNode *csl;        /* current source line */
  lineNode *crl;        /* current replacement line */

  csl = shead;
  crl = rhead;
  while (1)
    {
      /* skip over any comments */
      while (csl!=stail->next && csl->isComment)
        csl = csl->next;
      while (crl!=rtail->next && crl->isComment)
        crl = crl->next;

      /* quit if we reach the end */
      if ((csl==stail->next) || (crl==rtail->next) || crl->ic)
        break;

      if (matchLine(csl->line,crl->line,NULL))
        {
          crl->ic = csl->ic;
          csl = csl->next;
          crl = crl->next;
        }
      else
        break;
    }
}

static void
reassociate_ic_up (lineNode *shead, lineNode *stail,
                   lineNode *rhead, lineNode *rtail)
{
  lineNode *csl;        /* current source line */
  lineNode *crl;        /* current replacement line */

  csl = stail;
  crl = rtail;
  while (1)
    {
      /* skip over any comments */
      while (csl!=shead->prev && csl->isComment)
        csl = csl->prev;
      while (crl!=rhead->prev && crl->isComment)
        crl = crl->prev;

      /* quit if we reach the end */
      if ((csl==shead->prev) || (crl==rhead->prev) || crl->ic)
        break;

      if (matchLine(csl->line,crl->line,NULL))
        {
          crl->ic = csl->ic;
          csl = csl->prev;
          crl = crl->prev;
        }
      else
        break;
    }
}

/*------------------------------------------------------------------*/
/* reassociate_ic - reassociate replacement lines with origin iCode */
/*------------------------------------------------------------------*/
static void
reassociate_ic (lineNode *shead, lineNode *stail,
                lineNode *rhead, lineNode *rtail)
{
  lineNode *csl;        /* current source line */
  lineNode *crl;        /* current replacement line */
  bool single_iCode;
  iCode *ic;

  /* Check to see if all the source lines (excluding comments) came
  ** for the same iCode
  */
  ic = NULL;
  for (csl=shead;csl!=stail->next;csl=csl->next)
    if (csl->ic && !csl->isComment)
      {
        ic = csl->ic;
        break;
      }
  single_iCode = (ic!=NULL);
  for (csl=shead;csl!=stail->next;csl=csl->next)
    if ((csl->ic != ic) && !csl->isComment)
      {
        /* More than one iCode was found. However, if it's just the
        ** last line with the different iCode and it was not changed
        ** in the replacement, everything else must be the first iCode.
        */
        if ((csl==stail) && matchLine (stail->line, rtail->line, NULL))
          {
            rtail->ic = stail->ic;
            for (crl=rhead;crl!=rtail;crl=crl->next)
              crl->ic = ic;
            return;
          }

        single_iCode = FALSE;
        break;
      }

  /* If all of the source lines came from the same iCode, then so have
  ** all of the replacement lines too.
  */
  if (single_iCode)
    {
      for (crl=rhead;crl!=rtail->next;crl=crl->next)
        crl->ic = ic;
      return;
    }

  /* The source lines span iCodes, so we may end up with replacement
  ** lines that we don't know which iCode(s) to associate with. Do the
  ** best we can by using the following strategies:
  **    1) Start at the top and scan down. As long as the source line
  **       matches the replacement line, they have the same iCode.
  **    2) Start at the bottom and scan up. As long as the source line
  **       matches the replacement line, they have the same iCode.
  **    3) For any label in the source, look for a matching label in
  **       the replacement. If found, they have the same iCode. From
  **       these matching labels, scan down for additional matching
  **       lines; if found, they also have the same iCode.
  */

  /* Strategy #1: Start at the top and scan down for matches
  */
  reassociate_ic_down(shead,stail,rhead,rtail);

  /* Strategy #2: Start at the bottom and scan up for matches
  */
  reassociate_ic_up(shead,stail,rhead,rtail);

  /* Strategy #3: Try to match labels
  */
  csl = shead;
  while (1)
    {
      /* skip over any comments */
      while (csl!=stail->next && csl->isComment)
        csl = csl->next;
      if (csl==stail->next)
        break;

      if (csl->isLabel)
        {
          /* found a source line label; look for it in the replacement lines */
          crl = rhead;
          while (1)
            {
              while (crl!=rtail->next && crl->isComment)
                crl = crl->next;
              if (crl==rtail->next)
                break;
              if (matchLine(csl->line, crl->line, NULL))
                {
                  reassociate_ic_down(csl,stail,crl,rtail);
                  break;
                }
              else
                crl = crl->next;
            }
        }
      csl = csl->next;
    }

  /* Try to assign a meaningful iCode to any comment that is missing
     one. Since they are comments, it's ok to make mistakes; we are just
     trying to improve continuity to simplify other tests.
  */
  ic = NULL;
  for (crl=rtail;crl!=rhead->prev;crl=crl->prev)
    {
      if (!crl->ic && ic && crl->isComment)
        crl->ic = ic;
      ic = crl->ic;
    }
}


/*-----------------------------------------------------------------*/
/* replaceRule - does replacement of a matching pattern            */
/*-----------------------------------------------------------------*/
static void
replaceRule (lineNode **shead, lineNode *stail, const peepRule *pr)
{
  lineNode *cl = NULL;
  lineNode *pl = NULL, *lhead = NULL;
  /* a long function name and long variable name can evaluate to
     4x max pattern length e.g. "mov dptr,((fie_var>>8)<<8)+fie_var" */
  char lb[MAX_PATTERN_LEN*4];
  char *lbp;
  lineNode *comment = NULL;

  /* collect all the comment lines in the source */
  for (cl = *shead; cl != stail; cl = cl->next)
    {
      if (cl->line && (*cl->line == ';' || cl->isDebug))
        {
          pl = (pl ? connectLine (pl, newLineNode (cl->line)) :
                (comment = newLineNode (cl->line)));
          pl->isDebug = cl->isDebug;
          pl->isComment = cl->isComment || (*cl->line == ';');
        }
    }
  cl = NULL;

  /* for all the lines in the replacement pattern do */
  for (pl = pr->replace; pl; pl = pl->next)
    {
      char *v;
      char *l;
      lbp = lb;

      l = pl->line;

      while (*l)
        {
          /* if the line contains a variable */
          if (*l == '%' && ISCHARDIGIT (*(l + 1)))
            {
              v = hTabItemWithKey (pr->vars, keyForVar (l + 1));
              if (!v)
                {
                  fprintf (stderr, "used unbound variable in replacement\n");
                  l++;
                  continue;
                }
              while (*v) {
                *lbp++ = *v++;
              }
              l++;
              while (ISCHARDIGIT (*l)) {
                l++;
              }
              continue;
            }
          *lbp++ = *l++;
        }

      *lbp = '\0';
      if (cl)
        cl = connectLine (cl, newLineNode (lb));
      else
        lhead = cl = newLineNode (lb);
      cl->isComment = pl->isComment;
      cl->isLabel   = pl->isLabel;
    }

  /* add the comments if any to the head of list */
  if (comment)
    {
      lineNode *lc = comment;
      while (lc->next)
        lc = lc->next;
      if (lhead)
        {
          lc->next = lhead;
          lhead->prev = lc;
        }
      else
        cl = lc;
      lhead = comment;
    }

  if (lhead)
    {
      /* determine which iCodes the replacement lines relate to */
      reassociate_ic(*shead,stail,lhead,cl);

      /* now we need to connect / replace the original chain */
      /* if there is a prev then change it */
      if ((*shead)->prev)
        {
          (*shead)->prev->next = lhead;
          lhead->prev = (*shead)->prev;
        }
      *shead = lhead;
      /* now for the tail */
      if (stail && stail->next)
        {
          stail->next->prev = cl;
          cl->next = stail->next;
        }
    }
  else
    {
      /* the replacement is empty - delete the source lines */
      if ((*shead)->prev)
        (*shead)->prev->next = stail->next;
      if (stail->next)
        stail->next->prev = (*shead)->prev;
      *shead = stail->next;
    }
}

/* Returns TRUE if this line is a label definition.

 * If so, start will point to the start of the label name,
 * and len will be it's length.
 */
bool
isLabelDefinition (const char *line, const char **start, int *len, bool isPeepRule)
{
  const char *cp = line;

  /* This line is a label if it consists of:
   * [optional whitespace] followed by identifier chars
   * (alnum | $ | _ ) followed by a colon.
   */

  while (*cp && ISCHARSPACE (*cp))
    {
      cp++;
    }

  if (!*cp)
    {
      return FALSE;
    }

  *start = cp;

  while (ISCHARALNUM (*cp) || (*cp == '$') || (*cp == '_') ||
         (isPeepRule && (*cp == '%')))
    {
      cp++;
    }

  if ((cp == *start) || (*cp != ':'))
    {
      return FALSE;
    }

  *len = (cp - (*start));
  return TRUE;
}

/* Not perfect, will not find all references yet. 
   Will however find references in call on Z80, which is sufficient to fix #2970351. */
bool
isLabelReference (const char *line, const char **start, int *len)
{
  const char *s, *e;
  if (!TARGET_Z80_LIKE && !TARGET_IS_STM8 && !TARGET_PDK_LIKE)
    return FALSE;

  s = line;
  while (ISCHARSPACE (*s))
    ++s;

  if(strncmp(s, "call", 4))
    return FALSE;
  s += 4;

  while (ISCHARSPACE (*s))
    ++s;

  /* Skip condition in conditional call */
  if (strchr(s, ',')) 
    s = strchr(s, ',') + 1;

  e = s, *len = 0;
  while(*e && !ISCHARSPACE (*e) && *e != ';')
    ++e, ++(*len);

  *start = s;

  return TRUE;
}

/* Quick & dirty string hash function. */
static int
hashSymbolName (const char *name)
{
  int hash = 0;

  while (*name)
    {
      hash = ((unsigned)hash << 6) ^ *name;
      name++;
    }

  if (hash < 0)
    {
      hash = -hash;
    }

  return hash % HTAB_SIZE;
}

/* Build a hash of all labels in the passed set of lines
 * and how many times they are referenced.
 */
static void
buildLabelRefCountHash (lineNode *head)
{
  lineNode *line;
  const char *label;
  int labelLen;
  int i;

  assert (labelHash == NULL);
  labelHash = newHashTable (HTAB_SIZE);

  /* First pass: locate all the labels. */
  for (line = head; line; line = line->next)
    {
      bool ref = FALSE;
      /* run isLabelDefinition to:
         - look for labels in inline assembler
         - calculate labelLen
      */ 
      if ((line->isLabel || line->isInline) && isLabelDefinition (line->line, &label, &labelLen, FALSE) ||
        (ref = TRUE) && isLabelReference (line->line, &label, &labelLen))
        {
          labelHashEntry *entry, *e;

          assert (labelLen <= SDCC_NAME_MAX);

          entry = traceAlloc (&_G.labels, Safe_alloc(sizeof (labelHashEntry)));

          memcpy (entry->name, label, labelLen);
          entry->name[labelLen] = 0;
          entry->refCount = -1;

          for (e = hTabFirstItemWK (labelHash, hashSymbolName (entry->name)); e; e = hTabNextItemWK (labelHash))
            if (!strcmp (entry->name, e->name))
              goto c;

          /* Assume function entry points are referenced somewhere,   */
          /* even if we can't find a reference (might be from outside */
          /* the function) */
          if (line->ic && (line->ic->op == FUNCTION) || ref)
            entry->refCount++;

          hTabAddItem (&labelHash, hashSymbolName (entry->name), entry);
        }
      c:;
    }


  /* Second pass: for each line, note all the referenced labels. */
  /* This is ugly, O(N^2) stuff. Optimizations welcome... */
  for (line = head; line; line = line->next)
    {
      if (line->isComment)
        continue;

      /* Padauk skip instructions */
      if (TARGET_PDK_LIKE && !line->isInline &&
        (!strncmp(line->line, "ceqsn", 5) || !strncmp(line->line, "cneqsn", 6) ||
        !strncmp(line->line, "t0sn", 4) || !strncmp(line->line, "t1sn", 4) ||
        !strncmp(line->line, "izsn", 4) || !strncmp(line->line, "dzsn", 4)))
        {
          const lineNode *l = line;
          // Skip over following inst.
          do
                l = l->next;
          while(l && (l->isComment || l->isDebug || l->isLabel));
          if (l)
            do
                  l = l->next;
            while(l && (l->isComment || l->isDebug));

          if (l && l->isLabel && isLabelDefinition (l->line, &label, &labelLen, false))
            {
              char name[SDCC_NAME_MAX];
              strcpy(name, label);
              name[labelLen] = 0;

              labelHashEntry *e;
              for (e = hTabFirstItemWK (labelHash, hashSymbolName (name)); e; e = hTabNextItemWK (labelHash))
                if (!strcmp (name, e->name))
                 break;

              if (e)
                e->refCount++;
            }
          else
            werror (E_NO_SKIP_TARGET, line->line);
        }

      for (i = 0; i < HTAB_SIZE; i++)
        {
          labelHashEntry *thisEntry;

          thisEntry = hTabFirstItemWK (labelHash, i);

          while (thisEntry)
            {
              const char *s;
              if ((s = strstr (line->line, thisEntry->name)) && !ISCHARALNUM (*(s + strlen (thisEntry->name))) && (s == line->line || !ISCHARALNUM (*(s - 1))))
                thisEntry->refCount++;

              thisEntry = hTabNextItemWK (labelHash);
            }
        }
    }

#if 0
  /* Spew the contents of the table. Debugging fun only. */
  for (i = 0; i < HTAB_SIZE; i++)
    {
      labelHashEntry *thisEntry;

      thisEntry = hTabFirstItemWK (labelHash, i);

      while (thisEntry)
        {
          fprintf (stderr, "label: %s (%p) ref %d\n",
                   thisEntry->name, thisEntry, thisEntry->refCount);
          thisEntry = hTabNextItemWK (labelHash);
        }
    }
#endif
}

/* How does this work?
   peepHole
    For each rule,
     For each line,
      Try to match
      If it matches,
       replace and restart.

    matchRule
     matchLine

  Where is stuff allocated?

*/

/*-----------------------------------------------------------------*/
/* peepHole - matches & substitutes rules                          */
/*-----------------------------------------------------------------*/
void
peepHole (lineNode ** pls)
{
  lineNode *spl;
  peepRule *pr;
  lineNode *mtail = NULL;
  bool restart, replaced;
  unsigned long rule_application_counter = 0ul;

#if !OPT_DISABLE_PIC14 || !OPT_DISABLE_PIC16
  /* The PIC port uses a different peep hole optimizer based on "pCode" */
  if (TARGET_PIC_LIKE)
    return;
#endif

  assert(labelHash == NULL);

  do
    {
      restart = FALSE;

      /* for all rules */
      for (pr = rootRules; pr; pr = pr->next)
        {
          if (restart && pr->barrier)
            break;

          for (spl = *pls; spl; spl = replaced ? spl : spl->next)
            {
              replaced = FALSE;

              // Break out of an infinite loop of rule applications.
              if (rule_application_counter > 200000ul)
                {
                  werror (W_PEEPHOLE_RULE_LIMIT);
                  goto end;
                }

              /* if inline assembler then no peep hole */
              if (spl->isInline)
                continue;

              /* don't waste time starting a match on debug symbol
              ** or comment */
              if (spl->isDebug || spl->isComment || *(spl->line)==';')
                continue;

              mtail = NULL;

              /* Tidy up any data stored in the hTab */

              /* if it matches */
              if (matchRule (spl, &mtail, pr, *pls))
                {
                  rule_application_counter++;

                  /* restart at the replaced line */
                  replaced = TRUE;

                  /* then replace */
                  if (spl == *pls)
                    {
                      replaceRule (pls, mtail, pr);
                      spl = *pls;
                    }
                  else
                    replaceRule (&spl, mtail, pr);

                  /* if restart rule type then
                     start at the top again */
                  if (pr->restart)
                    {
                      restart = TRUE;
                    }
                }

              if (pr->vars)
                {
                  hTabDeleteAll (pr->vars);
                  Safe_free (pr->vars);
                  pr->vars = NULL;
                }

              freeTrace (&_G.values);
            }
        }
    } while (restart == TRUE);

end:
  if (labelHash)
    {
      hTabDeleteAll (labelHash);
      freeTrace (&_G.labels);
    }
  labelHash = NULL;
}


/*-----------------------------------------------------------------*/
/* readFileIntoBuffer - reads a file into a string buffer          */
/*-----------------------------------------------------------------*/
static char *
readFileIntoBuffer (char *fname)
{
  FILE *f;
  char *rs = NULL;
  int nch = 0;
  int ch;
  char lb[MAX_PATTERN_LEN];

  if (!(f = fopen (fname, "r")))
    {
      fprintf (stderr, "cannot open peep rule file\n");
      return NULL;
    }

  while ((ch = fgetc (f)) != EOF)
    {
      lb[nch++] = ch;

      /* if we maxed out our local buffer */
      if (nch >= (MAX_PATTERN_LEN - 2))
        {
          lb[nch] = '\0';
          /* copy it into allocated buffer */
          if (rs)
            {
              rs = Safe_realloc (rs, strlen (rs) + strlen (lb) + 1);
              strncatz (rs, lb,  strlen (rs) + strlen (lb) + 1);
            }
          else
            {
              rs = Safe_strdup (lb);
            }
          nch = 0;
        }
    }
  fclose (f);

  /* if some characters left over */
  if (nch)
    {
      lb[nch] = '\0';
      /* copy it into allocated buffer */
      if (rs)
        {
          rs = Safe_realloc (rs, strlen (rs) + strlen (lb) + 1);
          strncatz (rs, lb, strlen (rs) + strlen (lb) + 1);
        }
      else
        {
          rs = Safe_strdup (lb);
        }
    }
  return rs;
}

/*-----------------------------------------------------------------*/
/* initPeepHole - initialises the peep hole optimizer stuff        */
/*-----------------------------------------------------------------*/
void
initPeepHole (void)
{
  char *s;

  /* read in the default rules */
  if (!options.nopeep)
    {
      readRules (port->peep.default_rules);
    }

  /* if we have any additional file read it too */
  if (options.peep_file)
    {
      readRules (s = readFileIntoBuffer (options.peep_file));
      setToNull ((void *) &s);
      /* override nopeep setting, default rules have not been read */
      options.nopeep = 0;
    }

#if !OPT_DISABLE_PIC14
  /* Convert the peep rules into pcode.
     NOTE: this is only support in the PIC port (at the moment)
  */
  if (TARGET_IS_PIC14)
    peepRules2pCode (rootRules);
#endif

#if !OPT_DISABLE_PIC16
  /* Convert the peep rules into pcode.
     NOTE: this is only support in the PIC port (at the moment)
       and the PIC16 port (VR 030601)
  */
  if (TARGET_IS_PIC16)
    pic16_peepRules2pCode (rootRules);

#endif
}

/*-----------------------------------------------------------------*/
/* StrStr - case-insensitive strstr implementation                 */
/*-----------------------------------------------------------------*/
const char * StrStr (const char * str1, const char * str2)
{
  const char * cp = str1;
  const char * s1;
  const char * s2;

  if ( !*str2 )
    return str1;

  while (*cp)
    {
      s1 = cp;
      s2 = str2;

      while ( *s1 && *s2 && !(tolower(*s1)-tolower(*s2)) )
        s1++, s2++;

      if (!*s2)
        return( cp );

      cp++;
    }

  return (NULL) ;
}