int rateallocate(jpc_enc_t *enc, int numlyrs, uint_fast32_t *cumlens)
{
	jpc_flt_t lo;
	jpc_flt_t hi;
	jas_stream_t *out;
	uint_fast32_t cumlen;
	int lyrno;
	jpc_flt_t thresh;
	jpc_flt_t goodthresh;
	int success;
	long pos;
	long oldpos;
	int numiters;

	jpc_enc_tcmpt_t *comp;
	jpc_enc_tcmpt_t *endcomps;
	jpc_enc_rlvl_t *lvl;
	jpc_enc_rlvl_t *endlvls;
	jpc_enc_band_t *band;
	jpc_enc_band_t *endbands;
	jpc_enc_cblk_t *cblk;
	jpc_enc_cblk_t *endcblks;
	jpc_enc_pass_t *pass;
	jpc_enc_pass_t *endpasses;
	jpc_enc_pass_t *pass1;
	jpc_flt_t mxrdslope;
	jpc_flt_t mnrdslope;
	jpc_enc_tile_t *tile;
	jpc_enc_prc_t *prc;
	int prcno;

	JAS_DBGLOG(10, ("starting rate allocation\n"));

	tile = enc->curtile;

	for (lyrno = 1; lyrno < numlyrs - 1; ++lyrno) {
		if (cumlens[lyrno - 1] > cumlens[lyrno]) {
			abort();
		}
	}

	if (!(out = jas_stream_memopen(0, 0))) {
		return -1;
	}


	/* Find minimum and maximum R-D slope values. */
	mnrdslope = DBL_MAX;
	mxrdslope = 0;
	endcomps = &tile->tcmpts[tile->numtcmpts];
	for (comp = tile->tcmpts; comp != endcomps; ++comp) {
		endlvls = &comp->rlvls[comp->numrlvls];
		for (lvl = comp->rlvls; lvl != endlvls; ++lvl) {
			if (!lvl->bands) {
				continue;
			}
			endbands = &lvl->bands[lvl->numbands];
			for (band = lvl->bands; band != endbands; ++band) {
				if (!band->data) {
					continue;
				}
				for (prcno = 0, prc = band->prcs; prcno < lvl->numprcs;
				  ++prcno, ++prc) {
					if (!prc->cblks) {
						continue;
					}
					endcblks = &prc->cblks[prc->numcblks];
					for (cblk = prc->cblks; cblk != endcblks; ++cblk) {
						calcrdslopes(cblk);
						endpasses = &cblk->passes[cblk->numpasses];
						for (pass = cblk->passes; pass != endpasses; ++pass) {
							if (pass->rdslope > 0) {
								if (pass->rdslope < mnrdslope) {
									mnrdslope = pass->rdslope;
								}
								if (pass->rdslope > mxrdslope) {
									mxrdslope = pass->rdslope;
								}
							}
						}
					}
				}
			}
		}
	}
	JAS_DBGLOG(10, ("min rdslope = %f max rdslope = %f\n", mnrdslope,
	  mxrdslope));

	jpc_init_t2state(enc, 1);

	for (lyrno = 0; lyrno < numlyrs; ++lyrno) {

		lo = mnrdslope;
		hi = mxrdslope;

		success = 0;
		goodthresh = 0;
		numiters = 0;

		do {

			cumlen = cumlens[lyrno];
			if (cumlen == UINT_FAST32_MAX) {
				/* Only the last layer can be free of a rate
				  constraint (e.g., for lossless coding). */
				assert(lyrno == numlyrs - 1);
				goodthresh = -1;
				success = 1;
				break;
			}

			thresh = (lo + hi) / 2;

			/* Save the tier 2 coding state. */
			jpc_save_t2state(enc);
			oldpos = jas_stream_tell(out);
			assert(oldpos >= 0);

			/* Assign all passes with R-D slopes greater than or
			  equal to the current threshold to this layer. */
			endcomps = &tile->tcmpts[tile->numtcmpts];
			for (comp = tile->tcmpts; comp != endcomps; ++comp) {
				endlvls = &comp->rlvls[comp->numrlvls];
				for (lvl = comp->rlvls; lvl != endlvls; ++lvl) {
					if (!lvl->bands) {
						continue;
					}
					endbands = &lvl->bands[lvl->numbands];
					for (band = lvl->bands; band != endbands; ++band) {
						if (!band->data) {
							continue;
						}
						for (prcno = 0, prc = band->prcs; prcno < lvl->numprcs;
						  ++prcno, ++prc) {
							if (!prc->cblks) {
								continue;
							}
							endcblks = &prc->cblks[prc->numcblks];
							for (cblk = prc->cblks; cblk != endcblks; ++cblk) {
								if (cblk->curpass) {
									endpasses = &cblk->passes[cblk->numpasses];
									pass1 = cblk->curpass;
									for (pass = cblk->curpass; pass !=
									  endpasses; ++pass) {
										if (pass->rdslope >= thresh) {
											pass1 = &pass[1];
										}
									}
									for (pass = cblk->curpass; pass != pass1;
									  ++pass) {
										pass->lyrno = lyrno;
									}
									for (; pass != endpasses; ++pass) {
										pass->lyrno = -1;
									}
								}
							}
						}
					}
				}
			}

			/* Perform tier 2 coding. */
			endcomps = &tile->tcmpts[tile->numtcmpts];
			for (comp = tile->tcmpts; comp != endcomps; ++comp) {
				endlvls = &comp->rlvls[comp->numrlvls];
				for (lvl = comp->rlvls; lvl != endlvls; ++lvl) {
					if (!lvl->bands) {
						continue;
					}
					for (prcno = 0; prcno < lvl->numprcs; ++prcno) {
						if (jpc_enc_encpkt(enc, out, comp - tile->tcmpts,
						  lvl - comp->rlvls, prcno, lyrno)) {
							return -1;
						}
					}
				}
			}

			pos = jas_stream_tell(out);

			/* Check the rate constraint. */
			assert(pos >= 0);
			if (pos > cumlen) {
				/* The rate is too high. */
				lo = thresh;
			} else if (pos <= cumlen) {
				/* The rate is low enough, so try higher. */
				hi = thresh;
				if (!success || thresh < goodthresh) {
					goodthresh = thresh;
					success = 1;
				}
			}

			/* Save the tier 2 coding state. */
			jpc_restore_t2state(enc);
			if (jas_stream_seek(out, oldpos, SEEK_SET) < 0) {
				abort();
			}

			JAS_DBGLOG(10, ("maxlen=%08ld actuallen=%08ld thresh=%f\n",
			  cumlen, pos, thresh));

			++numiters;
		} while (lo < hi - 1e-3 && numiters < 32);

		if (!success) {
			jas_eprintf("warning: empty layer generated\n");
		}

		JAS_DBGLOG(10, ("success %d goodthresh %f\n", success, goodthresh));

		/* Assign all passes with R-D slopes greater than or
		  equal to the selected threshold to this layer. */
		endcomps = &tile->tcmpts[tile->numtcmpts];
		for (comp = tile->tcmpts; comp != endcomps; ++comp) {
			endlvls = &comp->rlvls[comp->numrlvls];
			for (lvl = comp->rlvls; lvl != endlvls; ++lvl) {
				if (!lvl->bands) {
					continue;
				}
				endbands = &lvl->bands[lvl->numbands];
				for (band = lvl->bands; band != endbands; ++band) {
					if (!band->data) {
						continue;
					}
					for (prcno = 0, prc = band->prcs; prcno < lvl->numprcs;
					  ++prcno, ++prc) {
						if (!prc->cblks) {
							continue;
						}
						endcblks = &prc->cblks[prc->numcblks];
						for (cblk = prc->cblks; cblk != endcblks; ++cblk) {
							if (cblk->curpass) {
								endpasses = &cblk->passes[cblk->numpasses];
								pass1 = cblk->curpass;
								if (success) {
									for (pass = cblk->curpass; pass !=
									  endpasses; ++pass) {
										if (pass->rdslope >= goodthresh) {
											pass1 = &pass[1];
										}
									}
								}
								for (pass = cblk->curpass; pass != pass1;
								  ++pass) {
									pass->lyrno = lyrno;
								}
								for (; pass != endpasses; ++pass) {
									pass->lyrno = -1;
								}
							}
						}
					}
				}
			}
		}

		/* Perform tier 2 coding. */
		endcomps = &tile->tcmpts[tile->numtcmpts];
		for (comp = tile->tcmpts; comp != endcomps; ++comp) {
			endlvls = &comp->rlvls[comp->numrlvls];
			for (lvl = comp->rlvls; lvl != endlvls; ++lvl) {
				if (!lvl->bands) {
					continue;
				}
				for (prcno = 0; prcno < lvl->numprcs; ++prcno) {
					if (jpc_enc_encpkt(enc, out, comp - tile->tcmpts,
					  lvl - comp->rlvls, prcno, lyrno)) {
						return -1;
					}
				}
			}
		}
	}

	if (jas_getdbglevel() >= 5) {
		dump_layeringinfo(enc);
	}

	jas_stream_close(out);

	JAS_DBGLOG(10, ("finished rate allocation\n"));

	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.