i386.c

早期freebsd实现

	/* We can't handle floating point constants;
	   PRINT_OPERAND must handle them.  */
	output_operand_lossage ("floating constant misused");
      break;

    case PLUS:
      /* Some assemblers need integer constants to appear last (eg masm).  */
      if (GET_CODE (XEXP (x, 0)) == CONST_INT)
	{
	  output_pic_addr_const (file, XEXP (x, 1), code);
	  if (INTVAL (XEXP (x, 0)) >= 0)
	    fprintf (file, "+");
	  output_pic_addr_const (file, XEXP (x, 0), code);
	}
      else
	{
	  output_pic_addr_const (file, XEXP (x, 0), code);
	  if (INTVAL (XEXP (x, 1)) >= 0)
	    fprintf (file, "+");
	  output_pic_addr_const (file, XEXP (x, 1), code);
	}
      break;

    case MINUS:
      output_pic_addr_const (file, XEXP (x, 0), code);
      fprintf (file, "-");
      output_pic_addr_const (file, XEXP (x, 1), code);
      break;

    default:
      output_operand_lossage ("invalid expression as operand");
    }
}

/* Meaning of CODE:
   f -- float insn (print a CONST_DOUBLE as a float rather than in hex).
   D,L,W,B,Q,S -- print the opcode suffix for specified size of operand.
   R -- print the prefix for register names.
   z -- print the opcode suffix for the size of the current operand.
   * -- print a star (in certain assembler syntax)
   w -- print the operand as if it's a "word" (HImode) even if it isn't.
   c -- don't print special prefixes before constant operands.
*/

void
print_operand (file, x, code)
     FILE *file;
     rtx x;
     int code;
{
  if (code)
    {
      switch (code)
	{
	case '*':
	  if (USE_STAR)
	    putc ('*', file);
	  return;

	case 'L':
	  PUT_OP_SIZE (code, 'l', file);
	  return;

	case 'W':
	  PUT_OP_SIZE (code, 'w', file);
	  return;

	case 'B':
	  PUT_OP_SIZE (code, 'b', file);
	  return;

	case 'Q':
	  PUT_OP_SIZE (code, 'l', file);
	  return;

	case 'S':
	  PUT_OP_SIZE (code, 's', file);
	  return;

	case 'z':
	  /* 387 opcodes don't get size suffixes if the operands are
	     registers. */

	  if (STACK_REG_P (x))
	    return;

	  /* this is the size of op from size of operand */
	  switch (GET_MODE_SIZE (GET_MODE (x)))
	    {
	    case 1:
	      PUT_OP_SIZE ('B', 'b', file);
	      return;

	    case 2:
	      PUT_OP_SIZE ('W', 'w', file);
	      return;

	    case 4:
	      if (GET_MODE (x) == SFmode)
		{
		  PUT_OP_SIZE ('S', 's', file);
		  return;
		}
	      else
		PUT_OP_SIZE ('L', 'l', file);
	      return;

	    case 8:
	      if (GET_MODE_CLASS (GET_MODE (x)) == MODE_INT)
		{
#ifdef GAS_MNEMONICS
		  PUT_OP_SIZE ('Q', 'q', file);
		  return;
#else
		  PUT_OP_SIZE ('Q', 'l', file);	/* Fall through */
#endif
		}

	      PUT_OP_SIZE ('Q', 'l', file);
	      return;
	    }

	case 'b':
	case 'w':
	case 'k':
	case 'h':
	case 'y':
	case 'P':
	  break;

	default:
	  {
	    char str[50];

	    sprintf (str, "invalid operand code `%c'", code);
	    output_operand_lossage (str);
	  }
	}
    }
  if (GET_CODE (x) == REG)
    {
      PRINT_REG (x, code, file);
    }
  else if (GET_CODE (x) == MEM)
    {
      PRINT_PTR (x, file);
      if (CONSTANT_ADDRESS_P (XEXP (x, 0)))
	{
	  if (flag_pic)
	    output_pic_addr_const (file, XEXP (x, 0), code);
	  else
	    output_addr_const (file, XEXP (x, 0));
	}
      else
	output_address (XEXP (x, 0));
    }
  else if (GET_CODE (x) == CONST_DOUBLE && GET_MODE (x) == SFmode)
    {
      union { double d; int i[2]; } u;
      union { float f; int i; } u1;
      u.i[0] = CONST_DOUBLE_LOW (x);
      u.i[1] = CONST_DOUBLE_HIGH (x);
      u1.f = u.d;
      PRINT_IMMED_PREFIX (file);
      fprintf (file, "0x%x", u1.i);
    }
  else if (GET_CODE (x) == CONST_DOUBLE && GET_MODE (x) == DFmode)
    {
      union { double d; int i[2]; } u;
      u.i[0] = CONST_DOUBLE_LOW (x);
      u.i[1] = CONST_DOUBLE_HIGH (x);
      fprintf (file, "%.22e", u.d);
    }
  else 
    {
      if (code != 'P')
	{
	  if (GET_CODE (x) == CONST_INT || GET_CODE (x) == CONST_DOUBLE)
	    PRINT_IMMED_PREFIX (file);
	  else if (GET_CODE (x) == CONST || GET_CODE (x) == SYMBOL_REF
		   || GET_CODE (x) == LABEL_REF)
	    PRINT_OFFSET_PREFIX (file);
	}
      if (flag_pic)
	output_pic_addr_const (file, x, code);
      else
	output_addr_const (file, x);
    }
}

/* Print a memory operand whose address is ADDR.  */

void
print_operand_address (file, addr)
     FILE *file;
     register rtx addr;
{
  register rtx reg1, reg2, breg, ireg;
  rtx offset;

  switch (GET_CODE (addr))
    {
    case REG:
      ADDR_BEG (file);
      fprintf (file, "%se", RP);
      fputs (hi_reg_name[REGNO (addr)], file);
      ADDR_END (file);
      break;

    case PLUS:
      reg1 = 0;
      reg2 = 0;
      ireg = 0;
      breg = 0;
      offset = 0;
      if (CONSTANT_ADDRESS_P (XEXP (addr, 0)))
	{
	  offset = XEXP (addr, 0);
	  addr = XEXP (addr, 1);
	}
      else if (CONSTANT_ADDRESS_P (XEXP (addr, 1)))
	{
	  offset = XEXP (addr, 1);
	  addr = XEXP (addr, 0);
	}
      if (GET_CODE (addr) != PLUS) ;
      else if (GET_CODE (XEXP (addr, 0)) == MULT)
	{
	  reg1 = XEXP (addr, 0);
	  addr = XEXP (addr, 1);
	}
      else if (GET_CODE (XEXP (addr, 1)) == MULT)
	{
	  reg1 = XEXP (addr, 1);
	  addr = XEXP (addr, 0);
	}
      else if (GET_CODE (XEXP (addr, 0)) == REG)
	{
	  reg1 = XEXP (addr, 0);
	  addr = XEXP (addr, 1);
	}
      else if (GET_CODE (XEXP (addr, 1)) == REG)
	{
	  reg1 = XEXP (addr, 1);
	  addr = XEXP (addr, 0);
	}
      if (GET_CODE (addr) == REG || GET_CODE (addr) == MULT)
	{
	  if (reg1 == 0) reg1 = addr;
	  else reg2 = addr;
	  addr = 0;
	}
      if (offset != 0)
	{
	  if (addr != 0) abort ();
	  addr = offset;
	}
      if ((reg1 && GET_CODE (reg1) == MULT)
	  || (reg2 != 0 && REGNO_OK_FOR_BASE_P (REGNO (reg2))))
	{
	  breg = reg2;
	  ireg = reg1;
	}
      else if (reg1 != 0 && REGNO_OK_FOR_BASE_P (REGNO (reg1)))
	{
	  breg = reg1;
	  ireg = reg2;
	}

      if (ireg != 0 || breg != 0)
	{
	  int scale = 1;

	  if (addr != 0)
	    {
	      if (GET_CODE (addr) == LABEL_REF)
		output_asm_label (addr);
	      else
		{
		  if (flag_pic)
		    output_pic_addr_const (file, addr, 0);
		  else
		    output_addr_const (file, addr);
		}
	    }

  	  if (ireg != 0 && GET_CODE (ireg) == MULT)
	    {
	      scale = INTVAL (XEXP (ireg, 1));
	      ireg = XEXP (ireg, 0);
	    }

	  /* The stack pointer can only appear as a base register,
	     never an index register, so exchange the regs if it is wrong. */

	  if (scale == 1 && ireg && REGNO (ireg) == STACK_POINTER_REGNUM)
	    {
	      rtx tmp;

	      tmp = breg;
	      breg = ireg;
	      ireg = tmp;
	    }

	  /* output breg+ireg*scale */
	  PRINT_B_I_S (breg, ireg, scale, file);
	  break;
	}

    case MULT:
      {
	int scale;
	if (GET_CODE (XEXP (addr, 0)) == CONST_INT)
	  {
	    scale = INTVAL (XEXP (addr, 0));
	    ireg = XEXP (addr, 1);
	  }
	else
	  {
	    scale = INTVAL (XEXP (addr, 1));
	    ireg = XEXP (addr, 0);
	  }
	output_addr_const (file, const0_rtx);
	PRINT_B_I_S ((rtx) 0, ireg, scale, file);
      }
      break;

    default:
      if (GET_CODE (addr) == CONST_INT
	  && INTVAL (addr) < 0x8000
	  && INTVAL (addr) >= -0x8000)
	fprintf (file, "%d", INTVAL (addr));
      else
	{
	  if (flag_pic)
	    output_pic_addr_const (file, addr, 0);
	  else
	    output_addr_const (file, addr);
	}
    }
}

/* Set the cc_status for the results of an insn whose pattern is EXP.
   On the 80386, we assume that only test and compare insns, as well
   as SI, HI, & DI mode ADD, SUB, NEG, AND, IOR, XOR, ASHIFT, LSHIFT,
   ASHIFTRT, and LSHIFTRT instructions set the condition codes usefully.
   Also, we assume that jumps, moves and sCOND don't affect the condition
   codes.  All else clobbers the condition codes, by assumption.

   We assume that ALL integer add, minus, etc. instructions effect the
   condition codes.  This MUST be consistent with i386.md.

   We don't record any float test or compare - the redundant test &
   compare check in final.c does not handle stack-like regs correctly. */

void
notice_update_cc (exp)
     rtx exp;
{
  if (GET_CODE (exp) == SET)
    {
      /* Jumps do not alter the cc's.  */
      if (SET_DEST (exp) == pc_rtx)
	return;
      /* Moving register or memory into a register:
	 it doesn't alter the cc's, but it might invalidate
	 the RTX's which we remember the cc's came from.
	 (Note that moving a constant 0 or 1 MAY set the cc's).  */
      if (REG_P (SET_DEST (exp))
	  && (REG_P (SET_SRC (exp)) || GET_CODE (SET_SRC (exp)) == MEM
	      || GET_RTX_CLASS (GET_CODE (SET_SRC (exp))) == '<'))
	{
	  if (cc_status.value1
	      && reg_overlap_mentioned_p (SET_DEST (exp), cc_status.value1))
	    cc_status.value1 = 0;
	  if (cc_status.value2
	      && reg_overlap_mentioned_p (SET_DEST (exp), cc_status.value2))
	    cc_status.value2 = 0;
	  return;
	}
      /* Moving register into memory doesn't alter the cc's.
	 It may invalidate the RTX's which we remember the cc's came from.  */
      if (GET_CODE (SET_DEST (exp)) == MEM
	  && (REG_P (SET_SRC (exp))
	      || GET_RTX_CLASS (GET_CODE (SET_SRC (exp))) == '<'))
	{
	  if (cc_status.value1 && GET_CODE (cc_status.value1) == MEM)
	    cc_status.value1 = 0;
	  if (cc_status.value2 && GET_CODE (cc_status.value2) == MEM)
	    cc_status.value2 = 0;
	  return;
	}
      /* Function calls clobber the cc's.  */
      else if (GET_CODE (SET_SRC (exp)) == CALL)
	{
	  CC_STATUS_INIT;
	  return;
	}
      /* Tests and compares set the cc's in predictable ways.  */
      else if (SET_DEST (exp) == cc0_rtx)
	{
	  CC_STATUS_INIT;
	  cc_status.value1 = SET_SRC (exp);
	  return;
	}
      /* Certain instructions effect the condition codes. */
      else if (GET_MODE (SET_SRC (exp)) == SImode
	       || GET_MODE (SET_SRC (exp)) == HImode
	       || GET_MODE (SET_SRC (exp)) == QImode)
	switch (GET_CODE (SET_SRC (exp)))
	  {
	  case ASHIFTRT: case LSHIFTRT:
	  case ASHIFT: case LSHIFT:
	    /* Shifts on the 386 don't set the condition codes if the
	       shift count is zero. */
	    if (GET_CODE (XEXP (SET_SRC (exp), 1)) != CONST_INT)
	      {
		CC_STATUS_INIT;
		break;
	      }
	    /* We assume that the CONST_INT is non-zero (this rtx would
	       have been deleted if it were zero. */

	  case PLUS: case MINUS: case NEG:
	  case AND: case IOR: case XOR:
	    cc_status.flags = CC_NO_OVERFLOW;
	    cc_status.value1 = SET_SRC (exp);
	    cc_status.value2 = SET_DEST (exp);
	    break;

	  default:
	    CC_STATUS_INIT;
	  }
      else
	{
	  CC_STATUS_INIT;
	}
    }
  else if (GET_CODE (exp) == PARALLEL
	   && GET_CODE (XVECEXP (exp, 0, 0)) == SET)
    {
      if (SET_DEST (XVECEXP (exp, 0, 0)) == pc_rtx)
	return;
      if (SET_DEST (XVECEXP (exp, 0, 0)) == cc0_rtx)
	{
	  CC_STATUS_INIT;
	  if (stack_regs_mentioned_p (SET_SRC (XVECEXP (exp, 0, 0))))
	    cc_status.flags |= CC_IN_80387;
	  else
	    cc_status.value1 = SET_SRC (XVECEXP (exp, 0, 0));
	  return;
	}
      CC_STATUS_INIT;
    }
  else
    {
      CC_STATUS_INIT;
    }
}