forked from OSchip/llvm-project
b769eb02b5
Summary: This change permits scalar bfloats to be loaded, stored, moved and used as function call arguments and return values, whenever the bf16 feature is supported by the subtarget. Previously that was only supported in the presence of the fullfp16 feature, because the code generation strategy depended on instructions from that extension. This change adds alternative code generation strategies so that those operations can be done even without fullfp16. The strategy for loads and stores is to replace VLDRH/VSTRH with integer LDRH/STRH plus a move between register classes. I've written isel patterns for those, conditional on //not// having the fullfp16 feature (so that in the fullfp16 case, the existing patterns will still be used). For function arguments and returns, instead of writing isel patterns to match `VMOVhr` and `VMOVrh`, I've avoided generating those SDNodes in the first place, by factoring out the code that constructs them into helper functions `MoveToHPR` and `MoveFromHPR` which have a fallback for non-fullfp16 subtargets. The current output code is not especially pretty: in the new test file you can see unnecessary store/load pairs implementing no-op bitcasts, and lots of pointless moves back and forth between FP registers and GPRs. But it at least works, which is an improvement on the previous situation. Reviewers: dmgreen, SjoerdMeijer, stuij, chill, miyuki, labrinea Reviewed By: dmgreen, labrinea Subscribers: labrinea, kristof.beyls, hiraditya, danielkiss, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D82372 |
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| test | ||
| tools | ||
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| .clang-format | ||
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| CODE_OWNERS.TXT | ||
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| LICENSE.TXT | ||
| LLVMBuild.txt | ||
| README.txt | ||
| RELEASE_TESTERS.TXT | ||
| configure | ||
| llvm.spec.in | ||
README.txt
The LLVM Compiler Infrastructure ================================ This directory and its subdirectories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and runtime environments. LLVM is open source software. You may freely distribute it under the terms of the license agreement found in LICENSE.txt. Please see the documentation provided in docs/ for further assistance with LLVM, and in particular docs/GettingStarted.rst for getting started with LLVM and docs/README.txt for an overview of LLVM's documentation setup. If you are writing a package for LLVM, see docs/Packaging.rst for our suggestions.