hubgeter opened a new pull request, #57614:
URL: https://github.com/apache/doris/pull/57614

   bp #57208
   Problem Summary:
   When parsing RLE_DICTIONARY encoding, the parquet reader uniformly uses 
memcpy. However, for INT32, INT64, etc., direct assignment is faster than 
memcpy.
   
   In Parquet dictionary encoding, the actual data is not stored contiguously, 
resulting in very small memcpy sizes. When analyzing the implementation of 
`memcpy`, we can see that for such small sizes, `__builtin_memcpy` is used 
instead. The implementation of `__builtin_memcpy` essentially behaves like a 
series of simple assignments. You can observe the corresponding assembly code 
here: https://godbolt.org/z/r9Ma1ozvd.
   
   ### 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 -->
   
   


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to