iverilog/vvp/compile.cc

/*
 * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
 *
 *    This source code is free software; you can redistribute it
 *    and/or modify it in source code form under the terms of the GNU
 *    General Public License as published by the Free Software
 *    Foundation; either version 2 of the License, 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, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */
#if !defined(WINNT)
#ident "$Id: compile.cc,v 1.57 2001/05/06 17:42:22 steve Exp $"
#endif

# include  "compile.h"
# include  "functor.h"
# include  "udp.h" 
# include  "memory.h" 
# include  "symbols.h"
# include  "codes.h"
# include  "schedule.h"
# include  "vpi_priv.h"
# include  "vthread.h"
# include  "parse_misc.h"
# include  <malloc.h>
# include  <stdlib.h>
# include  <string.h>
# include  <assert.h>

unsigned compile_errors = 0;

/*
 * The opcode table lists all the code mnemonics, along with their
 * opcode and operand types. The table is written sorted by mnemonic
 * so that it can be searched by binary search. The opcode_compare
 * function is a helper function for that lookup.
 */

enum operand_e {
	/* Place holder for unused operand */
      OA_NONE,
	/* The operand is a number, an immediate unsigned integer */
      OA_NUMBER,
	/* The operand is a thread bit index */
      OA_BIT1,
      OA_BIT2,
	/* The operand is a pointer to code space */
      OA_CODE_PTR,
	/* The operand is a variable or net pointer */
      OA_FUNC_PTR,
        /* The operand is a pointer to a memory */
      OA_MEM_PTR,
};

struct opcode_table_s {
      const char*mnemonic;
      vvp_code_fun opcode;

      unsigned argc;
      enum operand_e argt[OPERAND_MAX];
};

const static struct opcode_table_s opcode_table[] = {
      { "%add",    of_ADD,    3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
      { "%and",    of_AND,    3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
      { "%assign", of_ASSIGN, 3,  {OA_FUNC_PTR, OA_BIT1,     OA_BIT2} },
      { "%assign/m",of_ASSIGN_MEM,3,{OA_MEM_PTR,OA_BIT1,     OA_BIT2} },
      { "%breakpoint", of_BREAKPOINT, 0,  {OA_NONE, OA_NONE, OA_NONE} },
      { "%cmp/s",  of_CMPS,   3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
      { "%cmp/u",  of_CMPU,   3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
      { "%cmp/x",  of_CMPX,   3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
      { "%cmp/z",  of_CMPZ,   3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
      { "%delay",  of_DELAY,  1,  {OA_NUMBER,   OA_NONE,     OA_NONE} },
      { "%end",    of_END,    0,  {OA_NONE,     OA_NONE,     OA_NONE} },
      { "%inv",    of_INV,    2,  {OA_BIT1,     OA_BIT2,     OA_NONE} },
      { "%ix/add", of_IX_ADD, 2,  {OA_BIT1,     OA_NUMBER,   OA_NONE} },
      { "%ix/get", of_IX_GET, 2,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
      { "%ix/load",of_IX_LOAD,2,  {OA_BIT1,     OA_NUMBER,   OA_NONE} },
      { "%ix/mul", of_IX_MUL, 2,  {OA_BIT1,     OA_NUMBER,   OA_NONE} },
      { "%ix/sub", of_IX_SUB, 2,  {OA_BIT1,     OA_NUMBER,   OA_NONE} },
      { "%jmp",    of_JMP,    1,  {OA_CODE_PTR, OA_NONE,     OA_NONE} },
      { "%jmp/0",  of_JMP0,   2,  {OA_CODE_PTR, OA_BIT1,     OA_NONE} },
      { "%jmp/0xz",of_JMP0XZ, 2,  {OA_CODE_PTR, OA_BIT1,     OA_NONE} },
      { "%jmp/1",  of_JMP1,   2,  {OA_CODE_PTR, OA_BIT1,     OA_NONE} },
      { "%join",   of_JOIN,   0,  {OA_NONE,     OA_NONE,     OA_NONE} },
      { "%load",   of_LOAD,   2,  {OA_BIT1,     OA_FUNC_PTR, OA_NONE} },
      { "%load/m", of_LOAD_MEM,2, {OA_BIT1,     OA_MEM_PTR,  OA_NONE} },
      { "%mov",    of_MOV,    3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
      { "%noop",   of_NOOP,   0,  {OA_NONE,     OA_NONE,     OA_NONE} },
      { "%nor/r",  of_NORR,   3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
      { "%or",     of_OR,     3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
      { "%set",    of_SET,    2,  {OA_FUNC_PTR, OA_BIT1,     OA_NONE} },
      { "%set/m",  of_SET_MEM,2,  {OA_MEM_PTR,  OA_BIT1,     OA_NONE} },
      { "%sub",    of_SUB,    3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
      { "%wait",   of_WAIT,   1,  {OA_FUNC_PTR, OA_NONE,     OA_NONE} },
      { "%xnor",   of_XNOR,   3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
      { "%xor",    of_XOR,    3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
      { 0, of_NOOP, 0, {OA_NONE, OA_NONE, OA_NONE} }
};

static unsigned opcode_count = 0;
//static const unsigned opcode_count 
//                  = sizeof(opcode_table)/sizeof(*opcode_table) - 1; 
// No?

static int opcode_compare(const void*k, const void*r)
{
      const char*kp = (const char*)k;
      const struct opcode_table_s*rp = (const struct opcode_table_s*)r;
      return strcmp(kp, rp->mnemonic);
}

/*
 * Keep a symbol table of addresses within code space. Labels on
 * executable opcodes are mapped to their address here.
 */
static symbol_table_t sym_codespace = 0;

/*
 * Keep a symbol table of functors mentioned in the source. This table
 * is used to resolve references as they come.
 */
static symbol_table_t sym_functors = 0;

/*
 * VPI objects are indexed during compile time so that they can be
 * linked together as they are created. This symbol table matches
 * labels to vpiHandles.
 */
static symbol_table_t sym_vpi = 0;


/*
 * If a functor parameter makes a forward reference to a functor, then
 * I need to save that reference and resolve it after the functors are
 * created. Use this structure to keep the unresolved references in an
 * unsorted singly linked list.
 *
 * The postpone_functor_input arranges for a functor input to be
 * resolved and connected at cleanup. This is used if the symbol is
 * defined after its use in a functor. The ptr parameter is the
 * complete vvp_input_t for the input port.
 */
struct resolv_list_s {
      struct resolv_list_s*next;
      vvp_ipoint_t port;

      char*source;
      unsigned idx;
};

static struct resolv_list_s*resolv_list = 0;

static void postpone_functor_input(vvp_ipoint_t ptr, char*lab, unsigned idx)
{
      struct resolv_list_s*res = (struct resolv_list_s*)
	    calloc(1, sizeof(struct resolv_list_s));

      res->port    = ptr;
      res->source = lab;
      res->idx    = idx;
      res->next   = resolv_list;
      resolv_list = res;
}


/*
 * Instructions may make forward references to labels. In this case,
 * the compile makes one of these to remember to retry the
 * resolution.
 */
struct cresolv_list_s {
      struct cresolv_list_s*next;
      struct vvp_code_s*cp;
      char*lab;
};

static struct cresolv_list_s*cresolv_list = 0;

void compile_vpi_symbol(const char*label, vpiHandle obj)
{
      symbol_value_t val;
      val.ptr = obj;
      sym_set_value(sym_vpi, label, val);
}

/*
 * Initialize the compiler by allocation empty symbol tables and
 * initializing the various address spaces.
 */
void compile_init(void)
{
      sym_vpi = new_symbol_table();
      compile_vpi_symbol("$time", vpip_sim_time());

      sym_functors = new_symbol_table();
      functor_init();

      sym_codespace = new_symbol_table();
      codespace_init();

      opcode_count = 0;
      while (opcode_table[opcode_count].mnemonic)
	    opcode_count += 1;
}

void compile_load_vpi_module(char*name)
{
      vpip_load_module(name, module_path);
      free(name);
}

/*
 *  Add a functor to the symbol table
 */

static void define_functor_symbol(char*label, vvp_ipoint_t fdx)
{
  symbol_value_t val;
  val.num = fdx;
  sym_set_value(sym_functors, label, val);
}

/* 
 * Run through the arguments looking for the functors that are
 * connected to my input ports. For each source functor that I
 * find, connect the output of that functor to the indexed
 * input by inserting myself (complete with the port number in
 * the vvp_ipoint_t) into the list that the source heads.
 *   
 * If the source functor is not declared yet, then don't do
 * the link yet. Save the reference to be resolved later.
 *
 * If the source is a constant value, then set the ival of the functor
 * and skip the symbol lookup.
 */

static void inputs_connect(vvp_ipoint_t fdx, unsigned argc, struct symb_s*argv)
{

      for (unsigned idx = 0;  idx < argc;  idx += 1) {

	      /* Find the functor for this input. This assumes that
		 wide (more then 4 inputs) gates are consecutive
		 functors. */
	    vvp_ipoint_t ifdx = ipoint_input_index(fdx, idx);
	    functor_t iobj = functor_index(ifdx);

	    if (strcmp(argv[idx].text, "C<0>") == 0) {
		  free(argv[idx].text);
		  iobj->ival &= ~(3 << idx*2);
		  continue;
	    }

	    if (strcmp(argv[idx].text, "C<1>") == 0) {
		  free(argv[idx].text);
		  iobj->ival &= ~(3 << idx*2);
		  iobj->ival |= 1 << idx*2;
		  continue;
	    }

	    symbol_value_t val = sym_get_value(sym_functors, argv[idx].text);
	    vvp_ipoint_t tmp = val.num;

	    if (tmp) {
		  tmp = ipoint_index(tmp, argv[idx].idx);
		  functor_t fport = functor_index(tmp);
		  iobj->port[ipoint_port(ifdx)] = fport->out;
		  fport->out = ifdx;
		  free(argv[idx].text);
	    } else {
		  postpone_functor_input(ifdx, argv[idx].text, argv[idx].idx);
	    }
      }

      free(argv);
}

/*
 * The parser calls this function to create a functor. I allocate a
 * functor, and map the name to the vvp_ipoint_t address for the
 * functor. Also resolve the inputs to the functor.
 */
void compile_functor(char*label, char*type, unsigned argc, struct symb_s*argv)
{
      vvp_ipoint_t fdx = functor_allocate(1);
      functor_t obj = functor_index(fdx);

      define_functor_symbol(label, fdx);

      assert(argc <= 4);

      obj->ival = 0x33;
      obj->oval = 2;
      obj->mode = 0;

      if (strcmp(type, "OR") == 0) {
	    obj->table = ft_OR;

      } else if (strcmp(type, "AND") == 0) {
	    obj->table = ft_AND;

      } else if (strcmp(type, "BUF") == 0) {
	    obj->table = ft_BUF;

      } else if (strcmp(type, "BUFIF0") == 0) {
	    obj->table = ft_BUFIF0;

      } else if (strcmp(type, "BUFIF1") == 0) {
	    obj->table = ft_BUFIF1;

      } else if (strcmp(type, "MUXZ") == 0) {
	    obj->table = ft_MUXZ;

      } else if (strcmp(type, "NAND") == 0) {
	    obj->table = ft_NAND;

      } else if (strcmp(type, "NOR") == 0) {
	    obj->table = ft_NOR;

      } else if (strcmp(type, "NOT") == 0) {
	    obj->table = ft_NOT;

      } else if (strcmp(type, "XNOR") == 0) {
	    obj->table = ft_XNOR;

      } else if (strcmp(type, "XOR") == 0) {
	    obj->table = ft_XOR;

      } else {
	    yyerror("invalid functor type.");
      }

	/* Connect the inputs of this functor to the given symbols. If
	   there are C<X> inputs, set the ival appropriately. */
      inputs_connect(fdx, argc, argv);

	/* Recalculate the output based on the given ival. if the oval
	   turns out to *not* be x, then schedule the functor so that
	   the value gets propagated. */
      unsigned char out = obj->table[obj->ival >> 2];
      obj->oval = 3 & (out >> 2 * (obj->ival&3));
      if (obj->oval != 2)
	    schedule_functor(fdx, 0);

      free(label);
      free(type);
}

void compile_udp_def(int sequ, char *label, char *name,
		     unsigned nin, unsigned init, char **table)
{
  struct vvp_udp_s *u = udp_create(label);
  u->name = name;
  u->sequ = sequ;
  u->nin = nin;
  u->init = init;
  u->table = table;
  free(label);
}

char **compile_udp_table(char **table, char *row)
{
  if (table)
    assert(strlen(*table)==strlen(row));

  char **tt;
  for (tt = table; tt && *tt; tt++);
  int n = (tt-table) + 2;

  table = (char**)realloc(table, n*sizeof(char*));
  table[n-2] = row;
  table[n-1] = 0x0;

  return table;
}

void compile_udp_functor(char*label, char*type,
			 unsigned argc, struct symb_s*argv)
{
  struct vvp_udp_s *u = udp_find(type);
  assert (argc == u->nin);

  int nfun = (argc+3)/4;

  vvp_ipoint_t fdx = functor_allocate(nfun);
  functor_t obj = functor_index(fdx);

  define_functor_symbol(label, fdx);
  free(label);  

  for (unsigned idx = 0;  idx < argc;  idx += 4) 
    {
      vvp_ipoint_t ifdx = ipoint_input_index(fdx, idx);
      functor_t iobj = functor_index(ifdx);

      iobj->ival = 0xaa;
      iobj->old_ival = obj->ival;
      iobj->oval = u->init;
      iobj->mode = M42;
      if (idx)
	{
	  iobj->out = fdx;
	  iobj->obj = 0;
	}
      else
	{
	  iobj->obj = u;
	}
    }

  inputs_connect(fdx, argc, argv);
}


void compile_memory(char *label, char *name, int msb, int lsb,
		    unsigned idxs, long *idx)
{
  vvp_memory_t mem = memory_create(label);
  free(label);
  memory_new(mem, name, lsb, msb, idxs, idx);
}

void compile_memory_port(char *label, char *memid, 
			 unsigned msb, unsigned lsb,
			 unsigned argc, struct symb_s *argv)
{
  vvp_memory_t mem = memory_find(memid);
  free(memid);
  assert(mem);

  // These is not a Verilog bit range. 
  // These is a data port bit range. 
  assert (lsb >= 0  &&  lsb<=msb);
  assert (msb < memory_data_width(mem));
  unsigned nbits = msb-lsb+1;

  unsigned awidth = memory_addr_width(mem);
  unsigned nfun = (awidth + 3)/4;
  if (nfun < nbits)
    nfun = nbits;
      
  vvp_ipoint_t ix = functor_allocate(nfun);

  assert(argc == awidth);
  define_functor_symbol(label, ix);
  free(label);

  inputs_connect(ix, argc, argv);

  memory_port_new(mem, ix, nbits, lsb);
}

void compile_memory_init(char *memid, unsigned i, unsigned char val)
{
  static vvp_memory_t mem = 0x0;
  static unsigned idx;
  if (memid)
    {
      mem = memory_find(memid);
      free(memid);
      idx = i/4;
    }
  assert(mem);
  memory_init_nibble(mem, idx, val);
  idx++;
}


void compile_event(char*label, char*type,
		   unsigned argc, struct symb_s*argv)
{
      vvp_ipoint_t fdx = functor_allocate(1);
      functor_t obj = functor_index(fdx);

      define_functor_symbol(label, fdx);

      assert(argc <= 4);

	/* Run through the arguments looking for the functors that are
	   connected to my input ports. For each source functor that I
	   find, connect the output of that functor to the indexed
	   input by inserting myself (complete with the port number in
	   the vvp_ipoint_t) into the list that the source heads.

	   If the source functor is not declared yet, then don't do
	   the link yet. Save the reference to be resolved later. */

      inputs_connect(fdx, argc, argv);

      obj->ival = 0xaa;
      obj->oval = 2;
      obj->mode = 1;
      obj->out  = 0;

      obj->event = (struct vvp_event_s*) malloc(sizeof (struct vvp_event_s));
      obj->event->threads = 0;
      obj->event->ival = obj->ival;

      if (strcmp(type,"posedge") == 0)
	    obj->event->vvp_edge_tab = vvp_edge_posedge;
      else if (strcmp(type,"negedge") == 0)
	    obj->event->vvp_edge_tab = vvp_edge_negedge;
      else if (strcmp(type,"edge") == 0)
	    obj->event->vvp_edge_tab = vvp_edge_anyedge;
      else
	    obj->event->vvp_edge_tab = 0;

      free(type);
      free(label);
}

void compile_named_event(char*label, char*name)
{
      vvp_ipoint_t fdx = functor_allocate(1);
      functor_t obj = functor_index(fdx);

      define_functor_symbol(label, fdx);

      obj->ival = 0xaa;
      obj->oval = 2;
      obj->mode = 2;
      obj->out  = 0;

      obj->event = (struct vvp_event_s*) malloc(sizeof (struct vvp_event_s));
      obj->event->threads = 0;
      obj->event->ival = obj->ival;

      free(label);
      free(name);
}

void compile_event_or(char*label, unsigned argc, struct symb_s*argv)
{
      vvp_ipoint_t fdx = functor_allocate(1);
      functor_t obj = functor_index(fdx);

      define_functor_symbol(label, fdx);

      obj->ival = 0xaa;
      obj->oval = 2;
      obj->mode = 2;
      obj->out  = 0;

      obj->event = new struct vvp_event_s;
      obj->event->threads = 0;
      obj->event->ival = obj->ival;

	/* Link the outputs of the named events to me. */

      for (unsigned idx = 0 ;  idx < argc ;  idx += 1) {
	    symbol_value_t val = sym_get_value(sym_functors, argv[idx].text);
	    vvp_ipoint_t tmp = val.num;

	    assert(tmp);

	    tmp = ipoint_index(tmp, argv[idx].idx);

	    functor_t fport = functor_index(tmp);
	    assert(fport->out == 0);
	    fport->out = fdx;

	    free(argv[idx].text);

      }

      free(argv);
      free(label);
}

/*
 * The parser uses this function to compile an link an executable
 * opcode. I do this by looking up the opcode in the opcode_table. The
 * table gives the operand structure that is acceptible, so I can
 * process the operands here as well.
 */
void compile_code(char*label, char*mnem, comp_operands_t opa)
{
      vvp_cpoint_t ptr = codespace_allocate();

	/* First, I can give the label a value that is the current
	   codespace pointer. Don't need the text of the label after
	   this is done. */
      if (label) {
	    symbol_value_t val;
	    val.num = ptr;
	    sym_set_value(sym_codespace, label, val);
	    free(label);
      }

	/* Lookup the opcode in the opcode table. */
      struct opcode_table_s*op = (struct opcode_table_s*)
	    bsearch(mnem, opcode_table, opcode_count,
		    sizeof(struct opcode_table_s), &opcode_compare);
      if (op == 0) {
	    yyerror("Invalid opcode");
	    return;
      }

      assert(op);

	/* Build up the code from the information about the opcode and
	   the information from the comiler. */
      vvp_code_t code = codespace_index(ptr);
      code->opcode = op->opcode;

      if (op->argc != (opa? opa->argc : 0)) {
	    yyerror("operand count");
	    return;
      }

	/* Pull the operands that the instruction expects from the
	   list that the parser supplied. */

      for (unsigned idx = 0 ;  idx < op->argc ;  idx += 1) {
	    symbol_value_t tmp;

	    switch (op->argt[idx]) {
		case OA_NONE:
		  break;

		case OA_BIT1:
		  if (opa->argv[idx].ltype != L_NUMB) {
			yyerror("operand format");
			break;
		  }

		  code->bit_idx1 = opa->argv[idx].numb;
		  break;

		case OA_BIT2:
		  if (opa->argv[idx].ltype != L_NUMB) {
			yyerror("operand format");
			break;
		  }

		  code->bit_idx2 = opa->argv[idx].numb;
		  break;

		case OA_CODE_PTR:
		  if (opa->argv[idx].ltype != L_SYMB) {
			yyerror("operand format");
			break;
		  }

		  assert(opa->argv[idx].symb.idx == 0);
		  tmp = sym_get_value(sym_codespace, opa->argv[idx].symb.text);
		  code->cptr = tmp.num;
		  if (code->cptr == 0) {
			struct cresolv_list_s*res = (struct cresolv_list_s*)
			      calloc(1, sizeof(struct cresolv_list_s));
			res->cp = code;
			res->lab = opa->argv[idx].symb.text;
			res->next = cresolv_list;
			cresolv_list = res;

		  } else {

			free(opa->argv[idx].symb.text);
		  }

		  break;

		case OA_FUNC_PTR:
		  if (opa->argv[idx].ltype != L_SYMB) {
			yyerror("operand format");
			break;
		  }

		  tmp = sym_get_value(sym_functors, opa->argv[idx].symb.text);
		  if (tmp.num == 0) {
			yyerror("functor undefined");
			break;
		  }
		  code->iptr = ipoint_index(tmp.num, opa->argv[idx].symb.idx);

		  free(opa->argv[idx].symb.text);
		  break;

		case OA_NUMBER:
		  if (opa->argv[idx].ltype != L_NUMB) {
			yyerror("operand format");
			break;
		  }

		  code->number = opa->argv[idx].numb;
		  break;

        	case OA_MEM_PTR:
		  if (opa->argv[idx].ltype != L_SYMB) {
			yyerror("operand format");
			break;
		  }

		  code->mem = memory_find(opa->argv[idx].symb.text);
		  if (code->mem == 0) {
			yyerror("memory undefined");
		  }

		  free(opa->argv[idx].symb.text);
		  break;

	    }
      }

      if (opa) free(opa);

      free(mnem);
}

void compile_codelabel(char*label)
{
      symbol_value_t val;
      vvp_cpoint_t ptr = codespace_next();

      val.num = ptr;
      sym_set_value(sym_codespace, label, val);

      free(label);
}

void compile_disable(char*label, struct symb_s symb)
{
      vvp_cpoint_t ptr = codespace_allocate();

	/* First, I can give the label a value that is the current
	   codespace pointer. Don't need the text of the label after
	   this is done. */
      if (label) {
	    symbol_value_t val;
	    val.num = ptr;
	    sym_set_value(sym_codespace, label, val);
      }


	/* Fill in the basics of the %disable in the instruction. */
      vvp_code_t code = codespace_index(ptr);
      code->opcode = of_DISABLE;

	/* Figure out the target SCOPE. */
      code->handle = compile_vpi_lookup(symb.text);
      assert(code->handle);

      free(label);
      free(symb.text);
}

/*
 * The %fork instruction is a little different from other instructions
 * in that it has an extended field that holds the information needed
 * to create the new thread. This includes the target PC and scope.
 * I get these from the parser in the form of symbols.
 */
void compile_fork(char*label, struct symb_s dest, struct symb_s scope)
{
      symbol_value_t tmp;
      vvp_cpoint_t ptr = codespace_allocate();

	/* First, I can give the label a value that is the current
	   codespace pointer. Don't need the text of the label after
	   this is done. */
      if (label) {
	    symbol_value_t val;
	    val.num = ptr;
	    sym_set_value(sym_codespace, label, val);
      }

	/* Fill in the basics of the %fork in the instruction. */
      vvp_code_t code = codespace_index(ptr);
      code->opcode = of_FORK;
      code->fork = new struct fork_extend;

	/* Figure out the target PC. */
      tmp = sym_get_value(sym_codespace, dest.text);
      code->fork->cptr = tmp.num;
      if (code->fork->cptr == 0) {
	    struct cresolv_list_s*res = new cresolv_list_s;
	    res->cp = code;
	    res->lab = dest.text;
	    res->next = cresolv_list;
	    cresolv_list = res;
	    dest.text = 0;
      }

	/* Figure out the target SCOPE. */
      vpiHandle sh = compile_vpi_lookup(scope.text);
      assert(sh);
      code->fork->scope = (struct __vpiScope*)sh;

      free(label);
      free(dest.text);
      free(scope.text);
}

void compile_vpi_call(char*label, char*name, unsigned argc, vpiHandle*argv)
{
      vvp_cpoint_t ptr = codespace_allocate();

	/* First, I can give the label a value that is the current
	   codespace pointer. Don't need the text of the label after
	   this is done. */
      if (label) {
	    symbol_value_t val;
	    val.num = ptr;
	    sym_set_value(sym_codespace, label, val);
	    free(label);
      }

	/* Create an instruction in the code space. */
      vvp_code_t code = codespace_index(ptr);
      code->opcode = &of_VPI_CALL;

	/* Create a vpiHandle that bundles the call information, and
	   store that handle in the instruction. */
      code->handle = vpip_build_vpi_call(name, argc, argv);
      if (code->handle == 0)
	    compile_errors += 1;

	/* Done with the lexor-allocated name string. */
      free(name);
}

/*
 * When the parser finds a thread statement, I create a new thread
 * with the start address referenced by the program symbol passed to
 * me.
 */
void compile_thread(char*start_sym)
{
      symbol_value_t tmp = sym_get_value(sym_codespace, start_sym);
      vvp_cpoint_t pc = tmp.num;
      if (pc == 0) {
	    yyerror("unresolved address");
	    return;
      }

      vthread_t thr = vthread_new(pc, vpip_peek_current_scope());
      schedule_vthread(thr, 0);
      free(start_sym);
}

vpiHandle compile_vpi_lookup(const char*label)
{
      symbol_value_t val;

      val = sym_get_value(sym_vpi, label);
      return (vpiHandle) val.ptr;
}

/*
 * A variable is a special functor, so we allocate that functor and
 * write the label into the symbol table.
 */
void compile_variable(char*label, char*name, int msb, int lsb,
		      bool signed_flag)
{
      unsigned wid = ((msb > lsb)? msb-lsb : lsb-msb) + 1;
      vvp_ipoint_t fdx = functor_allocate(wid);

      define_functor_symbol(label, fdx);

      for (unsigned idx = 0 ;  idx < wid ;  idx += 1) {
	    functor_t obj = functor_index(ipoint_index(fdx,idx));
	    obj->table = ft_var;
	    obj->ival  = 0x22;
	    obj->oval  = 0x02;
	    obj->mode  = 0;
      }

	/* Make the vpiHandle for the reg. */
      vpiHandle obj = vpip_make_reg(name, msb, lsb, signed_flag, fdx);
      compile_vpi_symbol(label, obj);

      free(label);
}

void compile_net(char*label, char*name, int msb, int lsb, bool signed_flag,
		 unsigned argc, struct symb_s*argv)
{
      unsigned wid = ((msb > lsb)? msb-lsb : lsb-msb) + 1;
      vvp_ipoint_t fdx = functor_allocate(wid);

      define_functor_symbol(label, fdx);

	/* Allocate all the functors for the net itself. */
      for (unsigned idx = 0 ;  idx < wid ;  idx += 1) {
	    functor_t obj = functor_index(ipoint_index(fdx,idx));
	    obj->table = ft_var;
	    obj->ival  = 0x22;
	    obj->oval  = 0x02;
	    obj->mode  = 0;
      }

      assert(argc == wid);

	/* Connect port[0] of each of the net functors to the output
	   of the addressed object. */
      for (unsigned idx = 0 ;  idx < wid ;  idx += 1) {
	    vvp_ipoint_t ptr = ipoint_index(fdx,idx);
	    functor_t obj = functor_index(ptr);

	      /* Skip unconnected nets. */
	    if (argv[idx].text == 0) {
		  obj->oval = 3;
		  continue;
	    }

	    if (strcmp(argv[idx].text, "C<0>") == 0) {
		  obj->oval = 0;
		  schedule_functor(ptr, 0);
		  continue;
	    }

	    if (strcmp(argv[idx].text, "C<1>") == 0) {
		  obj->oval = 1;
		  schedule_functor(ptr, 0);
		  continue;
	    }

	    if (strcmp(argv[idx].text, "C<x>") == 0) {
		  obj->oval = 2;
		  continue;
	    }

	    if (strcmp(argv[idx].text, "C<z>") == 0) {
		  obj->oval = 3;
		  schedule_functor(ptr, 0);
		  continue;
	    }

	    symbol_value_t val = sym_get_value(sym_functors, argv[idx].text);
	    if (val.num) {

		  functor_t src = functor_index(ipoint_index(val.num,
							     argv[idx].idx));
		  obj->port[0] = src->out;
		  src->out = ptr;

	    } else {
		  postpone_functor_input(ipoint_make(ptr, 0),
					 argv[idx].text,
					 argv[idx].idx);
	    }
      }

	/* Make the vpiHandle for the reg. */
      vpiHandle obj = vpip_make_net(name, msb, lsb, signed_flag, fdx);
      compile_vpi_symbol(label, obj);

      free(label);
      free(argv);
}

/*
 * When parsing is otherwise complete, this function is called to do
 * the final stuff. Clean up deferred linking here.
 */
void compile_cleanup(void)
{
      struct resolv_list_s*tmp_list = resolv_list;
      resolv_list = 0;

      while (tmp_list) {
	    struct resolv_list_s*res = tmp_list;
	    tmp_list = res->next;

	      /* Get the addressed functor object and select the input
		 port that needs resolution. */
	    functor_t obj = functor_index(res->port);
	    unsigned idx = ipoint_port(res->port);

	      /* Try again to look up the symbol that was not defined
		 the first time around. */
	    symbol_value_t val = sym_get_value(sym_functors, res->source);
	    vvp_ipoint_t tmp = val.num;

	    if (tmp != 0) {
		    /* The symbol is defined, link the functor input
		       to the resolved output. */

		  tmp = ipoint_index(tmp, res->idx);
		  functor_t fport = functor_index(tmp);
		  obj->port[idx] = fport->out;
		  fport->out = res->port;

		  free(res->source);
		  free(res);

	    } else {
		    /* Still not resolved. put back into the list. */
		  fprintf(stderr, "unresolved functor reference: %s\n",
			  res->source);
		  res->next = resolv_list;
		  resolv_list = res;
	    }
      }

      struct cresolv_list_s*tmp_clist = cresolv_list;
      cresolv_list = 0;

      while (tmp_clist) {
	    struct cresolv_list_s*res = tmp_clist;
	    tmp_clist = res->next;

	    symbol_value_t val = sym_get_value(sym_codespace, res->lab);
	    vvp_cpoint_t tmp = val.num;

	    if (tmp != 0) {
		    /* Resolved the reference. If this is a %fork,
		       then handle it slightly differently. */
		  if (res->cp->opcode == of_FORK)
			res->cp->fork->cptr = tmp;
		  else
			res->cp->cptr = tmp;
		  free(res->lab);
		  
	    } else {
		  fprintf(stderr, "unresolved code label: %s\n", res->lab);
		  res->next = cresolv_list;
		  cresolv_list = res;
	    }
      }
}

void compile_dump(FILE*fd)
{
      fprintf(fd, "FUNCTOR SYMBOL TABLE:\n");
      sym_dump(sym_functors, fd);
      fprintf(fd, "FUNCTORS:\n");
      functor_dump(fd);
      fprintf(fd, "UNRESOLVED PORT INPUTS:\n");
      for (struct resolv_list_s*cur = resolv_list ;  cur ;  cur = cur->next)
	    fprintf(fd, "    %08x: %s\n", cur->port, cur->source);

      fprintf(fd, "CODE SPACE SYMBOL TABLE:\n");
      sym_dump(sym_codespace, fd);

      fprintf(fd, "CODE SPACE DISASSEMBLY:\n");
      codespace_dump(fd);
}

/*
 * $Log: compile.cc,v $
 * Revision 1.57  2001/05/06 17:42:22  steve
 *  Add the %ix/get instruction. (Stephan Boettcher)
 *
 * Revision 1.56  2001/05/06 03:51:37  steve
 *  Regularize the mode-42 functor handling.
 *
 * Revision 1.55  2001/05/06 00:18:13  steve
 *  Propagate non-x constant net values.
 *
 * Revision 1.54  2001/05/05 23:55:46  steve
 *  Add the beginnings of an interactive debugger.
 *
 * Revision 1.53  2001/05/02 23:16:50  steve
 *  Document memory related opcodes,
 *  parser uses numbv_s structures instead of the
 *  symbv_s and a mess of unions,
 *  Add the %is/sub instruction.
 *        (Stephan Boettcher)
 *
 * Revision 1.52  2001/05/02 04:05:17  steve
 *  Remove the init parameter of functors, and instead use
 *  the special C<?> symbols to initialize inputs. This is
 *  clearer and more regular.
 *
 * Revision 1.51  2001/05/02 01:57:25  steve
 *  Support behavioral subtraction.
 *
 * Revision 1.50  2001/05/01 05:00:02  steve
 *  Implement %ix/load.
 *
 * Revision 1.49  2001/05/01 02:18:15  steve
 *  Account for ipoint_input_index behavior in inputs_connect.
 *
 * Revision 1.48  2001/05/01 01:09:39  steve
 *  Add support for memory objects. (Stephan Boettcher)
 *
 * Revision 1.47  2001/04/30 03:53:19  steve
 *  Fix up functor inputs to support C<?> values.
 *
 * Revision 1.46  2001/04/29 23:13:33  steve
 *  Add bufif0 and bufif1 functors.
 *
 * Revision 1.45  2001/04/29 22:59:46  steve
 *  Support .net constant inputs.
 *
 * Revision 1.44  2001/04/28 20:24:03  steve
 *  input connect cleanup. (Stephan Boettcher)
 *
 * Revision 1.43  2001/04/26 15:52:22  steve
 *  Add the mode-42 functor concept to UDPs.
 *
 * Revision 1.42  2001/04/26 05:12:02  steve
 *  Implement simple MUXZ for ?: operators.
 *
 * Revision 1.41  2001/04/26 03:10:55  steve
 *  Redo and simplify UDP behavior.
 *
 * Revision 1.40  2001/04/24 03:48:53  steve
 *  Fix underflow when UDP has 1 input.
 *
 * Revision 1.39  2001/04/24 02:23:59  steve
 *  Support for UDP devices in VVP (Stephen Boettcher)
 *
 * Revision 1.38  2001/04/23 00:37:58  steve
 *  Support unconnected .net objects.
 *
 * Revision 1.37  2001/04/21 02:04:01  steve
 *  Add NAND and XNOR functors.
 *
 * Revision 1.36  2001/04/18 05:03:49  steve
 *  Resolve forward references for %fork.
 *
 * Revision 1.35  2001/04/18 04:21:23  steve
 *  Put threads into scopes.
 *
 * Revision 1.34  2001/04/15 16:37:48  steve
 *  add XOR support.
 *
 * Revision 1.33  2001/04/15 04:07:56  steve
 *  Add support for behavioral xnor.
 *
 * Revision 1.32  2001/04/14 05:10:56  steve
 *  support the .event/or statement.
 *
 * Revision 1.31  2001/04/13 03:55:18  steve
 *  More complete reap of all threads.
 *
 * Revision 1.30  2001/04/05 01:34:26  steve
 *  Add the .var/s and .net/s statements for VPI support.
 *
 * Revision 1.29  2001/04/05 01:12:28  steve
 *  Get signed compares working correctly in vvp.
 *
 * Revision 1.28  2001/04/01 22:25:33  steve
 *  Add the reduction nor instruction.
 *
 * Revision 1.27  2001/04/01 21:31:46  steve
 *  Add the buf functor type.
 *
 * Revision 1.26  2001/04/01 07:22:08  steve
 *  Implement the less-then and %or instructions.
 *
 * Revision 1.25  2001/04/01 06:40:45  steve
 *  Support empty statements for hanging labels.
 *
 * Revision 1.24  2001/04/01 06:12:13  steve
 *  Add the bitwise %and instruction.
 *
 * Revision 1.23  2001/04/01 04:34:28  steve
 *  Implement %cmp/x and %cmp/z instructions.
 *
 * Revision 1.22  2001/03/31 19:00:43  steve
 *  Add VPI support for the simulation time.
 *
 * Revision 1.21  2001/03/31 17:36:02  steve
 *  Add the jmp/1 instruction.
 *
 * Revision 1.20  2001/03/31 01:59:59  steve
 *  Add the ADD instrunction.
 *
 * Revision 1.19  2001/03/30 04:55:22  steve
 *  Add fork and join instructions.
 *
 * Revision 1.18  2001/03/29 03:46:36  steve
 *  Support named events as mode 2 functors.
 *
 * Revision 1.17  2001/03/28 17:24:32  steve
 *  include string.h for strcmp et al.
 *
 * Revision 1.16  2001/03/26 04:00:39  steve
 *  Add the .event statement and the %wait instruction.
 *
 * Revision 1.15  2001/03/25 19:38:23  steve
 *  Support NOR and NOT gates.
 *
 * Revision 1.14  2001/03/25 03:54:26  steve
 *  Add JMP0XZ and postpone net inputs when needed.
 *
 * Revision 1.13  2001/03/25 00:35:35  steve
 *  Add the .net statement.
 */