static jpc_enc_prc_t *prc_create(jpc_enc_prc_t *prc, jpc_enc_cp_t *cp, jpc_enc_band_t *band)
{
	uint_fast32_t prcno;
	uint_fast32_t prcxind;
	uint_fast32_t prcyind;
	uint_fast32_t cbgtlx;
	uint_fast32_t cbgtly;
	uint_fast32_t tlprctlx;
	uint_fast32_t tlprctly;
	uint_fast32_t tlcbgtlx;
	uint_fast32_t tlcbgtly;
	uint_fast16_t rlvlno;
	jpc_enc_rlvl_t *rlvl;
	uint_fast32_t tlcblktlx;
	uint_fast32_t tlcblktly;
	uint_fast32_t brcblkbrx;
	uint_fast32_t brcblkbry;
	uint_fast32_t cblkno;
	jpc_enc_cblk_t *cblk;
	jpc_enc_tcmpt_t *tcmpt;

	prc->cblks = 0;
	prc->incltree = 0;
	prc->savincltree = 0;
	prc->nlibtree = 0;
	prc->savnlibtree = 0;

	rlvl = band->rlvl;
	tcmpt = rlvl->tcmpt;
rlvlno = rlvl - tcmpt->rlvls;
	prcno = prc - band->prcs;
	prcxind = prcno % rlvl->numhprcs;
	prcyind = prcno / rlvl->numhprcs;
	prc->band = band;

tlprctlx = JPC_FLOORTOMULTPOW2(rlvl->tlx, rlvl->prcwidthexpn);
tlprctly = JPC_FLOORTOMULTPOW2(rlvl->tly, rlvl->prcheightexpn);
if (!rlvlno) {
	tlcbgtlx = tlprctlx;
	tlcbgtly = tlprctly;
} else {
	tlcbgtlx = JPC_CEILDIVPOW2(tlprctlx, 1);
	tlcbgtly = JPC_CEILDIVPOW2(tlprctly, 1);
}

	/* Compute the coordinates of the top-left and bottom-right
	  corners of the precinct. */
	cbgtlx = tlcbgtlx + (prcxind << rlvl->cbgwidthexpn);
	cbgtly = tlcbgtly + (prcyind << rlvl->cbgheightexpn);
	prc->tlx = JAS_MAX(jas_seq2d_xstart(band->data), cbgtlx);
	prc->tly = JAS_MAX(jas_seq2d_ystart(band->data), cbgtly);
	prc->brx = JAS_MIN(jas_seq2d_xend(band->data), cbgtlx +
	  (1 << rlvl->cbgwidthexpn));
	prc->bry = JAS_MIN(jas_seq2d_yend(band->data), cbgtly +
	  (1 << rlvl->cbgheightexpn));

	if (prc->tlx < prc->brx && prc->tly < prc->bry) {
		/* The precinct contains at least one code block. */

		tlcblktlx = JPC_FLOORTOMULTPOW2(prc->tlx, rlvl->cblkwidthexpn);
		tlcblktly = JPC_FLOORTOMULTPOW2(prc->tly, rlvl->cblkheightexpn);
		brcblkbrx = JPC_CEILTOMULTPOW2(prc->brx, rlvl->cblkwidthexpn);
		brcblkbry = JPC_CEILTOMULTPOW2(prc->bry, rlvl->cblkheightexpn);
		prc->numhcblks = JPC_FLOORDIVPOW2(brcblkbrx - tlcblktlx,
		  rlvl->cblkwidthexpn);
		prc->numvcblks = JPC_FLOORDIVPOW2(brcblkbry - tlcblktly,
		  rlvl->cblkheightexpn);
		prc->numcblks = prc->numhcblks * prc->numvcblks;

		if (!(prc->incltree = jpc_tagtree_create(prc->numhcblks,
		  prc->numvcblks))) {
			goto error;
		}
		if (!(prc->nlibtree = jpc_tagtree_create(prc->numhcblks,
		  prc->numvcblks))) {
			goto error;
		}
		if (!(prc->savincltree = jpc_tagtree_create(prc->numhcblks,
		  prc->numvcblks))) {
			goto error;
		}
		if (!(prc->savnlibtree = jpc_tagtree_create(prc->numhcblks,
		  prc->numvcblks))) {
			goto error;
		}

		if (!(prc->cblks = jas_alloc2(prc->numcblks, sizeof(jpc_enc_cblk_t)))) {
			goto error;
		}
		for (cblkno = 0, cblk = prc->cblks; cblkno < prc->numcblks;
		  ++cblkno, ++cblk) {
			cblk->passes = 0;
			cblk->stream = 0;
			cblk->mqenc = 0;
			cblk->data = 0;
			cblk->flags = 0;
			cblk->prc = prc;
		}
		for (cblkno = 0, cblk = prc->cblks; cblkno < prc->numcblks;
		  ++cblkno, ++cblk) {
			if (!cblk_create(cblk, cp, prc)) {
				goto error;
			}
		}
	} else {
		/* The precinct does not contain any code blocks. */
		prc->tlx = prc->brx;
		prc->tly = prc->bry;
		prc->numcblks = 0;
		prc->numhcblks = 0;
		prc->numvcblks = 0;
		prc->cblks = 0;
		prc->incltree = 0;
		prc->nlibtree = 0;
		prc->savincltree = 0;
		prc->savnlibtree = 0;
	}

	return prc;

error:
	prc_destroy(prc);
	return 0;
}

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.