[DAGCombiner] Refactor and improve ReduceLoadOpStoreWidth (#119564) This patch make a couple of improvements to ReduceLoadOpStoreWidth. When determining the minimum size of "NewBW" we now take byte boundaries into account. If we for example touch bits 6-10 we shouldn't accept NewBW=8, because we would fail later when detecting that we can't access bits from two different bytes in memory using a single load. Instead we make sure to align LSB/MSB according to byte size boundaries up front before searching for a viable "NewBW". In the past we only tried to find a "ShAmt" that was a multiple of "NewBW", but now we use a sliding window technique to scan for a viable "ShAmt" that is a multiple of the byte size. This can help out finding more opportunities for optimization (specially if the original type isn't byte sized, and for big-endian targets when the original load/store is aligned on the most significant bit).
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.