| 66 | |
| 67 | // this method is used by byte-code generator |
| 68 | public static int compare(Long256 a, Long256 b) { |
| 69 | |
| 70 | // Special handling for NULLs. Q: Why is it needed? |
| 71 | // A: We use 4xLong.MIN_VALUEs to represent Long256 null value. |
| 72 | // However, Long256 is unsigned and Long.MIN_VALUE has the highest bit is 1, all others bits are 0. |
| 73 | // Without this special handling some values would be considered higher than NULL and some lower. |
| 74 | // Having nulls values in the middle of the range would be confusing. INT and LONG types consider NULL |
| 75 | // to be the lowest possible value so we follow the same convention here. |
| 76 | if (Long256Impl.isNull(a)) { |
| 77 | return Long256Impl.isNull(b) ? 0 : -1; |
| 78 | } else if (Long256Impl.isNull(b)) { |
| 79 | return 1; |
| 80 | } |
| 81 | |
| 82 | int cmp = Long.compareUnsigned(a.getLong3(), b.getLong3()); |
| 83 | if (cmp != 0) { |
| 84 | return cmp; |
| 85 | } |
| 86 | |
| 87 | cmp = Long.compareUnsigned(a.getLong2(), b.getLong2()); |
| 88 | if (cmp != 0) { |
| 89 | return cmp; |
| 90 | } |
| 91 | |
| 92 | cmp = Long.compareUnsigned(a.getLong1(), b.getLong1()); |
| 93 | if (cmp != 0) { |
| 94 | return cmp; |
| 95 | } |
| 96 | |
| 97 | return Long.compareUnsigned(a.getLong0(), b.getLong0()); |
| 98 | } |
| 99 | } |