main.c

/*
  wla - part of wla dx gb-z80/z80/6502/65c02/6510/6800/6801/6809/65816/huc6280/spc-700/8008/8080
  macro assembler package by ville helin <vhelin@iki.fi>. this is gpl software.
*/

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#ifdef UNIX
#include <unistd.h>
#elif defined(WIN32)
/* Windows.h can't be included since it relies on compiler extensions */
typedef unsigned long DWORD;
DWORD __stdcall GetCurrentProcessId(void);
#endif

#include "main.h"
#include "defines.h"

#include "parse.h"
#include "include_file.h"
#include "pass_1.h"
#include "pass_2.h"
#include "pass_3.h"
#include "pass_4.h"
#include "listfile.h"
#include "hashmap.h"
#include "printf.h"


FILE *file_out_ptr = NULL;

/* amiga specific definitions */

#ifdef AMIGA
__near long __stack = 200000;
#endif

char version_string[] = "$VER: wla-" WLA_NAME " 9.12a (9.1.2021)";
char wla_version[] = "9.12";

char *tmp_name = NULL;

extern struct incbin_file_data *incbin_file_data_first, *ifd_tmp;
extern struct file_name_info *file_name_info_first;
extern struct label_def *label_tmp, *labels;
extern struct map_t *global_unique_label_map;
extern struct macro_static *macros_first;
extern struct definition *tmp_def;
extern struct map_t *defines_map;
extern struct export_def *export_first, *export_last;
extern struct stack *stacks_first, *stacks_tmp, *stacks_last, *stacks_header_first, *stacks_header_last;
extern struct repeat_runtime *repeat_stack;
extern struct section_def *sections_first;
extern struct macro_runtime *macro_stack;
extern struct label_def *unknown_labels;
extern struct filepointer *filepointers;
extern struct map_t *namespace_map;
extern struct append_section *append_sections;
extern struct label_sizeof *label_sizeofs;
extern struct block_name *block_names;
extern struct stringmaptable *stringmaptables;
extern char mem_insert_action[MAX_NAME_LENGTH*3 + 1024];
extern char *unfolded_buffer, *label_stack[256];
extern char *include_in_tmp, *tmp_a;
extern char *rom_banks, *rom_banks_usage_table;
extern char *include_dir, *buffer, *full_name;
extern int include_in_tmp_size, tmp_a_size, *banks, *bankaddress;

int output_format = OUTPUT_NONE, verbose_mode = OFF, test_mode = OFF;
int extra_definitions = OFF, commandline_parsing = ON, makefile_rules = NO;
int listfile_data = NO, quiet = NO, use_incdir = NO, little_endian = YES;
int create_sizeof_definitions = YES;

char *final_name = NULL, *asm_name = NULL;

struct ext_include_collection ext_incdirs;



int main(int argc, char *argv[]) {

  int parse_flags_result, n_ctr, q, include_size = 0;
  
  if (sizeof(double) != 8) {
    fprintf(stderr, "MAIN: sizeof(double) == %d != 8. WLA will not work properly.\n", (int)sizeof(double));
    return -1;
  }

  atexit(procedures_at_exit);

  /* init the randon number generator */
  init_genrand((unsigned long)time(NULL));

  /* initialize our external include dir collection */
  ext_incdirs.count = 0;
  ext_incdirs.names = NULL;
  ext_incdirs.max_name_size_bytes = MAX_NAME_LENGTH + 1;

  /* select little/big endianess */
#if defined(MC6800) || defined(MC6801) || defined(MC6809)
  little_endian = NO;
#else
  little_endian = YES;
#endif
  
  /* init mem_insert() buffer */
  mem_insert_action[0] = 0;
  
  /* init hashmaps */
  defines_map = hashmap_new();
  global_unique_label_map = hashmap_new();
  namespace_map = hashmap_new();

  /* init label stack */
  for (q = 0; q < 256; q++)
    label_stack[q] = NULL;
  for (q = 0; q < 256; q++) {
    label_stack[q] = calloc(MAX_NAME_LENGTH + 1, 1);
    if (label_stack[q] == NULL)
      return 1;
  }
  
  parse_flags_result = FAILED;
  if (argc >= 2) {
    parse_flags_result = parse_flags(argv, argc);
    
    if (output_format == OUTPUT_NONE) {
      if (parse_flags_result == SUCCEEDED) {
        /* assume object file output name */
        output_format = OUTPUT_OBJECT;
        final_name = calloc(strlen(asm_name)+1, 1);
        for (n_ctr = 0; n_ctr < (int)strlen(asm_name) && *((asm_name) + n_ctr) != '.'; n_ctr++)
          final_name[n_ctr] = *((asm_name) + n_ctr);
	final_name[n_ctr++] = '.';
        final_name[n_ctr++] = 'o';
        final_name[n_ctr] = 0;
      }
    }
  }
  
  if (output_format == OUTPUT_NONE || parse_flags_result == FAILED) {
    printf("\nWLA " ARCH_STR " Macro Assembler v9.12a\n");
    printf("Written by Ville Helin in 1998-2008 - In GitHub since 2014: https://github.com/vhelin/wla-dx\n");
#ifdef WLA_DEBUG
    printf("*** WLA_DEBUG defined - this executable is running in DEBUG mode ***\n");
#endif
    printf("%s\n\n", version_string);
    printf("USAGE: %s [OPTIONS] <OUTPUT> <ASM FILE>\n\n", argv[0]);
    printf("Options:\n");
    printf("-i  Add list file information\n");
    printf("-M  Output makefile rules\n");
    printf("-q  Quiet\n");
    printf("-s  Don't create _sizeof_* definitions\n");
    printf("-t  Test compile\n");
    printf("-v  Verbose messages\n");
    printf("-x  Extra compile time labels & definitions\n");
    printf("-I <DIR>  Include directory\n");
    printf("-D <DEF>  Declare definition\n\n");
    printf("Output:\n");
    printf("-o <FILE>  Output object file\n");
    printf("-l <FILE>  Output library file\n\n");
    printf("EXAMPLE: %s -D VERSION=1 -D TWO=2 -v -o main.obj main.asm\n\n", argv[0]);
    return 0;
  }

  if (strcmp(asm_name, final_name) == 0) {
    fprintf(stderr, "MAIN: Input and output files share the same name!\n");
    return 1;
  }

  generate_tmp_name(&tmp_name);

  file_out_ptr = fopen(tmp_name, "wb");
  if (file_out_ptr == NULL) {
    fprintf(stderr, "MAIN: Error opening file \"%s\" for writing.\n", tmp_name);
    return 1;
  }

  /* small inits */
  if (extra_definitions == ON)
    generate_extra_definitions();

  commandline_parsing = OFF;

  /* start the process */
  if (include_file(asm_name, &include_size, NULL) == FAILED)
    return 1;

  if (pass_1() == FAILED)
    return 1;
  if (pass_2() == FAILED)
    return 1;
  if (pass_3() == FAILED)
    return 1;
  if (listfile_data == YES) {
    if (listfile_collect() == FAILED)
      return 1;
  }
  if (pass_4() == FAILED)
    return 1;

  return 0;
}


int parse_flags(char **flags, int flagc) {

  int asm_name_def = 0, count;
  char *str_build;
  
  for (count = 1; count < flagc; count++) {
    if (!strcmp(flags[count], "-o")) {
      if (output_format != OUTPUT_NONE)
	return FAILED;
      output_format = OUTPUT_OBJECT;
      if (count + 1 < flagc) {
        /* set output */
        final_name = calloc(strlen(flags[count+1])+1, 1);
        strcpy(final_name, flags[count+1]);
      }
      else
        return FAILED;

      count++;
      continue;
    }
    else if (!strcmp(flags[count], "-l")) {
      if (output_format != OUTPUT_NONE)
	return FAILED;
      output_format = OUTPUT_LIBRARY;
      if (count + 1 < flagc) {
        /* set output */
        final_name = calloc(strlen(flags[count+1])+1, 1);
        strcpy(final_name, flags[count+1]);
      }
      else
        return FAILED;

      count++;
      continue;
    }
    else if (!strcmp(flags[count], "-D")) {
      if (count + 1 < flagc) {
        if (count + 3 < flagc) {
          if (!strcmp(flags[count+2], "=")) {
	    int length = (int)strlen(flags[count+1])+(int)strlen(flags[count+3])+2;
            str_build = calloc(length, 1);
            snprintf(str_build, length, "%s=%s", flags[count+1], flags[count+3]);
            parse_and_add_definition(str_build, NO);
            free(str_build);
            count += 2;
          }
	  else
            parse_and_add_definition(flags[count+1], NO);
        }
	else
          parse_and_add_definition(flags[count+1], NO);
      }
      else
        return FAILED;

      count++;
      continue;
    }
    else if (!strcmp(flags[count], "-I")) {
      if (count + 1 < flagc) {
        /* get arg */
        parse_and_add_incdir(flags[count+1], NO);
      }
      else
        return FAILED;

      count++;
      continue;
    }
    else if (!strcmp(flags[count], "-i")) {
      listfile_data = YES;
      continue;
    }
    else if (!strcmp(flags[count], "-v")) {
      verbose_mode = ON;
      continue;
    }
    else if (!strcmp(flags[count], "-s")) {
      create_sizeof_definitions = NO;
      continue;
    }
    else if (!strcmp(flags[count], "-t")) {
      test_mode = ON;
      continue;
    }
    else if (!strcmp(flags[count], "-M")) {
      makefile_rules = YES;
      test_mode = ON;
      verbose_mode = OFF;
      quiet = YES;
      continue;
    }
    else if (!strcmp(flags[count], "-q")) {
      quiet = YES;
      continue;
    }
    else if (!strcmp(flags[count], "-x")) {
      extra_definitions = ON;
      continue;
    }
    else {
      if (count == flagc - 1) {
	asm_name = calloc(strlen(flags[count]) + 1, 1);
	strcpy(asm_name, flags[count]);
	count++;
	asm_name_def++;
      }
      else {
	/* legacy support? */
	if (strncmp(flags[count], "-D", 2) == 0) {
	  /* old define */
	  parse_and_add_definition(flags[count], YES);
	  continue;
	}
	else if (strncmp(flags[count], "-I", 2) == 0) {
	  /* old include directory */
	  parse_and_add_incdir(flags[count], YES);
	  continue;
	}
	else
	  return FAILED;
      }
    }
  }
  
  if (asm_name_def <= 0)
    return FAILED;
  
  return SUCCEEDED;
}


void procedures_at_exit(void) {

  struct file_name_info *f, *ft;
  struct export_def *export_tmp;
  struct section_def *s1, *s2;
  struct label_def *l1, *l2;
  struct macro_static *m;
  struct filepointer *f1, *f2;
  struct append_section *as;
  struct label_sizeof *ls;
  struct block_name *bn;
  int i, index;
  
  /* free all the dynamically allocated data structures and close open files */
  if (file_out_ptr != NULL)
    fclose(file_out_ptr);

  free(macro_stack);
  free(repeat_stack);
  free(final_name);
  free(asm_name);
  free(include_dir);
  free(full_name);

  for (i = 0; i < 256; i++)
    free(label_stack[i]);

  if (defines_map != NULL) {
    hashmap_free_all_elements(defines_map);
    hashmap_free(defines_map);
  }

  if (global_unique_label_map != NULL) {
    /* don't free_all_elements, since labels contains _all_ labels. */
    hashmap_free(global_unique_label_map);
  }

  if (namespace_map != NULL) {
    hashmap_free_all_elements(namespace_map);
    hashmap_free(namespace_map);
  }

  m = macros_first;
  while (m != NULL) {
    /* free the argument labels */
    if (m->nargument_names > 0) {
      for (i = 0; i < m->nargument_names; i++)
	free(m->argument_names[i]);
      free(m->argument_names);
    }
    macros_first = m->next;
    free(m);
    m = macros_first;
  }

  label_tmp = labels;
  while (label_tmp != NULL) {
    labels = label_tmp->next;
    free(label_tmp);
    label_tmp = labels;
  }

  l1 = unknown_labels;
  while (l1 != NULL) {
    l2 = l1->next;
    free(l1);
    l1 = l2;
  }

  ls = label_sizeofs;
  while (ls != NULL) {
    label_sizeofs = ls->next;
    free(ls);
    ls = label_sizeofs;
  }

  bn = block_names;
  while (bn != NULL) {
    block_names = bn->next;
    free(bn);
    bn = block_names;
  }
  
  export_tmp = export_first;
  while (export_tmp != NULL) {
    export_last = export_tmp->next;
    free(export_tmp);
    export_tmp = export_last;
  }

  ifd_tmp = incbin_file_data_first;
  while(ifd_tmp != NULL) {
    incbin_file_data_first = ifd_tmp->next;
    free(ifd_tmp->data);
    free(ifd_tmp->name);
    free(ifd_tmp);
    ifd_tmp = incbin_file_data_first;
  }

  stacks_tmp = stacks_first;
  while (stacks_tmp != NULL) {
    free(stacks_tmp->stack);
    stacks_first = stacks_tmp->next;
    free(stacks_tmp);
    stacks_tmp = stacks_first;
  }

  stacks_tmp = stacks_header_first;
  while (stacks_tmp != NULL) {
    free(stacks_tmp->stack);
    stacks_first = stacks_tmp->next;
    free(stacks_tmp);
    stacks_tmp = stacks_first;
  }

  as = append_sections;
  while (as != NULL) {
    append_sections = as->next;
    free(as);
    as = append_sections;
  }

  free(unfolded_buffer);
  free(buffer);
  free(include_in_tmp);
  free(tmp_a);
  free(rom_banks);
  free(rom_banks_usage_table);
  free(banks);
  free(bankaddress);

  f = file_name_info_first;
  while (f != NULL) {
    free(f->name);
    ft = f->next;
    free(f);
    f = ft;
  }

  s1 = sections_first;
  while (s1 != NULL) {
    free(s1->data);
    free(s1->listfile_cmds);
    free(s1->listfile_ints);
    hashmap_free(s1->label_map);
    s2 = s1->next;
    free(s1);
    s1 = s2;
  }

  f1 = filepointers;
  while (f1 != NULL) {
    f2 = f1->next;
    if (f1->f != NULL)
      fclose(f1->f);
    free(f1->filename);
    free(f1);
    f1 = f2;
  }

  while (stringmaptables != NULL) {
    struct stringmaptable *sm = stringmaptables;
    while (sm->entries != NULL) {
      struct stringmap_entry *e = sm->entries;
      free(e->bytes);
      free(e->text);
      sm->entries = e->next;
      free(e);
    }
    stringmaptables = sm->next;
    free(sm);
  }

  /* remove the tmp files */
  if (tmp_name != NULL)
    remove(tmp_name);

  /* cleanup any incdirs we added */
  for (index = 0; index < ext_incdirs.count; index++)
      free(ext_incdirs.names[index]);
  free(ext_incdirs.names);
}


int generate_tmp_name(char **filename) {

#if defined(UNIX) || defined(WIN32)
  static char name[32]; /* should be enough */
  int status;
  int pid;

#if defined(UNIX)
  pid = (int)getpid();
#elif defined(WIN32)
  pid = GetCurrentProcessId();
#else
  #error "Invalid configuration!"
#endif

  status = snprintf(name, sizeof(name)-1, ".wla%da", pid) + 1;
  if (status >= (int)sizeof(name)) {
    fprintf(stderr, "MAIN: Temp filename exceeded limit: %d >= %d! "
	    "Aborting...\n", status, (int)sizeof(name));
    abort();
  }

  *filename = name;
#else /* AMIGA, WIN32, MSDOS and others */
  *filename = "wla_a.tmp";
#endif

  return SUCCEEDED;
}


int generate_extra_definitions(void) {

  char *q, tmp[256];
  time_t ti;
  int i, length;

  /* generate WLA_TIME */
  time(&ti);
  q = ctime(&ti);
  strcpy(tmp, q);
  /* remove the linefeed */
  length = (int)strlen(tmp);
  for (i = 0; i < length; i++) {
    if (tmp[i] == 0x0A) {
      tmp[i] = 0;
      break;
    }
  }

  if (add_a_new_definition("WLA_TIME", 0.0, tmp, DEFINITION_TYPE_STRING, (int)strlen(tmp)) == FAILED)
    return FAILED;
  if (add_a_new_definition("wla_time", 0.0, tmp, DEFINITION_TYPE_STRING, (int)strlen(tmp)) == FAILED)
    return FAILED;
  if (add_a_new_definition("WLA_VERSION", 0.0, wla_version, DEFINITION_TYPE_STRING, (int)strlen(wla_version)) == FAILED)
    return FAILED;
  if (add_a_new_definition("wla_version", 0.0, wla_version, DEFINITION_TYPE_STRING, (int)strlen(wla_version)) == FAILED)
    return FAILED;

  return SUCCEEDED;
}


int parse_and_add_definition(char *c, int contains_flag) {

  char n[MAX_NAME_LENGTH + 1], *value;
  int i;

  /* skip the flag? */
  if (contains_flag == YES)
    c += 2;
  
  for (i = 0; i < MAX_NAME_LENGTH && *c != 0 && *c != '='; i++, c++)
    n[i] = *c;
  n[i] = 0;

  if (*c == 0)
    return add_a_new_definition(n, 0.0, NULL, DEFINITION_TYPE_VALUE, 0);
  else if (*c == '=') {
    c++;
    if (*c == 0)
      return FAILED;

    value = c;
    
    /* hexadecimal value? */
    if (*c == '$' || ((c[strlen(c)-1] == 'h' || c[strlen(c)-1] == 'H') && (*c >= '0' && *c <= '9'))) {
      if (*c == '$')
	c++;
      for (i = 0; *c != 0; c++) {
	if (*c >= '0' && *c <= '9')
	  i = (i << 4) + *c - '0';
	else if (*c >= 'a' && *c <= 'f')
	  i = (i << 4) + *c - 'a' + 10;
	else if (*c >= 'A' && *c <= 'F')
	  i = (i << 4) + *c - 'A' + 10;
	else if ((*c == 'h' || *c == 'H') && *(c+1) == 0)
	  break;
	else {
	  fprintf(stderr, "PARSE_AND_ADD_DEFINITION: Error in value (%s).\n", value);
	  return FAILED;
	}
      }
      return add_a_new_definition(n, (double)i, NULL, DEFINITION_TYPE_VALUE, 0);
    }

    /* decimal value? */
    if (*c >= '0' && *c <= '9') {
      for (i = 0; *c != 0; c++) {
	if (*c >= '0' && *c <= '9')
	  i = (i * 10) + *c - '0';
	else {
	  fprintf(stderr, "PARSE_AND_ADD_DEFINITION: Error in value (%s).\n", value);
	  return FAILED;
	}
      }
      return add_a_new_definition(n, (double)i, NULL, DEFINITION_TYPE_VALUE, 0);
    }

    /* quoted string? */
    if (*c == '"' && c[strlen(c) - 1] == '"') {
      int t;
      char *s = calloc(strlen(c) + 1, 1);
      int result;

      c++;
      for (t = 0; *c != 0; c++, t++) {
        if (*c == '\\' && *(c + 1) == '"') {
          c++;
          s[t] = '"';
        }
	else if (*c == '"') {
          c++;
          break;
        }
	else
          s[t] = *c;
      }
      s[t] = 0;
      
      if (*c == 0)
        result = add_a_new_definition(n, 0.0, s, DEFINITION_TYPE_STRING, (int)strlen(s));
      else {
        fprintf(stderr, "PARSE_AND_ADD_DEFINITION: Incorrectly terminated quoted string (%s).\n", value);
        result = FAILED;
      }
      
      free(s);
      return result;
    }

    /* unquoted string */
    return add_a_new_definition(n, 0.0, c, DEFINITION_TYPE_STRING, (int)strlen(c));
  }

  return FAILED;
}


int parse_and_add_incdir(char* c, int contains_flag) {

  int old_count = ext_incdirs.count, index, buffer_size, j;
  char **new_array;
  char n[MAX_NAME_LENGTH + 1];

  /* increment for the new entry, then re-allocate the array */
  ext_incdirs.count++;
  new_array = calloc(ext_incdirs.count * sizeof(char*), 1);
  for (index = 0; index < old_count; index++)
    new_array[index] = ext_incdirs.names[index];
 
  free(ext_incdirs.names);
  ext_incdirs.names = new_array;
  buffer_size = ext_incdirs.max_name_size_bytes;
  ext_incdirs.names[old_count] = calloc(buffer_size, 1);

  /* skip the flag? */
  if (contains_flag == YES)
    c += 2;

  for (j = 0; j < MAX_NAME_LENGTH && *c != 0; j++, c++)
    n[j] = *c;
  n[j] = 0;

  if (*c != 0)
    return FAILED;

  localize_path(n);

#if defined(MSDOS)
  snprintf(ext_incdirs.names[old_count], buffer_size, "%s\\", n);
#else
  snprintf(ext_incdirs.names[old_count], buffer_size, "%s/", n);
#endif

  use_incdir = YES;

  return SUCCEEDED;
}


/*
 *
 *
 * MERSENNE TWISTER
 *
 *
 */

/* 
   A C-program for MT19937, with initialization improved 2002/1/26.
   Coded by Takuji Nishimura and Makoto Matsumoto.

   Before using, initialize the state by using init_genrand(seed)  
   or init_by_array(init_key, key_length).

   Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
   All rights reserved.                          

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

     1. Redistributions of source code must retain the above copyright
        notice, this list of conditions and the following disclaimer.

     2. Redistributions in binary form must reproduce the above copyright
        notice, this list of conditions and the following disclaimer in the
        documentation and/or other materials provided with the distribution.

     3. The names of its contributors may not be used to endorse or promote 
        products derived from this software without specific prior written 
        permission.

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


   Any feedback is very welcome.
   http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
   email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)
*/

/* Period parameters */  
#define N 624
#define M 397
#define MATRIX_A 0x9908b0dfUL   /* constant vector a */
#define UPPER_MASK 0x80000000UL /* most significant w-r bits */
#define LOWER_MASK 0x7fffffffUL /* least significant r bits */

static unsigned long mt[N]; /* the array for the state vector  */
static int mti = N+1; /* mti==N+1 means mt[N] is not initialized */

/* initializes mt[N] with a seed */
void init_genrand(unsigned long s) {
  
  mt[0]= s & 0xffffffffUL;
  for (mti = 1; mti < N; mti++) {
    mt[mti] = (1812433253UL * (mt[mti-1] ^ (mt[mti-1] >> 30)) + mti); 
    /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
    /* In the previous versions, MSBs of the seed affect   */
    /* only MSBs of the array mt[].                        */
    /* 2002/01/09 modified by Makoto Matsumoto             */
    mt[mti] &= 0xffffffffUL;
    /* for >32 bit machines */
  }
}

/* generates a random number on [0,0xffffffff]-interval */
unsigned long genrand_int32(void) {
  
  unsigned long y;
  static unsigned long mag01[2] = {0x0UL, MATRIX_A};
  /* mag01[x] = x * MATRIX_A  for x=0,1 */

  if (mti >= N) { /* generate N words at one time */
    int kk;

    if (mti == N+1)   /* if init_genrand() has not been called, */
      init_genrand(5489UL); /* a default initial seed is used */

    for (kk = 0; kk < N-M; kk++) {
      y = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK);
      mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1UL];
    }
    for (; kk < N-1; kk++) {
      y = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK);
      mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1UL];
    }
    y = (mt[N-1] & UPPER_MASK) | (mt[0] & LOWER_MASK);
    mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1UL];

    mti = 0;
  }
  
  y = mt[mti++];

  /* tempering */
  y ^= (y >> 11);
  y ^= (y << 7) & 0x9d2c5680UL;
  y ^= (y << 15) & 0xefc60000UL;
  y ^= (y >> 18);

  return y;
}