static zend_always_inline int zend_hash_compare_impl(HashTable *ht1, HashTable *ht2, compare_func_t compar, zend_bool ordered) {
	uint32_t idx1, idx2;

	if (ht1->nNumOfElements != ht2->nNumOfElements) {
		return ht1->nNumOfElements > ht2->nNumOfElements ? 1 : -1;
	}

	for (idx1 = 0, idx2 = 0; idx1 < ht1->nNumUsed; idx1++) {
		Bucket *p1 = ht1->arData + idx1, *p2;
		zval *pData1, *pData2;
		int result;

		if (Z_TYPE(p1->val) == IS_UNDEF) continue;
		if (ordered) {
			while (1) {
				ZEND_ASSERT(idx2 != ht2->nNumUsed);
				p2 = ht2->arData + idx2;
				if (Z_TYPE(p2->val) != IS_UNDEF) break;
				idx2++;
			}
			if (p1->key == NULL && p2->key == NULL) { /* numeric indices */
				if (p1->h != p2->h) {
					return p1->h > p2->h ? 1 : -1;
				}
			} else if (p1->key != NULL && p2->key != NULL) { /* string indices */
				if (ZSTR_LEN(p1->key) != ZSTR_LEN(p2->key)) {
					return ZSTR_LEN(p1->key) > ZSTR_LEN(p2->key) ? 1 : -1;
				}

				result = memcmp(ZSTR_VAL(p1->key), ZSTR_VAL(p2->key), ZSTR_LEN(p1->key));
				if (result != 0) {
					return result;
				}
			} else {
				/* Mixed key types: A string key is considered as larger */
				return p1->key != NULL ? 1 : -1;
			}
			pData2 = &p2->val;
			idx2++;
		} else {
			if (p1->key == NULL) { /* numeric index */
				pData2 = zend_hash_index_find(ht2, p1->h);
				if (pData2 == NULL) {
					return 1;
				}
			} else { /* string index */
				pData2 = zend_hash_find(ht2, p1->key);
				if (pData2 == NULL) {
					return 1;
				}
			}
		}

		pData1 = &p1->val;
		if (Z_TYPE_P(pData1) == IS_INDIRECT) {
			pData1 = Z_INDIRECT_P(pData1);
		}
		if (Z_TYPE_P(pData2) == IS_INDIRECT) {
			pData2 = Z_INDIRECT_P(pData2);
		}

		if (Z_TYPE_P(pData1) == IS_UNDEF) {
			if (Z_TYPE_P(pData2) != IS_UNDEF) {
				return -1;
			}
		} else if (Z_TYPE_P(pData2) == IS_UNDEF) {
			return 1;
		} else {
			result = compar(pData1, pData2);
			if (result != 0) {
				return result;
			}
		}
	}

	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.