[IMPALA-11504] Speed up Decimal16Value division by specializing DecimalUtil::GetScaleMultiplier<int256_t>()

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: Impala 4.2.0
• Epic Color: ghx-label-9
• Assignee: XiangYang
• Reporter: XiangYang
• Created: 17/Aug/22 03:29
• Updated: 12/Oct/22 03:27
• Resolved: 12/Oct/22 03:27

Description

There exists a call chain:

DecimalValue<int128_t>::Divide() -> 
DecimalUtil::MultiplyByScale<int256_t>() ->
DecimalUtil::GetScaleMultiplier()

but decimal-util.h didn't specialize DecimalUtil::GetScaleMultiplier<int256_t>(), causing more performance loss.