#include "sort.h"                                       /*   SORT.C  */

sort()
{
	register SRTBLK *bp;

	if ((bp = frstbp) == NULL)
		return;
        do  switch(bp->text[0]) {
		case 'i':
			if (bp->insno < 0)
				bp->preced = 'a';
			else bp->preced = 'd';
			break;
		case 'f':
			bp->preced = 'b';
			break;
		case 'a':
			bp->preced = 'c';
			break;
		case 'w':
                case 't':
		case 's':
		case 'e':
			break;
		default:
			fprintf(stderr,"sort: illegal opcode\n");
			break;
		}
	while ((bp = bp->nxtblk) != NULL);
	sorter();
}                                  


sorter()                                /* the main sorting routine */
{
	register SRTBLK *newbp, *prvbp;
	SRTBLK *bp;
	char c, pc;
	float diff;
	int prdiff, indiff;

	bp = frstbp;
	while ((newbp = bp->nxtblk) != NULL
	  && (c = newbp->text[0]) != 's' && c != 'e') {
		prvbp = newbp;
		while ((prvbp = prvbp->prvblk) != NULL
		  && (pc = prvbp->text[0]) != 'w'
		  && (c == 'w'
		     || (pc != 't'
		      && (c == 't'
			 || ((diff = newbp->newp2 - prvbp->newp2) < 0
			 || !diff
			  && ((prdiff = newbp->preced - prvbp->preced) < 0
			     || !prdiff
			      && c == 'i'
			      && ((indiff = newbp->insno - prvbp->insno) < 0
				 || !indiff
				  && newbp->newp3 < prvbp->newp3 )))))))
			;

		if (prvbp != bp) {                      /*   if re-ordered,  */
			if ((bp->nxtblk = newbp->nxtblk) != NULL)
				newbp->nxtblk->prvblk = bp;       /* unlink, */
			if ((newbp->prvblk = prvbp) != NULL) {    /*  relink */
				newbp->nxtblk = prvbp->nxtblk;    /*  in mid */
				prvbp->nxtblk = prvbp->nxtblk->prvblk = newbp;
			}
			else {
				newbp->nxtblk = frstbp;         /* or at top */
				frstbp = frstbp->prvblk = newbp;
			}
		}
		else bp = newbp;                        /*  else loop nxtblk */
	}
}