c727b48287
On loongarch64 with lsx extension, we select `VBITREV_W` for `v4i32 (xor X, (shl splat(1), Y))`:8e66303916/llvm/lib/Target/LoongArch/LoongArchLSXInstrInfo.td (L1583-L1584)And `vsplat_imm_eq_1` is defined as:8e66303916/llvm/lib/Target/LoongArch/LoongArchLSXInstrInfo.td (L77-L87)For the `(bitconvert (v4i32 (build_vector)))` case, the pattern is expected to be: ``` PATTERN: (xor:{ *:[v4i32] } v4i32:{ *:[v4i32] }:$vj, (shl:{ *:[v4i32] } (bitconvert:{ *:[v4i32] } (build_vector:{ *:[v4i32] }))<<P:Predicate_vsplat_imm_eq_1>>, v4i32:{ *:[v4i32] }:$vk)) RESULT: (VBITREV_W:{ *:[v4i32] } v4i32:{ *:[v4i32] }:$vj, v4i32:{ *:[v4i32] }:$vk) ``` However, `simplifyTree` drops the `bitconvert` node and its predicates:8e66303916/llvm/utils/TableGen/Common/CodeGenDAGPatterns.cpp (L3036-L3062)Then llvm will match `vsplat_imm_eq_1` for any v4i32 splats and cause a miscompilation: ``` PATTERN: (xor:{ *:[v4i32] } v4i32:{ *:[v4i32] }:$vj, (shl:{ *:[v4i32] } (build_vector:{ *:[v4i32] }), v4i32:{ *:[v4i32] }:$vk)) RESULT: (VBITREV_W:{ *:[v4i32] } v4i32:{ *:[v4i32] }:$vj, v4i32:{ *:[v4i32] }:$vk) ``` This patch adds additional checks for predicates associated with the trivial bitconvert node. Unused patterns in the LoongArch target are also removed. Fixes https://github.com/llvm/llvm-project/issues/116008.
The LLVM Compiler Infrastructure
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.
Getting the Source Code and Building LLVM
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.
Getting in touch
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.