minimips.md

基于4个mips核的noc设计

    case RSH + I:
    case LSH + I:
    case RSH + U:
    case LSH + U:
      if (generic (p->kids[1]->op) != CNST)
	spill (INTTMP, IREG, p);
      break;
    case CALL + V:
      spill (INTTMP | INTRET, IREG, p);
      break;
    }
}

static void
emit2shift (Node p, char *shift_opcode)
{
  int distance = p->kids[1]->syms[0]->u.c.v.i & 31;
  int src = getregnum (p->x.kids[0]);
  int dst = getregnum (p);

  if (distance == 0)
    print ("\tmove $%d, $%d\n", dst, src);
  else
    {
      if (distance & 1)
	{
	  print ("\t%s $%d, $%d, 1\n", shift_opcode, dst, src);
	  src = dst;
	}
      if (distance & 2)
	{
	  print ("\t%s $%d, $%d, 2\n", shift_opcode, dst, src);
	  src = dst;
	}
      if (distance & 4)
	{
	  print ("\t%s $%d, $%d, 2\n", shift_opcode, dst, src);
	  print ("\t%s $%d, $%d, 2\n", shift_opcode, dst, dst);
	  src = dst;
	}
      if (distance & 8)
	{
	  print ("\t%s $%d, $%d, 8\n", shift_opcode, dst, src);
	  src = dst;
	}
      if (distance & 16)
	{
	  print ("\t%s $%d, $%d, 8\n", shift_opcode, dst, src);
	  print ("\t%s $%d, $%d, 8\n", shift_opcode, dst, dst);
	  src = dst;
	}
    }
}

static void
emit2 (Node p)
{
  int src, sz, ty;
  static int ty0;
  Symbol q;

  switch (specific (p->op))
    {
    case ARG + F:
    case ARG + I:
    case ARG + P:
    case ARG + U:
      ty = optype (p->op);
      sz = opsize (p->op);
      if (p->x.argno == 0)
	ty0 = ty;
      q = argreg (p->x.argno, p->syms[2]->u.c.v.i, ty, sz, ty0);
      src = getregnum (p->x.kids[0]);
      if (q == NULL)
	print ("\tsw $%d,%d($sp)\n", src, p->syms[2]->u.c.v.i);
      break;
    case ASGN + B:
      dalign = salign = p->syms[1]->u.c.v.i;
      blkcopy (getregnum (p->x.kids[0]), 0,
	       getregnum (p->x.kids[1]), 0, p->syms[0]->u.c.v.i, tmpregs);
      break;
    case LSH + I:
    case LSH + U:
      emit2shift (p, "sll");
      break;
    case RSH + I:
      emit2shift (p, "sra");
      break;
    case RSH + U:
      emit2shift (p, "srl");
      break;
    }
}

static Symbol
argreg (int argno, int offset, int ty, int sz, int ty0)
{
  assert ((offset & 3) == 0);

  if (offset > 12)
    return NULL;
  else
    return ireg[(offset / 4) + 4];
}

static void
doarg (Node p)
{
  static int argno;
  int align;

  if (argoffset == 0)
    argno = 0;
  p->x.argno = argno++;
  align = p->syms[1]->u.c.v.i < 4 ? 4 : p->syms[1]->u.c.v.i;
  p->syms[2] = intconst (mkactual (align, p->syms[0]->u.c.v.i));
}

static void
local (Symbol p)
{
  if (askregvar (p, rmap (ttob (p->type))) == 0)
    mkauto (p);
}

static void
function (Symbol f, Symbol caller[], Symbol callee[], int ncalls)
{
  int i, saved, sizeisave, varargs;
  Symbol r, argregs[4];

  usedmask[0] = usedmask[1] = 0;
  freemask[0] = freemask[1] = ~(unsigned) 0;
  offset = maxoffset = maxargoffset = 0;
  for (i = 0; callee[i]; i++)
    ;
  varargs = variadic (f->type)
    || i > 0 && strcmp (callee[i - 1]->name, "va_alist") == 0;
  for (i = 0; callee[i]; i++)
    {
      Symbol p = callee[i];
      Symbol q = caller[i];
      assert (q);
      offset = roundup (offset, q->type->align);
      p->x.offset = q->x.offset = offset;
      p->x.name = q->x.name = stringd (offset);
      r = argreg (i, offset, optype (ttob (q->type)), q->type->size,
		  optype (ttob (caller[0]->type)));
      if (i < 4)
	argregs[i] = r;
      offset = roundup (offset + q->type->size, 4);
      if (varargs)
	p->sclass = AUTO;
      else if (r && ncalls == 0 &&
	       !isstruct (q->type) && !p->addressed &&
	       !(isfloat (q->type) && r->x.regnode->set == IREG))
	{
	  p->sclass = q->sclass = REGISTER;
	  askregvar (p, r);
	  assert (p->x.regnode && p->x.regnode->vbl == p);
	  q->x = p->x;
	  q->type = p->type;
	}
      else if (askregvar (p, rmap (ttob (p->type)))
	       && r != NULL && (isint (p->type) || p->type == q->type))
	{
	  assert (q->sclass != REGISTER);
	  p->sclass = q->sclass = REGISTER;
	  q->type = p->type;
	}
    }
  assert (!caller[i]);
  offset = 0;
  gencode (caller, callee);
  if (ncalls)
    usedmask[IREG] |= ((unsigned) 1) << 31;
  usedmask[IREG] &= 0xc0ff0000;
  maxargoffset = roundup (maxargoffset, 4);
  if (ncalls && maxargoffset < 16)
    maxargoffset = 16;
  sizeisave = 4 * bitcount (usedmask[IREG]);
  framesize = roundup (maxargoffset + sizeisave + maxoffset, 8);
  segment (CODE);
  print ("\t.align 2\n");
  print ("\t.ent %s\n", f->x.name);
  print ("%s:\n", f->x.name);
  i = maxargoffset - framesize;
  print ("\t.frame $sp,%d,$31\n", framesize);
  if (framesize > 0)
    print ("\taddu $sp,$sp,%d\n", -framesize);
  if (usedmask[IREG])
    print ("\t.mask 0x%x,%d\n", usedmask[IREG], i + sizeisave - 4);
  saved = maxargoffset;

  for (i = 16; i <= 31; i++)
    if (usedmask[IREG] & (1 << i))
      {
	print ("\tsw $%d,%d($sp)\n", i, saved);
	saved += 4;
      }
  for (i = 0; i < 4 && callee[i]; i++)
    {
      r = argregs[i];
      if (r && r->x.regnode != callee[i]->x.regnode)
	{
	  Symbol out = callee[i];
	  Symbol in = caller[i];
	  int rn = r->x.regnode->number;

	  assert (out && in && r && r->x.regnode);
	  assert (out->sclass != REGISTER || out->x.regnode);
	  if (out->sclass == REGISTER
	      && (isint (out->type) || out->type == in->type))
	    {
	      int outn = out->x.regnode->number;
	      print ("\tmove $%d,$%d\n", outn, rn);
	    }
	  else
	    {
	      int off = in->x.offset + framesize;
	      {
		int i, n = (in->type->size + 3) / 4;
		for (i = rn; i < rn + n && i <= 7; i++)
		  print ("\tsw $%d,%d($sp)\n", i, off + (i - rn) * 4);
	      }
	    }
	}
    }
  if (varargs && callee[i - 1])
    {
      i = callee[i - 1]->x.offset + callee[i - 1]->type->size;
      for (i = roundup (i, 4) / 4; i <= 3; i++)
	print ("\tsw $%d,%d($sp)\n", i + 4, framesize + 4 * i);
    }
  emitcode ();
  saved = maxargoffset;
  for (i = 16; i <= 31; i++)
    if (usedmask[IREG] & (1 << i))
      {
	print ("\tlw $%d,%d($sp)\n", i, saved);
	saved += 4;
      }
  if (framesize > 0)
    print ("\taddu $sp,$sp,%d\n", framesize);
  print ("\tj $31\n");
  print ("\t.end %s\n", f->x.name);
}

static void
defconst (int suffix, int size, Value v)
{
  if (suffix == F)
    {
      float f = v.d;
      print ("\t.word 0x%x\n", *(unsigned *) &f);
    }
  else if (suffix == P)
    print ("\t.word 0x%x\n", v.p);
  else if (size == 1)
    print ("\t.byte 0x%x\n", suffix == I ? v.i : v.u);
  else if (size == 2)
    print ("\t.half 0x%x\n", suffix == I ? v.i : v.u);
  else if (size == 4)
    print ("\t.word 0x%x\n", suffix == I ? v.i : v.u);
}

static void
defaddress (Symbol p)
{
  print ("\t.word %s\n", p->x.name);
}

static void
defstring (int n, char *str)
{
  char *s;

  for (s = str; s < str + n; s++)
    print ("\t.byte %d\n", (*s) & 0377);
}

static void
export (Symbol p)
{
  print ("\t.globl %s\n", p->x.name);
}

static void
import (Symbol p)
{
  if (!isfunc (p->type))
    print ("\t.extern %s %d\n", p->name, p->type->size);
}

static void
defsymbol (Symbol p)
{
  if (p->scope >= LOCAL && p->sclass == STATIC)
    p->x.name = stringf ("L.%d", genlabel (1));
  else if (p->generated)
    p->x.name = stringf ("L.%s", p->name);
  else
    assert (p->scope != CONSTANTS || isint (p->type) || isptr (p->type)),
      p->x.name = p->name;
}

static void
address (Symbol q, Symbol p, long n)
{
  if (p->scope == GLOBAL || p->sclass == STATIC || p->sclass == EXTERN)
    q->x.name = stringf ("%s%s%D", p->x.name, n >= 0 ? "+" : "", n);
  else
    {
      assert (n <= INT_MAX && n >= INT_MIN);
      q->x.offset = p->x.offset + n;
      q->x.name = stringd (q->x.offset);
    }
}

static void global (Symbol p)
{
  if (p->u.seg == BSS)
    {
      if (p->sclass == STATIC || Aflag >= 2)
	print ("\t.lcomm %s,%d\n", p->x.name, p->type->size);
      else
	print ("\t.comm %s,%d\n", p->x.name, p->type->size);
    }
  else
    {
      print ("\t.data\n");
      print ("\t.align %c\n", ".01.2...3"[p->type->align]);
      print ("%s:\n", p->x.name);
    }
}

static void
segment (int n)
{
  cseg = n;
  switch (n)
    {
    case CODE:
      print ("\t.text\n");
      break;
    case LIT:
      print ("\t.rdata\n");
      break;
    }
}

static void
space (int n)
{
  if (cseg != BSS)
    print ("\t.space %d\n", n);
}

static void
blkloop (int dreg, int doff, int sreg, int soff, int size, int tmps[])
{
  int lab = genlabel (1);

  print ("\taddu $%d,$%d,%d\n", sreg, sreg, size & ~7);
  print ("\taddu $%d,$%d,%d\n", tmps[2], dreg, size & ~7);
  blkcopy (tmps[2], doff, sreg, soff, size & 7, tmps);
  print ("L.%d:\n", lab);
  print ("\taddu $%d,$%d,%d\n", sreg, sreg, -8);
  print ("\taddu $%d,$%d,%d\n", tmps[2], tmps[2], -8);
  blkcopy (tmps[2], doff, sreg, soff, 8, tmps);
  print ("\tbltu $%d,$%d,L.%d\n", dreg, tmps[2], lab);
}

static void
blkfetch (int size, int off, int reg, int tmp)
{
  assert (size == 1 || size == 2 || size == 4);
  assert (tmp != reg);

  if (size == 1)
    print ("\tlb $%d,%d($%d)\n", tmp, off, reg);
  else if (size == 2)
    {
      print ("\tlb $%d,%d($%d)\n", tmp, off + 1, reg);
      print ("\tsll $%d,$%d,8\n", tmp, tmp);
      print ("\tlb $%d,%d($%d)\n", 30, off + 0, reg);
      print ("\tor $%d,$%d,$%d\n", tmp, tmp, 30);
    }
  else
    {
      if (salign >= size)
	print ("\tlw $%d,%d($%d)\n", tmp, off, reg);
      else
	{
	  print ("\tlb $%d,%d($%d)\n", tmp, off + 3, reg);
	  print ("\tsll $%d,$%d,8\n", tmp, tmp);
	  print ("\tlb $%d,%d($%d)\n", 30, off + 2, reg);
	  print ("\tor $%d,$%d,$%d\n", tmp, tmp, 30);
	  print ("\tsll $%d,$%d,8\n", tmp, tmp);
	  print ("\tlb $%d,%d($%d)\n", 30, off + 1, reg);
	  print ("\tor $%d,$%d,$%d\n", tmp, tmp, 30);
	  print ("\tsll $%d,$%d,8\n", tmp, tmp);
	  print ("\tlb $%d,%d($%d)\n", 30, off + 0, reg);
	  print ("\tor $%d,$%d,$%d\n", tmp, tmp, 30);
	}
    }
}

static void
blkstore (int size, int off, int reg, int tmp)
{
  assert (size == 1 || size == 2 || size == 4);
  assert (tmp != reg);

  if (size == 1)
    print ("\tsb $%d,%d($%d)\n", tmp, off, reg);
  else if (size == 2)
    {
      print ("\tsb $%d,%d($%d)\n", tmp, off, reg);
      print ("\tsrl $%d,$%d,8\n", 30, tmp);
      print ("\tsb $%d,%d($%d)\n", 30, off + 1, reg);
    }
  else
    {
      if (dalign >= size)
	print ("sw $%d,%d($%d)\n", tmp, off, reg);
      else
	{
	  print ("\tsb $%d,%d($%d)\n", tmp, off, reg);
	  print ("\tsrl $%d,$%d,8\n", 30, tmp);
	  print ("\tsb $%d,%d($%d)\n", 30, off + 1, reg);
	  print ("\tsrl $%d,$%d,8\n", 30, 30);
	  print ("\tsb $%d,%d($%d)\n", 30, off + 2, reg);
	  print ("\tsrl $%d,$%d,8\n", 30, 30);
	  print ("\tsb $%d,%d($%d)\n", 30, off + 3, reg);
	}
    }
}

static int
bitcount (unsigned mask)
{
  unsigned i, n = 0;

  for (i = 1; i; i <<= 1)
    if (mask & i)
      n++;
  return n;
}

static int
mulops_calls (int op)
{
  if (generic (op) == DIV || generic (op) == MOD || generic (op) == MUL)
    return 1;

  if (generic (op) == LSH || generic (op) == RSH)
    return 1;

  if ((generic (op) == ADD || generic (op) == SUB) && optype (op) == F)
    return 1;

  if (generic (op) == NEG && optype (op) == F)
    return 1;

  if (generic (op) == CVI && optype (op) == F)
    return 1;

  if (generic (op) == CVF && optype (op) == I)
    return 1;

  return 0;
}

Interface minimipsIR = {
  1, 1, 0,			/* char */
  4, 4, 0,			/* short */
  4, 4, 0,			/* int */
  4, 4, 0,			/* long */
  4, 4, 0,			/* long long */
  4, 4, 1,			/* float */
  4, 4, 1,			/* double */
  4, 4, 1,			/* long double */
  4, 4, 0,			/* T * */
  0, 1, 0,			/* struct */
  0,				/* little_endian */
  mulops_calls,			/* mulops_calls */
  0,				/* wants_callb */
  0,				/* wants_argb */
  1,				/* left_to_right */
  0,				/* wants_dag */
  0,				/* unsigned_char */
  address,
  blockbeg,
  blockend,
  defaddress,
  defconst,
  defstring,
  defsymbol,
  emit,
  export,
  function,
  gen,
  global,
  import,
  local,
  progbeg,
  progend,
  segment,
  space,
  0, 0, 0, 0, 0, 0, 0,
  {
   4,				/* max_unaligned_load */
   rmap,
   blkfetch, blkstore, blkloop,
   _label,
   _rule,
   _nts,
   _kids,
   _string,
   _templates,
   _isinstruction,
   _ntname,
   emit2,
   doarg,
   target,
   clobber,
   }
};