Mryange opened a new pull request, #66476:
URL: https://github.com/apache/doris/pull/66476
### What problem does this PR solve?
Checked `int128` multiplication used a 128-bit division on the common path,
making Decimal
multiplication unnecessarily expensive. Replace the division-based overflow
check with 64-bit limb
multiplication and carry detection while preserving signed overflow
semantics and the low 128 result
bits.
For the query-like `DECIMAL64(10,7) * DECIMAL128(38,2) -> DECIMAL128(38,9)`
benchmark with 65,536
items per batch:
| Implementation | Mean CPU time | CV | Change |
|---|---:|---:|---:|
| Before | 14.58 ns/item | 4.34% | Baseline |
| After | 6.32 ns/item | 2.76% | **-56.62%** |
The change also adds boundary coverage and 10,000 deterministic random input
pairs checked against
an `Int256` oracle.
### Release note
None
### Check List (For Author)
- Test: Manual test
- Release benchmark build: sh build.sh --benchmark -j48
- Benchmark correctness validation against Int256 oracle
- clang-format 16 check
- Behavior changed: No
- Does this need documentation: No
### What problem does this PR solve?
Issue Number: close #xxx
Related PR: #xxx
Problem Summary:
### Release note
None
### Check List (For Author)
- Test <!-- At least one of them must be included. -->
- [ ] Regression test
- [ ] Unit Test
- [ ] Manual test (add detailed scripts or steps below)
- [ ] No need to test or manual test. Explain why:
- [ ] This is a refactor/code format and no logic has been changed.
- [ ] Previous test can cover this change.
- [ ] No code files have been changed.
- [ ] Other reason <!-- Add your reason? -->
- Behavior changed:
- [ ] No.
- [ ] Yes. <!-- Explain the behavior change -->
- Does this need documentation?
- [ ] No.
- [ ] Yes. <!-- Add document PR link here. eg:
https://github.com/apache/doris-website/pull/1214 -->
### Check List (For Reviewer who merge this PR)
- [ ] Confirm the release note
- [ ] Confirm test cases
- [ ] Confirm document
- [ ] Add branch pick label <!-- Add branch pick label that this PR should
merge into -->
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