readpla.cpp

Implement the step 2 of two-level logic minimization. Our goal is to find the minimum (exact minim

#include "pla.h"

main(int argc, char *argv[])
{
   FILE *fp;
   pPla func;
   int i,j,mcost,mlit;
   char *mpath;
   set result;
   cublist *cnode,*dnode;

   fp=NULL;
   if (argc!=2)   // unmatched argument numbers
      printf("Usage: findcost input_file\n");
   else if ((fp=fopen(argv[1],"r"))==NULL)   // open file failed
      printf("File open error!!\n");
   else if ((func=readpla(fp))==NULL)   // read input file failed
      printf("Read PLA file failed!!\n");
   else {
      mcost=func->cubes;   // variables for minimum cost
      mpath=new char[func->cubes];   // minimum selection, 1: choose, 0: not
      for (i=0,mlit=0;i<(func->cubes);i++) {
         mlit+=func->lit[i];
         mpath[i]=1;
      }
      findcost(func,mpath,&mcost,&mlit);   // mlit: minimum number of literals

      for (i=0;i<(func->cubes);i++) {
         if (mpath[i])
            print_cube(func->inputs,func->cubarr[i]);
      }
      printf("cost=(%d,%d)\n",mcost,mlit);

      /* free the used memory */
      delete mpath;
      for (i=0;i<(func->cubes);i++) delete func->cubarr[i];
      delete func->cubarr;
      delete func->lit;
      cnode=func->onset;
      while (cnode) {
         dnode=cnode;
         cnode=cnode->next;
         delete dnode->cube;
         delete dnode;
      }
      delete func;
   }

   if (fp) fclose(fp);
   return 0;
}


pPla readpla(FILE *fp)
{
   int i,j,k,tmp,tmp1,stleng,litmp;
   int *litarr;
   set itemp,*readin;
   pset *ctemp;
   pPla ptemp;
   char temp[256];
   cublist *newnode,*onend;
   ptemp=new Pla;
   ptemp->inputs=0;
   ptemp->wsize=1;
   ptemp->cubes=0;
   ptemp->cubarr=NULL;
   ptemp->onno=0;
   ptemp->onset=NULL;
   ptemp->lit=NULL;
   onend=NULL;
   readin=NULL;

      /* readin option */
   while ((fgets(temp,256,fp))!=NULL) {
      stleng=strlen(temp);
      for (i=0;i<stleng;i++) if (temp[i]!=' ') break;   // skip space
      if (temp[i]=='\n') continue;
      if (temp[i]!='.') {   // wrong format
         printf("Format Error!!\n");
         delete ptemp;
         delete readin;
         return NULL;
      }
      else if (temp[i+1]=='i' || temp[i+1]=='I') {   // input no
         if (temp[i+2]!=' ') continue;
	 for (i+=2;i<stleng;i++) if (temp[i]!=' ') break;   // skip space
	 ptemp->inputs=atoi(temp+i);
         ptemp->wsize=(ptemp->inputs)*2/BPI+1;
         readin=new set[ptemp->wsize];
      }
      else if (temp[i+1]=='m' || temp[i+1]=='M') {   // minterms
         fgets(temp,256,fp);
         stleng=strlen(temp);
         i=0;
         while (i < stleng && temp[i] != '\n') {
            for (;i<stleng;i++) if (temp[i]!=' ') break;   // skip space
            if (temp[i] >= '0' && temp[i] <= '9') { 
               tmp=atoi(temp+i);
                  /* translate minterm number into cube format */
               for (j=0;j<(ptemp->wsize);j++) readin[j]=0;  
               for (j=(ptemp->inputs-1),k=1;j>=0;j--,k*=2) {
                  tmp1 = tmp&k;
                  if (tmp1 == 0) itemp=ZERO;
                  else itemp=ONE;
                  itemp = itemp << ((2*j)%BPI);
                  readin[(2*j)/BPI] = readin[(2*j)/BPI] | itemp;
               }
                  /* save minterm cubes into link list */
               newnode=new cublist;
               newnode->cube=new set[ptemp->wsize];
               newnode->next=NULL;
               for (j=0;j<(ptemp->wsize);j++)
                  newnode->cube[j]=readin[j];
               if (onend==NULL) ptemp->onset=newnode;
               else onend->next=newnode;
               onend=newnode;
               (ptemp->onno)++;
            }
            for (;i<stleng;i++) if (temp[i]==' ' || temp[i]=='\n') break;
         }
      }
      else if (temp[i+1]=='d' || temp[i+1]=='D')   // don't care
         fgets(temp,256,fp);   // just ignore it
      else if (temp[i+1]=='p' || temp[i+1]=='P')   // product terms
         break;
      else {   // unknown options
         printf("Unknown Options!!\n");
         delete ptemp;
         delete readin;
         return NULL;
      }
   }
   if (feof(fp)) {   /* wrong format : no truth table */
      printf("Error: No Truth Table!!\n");
      delete ptemp;
      delete readin;
      return NULL;
   }

      /* readin truth table */
   while ((fgets(temp,256,fp))!=NULL) {
      stleng=strlen(temp);

	 /* skipping the space in head */
      for (i=0;i<stleng;i++) if (temp[i]!=' ') break;

	 /* checking if the end mark appear */
      if (temp[i]=='.' && (temp[i+4]==' ' || temp[i+4]=='\n' || temp[i+4]==0)) {
         temp[i+4]=NULL;
         if (strcmp(temp+1,"end") || strcmp(temp+1,"END")) // end found
            break;
         else {   // unknown option
            printf("Unknown Options!!\n");
            delete ptemp;
            delete readin;
            return NULL;
         }
      }
      else if (temp[i]=='\n') continue;

	 /* read input field */
      itemp=0; litmp=0;
      for (j=0;j<(ptemp->wsize);j++) readin[j]=0;
      for (j=0;j<(ptemp->inputs);j++) {
         switch (temp[i+j]) {
	    case '0':
	       itemp=ZERO;
               litmp++;
	       break;
	    case '1':
	       itemp=ONE;
               litmp++;
	       break;
	    case '-':
	       itemp=DASH;
	       break;
	    default:
	       itemp=0;
	       break;
	 }
         if (itemp==0) {
            printf("Error: Unknown Symbol in Truth Table!!\n");
            delete ptemp;
            delete readin;
            return NULL;
         }
         else {
            itemp = itemp << ((2*j)%BPI);
            readin[(2*j)/BPI] = readin[(2*j)/BPI] | itemp;
         }
      }

	 /* add a new cube */
      if ((ptemp->cubes)==0) {
         ptemp->cubarr=new pset;
         ptemp->lit=new int;
      }
      else {   // create a larger sized array and copy the old contents
         ctemp=new pset[ptemp->cubes+1];
         litarr=new int[ptemp->cubes+1];   
         for (i=0;i<(ptemp->cubes);i++) { 
            ctemp[i]=ptemp->cubarr[i];
            litarr[i]=ptemp->lit[i];
         }
         delete ptemp->cubarr;
         delete ptemp->lit;
         ptemp->cubarr=ctemp;
         ptemp->lit=litarr;
      }
      ptemp->cubarr[ptemp->cubes]=new set;
      for (i=0;i<(ptemp->wsize);i++)
         (ptemp->cubarr[ptemp->cubes])[i]=readin[i];
      ptemp->lit[ptemp->cubes]=litmp;
      (ptemp->cubes)++;

	 /* accross output pattern & skipping the space in the end */
      for (i+=j;i<stleng;i++) if (temp[i]==' ') break;
      for (;i<stleng;i++) if (temp[i]!=' ') break;
      if (i!=stleng && temp[i]!='\n') {
         /* wrong format, has term after output */
         printf("Format Error!!\n");
         delete ptemp;
	 delete readin;
	 return NULL;
      }
   }

   delete readin;
   if (temp[i]=='.') return ptemp;   // normal end with .end
   else {
      delete ptemp;
      return NULL;
   }
}


void print_cube(int inputs, pset cube)
{
   int i;
   set result;

   if (!cube) return;
   for (i=0;i<inputs;i++) {
      result = (cube[(2*i)/BPI] >> ((2*i)%BPI)) & 3;
      if (result==ZERO) printf("0");
      else if (result==ONE) printf("1");
      else if (result==DASH) printf("-");
   }
   printf("\n");
}