[IMPALA-4291] Lazy creation of IRFunction::Type to Function* mapping

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: Impala 2.8.0
• Fix Version/s: Impala 2.8.0
• Component/s: Backend
• Labels: codegen
• Assignee: Michael Ho
• Reporter: Michael Ho
• Created: 13/Oct/16 18:37
• Updated: 30/Aug/18 18:49
• Resolved: 20/Oct/16 05:58

Description

For simple queries with one or two functions to codegen, we spent about 23ms or more out of 40ms of codegen time in preparation. We can save some time by not eagerly populating the map of IRFunction::Type to llvm::Function* map. This should help with the fixes for IMPALA-3638 when we create the LLVM module unconditionally.