/*---------------------------------------------------------*\
    Ficheiro:     SGNBTROM.C
    Alteração:    03-05-96
    Alterado por: A.Esteves
\*---------------------------------------------------------*/

#include "datadef.h"

/*    CALCULO DO BIT DE SINAL    */

void overf_this (void)
{
  WORD aux[SIZE];
  /* cy  = alu_output ( overflow ) */
  /* tag = alu_output ( sum )      */

  switch (linhas)
  {
    case 111 :  /* MD0 MD1 CY_IN */
      tag[0] = cy[0] ^ (md0[0] ^ md1[0]);
      tag[1] = cy[1] ^ (md0[1] ^ md1[1]);
      cy[0] = ~(md0[0] ^ md1[0]) & (md0[0] ^ cy[0]) & ms[0];
      cy[1] = ~(md0[1] ^ md1[1]) & (md0[1] ^ cy[1]) & ms[1];
      break;

    case 131 :  /* MD0 NOT_MD1 CY_IN */
      tag[0] = cy[0] ^ (md0[0] ^ (~md1[0]));
      tag[1] = cy[1] ^ (md0[1] ^ (~md1[1]));
      cy[0] = ~(md0[0] ^ (~md1[0])) & (md0[0] ^ cy[0]) & ms[0];
      cy[1] = ~(md0[1] ^ (~md1[1])) & (md0[1] ^ cy[1]) & ms[1];
      break;

    case 141 :  /* MD0 TAG_IN CY_IN */
       aux[0] = tag[0];
       aux[1] = tag[1];
       tag[0] = cy[0] ^ (md0[0] ^ tag[0]);
       tag[1] = cy[1] ^ (md0[1] ^ tag[1]);
       cy[0] = ~(md0[0] ^ aux[0]) & (md0[0] ^ cy[0]) & ms[0];
       cy[1] = ~(md0[1] ^ aux[1]) & (md0[1] ^ cy[1]) & ms[1];
/*
    case 151 :  MD0 NOT_TAG_IN CY_IN
       aux[0] = tag[0];
       aux[1] = tag[1];
       tag[0] = cy[0] ^ (md0[0] ^ (~tag[0]));
       tag[1] = cy[1] ^ (md0[1] ^ (~tag[1]));
       cy[0] = ~(md0[0] ^ (~aux[0])) & (md0[0] ^ cy[0]) & ms[0];
       cy[1] = ~(md0[1] ^ (~aux[1])) & (md0[1] ^ cy[1]) & ms[1];
       break;
*/
    case 311 :  /* NOT_MD0 MD1 CY_IN */
       tag[0] = cy[0] ^ (~md0[0] ^ md1[0]);
       tag[1] = cy[1] ^ (~md0[1] ^ md1[1]);
       cy[0] = ~(~md0[0] ^ md1[0]) & (~md0[0] ^ cy[0]) & ms[0];
       cy[1] = ~(~md0[1] ^ md1[1]) & (~md0[1] ^ cy[1]) & ms[1];
       break;

    case 331 :  /* NOT_MD0 NOT_MD1 CY_IN */
       tag[0] = cy[0] ^ (~md0[0] ^ ~md1[0]);
       tag[1] = cy[1] ^ (~md0[1] ^ ~md1[1]);
       cy[0] = ~(~md0[0] ^ ~md1[0]) & (~md0[0] ^ cy[0]) & ms[0];
       cy[1] = ~(~md0[1] ^ ~md1[1]) & (~md0[1] ^ cy[1]) & ms[1];
       break;

    case 341 :  /* NOT_MD0 TAG_IN CY_IN */
       aux[0] = tag[0];
       aux[1] = tag[1];
       tag[0] = cy[0] ^ (~md0[0] ^ tag[0]);
       tag[1] = cy[1] ^ (~md0[1] ^ tag[1]);
       cy[0] = ~(~md0[0] ^ aux[0]) & (~md0[0] ^ cy[0]) & ms[0];
       cy[1] = ~(~md0[1] ^ aux[1]) & (~md0[1] ^ cy[1]) & ms[1];
                break;

    case 351 :  /* NOT_MD0 NOT_TAG_IN CY_IN */
       aux[0] = tag[0];
       aux[1] = tag[1];
       tag[0] = cy[0] ^ (~md0[0] ^ ~tag[0]);
       tag[1] = cy[1] ^ (~md0[1] ^ ~tag[1]);
       cy[0] = ~(~md0[0] ^ ~aux[0]) & (~md0[0] ^ cy[0]) & ms[0];
       cy[1] = ~(~md0[1] ^ ~aux[1]) & (~md0[1] ^ cy[1]) & ms[1];
       break;
    default:  erro("\nERRO na funcao overf_this(). \n"); break;
   }
}

/*###############################################################*/
void overf_above (void)
{
  /* cy  = alu_output ( overflow ) */
  /* tag = alu_output ( sum )   */
  /* tag_rout -> above
     Isto implica que o valor da tag do PE vizinho sera' fornecido
     como o valor do MD1.
     Igual 'a funcao overf_this excepto que e' feito uma
     "migracao" das tags dos PEs "de cima" para os seus vizinhos.
   */

  TagAbove();  /* Preparar as tags */

  switch (linhas)
  /* Nao se invoca logo overf_this por questoes de validacao */
  {
    case 141 :  /* MD0 TAG_IN CY_IN */
/*  case 151 : */ /* MD0 NOT_TAG_IN CY_IN */
    case 341 :  /* NOT_MD0 TAG_IN CY_IN */
    case 351 :  /* NOT_MD0 NOT_TAG_IN CY_IN */
       overf_this();
       break;
    default  : erro("\nErro na funcao overf_above(). \n"); break;
  }
}

/*###############################################################*/
void overf_below (void)
{
  /* cy  = alu_output ( overflow ) */
  /* tag = alu_output ( sum )   */
  /* tag_rout -> below
     Isto implica que o valor da tag do PE vizinho sera' fornecido
     como o valor do MD1.
     Igual 'a funcao overf_this excepto que e' feito uma
     "migracao" das tags dos PEs "de baixo" para os seus vizinhos.
            */

  TagBelow();  /* Preparar as tags */

  switch (linhas)
  /* Nao se invoca logo overf_this por questoes de validacao */
  {
    case 141 :  /* MD0 TAG_IN CY_IN */
/*  case 151 : */  /* MD0 NOT_TAG_IN CY_IN */
    case 341 :  /* NOT_MD0 TAG_IN CY_IN */
    case 351 :  /* NOT_MD0 NOT_TAG_IN CY_IN */
        overf_this();
        break;
    default  : erro("\nErro na funcao overf_below(). \n"); break;
  }
}

/*###############################################################*/
void overf_image (void)
{
  /* cy  = alu_output ( overflow ) */
  /* tag = alu_output ( sum )   */
  /* tag_rout -> image
     Igual 'a funcao overf_this excepto que e' feito uma atribuicao
     dos valores vindos do VSR para a tag.
  */

  TagImage();  /* Preparar as tags */

  switch (linhas)
  /* Nao se invoca logo overf_this por questoes de validacao */
  {
    case 141 :  /* MD0 TAG_IN CY_IN */
/*  case 151 :*/  /* MD0 NOT_TAG_IN CY_IN */
    case 341 :  /* NOT_MD0 TAG_IN CY_IN */
    case 351 :  /* NOT_MD0 NOT_TAG_IN CY_IN */
       overf_this();
       break;
    default  : erro("\nErro na funcao overf_image(). \n"); break;
  }
}

/*###############################################################*/
void overfholdms (void)
{
    /* cy  = alu_output ( overflow ) */
    /* tag = alu_output ( sum )      */
    ms[0]=msbak[0];   /* Hold ms */
    ms[1]=msbak[1];
    overf_this ();

/* A funcao overfholdms invoca overf_this depois de restaurar ms */
}