[X86] Explicitly widen larger than v4f16 to the legal v8f16 (NFC) (#153839) This patch makes the current behavior explicit to prepare for adding VTs for v[567]f16. Right now these types are EVTs and hence don't fall under getPreferredVectorAction and are simply widened to the next legal power-of-two vector type. For SSE2 this is v8f16. Without the preparatory patch however, the behavior would change after adding these types. getPreferredVectorAction would try to split them because this is the current behavior for any f16 vector type that is not legal. There is a lot more detail at https://github.com/llvm/llvm-project/issues/152150 in particular how splitting these new types leads to an inconsistency between NumRegistersForVT and getTypeAction. The patch ensures that after the new types are added they would continue to be widened rather than split. Once the patch to enable v[567]f16 lands, it will be an NFC for x86.
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.