Description
Canonicalize either one's-complement zero pattern.
A fixed-width bit pattern and the number it represents are different concepts. Unsigned, two's-complement, one's-complement, sign-magnitude and biased encodings use different sign and zero conventions, so a bit-preserving transformation need not preserve numerical meaning.
Canonicalize either one's-complement zero pattern.
When to use this tool
Use Ones Complement Checksum Zero Canonicalizer when checking the stated fixed-width representation or encoding convention.
How to use the tool and how it works
- Enter word, width, negativeZero. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read word, changed. Inspect changed before interpreting the associated values.
Canonicalize either one's-complement zero pattern. Require width 1..128 and bounded word; zero or all ones becomes the requested zero pattern under negativeZero, while nonzero words stay unchanged; changed compares patterns.1
One's-complement checksum arithmetic uses end-around carry and has two zero encodings. A single word operation is only part of a complete message checksum.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| word | Word | Required. Text; maximum UTF-16 length 8192. Integer syntax: optional + or - and 1-128 decimal digits; leading zeros accepted. Apply the sign restriction above. |
| width | Width under the stated bit, interval or geometry convention; apply the field-specific units and bounds. | Required. Safe integer; minimum 1; maximum 128. |
| negativeZero | Negative Zero | Required. Boolean. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| word | Word | Required. Text; maximum UTF-16 length 8192. |
| changed | Changed | Required. Boolean. |
{
"input": {
"word": "0",
"width": 16,
"negativeZero": true
},
"output": {
"word": "65535",
"changed": true
}
}Limitations and assumptions
- This only rewrites zero representation, without calculating or validating a checksum.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Choose an explicit representation and width, validate the complete encoded value and use the matching signed or unsigned conversion for the intended numerical interpretation.
References
-
Calculation and input contract: bitwise/ones-complement-checksum-zero-canonicalizer — tool.io
-
Computing the Internet Checksum, RFC 1071 — Internet Engineering Task Force
Similar or alternative tools
- Ones Complement Dual Zero Equality
Compare one's-complement words with dual-zero equality.
- Ones Complement End Around Carry Step
Apply one end-around-carry addition step.