[SimplifyCFG] Fix `SimplifyCFG` pass to skip folding when both blocks contain convergence loop/entry intrinsics. (#166452) Fixes a bug https://github.com/llvm/llvm-project/issues/165642. [Similar fix](https://github.com/llvm/llvm-project/pull/165643) is being made in `IndVarSimplify` pass to account for convergence tokens. [LLVM Spec](https://llvm.org/docs/ConvergentOperations.html#llvm-experimental-convergence-loop) states that only a single loop / entry convergence token can be included in a basic block. This PR fixes the issue in `SimplifyCFG` pass so that when a basic block and its predecessor both contain such convergence intrinsics, it skips merging the two blocks.
Welcome to the LLVM project!
This repository contains the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.
The LLVM project has multiple components. The core of the project is itself called “LLVM”. This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer.
C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.
Other components include: the libc++ C++ standard library, the LLD linker, and more.
Consult the Getting Started with LLVM page for information on building and running LLVM.
For information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.
Join the LLVM Discourse forums, Discord chat, LLVM Office Hours or Regular sync-ups.
The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.