xtensa.c

Mac OS X 10.4.9 for x86 Source Code gcc 实现源代码

    return nonimmed_operand (op, mode);
  return mem_operand (op, mode);
}


int
sext_fldsz_operand (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return ((GET_CODE (op) == CONST_INT) && xtensa_tp7 (INTVAL (op) - 1));
}


int
lsbitnum_operand (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  if (GET_CODE (op) == CONST_INT)
    {
      return (BITS_BIG_ENDIAN
	      ? (INTVAL (op) == BITS_PER_WORD-1)
	      : (INTVAL (op) == 0));
    }
  return FALSE;
}


static int
b4const_or_zero (int v)
{
  if (v == 0)
    return TRUE;
  return xtensa_b4const (v);
}


int
branch_operand (rtx op, enum machine_mode mode)
{
  if (GET_CODE (op) == CONST_INT)
    return b4const_or_zero (INTVAL (op));

  return register_operand (op, mode);
}


int
ubranch_operand (rtx op, enum machine_mode mode)
{
  if (GET_CODE (op) == CONST_INT)
    return xtensa_b4constu (INTVAL (op));

  return register_operand (op, mode);
}


int
call_insn_operand (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  if ((GET_CODE (op) == REG)
      && (op != arg_pointer_rtx)
      && ((REGNO (op) < FRAME_POINTER_REGNUM)
	  || (REGNO (op) > LAST_VIRTUAL_REGISTER)))
    return TRUE;

  if (CONSTANT_ADDRESS_P (op))
    {
      /* Direct calls only allowed to static functions with PIC.  */
      if (flag_pic)
	{
	  tree callee, callee_sec, caller_sec;

	  if (GET_CODE (op) != SYMBOL_REF
	      || !SYMBOL_REF_LOCAL_P (op) || SYMBOL_REF_EXTERNAL_P (op))
	    return FALSE;

	  /* Don't attempt a direct call if the callee is known to be in
	     a different section, since there's a good chance it will be
	     out of range.  */

	  if (flag_function_sections
	      || DECL_ONE_ONLY (current_function_decl))
	    return FALSE;
	  caller_sec = DECL_SECTION_NAME (current_function_decl);
	  callee = SYMBOL_REF_DECL (op);
	  if (callee)
	    {
	      if (DECL_ONE_ONLY (callee))
		return FALSE;
	      callee_sec = DECL_SECTION_NAME (callee);
	      if (((caller_sec == NULL_TREE) ^ (callee_sec == NULL_TREE))
		  || (caller_sec != NULL_TREE
		      && strcmp (TREE_STRING_POINTER (caller_sec),
				 TREE_STRING_POINTER (callee_sec)) != 0))
		return FALSE;
	    }
	  else if (caller_sec != NULL_TREE)
	    return FALSE;
	}
      return TRUE;
    }

  return FALSE;
}


int
move_operand (rtx op, enum machine_mode mode)
{
  if (register_operand (op, mode)
      || memory_operand (op, mode))
    return TRUE;

  switch (mode)
    {
    case DFmode:
    case SFmode:
      return TARGET_CONST16 && CONSTANT_P (op);

    case DImode:
    case SImode:
      if (TARGET_CONST16)
	return CONSTANT_P (op);
      /* Fall through.  */

    case HImode:
    case QImode:
      if (GET_CODE (op) == CONST_INT && xtensa_simm12b (INTVAL (op)))
	return TRUE;
      break;

    default:
      break;
    }

  return FALSE;
}


int
smalloffset_mem_p (rtx op)
{
  if (GET_CODE (op) == MEM)
    {
      rtx addr = XEXP (op, 0);
      if (GET_CODE (addr) == REG)
	return REG_OK_FOR_BASE_P (addr);
      if (GET_CODE (addr) == PLUS)
	{
	  rtx offset = XEXP (addr, 0);
	  if (GET_CODE (offset) != CONST_INT)
	    offset = XEXP (addr, 1);
	  if (GET_CODE (offset) != CONST_INT)
	    return FALSE;
	  return xtensa_lsi4x4 (INTVAL (offset));
	}
    }
  return FALSE;
}


int
constantpool_address_p (rtx addr)
{
  rtx sym = addr;

  if (GET_CODE (addr) == CONST)
    {
      rtx offset;

      /* Only handle (PLUS (SYM, OFFSET)) form.  */
      addr = XEXP (addr, 0);
      if (GET_CODE (addr) != PLUS)
	return FALSE;

      /* Make sure the address is word aligned.  */
      offset = XEXP (addr, 1);
      if ((GET_CODE (offset) != CONST_INT)
	  || ((INTVAL (offset) & 3) != 0))
	return FALSE;

      sym = XEXP (addr, 0);
    }

  if ((GET_CODE (sym) == SYMBOL_REF)
      && CONSTANT_POOL_ADDRESS_P (sym))
    return TRUE;
  return FALSE;
}


int
constantpool_mem_p (rtx op)
{
  if (GET_CODE (op) == MEM)
    return constantpool_address_p (XEXP (op, 0));
  return FALSE;
}


/* Accept the floating point constant 1 in the appropriate mode.  */

int
const_float_1_operand (rtx op, enum machine_mode mode)
{
  REAL_VALUE_TYPE d;
  static REAL_VALUE_TYPE onedf;
  static REAL_VALUE_TYPE onesf;
  static int one_initialized;

  if ((GET_CODE (op) != CONST_DOUBLE)
      || (mode != GET_MODE (op))
      || (mode != DFmode && mode != SFmode))
    return FALSE;

  REAL_VALUE_FROM_CONST_DOUBLE (d, op);

  if (! one_initialized)
    {
      onedf = REAL_VALUE_ATOF ("1.0", DFmode);
      onesf = REAL_VALUE_ATOF ("1.0", SFmode);
      one_initialized = TRUE;
    }

  if (mode == DFmode)
    return REAL_VALUES_EQUAL (d, onedf);
  else
    return REAL_VALUES_EQUAL (d, onesf);
}


int
fpmem_offset_operand (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  if (GET_CODE (op) == CONST_INT)
    return xtensa_mem_offset (INTVAL (op), SFmode);
  return 0;
}


void
xtensa_extend_reg (rtx dst, rtx src)
{
  rtx temp = gen_reg_rtx (SImode);
  rtx shift = GEN_INT (BITS_PER_WORD - GET_MODE_BITSIZE (GET_MODE (src)));

  /* Generate paradoxical subregs as needed so that the modes match.  */
  src = simplify_gen_subreg (SImode, src, GET_MODE (src), 0);
  dst = simplify_gen_subreg (SImode, dst, GET_MODE (dst), 0);

  emit_insn (gen_ashlsi3 (temp, src, shift));
  emit_insn (gen_ashrsi3 (dst, temp, shift));
}


int
branch_operator (rtx x, enum machine_mode mode)
{
  if (GET_MODE (x) != mode)
    return FALSE;

  switch (GET_CODE (x))
    {
    case EQ:
    case NE:
    case LT:
    case GE:
      return TRUE;
    default:
      break;
    }
  return FALSE;
}


int
ubranch_operator (rtx x, enum machine_mode mode)
{
  if (GET_MODE (x) != mode)
    return FALSE;

  switch (GET_CODE (x))
    {
    case LTU:
    case GEU:
      return TRUE;
    default:
      break;
    }
  return FALSE;
}


int
boolean_operator (rtx x, enum machine_mode mode)
{
  if (GET_MODE (x) != mode)
    return FALSE;

  switch (GET_CODE (x))
    {
    case EQ:
    case NE:
      return TRUE;
    default:
      break;
    }
  return FALSE;
}


int
xtensa_mask_immediate (int v)
{
#define MAX_MASK_SIZE 16
  int mask_size;

  for (mask_size = 1; mask_size <= MAX_MASK_SIZE; mask_size++)
    {
      if ((v & 1) == 0)
	return FALSE;
      v = v >> 1;
      if (v == 0)
	return TRUE;
    }

  return FALSE;
}


int
xtensa_mem_offset (unsigned v, enum machine_mode mode)
{
  switch (mode)
    {
    case BLKmode:
      /* Handle the worst case for block moves.  See xtensa_expand_block_move
	 where we emit an optimized block move operation if the block can be
	 moved in < "move_ratio" pieces.  The worst case is when the block is
	 aligned but has a size of (3 mod 4) (does this happen?) so that the
	 last piece requires a byte load/store.  */
      return (xtensa_uimm8 (v)
	      && xtensa_uimm8 (v + MOVE_MAX * LARGEST_MOVE_RATIO));

    case QImode:
      return xtensa_uimm8 (v);

    case HImode:
      return xtensa_uimm8x2 (v);

    case DFmode:
      return (xtensa_uimm8x4 (v) && xtensa_uimm8x4 (v + 4));

    default:
      break;
    }

  return xtensa_uimm8x4 (v);
}


/* Make normal rtx_code into something we can index from an array.  */

static enum internal_test
map_test_to_internal_test (enum rtx_code test_code)
{
  enum internal_test test = ITEST_MAX;

  switch (test_code)
    {
    default:			break;
    case EQ:  test = ITEST_EQ;  break;
    case NE:  test = ITEST_NE;  break;
    case GT:  test = ITEST_GT;  break;
    case GE:  test = ITEST_GE;  break;
    case LT:  test = ITEST_LT;  break;
    case LE:  test = ITEST_LE;  break;
    case GTU: test = ITEST_GTU; break;
    case GEU: test = ITEST_GEU; break;
    case LTU: test = ITEST_LTU; break;
    case LEU: test = ITEST_LEU; break;
    }

  return test;
}


/* Generate the code to compare two integer values.  The return value is
   the comparison expression.  */

static rtx
gen_int_relational (enum rtx_code test_code, /* relational test (EQ, etc) */
		    rtx cmp0, /* first operand to compare */
		    rtx cmp1, /* second operand to compare */
		    int *p_invert /* whether branch needs to reverse test */)
{
  struct cmp_info
  {
    enum rtx_code test_code;	/* test code to use in insn */
    int (*const_range_p) (int);	/* predicate function to check range */
    int const_add;		/* constant to add (convert LE -> LT) */
    int reverse_regs;		/* reverse registers in test */
    int invert_const;		/* != 0 if invert value if cmp1 is constant */
    int invert_reg;		/* != 0 if invert value if cmp1 is register */
    int unsignedp;		/* != 0 for unsigned comparisons.  */
  };

  static struct cmp_info info[ (int)ITEST_MAX ] = {

    { EQ,	b4const_or_zero,	0, 0, 0, 0, 0 },	/* EQ  */
    { NE,	b4const_or_zero,	0, 0, 0, 0, 0 },	/* NE  */

    { LT,	b4const_or_zero,	1, 1, 1, 0, 0 },	/* GT  */
    { GE,	b4const_or_zero,	0, 0, 0, 0, 0 },	/* GE  */
    { LT,	b4const_or_zero,	0, 0, 0, 0, 0 },	/* LT  */
    { GE,	b4const_or_zero,	1, 1, 1, 0, 0 },	/* LE  */

    { LTU,	xtensa_b4constu,	1, 1, 1, 0, 1 },	/* GTU */
    { GEU,	xtensa_b4constu,	0, 0, 0, 0, 1 },	/* GEU */
    { LTU,	xtensa_b4constu,	0, 0, 0, 0, 1 },	/* LTU */
    { GEU,	xtensa_b4constu,	1, 1, 1, 0, 1 },	/* LEU */
  };

  enum internal_test test;
  enum machine_mode mode;
  struct cmp_info *p_info;

  test = map_test_to_internal_test (test_code);
  if (test == ITEST_MAX)
    abort ();

  p_info = &info[ (int)test ];

  mode = GET_MODE (cmp0);
  if (mode == VOIDmode)
    mode = GET_MODE (cmp1);

  /* Make sure we can handle any constants given to us.  */
  if (GET_CODE (cmp1) == CONST_INT)
    {
      HOST_WIDE_INT value = INTVAL (cmp1);
      unsigned HOST_WIDE_INT uvalue = (unsigned HOST_WIDE_INT)value;

      /* if the immediate overflows or does not fit in the immediate field,
	 spill it to a register */

      if ((p_info->unsignedp ?
	   (uvalue + p_info->const_add > uvalue) :
	   (value + p_info->const_add > value)) != (p_info->const_add > 0))
	{
	  cmp1 = force_reg (mode, cmp1);
	}
      else if (!(p_info->const_range_p) (value + p_info->const_add))
	{
	  cmp1 = force_reg (mode, cmp1);
	}
    }
  else if ((GET_CODE (cmp1) != REG) && (GET_CODE (cmp1) != SUBREG))
    {
      cmp1 = force_reg (mode, cmp1);
    }

  /* See if we need to invert the result.  */
  *p_invert = ((GET_CODE (cmp1) == CONST_INT)
	       ? p_info->invert_const
	       : p_info->invert_reg);

  /* Comparison to constants, may involve adding 1 to change a LT into LE.
     Comparison between two registers, may involve switching operands.  */
  if (GET_CODE (cmp1) == CONST_INT)
    {
      if (p_info->const_add != 0)
	cmp1 = GEN_INT (INTVAL (cmp1) + p_info->const_add);

    }
  else if (p_info->reverse_regs)
    {
      rtx temp = cmp0;
      cmp0 = cmp1;
      cmp1 = temp;
    }

  return gen_rtx_fmt_ee (p_info->test_code, VOIDmode, cmp0, cmp1);
}


/* Generate the code to compare two float values.  The return value is
   the comparison expression.  */

static rtx
gen_float_relational (enum rtx_code test_code, /* relational test (EQ, etc) */
		      rtx cmp0, /* first operand to compare */
		      rtx cmp1 /* second operand to compare */)
{
  rtx (*gen_fn) (rtx, rtx, rtx);
  rtx brtmp;
  int reverse_regs, invert;

  switch (test_code)
    {
    case EQ: reverse_regs = 0; invert = 0; gen_fn = gen_seq_sf; break;
    case NE: reverse_regs = 0; invert = 1; gen_fn = gen_seq_sf; break;
    case LE: reverse_regs = 0; invert = 0; gen_fn = gen_sle_sf; break;
    case GT: reverse_regs = 1; invert = 0; gen_fn = gen_slt_sf; break;
    case LT: reverse_regs = 0; invert = 0; gen_fn = gen_slt_sf; break;
    case GE: reverse_regs = 1; invert = 0; gen_fn = gen_sle_sf; break;
    default:
      fatal_insn ("bad test", gen_rtx_fmt_ee (test_code, VOIDmode, cmp0, cmp1));
      reverse_regs = 0; invert = 0; gen_fn = 0; /* avoid compiler warnings */
    }