621fc8774e
AMDGPU previously had no target-specific LSR cost model, so the generic heuristic would often introduce extra induction variables and base-add chains that hurt VALU throughput on GFX9+ (observed on gfx942). Implement a custom cost model: - isLSRCostLess(): prioritize per-iteration instruction count over setup costs, penalize IV multiplies, and demote register count. Pre-GFX9 falls back to the default comparator. - getScalingFactorCost(): report that base+scale*index addressing requires an extra ADD instruction. - isNumRegsMajorCostOfLSR(): return false. - shouldDropLSRSolutionIfLessProfitable(): return true. Assisted-by: Claude Opus
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.