[JT][CT] Preserve exisiting BPI/BFI during JumpThreading
authorEvgeniy Brevnov <ybrevnov@azul.com>
Tue, 14 Feb 2023 10:03:42 +0000 (17:03 +0700)
committerEvgeniy Brevnov <ybrevnov@azul.com>
Thu, 16 Feb 2023 09:08:34 +0000 (16:08 +0700)
commita1b78fb929fccf96acaa0212cf68fee82298e747
tree767b486b6c29bd72dee1abafa869d73911d4c56f
parentf8d5f0e53b04040cebbba639530133b261a4432f
[JT][CT] Preserve exisiting BPI/BFI during JumpThreading

Currently, JT creates and updates local instances of BPI\BFI. As a result global ones have to be invalidated if JT made any changes.
In fact, JT doesn't use any information from BPI/BFI for the sake of the transformation itself. It only creates BPI/BFI to keep them up to date. But since it updates local copies (besides cases when it updates profile metadata) it just waste of time.

Current patch is a rework of D124439. D124439 makes one step and replaces local copies with global ones retrieved through AnalysisPassManager. Here we do one more step and don't create BPI/BFI if the only reason of creation is to keep BPI/BFI up to date. Overall logic is the following. If there is cached BPI/BFI then update it along the transformations. If there is no existing BPI/BFI, then create it only if it is required to update profile metadata.

Please note if BPI/BFI exists on exit from JT (either cached or created) it is always up to date and no reason to invalidate it.

Reviewed By: mkazantsev

Differential Revision: https://reviews.llvm.org/D136827
llvm/include/llvm/Transforms/Scalar/JumpThreading.h
llvm/lib/Transforms/Scalar/JumpThreading.cpp
llvm/test/Transforms/JumpThreading/select.ll
llvm/test/Transforms/JumpThreading/thread-prob-2.ll
llvm/test/Transforms/JumpThreading/thread-prob-3.ll
llvm/test/Transforms/JumpThreading/thread-prob-4.ll
llvm/test/Transforms/JumpThreading/thread-prob-5.ll
llvm/test/Transforms/JumpThreading/thread-prob-6.ll
llvm/test/Transforms/JumpThreading/threading_prof1.ll
llvm/test/Transforms/JumpThreading/threading_prof2.ll
llvm/test/Transforms/JumpThreading/threading_prof3.ll