[ARROW-9131] [C++] Faster ascii_lower and ascii_upper

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.0.0
• Component/s: C++
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/25242
• Assignee: Maarten Breddels
• Reporter: Maarten Breddels
• Created: 15/Jun/20 08:57
• Updated: 11/Jan/23 08:04
• Resolved: 15/Jun/20 12:31

Description

The current version is using a lookup table for doing the case conversion. Using http://quick-bench.com/JaDErmVCY23Z1tu6YZns_KBt0qU it seems using a boolean check and +/-32 seems ~5x times faster (4.6x for clang 9, 6.4x for GCC  9.2).

 

Issue Links

• is related to: ARROW-555 [C++] String algorithm library for StringArray/BinaryArray
• links to: GitHub Pull Request #7434