tc-vax.c

基于4个mips核的noc设计

			      else
				{
				  know (operandP->vop_width == VAX_WIDTH_BYTE_JUMP);
				  p = frag_more (10);
				  p[0] = 2;
				  p[1] = VAX_BRB;
				  p[2] = 6;
				  p[3] = VAX_JMP;
				  p[4] = VAX_PC_RELATIVE_MODE;
				  fix_new (frag_now,
					   p + 5 - frag_now->fr_literal,
					   4, this_add_symbol,
					   this_add_number, 1, NO_RELOC);
				  /*
				   * Now (eg)	xOBxxx	1f
				   *		BRB	2f
				   *	1:	JMP	foo
				   *	2:
				   */
				}
			    }
			}
		      else
			{
			  know (operandP->vop_width == VAX_WIDTH_CONDITIONAL_JUMP);
			  *opcode_low_byteP ^= 1;	/* Reverse branch condition.  */
			  p = frag_more (7);
			  p[0] = 6;
			  p[1] = VAX_JMP;
			  p[2] = VAX_PC_RELATIVE_MODE;
			  fix_new (frag_now, p + 3 - frag_now->fr_literal,
				   4, this_add_symbol,
				   this_add_number, 1, NO_RELOC);
			}
		    }
		}
	    }
	}
      else
	{
	  know (operandP->vop_access != 'b');	/* So it is ordinary operand.  */
	  know (operandP->vop_access != ' ');	/* ' ' target-independent: elsewhere.  */
	  know (operandP->vop_access == 'a'
		|| operandP->vop_access == 'm'
		|| operandP->vop_access == 'r'
		|| operandP->vop_access == 'v'
		|| operandP->vop_access == 'w');
	  if (operandP->vop_short == 's')
	    {
	      if (to_seg == SEG_ABSOLUTE)
		{
		  if (this_add_number >= 64)
		    {
		      as_warn (_("Short literal overflow(%ld.), immediate mode assumed."),
			       (long) this_add_number);
		      operandP->vop_short = 'i';
		      operandP->vop_mode = 8;
		      operandP->vop_reg = 0xF;
		    }
		}
	      else
		{
		  as_warn (_("Forced short literal to immediate mode. now_seg=%s to_seg=%s"),
			   segment_name (now_seg), segment_name (to_seg));
		  operandP->vop_short = 'i';
		  operandP->vop_mode = 8;
		  operandP->vop_reg = 0xF;
		}
	    }
	  if (operandP->vop_reg >= 0 && (operandP->vop_mode < 8
		  || (operandP->vop_reg != 0xF && operandP->vop_mode < 10)))
	    {
	      /* One byte operand.  */
	      know (operandP->vop_mode > 3);
	      FRAG_APPEND_1_CHAR (operandP->vop_mode << 4 | operandP->vop_reg);
	      /* All 1-bytes except S^# happen here.  */
	    }
	  else
	    {
	      /* {@}{q^}foo{(Rn)} or S^#foo */
	      if (operandP->vop_reg == -1 && operandP->vop_short != 's')
		{
		  /* "{@}{q^}foo" */
		  if (to_seg == now_seg)
		    {
		      if (length == 0)
			{
			  know (operandP->vop_short == ' ');
			  p = frag_var (rs_machine_dependent, 10, 2,
			       ENCODE_RELAX (STATE_PC_RELATIVE, STATE_BYTE),
					this_add_symbol, this_add_number,
					opcode_low_byteP);
			  know (operandP->vop_mode == 10 + at);
			  *p = at << 4;
			  /* At is the only context we need to carry
			     to other side of relax() process.  Must
			     be in the correct bit position of VAX
			     operand spec. byte.  */
			}
		      else
			{
			  know (length);
			  know (operandP->vop_short != ' ');
			  p = frag_more (length + 1);
			  p[0] = 0xF | ((at + "?\12\14?\16"[length]) << 4);
			  fix_new (frag_now, p + 1 - frag_now->fr_literal,
				   length, this_add_symbol,
				   this_add_number, 1, NO_RELOC);
			}
		    }
		  else
		    {		/* to_seg != now_seg */
		      if (this_add_symbol == NULL)
			{
			  know (to_seg == SEG_ABSOLUTE);
			  /* Do @#foo: simpler relocation than foo-.(pc) anyway.  */
			  p = frag_more (5);
			  p[0] = VAX_ABSOLUTE_MODE;	/* @#...  */
			  md_number_to_chars (p + 1, this_add_number, 4);
			  if (length && length != 4)
			    {
			      as_warn (_("Length specification ignored. Address mode 9F used"));
			    }
			}
		      else
			{
			  /* {@}{q^}other_seg */
			  know ((length == 0 && operandP->vop_short == ' ')
			     || (length > 0 && operandP->vop_short != ' '));
			  if (is_undefined)
			    {
			      /*
			       * We have a SEG_UNKNOWN symbol. It might
			       * turn out to be in the same segment as
			       * the instruction, permitting relaxation.
			       */
			      p = frag_var (rs_machine_dependent, 5, 2,
			       ENCODE_RELAX (STATE_PC_RELATIVE, STATE_UNDF),
					    this_add_symbol, this_add_number,
					    0);
			      p[0] = at << 4;
			    }
			  else
			    {
			      if (length == 0)
				{
				  know (operandP->vop_short == ' ');
				  length = 4;	/* Longest possible.  */
				}
			      p = frag_more (length + 1);
			      p[0] = 0xF | ((at + "?\12\14?\16"[length]) << 4);
			      md_number_to_chars (p + 1, this_add_number, length);
			      fix_new (frag_now,
				       p + 1 - frag_now->fr_literal,
				       length, this_add_symbol,
				       this_add_number, 1, NO_RELOC);
			    }
			}
		    }
		}
	      else
		{
		  /* {@}{q^}foo(Rn) or S^# or I^# or # */
		  if (operandP->vop_mode < 0xA)
		    {
		      /* # or S^# or I^# */
		      if (operandP->vop_access == 'v'
			  || operandP->vop_access == 'a')
			{
			  if (operandP->vop_access == 'v')
			    as_warn (_("Invalid operand:  immediate value used as base address."));
			  else
			    as_warn (_("Invalid operand:  immediate value used as address."));
			  /* gcc 2.6.3 is known to generate these in at least
			     one case.  */
			}
		      if (length == 0
			  && to_seg == SEG_ABSOLUTE && (expP->X_op != O_big)
			  && operandP->vop_mode == 8	/* No '@'.  */
			  && this_add_number < 64)
			{
			  operandP->vop_short = 's';
			}
		      if (operandP->vop_short == 's')
			{
			  FRAG_APPEND_1_CHAR (this_add_number);
			}
		      else
			{
			  /* I^#...  */
			  know (nbytes);
			  p = frag_more (nbytes + 1);
			  know (operandP->vop_reg == 0xF);
			  p[0] = (operandP->vop_mode << 4) | 0xF;
			  if ((to_seg == SEG_ABSOLUTE) && (expP->X_op != O_big))
			    {
			      /*
			       * If nbytes > 4, then we are scrod. We
			       * don't know if the high order bytes
			       * are to be 0xFF or 0x00.  BSD4.2 & RMS
			       * say use 0x00. OK --- but this
			       * assembler needs ANOTHER rewrite to
			       * cope properly with this bug.  */
			      md_number_to_chars (p + 1, this_add_number, min (4, nbytes));
			      if (nbytes > 4)
				{
				  memset (p + 5, '\0', nbytes - 4);
				}
			    }
			  else
			    {
			      if (expP->X_op == O_big)
				{
				  /*
				   * Problem here is to get the bytes
				   * in the right order.  We stored
				   * our constant as LITTLENUMs, not
				   * bytes.  */
				  LITTLENUM_TYPE *lP;

				  lP = floatP->low;
				  if (nbytes & 1)
				    {
				      know (nbytes == 1);
				      p[1] = *lP;
				    }
				  else
				    {
				      for (p++; nbytes; nbytes -= 2, p += 2, lP++)
					{
					  md_number_to_chars (p, *lP, 2);
					}
				    }
				}
			      else
				{
				  fix_new (frag_now, p + 1 - frag_now->fr_literal,
					   nbytes, this_add_symbol,
					   this_add_number, 0, NO_RELOC);
				}
			    }
			}
		    }
		  else
		    {		/* {@}{q^}foo(Rn) */
		      know ((length == 0 && operandP->vop_short == ' ')
			    || (length > 0 && operandP->vop_short != ' '));
		      if (length == 0)
			{
			  if (to_seg == SEG_ABSOLUTE)
			    {
			      long test;

			      test = this_add_number;

			      if (test < 0)
				test = ~test;

			      length = test & 0xffff8000 ? 4
				: test & 0xffffff80 ? 2
				: 1;
			    }
			  else
			    {
			      length = 4;
			    }
			}
		      p = frag_more (1 + length);
		      know (operandP->vop_reg >= 0);
		      p[0] = operandP->vop_reg
			| ((at | "?\12\14?\16"[length]) << 4);
		      if (to_seg == SEG_ABSOLUTE)
			{
			  md_number_to_chars (p + 1, this_add_number, length);
			}
		      else
			{
			  fix_new (frag_now, p + 1 - frag_now->fr_literal,
				   length, this_add_symbol,
				   this_add_number, 0, NO_RELOC);
			}
		    }
		}
	    }			/* if(single-byte-operand) */
	}
    }				/* for(operandP) */
}				/* vax_assemble() */

/* md_estimate_size_before_relax(), called just before relax().
   Any symbol that is now undefined will not become defined.
   Return the correct fr_subtype in the frag and the growth beyond
   fr_fix.  */
int
md_estimate_size_before_relax (fragP, segment)
     fragS *fragP;
     segT segment;
{
  if (RELAX_LENGTH (fragP->fr_subtype) == STATE_UNDF)
    {
      if (S_GET_SEGMENT (fragP->fr_symbol) != segment)
	{
	  /* Non-relaxable cases.  */
	  char *p;
	  int old_fr_fix;

	  old_fr_fix = fragP->fr_fix;
	  p = fragP->fr_literal + old_fr_fix;
	  switch (RELAX_STATE (fragP->fr_subtype))
	    {
	    case STATE_PC_RELATIVE:
	      p[0] |= VAX_PC_RELATIVE_MODE;	/* Preserve @ bit.  */
	      fragP->fr_fix += 1 + 4;
	      fix_new (fragP, old_fr_fix + 1, 4, fragP->fr_symbol,
		       fragP->fr_offset, 1, NO_RELOC);
	      break;

	    case STATE_CONDITIONAL_BRANCH:
	      *fragP->fr_opcode ^= 1;		/* Reverse sense of branch.  */
	      p[0] = 6;
	      p[1] = VAX_JMP;
	      p[2] = VAX_PC_RELATIVE_MODE;	/* ...(PC) */
	      fragP->fr_fix += 1 + 1 + 1 + 4;
	      fix_new (fragP, old_fr_fix + 3, 4, fragP->fr_symbol,
		       fragP->fr_offset, 1, NO_RELOC);
	      break;

	    case STATE_COMPLEX_BRANCH:
	      p[0] = 2;
	      p[1] = 0;
	      p[2] = VAX_BRB;
	      p[3] = 6;
	      p[4] = VAX_JMP;
	      p[5] = VAX_PC_RELATIVE_MODE;	/* ...(pc) */
	      fragP->fr_fix += 2 + 2 + 1 + 1 + 4;
	      fix_new (fragP, old_fr_fix + 6, 4, fragP->fr_symbol,
		       fragP->fr_offset, 1, NO_RELOC);
	      break;

	    case STATE_COMPLEX_HOP:
	      p[0] = 2;
	      p[1] = VAX_BRB;
	      p[2] = 6;
	      p[3] = VAX_JMP;
	      p[4] = VAX_PC_RELATIVE_MODE;	/* ...(pc) */
	      fragP->fr_fix += 1 + 2 + 1 + 1 + 4;
	      fix_new (fragP, old_fr_fix + 5, 4, fragP->fr_symbol,
		       fragP->fr_offset, 1, NO_RELOC);
	      break;

	    case STATE_ALWAYS_BRANCH:
	      *fragP->fr_opcode += VAX_WIDEN_LONG;
	      p[0] = VAX_PC_RELATIVE_MODE;	/* ...(PC) */
	      fragP->fr_fix += 1 + 4;
	      fix_new (fragP, old_fr_fix + 1, 4, fragP->fr_symbol,
		       fragP->fr_offset, 1, NO_RELOC);
	      break;

	    default:
	      abort ();
	    }
	  frag_wane (fragP);

	  /* Return the growth in the fixed part of the frag.  */
	  return fragP->fr_fix - old_fr_fix;
	}

      /* Relaxable cases.  Set up the initial guess for the variable
	 part of the frag.  */
      switch (RELAX_STATE (fragP->fr_subtype))
	{
	case STATE_PC_RELATIVE:
	  fragP->fr_subtype = ENCODE_RELAX (STATE_PC_RELATIVE, STATE_BYTE);
	  break;
	case STATE_CONDITIONAL_BRANCH:
	  fragP->fr_subtype = ENCODE_RELAX (STATE_CONDITIONAL_BRANCH, STATE_BYTE);
	  break;
	case STATE_COMPLEX_BRANCH:
	  fragP->fr_subtype = ENCODE_RELAX (STATE_COMPLEX_BRANCH, STATE_WORD);
	  break;
	case STATE_COMPLEX_HOP:
	  fragP->fr_subtype = ENCODE_RELAX (STATE_COMPLEX_HOP, STATE_BYTE);
	  break;
	case STATE_ALWAYS_BRANCH:
	  fragP->fr_subtype = ENCODE_RELAX (STATE_ALWAYS_BRANCH, STATE_BYTE);
	  break;
	}
    }

  if (fragP->fr_subtype >= sizeof (md_relax_table) / sizeof (md_relax_table[0]))
    abort ();

  /* Return the size of the variable part of the frag.  */
  return md_relax_table[fragP->fr_subtype].rlx_length;
}

/*
 *			md_convert_frag();
 *
 * Called after relax() is finished.
 * In:	Address of frag.
 *	fr_type == rs_machine_dependent.
 *	fr_subtype is what the address relaxed to.
 *
 * Out:	Any fixSs and constants are set up.
 *	Caller will turn frag into a ".space 0".
 */
void
md_convert_frag (headers, seg, fragP)
     object_headers *headers;
     segT seg;
     fragS *fragP;
{
  char *addressP;		/* -> _var to change.  */
  char *opcodeP;		/* -> opcode char(s) to change.  */
  short int extension = 0;	/* Size of relaxed address.  */
  /* Added to fr_fix: incl. ALL var chars.  */
  symbolS *symbolP;
  long where;
  long address_of_var;
  /* Where, in file space, is _var of *fragP? */
  long target_address = 0;
  /* Where, in file space, does addr point? */

  know (fragP->fr_type == rs_machine_dependent);
  where = fragP->fr_fix;
  addressP = fragP->fr_literal + where;
  opcodeP = fragP->fr_opcode;
  symbolP = fragP->fr_symbol;
  know (symbolP);
  target_address = S_GET_VALUE (symbolP) + fragP->fr_offset;
  address_of_var = fragP->fr_address + where;