e4ecd83fe9
This only applies to FastIsel. GlobalIsel seems to sidestep the issue. This fixes https://bugs.llvm.org/show_bug.cgi?id=46996 One of the things we do in llvm is decide if a type needs consecutive registers. Previously, we just checked if it was an array or not. (plus an SVE specific check that is not changing here) This causes some confusion when you arbitrary IR like: ``` %T1 = type { double, i1 }; define [ 1 x %T1 ] @foo() { entry: ret [ 1 x %T1 ] zeroinitializer } ``` We see it is an array so we call CC_AArch64_Custom_Block which bails out when it sees the i1, a type we don't want to put into a block. This leaves the location of the double in some kind of intermediate state and leads to odd codegen. Which then crashes the backend because it doesn't know how to implement what it's been asked for. You get this: ``` renamable $d0 = FMOVD0 $w0 = COPY killed renamable $d0 ``` Rather than this: ``` $d0 = FMOVD0 $w0 = COPY $wzr ``` The backend knows how to copy 64 bit to 64 bit registers, but not 64 to 32. It can certainly be taught how but the real issue seems to be us even trying to assign a register block in the first place. This change makes the logic of AArch64TargetLowering::functionArgumentNeedsConsecutiveRegisters a bit more in depth. If we find an array, also check that all the nested aggregates in that array have a single member type. Then CC_AArch64_Custom_Block's assumption of a type that looks like [ N x type ] will be valid and we get the expected codegen. New tests have been added to exercise these situations. Note that some of the output is not ABI compliant. The aim of this change is to simply handle these situations and not to make our processing of arbitrary IR ABI compliant. Reviewed By: efriedma Differential Revision: https://reviews.llvm.org/D104123 |
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| .github | ||
| clang | ||
| clang-tools-extra | ||
| compiler-rt | ||
| debuginfo-tests | ||
| flang | ||
| libc | ||
| libclc | ||
| libcxx | ||
| libcxxabi | ||
| libunwind | ||
| lld | ||
| lldb | ||
| llvm | ||
| mlir | ||
| openmp | ||
| parallel-libs | ||
| polly | ||
| pstl | ||
| runtimes | ||
| utils/arcanist | ||
| .arcconfig | ||
| .arclint | ||
| .clang-format | ||
| .clang-tidy | ||
| .git-blame-ignore-revs | ||
| .gitignore | ||
| .mailmap | ||
| CONTRIBUTING.md | ||
| README.md | ||
| SECURITY.md | ||
README.md
The LLVM Compiler Infrastructure
This directory and its sub-directories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.
The README briefly describes how to get started with building LLVM. For more information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.
Getting Started with the LLVM System
Taken from https://llvm.org/docs/GettingStarted.html.
Overview
Welcome to the LLVM project!
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. It also contains basic regression tests.
C-like languages use the Clang front end. 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
The LLVM Getting Started documentation may be out of date. The Clang Getting Started page might have more accurate information.
This is an example work-flow and configuration to get and build the LLVM source:
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Checkout LLVM (including related sub-projects like Clang):
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git clone https://github.com/llvm/llvm-project.git -
Or, on windows,
git clone --config core.autocrlf=false https://github.com/llvm/llvm-project.git
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Configure and build LLVM and Clang:
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cd llvm-project -
cmake -S llvm -B build -G <generator> [options]Some common build system generators are:
Ninja--- for generating Ninja build files. Most llvm developers use Ninja.Unix Makefiles--- for generating make-compatible parallel makefiles.Visual Studio--- for generating Visual Studio projects and solutions.Xcode--- for generating Xcode projects.
Some Common options:
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-DLLVM_ENABLE_PROJECTS='...'--- semicolon-separated list of the LLVM sub-projects you'd like to additionally build. Can include any of: clang, clang-tools-extra, libcxx, libcxxabi, libunwind, lldb, compiler-rt, lld, polly, or debuginfo-tests.For example, to build LLVM, Clang, libcxx, and libcxxabi, use
-DLLVM_ENABLE_PROJECTS="clang;libcxx;libcxxabi". -
-DCMAKE_INSTALL_PREFIX=directory--- Specify for directory the full path name of where you want the LLVM tools and libraries to be installed (default/usr/local). -
-DCMAKE_BUILD_TYPE=type--- Valid options for type are Debug, Release, RelWithDebInfo, and MinSizeRel. Default is Debug. -
-DLLVM_ENABLE_ASSERTIONS=On--- Compile with assertion checks enabled (default is Yes for Debug builds, No for all other build types).
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cmake --build build [-- [options] <target>]or your build system specified above directly.-
The default target (i.e.
ninjaormake) will build all of LLVM. -
The
check-alltarget (i.e.ninja check-all) will run the regression tests to ensure everything is in working order. -
CMake will generate targets for each tool and library, and most LLVM sub-projects generate their own
check-<project>target. -
Running a serial build will be slow. To improve speed, try running a parallel build. That's done by default in Ninja; for
make, use the option-j NNN, whereNNNis the number of parallel jobs, e.g. the number of CPUs you have.
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For more information see CMake
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Consult the Getting Started with LLVM page for detailed information on configuring and compiling LLVM. You can visit Directory Layout to learn about the layout of the source code tree.