tc-vax.c

基于4个mips核的noc设计

	       * modified frag type and then coding up a frag for this
	       * case will be easy. SEG_OP was invented for the
	       * .words after a CASE opcode, and was never intended for
	       * instruction operands.
	       */
	      need_pass_2 = 1;
	      as_warn (_("Can't relocate expression"));
	      break;

	    case O_big:
	      /* Preserve the bits.  */
	      if (expP->X_add_number > 0)
		{
		  bignum_copy (generic_bignum, expP->X_add_number,
			       floatP->low, SIZE_OF_LARGE_NUMBER);
		}
	      else
		{
		  know (expP->X_add_number < 0);
		  flonum_copy (&generic_floating_point_number,
			       floatP);
		  if (strchr ("s i", operandP->vop_short))
		    {
		      /* Could possibly become S^# */
		      flonum_gen2vax (-expP->X_add_number, floatP, literal_float);
		      switch (-expP->X_add_number)
			{
			case 'f':
			  can_be_short =
			    (literal_float[0] & 0xFC0F) == 0x4000
			    && literal_float[1] == 0;
			  break;

			case 'd':
			  can_be_short =
			    (literal_float[0] & 0xFC0F) == 0x4000
			    && literal_float[1] == 0
			    && literal_float[2] == 0
			    && literal_float[3] == 0;
			  break;

			case 'g':
			  can_be_short =
			    (literal_float[0] & 0xFF81) == 0x4000
			    && literal_float[1] == 0
			    && literal_float[2] == 0
			    && literal_float[3] == 0;
			  break;

			case 'h':
			  can_be_short = ((literal_float[0] & 0xFFF8) == 0x4000
					  && (literal_float[1] & 0xE000) == 0
					  && literal_float[2] == 0
					  && literal_float[3] == 0
					  && literal_float[4] == 0
					  && literal_float[5] == 0
					  && literal_float[6] == 0
					  && literal_float[7] == 0);
			  break;

			default:
			  BAD_CASE (-expP->X_add_number);
			  break;
			}	/* switch (float type) */
		    }		/* if (could want to become S^#...) */
		}		/* bignum or flonum ? */

	      if (operandP->vop_short == 's'
		  || operandP->vop_short == 'i'
		  || (operandP->vop_short == ' '
		      && operandP->vop_reg == 0xF
		      && (operandP->vop_mode & 0xE) == 0x8))
		{
		  /* Saw a '#'.  */
		  if (operandP->vop_short == ' ')
		    {
		      /* We must chose S^ or I^.  */
		      if (expP->X_add_number > 0)
			{
			  /* Bignum: Short literal impossible.  */
			  operandP->vop_short = 'i';
			  operandP->vop_mode = 8;
			  operandP->vop_reg = 0xF;	/* VAX PC.  */
			}
		      else
			{
			  /* Flonum: Try to do it.  */
			  if (can_be_short)
			    {
			      operandP->vop_short = 's';
			      operandP->vop_mode = 0;
			      operandP->vop_ndx = -1;
			      operandP->vop_reg = -1;
			      expP->X_op = O_constant;
			    }
			  else
			    {
			      operandP->vop_short = 'i';
			      operandP->vop_mode = 8;
			      operandP->vop_reg = 0xF;	/* VAX PC */
			    }
			}	/* bignum or flonum ? */
		    }		/*  if #, but no S^ or I^ seen.  */
		  /* No more ' ' case: either 's' or 'i'.  */
		  if (operandP->vop_short == 's')
		    {
		      /* Wants to be a short literal.  */
		      if (expP->X_add_number > 0)
			{
			  as_warn (_("Bignum not permitted in short literal. Immediate mode assumed."));
			  operandP->vop_short = 'i';
			  operandP->vop_mode = 8;
			  operandP->vop_reg = 0xF;	/* VAX PC.  */
			}
		      else
			{
			  if (!can_be_short)
			    {
			      as_warn (_("Can't do flonum short literal: immediate mode used."));
			      operandP->vop_short = 'i';
			      operandP->vop_mode = 8;
			      operandP->vop_reg = 0xF;	/* VAX PC.  */
			    }
			  else
			    {	/* Encode short literal now.  */
			      int temp = 0;

			      switch (-expP->X_add_number)
				{
				case 'f':
				case 'd':
				  temp = literal_float[0] >> 4;
				  break;

				case 'g':
				  temp = literal_float[0] >> 1;
				  break;

				case 'h':
				  temp = ((literal_float[0] << 3) & 070)
				    | ((literal_float[1] >> 13) & 07);
				  break;

				default:
				  BAD_CASE (-expP->X_add_number);
				  break;
				}

			      floatP->low[0] = temp & 077;
			      floatP->low[1] = 0;
			    }	/* if can be short literal float */
			}	/* flonum or bignum ? */
		    }
		  else
		    {		/* I^# seen: set it up if float.  */
		      if (expP->X_add_number < 0)
			{
			  memcpy (floatP->low, literal_float, sizeof (literal_float));
			}
		    }		/* if S^# seen.  */
		}
	      else
		{
		  as_warn (_("A bignum/flonum may not be a displacement: 0x%lx used"),
			   (expP->X_add_number = 0x80000000L));
		  /* Chosen so luser gets the most offset bits to patch later.  */
		}
	      expP->X_add_number = floatP->low[0]
		| ((LITTLENUM_MASK & (floatP->low[1])) << LITTLENUM_NUMBER_OF_BITS);
	      /*
	       * For the O_big case we have:
	       * If vop_short == 's' then a short floating literal is in the
	       *	lowest 6 bits of floatP -> low [0], which is
	       *	big_operand_bits [---] [0].
	       * If vop_short == 'i' then the appropriate number of elements
	       *	of big_operand_bits [---] [...] are set up with the correct
	       *	bits.
	       * Also, just in case width is byte word or long, we copy the lowest
	       * 32 bits of the number to X_add_number.
	       */
	      break;
	    }
	  if (input_line_pointer != operandP->vop_expr_end + 1)
	    {
	      as_warn ("Junk at end of expression \"%s\"", input_line_pointer);
	      goofed = 1;
	    }
	  operandP->vop_expr_end[1] = c_save;
	}
    }				/* for(each operand) */

  input_line_pointer = save_input_line_pointer;

  if (need_pass_2 || goofed)
    {
      return;
    }

  /* Emit op-code.  */
  /* Remember where it is, in case we want to modify the op-code later.  */
  opcode_low_byteP = frag_more (v.vit_opcode_nbytes);
  memcpy (opcode_low_byteP, v.vit_opcode, v.vit_opcode_nbytes);
  opcode_as_number = md_chars_to_number (opcode_as_chars = v.vit_opcode, 4);
  for (operandP = v.vit_operand,
       expP = exp_of_operand,
       segP = seg_of_operand,
       floatP = float_operand,
       end_operandP = v.vit_operand + v.vit_operands;

       operandP < end_operandP;

       operandP++,
       floatP++,
       segP++,
       expP++)
    {
      if (operandP->vop_ndx >= 0)
	{
	  /* indexed addressing byte */
	  /* Legality of indexed mode already checked: it is OK */
	  FRAG_APPEND_1_CHAR (0x40 + operandP->vop_ndx);
	}			/* if(vop_ndx>=0) */

      /* Here to make main operand frag(s).  */
      this_add_number = expP->X_add_number;
      this_add_symbol = expP->X_add_symbol;
      to_seg = *segP;
      is_undefined = (to_seg == SEG_UNKNOWN);
      at = operandP->vop_mode & 1;
      length = (operandP->vop_short == 'b'
		? 1 : (operandP->vop_short == 'w'
		       ? 2 : (operandP->vop_short == 'l'
			      ? 4 : 0)));
      nbytes = operandP->vop_nbytes;
      if (operandP->vop_access == 'b')
	{
	  if (to_seg == now_seg || is_undefined)
	    {
	      /* If is_undefined, then it might BECOME now_seg.  */
	      if (nbytes)
		{
		  p = frag_more (nbytes);
		  fix_new (frag_now, p - frag_now->fr_literal, nbytes,
			   this_add_symbol, this_add_number, 1, NO_RELOC);
		}
	      else
		{		/* to_seg==now_seg || to_seg == SEG_UNKNOWN */
		  /* nbytes==0 */
		  length_code = is_undefined ? STATE_UNDF : STATE_BYTE;
		  if (opcode_as_number & VIT_OPCODE_SPECIAL)
		    {
		      if (operandP->vop_width == VAX_WIDTH_UNCONDITIONAL_JUMP)
			{
			  /* br or jsb */
			  frag_var (rs_machine_dependent, 5, 1,
			    ENCODE_RELAX (STATE_ALWAYS_BRANCH, length_code),
				    this_add_symbol, this_add_number,
				    opcode_low_byteP);
			}
		      else
			{
			  if (operandP->vop_width == VAX_WIDTH_WORD_JUMP)
			    {
			      length_code = STATE_WORD;
			      /* JF: There is no state_byte for this one! */
			      frag_var (rs_machine_dependent, 10, 2,
					ENCODE_RELAX (STATE_COMPLEX_BRANCH, length_code),
					this_add_symbol, this_add_number,
					opcode_low_byteP);
			    }
			  else
			    {
			      know (operandP->vop_width == VAX_WIDTH_BYTE_JUMP);
			      frag_var (rs_machine_dependent, 9, 1,
			      ENCODE_RELAX (STATE_COMPLEX_HOP, length_code),
					this_add_symbol, this_add_number,
					opcode_low_byteP);
			    }
			}
		    }
		  else
		    {
		      know (operandP->vop_width == VAX_WIDTH_CONDITIONAL_JUMP);
		      frag_var (rs_machine_dependent, 7, 1,
		       ENCODE_RELAX (STATE_CONDITIONAL_BRANCH, length_code),
				this_add_symbol, this_add_number,
				opcode_low_byteP);
		    }
		}
	    }
	  else
	    {
	      /* to_seg != now_seg && to_seg != SEG_UNKNOWN */
	      /*
	       * --- SEG FLOAT MAY APPEAR HERE ----
	       */
	      if (to_seg == SEG_ABSOLUTE)
		{
		  if (nbytes)
		    {
		      know (!(opcode_as_number & VIT_OPCODE_SYNTHETIC));
		      p = frag_more (nbytes);
		      /* Conventional relocation.  */
		      fix_new (frag_now, p - frag_now->fr_literal,
			       nbytes, &abs_symbol, this_add_number,
			       1, NO_RELOC);
		    }
		  else
		    {
		      know (opcode_as_number & VIT_OPCODE_SYNTHETIC);
		      if (opcode_as_number & VIT_OPCODE_SPECIAL)
			{
			  if (operandP->vop_width == VAX_WIDTH_UNCONDITIONAL_JUMP)
			    {
			      /* br or jsb */
			      *opcode_low_byteP = opcode_as_chars[0] + VAX_WIDEN_LONG;
			      know (opcode_as_chars[1] == 0);
			      p = frag_more (5);
			      p[0] = VAX_ABSOLUTE_MODE;	/* @#...  */
			      md_number_to_chars (p + 1, this_add_number, 4);
			      /* Now (eg) JMP @#foo or JSB @#foo.  */
			    }
			  else
			    {
			      if (operandP->vop_width == VAX_WIDTH_WORD_JUMP)
				{
				  p = frag_more (10);
				  p[0] = 2;
				  p[1] = 0;
				  p[2] = VAX_BRB;
				  p[3] = 6;
				  p[4] = VAX_JMP;
				  p[5] = VAX_ABSOLUTE_MODE;	/* @#...  */
				  md_number_to_chars (p + 6, this_add_number, 4);
				  /*
				   * Now (eg)	ACBx	1f
				   *		BRB	2f
				   *	1:	JMP	@#foo
				   *	2:
				   */
				}
			      else
				{
				  know (operandP->vop_width == VAX_WIDTH_BYTE_JUMP);
				  p = frag_more (9);
				  p[0] = 2;
				  p[1] = VAX_BRB;
				  p[2] = 6;
				  p[3] = VAX_JMP;
                                  p[4] = VAX_ABSOLUTE_MODE;     /* @#...  */
				  md_number_to_chars (p + 5, this_add_number, 4);
				  /*
				   * Now (eg)	xOBxxx	1f
				   *		BRB	2f
				   *	1:	JMP	@#foo
				   *	2:
				   */
				}
			    }
			}
		      else
			{
			  /* b<cond> */
			  *opcode_low_byteP ^= 1;
			  /* To reverse the condition in a VAX branch,
			     complement the lowest order bit.  */
			  p = frag_more (7);
			  p[0] = 6;
			  p[1] = VAX_JMP;
			  p[2] = VAX_ABSOLUTE_MODE;	/* @#...  */
			  md_number_to_chars (p + 3, this_add_number, 4);
			  /*
			   * Now (eg)	BLEQ	1f
			   *		JMP	@#foo
			   *	1:
			   */
			}
		    }
		}
	      else
		{
		  /* to_seg != now_seg && to_seg != SEG_UNKNOWN && to_Seg != SEG_ABSOLUTE */
		  if (nbytes > 0)
		    {
		      /* Pc-relative. Conventional relocation.  */
		      know (!(opcode_as_number & VIT_OPCODE_SYNTHETIC));
		      p = frag_more (nbytes);
		      fix_new (frag_now, p - frag_now->fr_literal,
			       nbytes, &abs_symbol, this_add_number,
			       1, NO_RELOC);
		    }
		  else
		    {
		      know (opcode_as_number & VIT_OPCODE_SYNTHETIC);
		      if (opcode_as_number & VIT_OPCODE_SPECIAL)
			{
			  if (operandP->vop_width == VAX_WIDTH_UNCONDITIONAL_JUMP)
			    {
			      /* br or jsb */
			      know (opcode_as_chars[1] == 0);
			      *opcode_low_byteP = opcode_as_chars[0] + VAX_WIDEN_LONG;
			      p = frag_more (5);
			      p[0] = VAX_PC_RELATIVE_MODE;
			      fix_new (frag_now,
				       p + 1 - frag_now->fr_literal, 4,
				       this_add_symbol,
				       this_add_number, 1, NO_RELOC);
			      /* Now eg JMP foo or JSB foo.  */
			    }
			  else
			    {
			      if (operandP->vop_width == VAX_WIDTH_WORD_JUMP)
				{
				  p = frag_more (10);
				  p[0] = 0;
				  p[1] = 2;
				  p[2] = VAX_BRB;
				  p[3] = 6;
				  p[4] = VAX_JMP;
				  p[5] = VAX_PC_RELATIVE_MODE;
				  fix_new (frag_now,
					   p + 6 - frag_now->fr_literal, 4,
					   this_add_symbol,
					   this_add_number, 1, NO_RELOC);
				  /*
				   * Now (eg)	ACBx	1f
				   *		BRB	2f
				   *	1:	JMP	foo
				   *	2:
				   */
				}