forked from OSchip/llvm-project
170a903144
This change introduces a new intrinsic, `llvm.is.fpclass`, which checks if the provided floating-point number belongs to any of the the specified value classes. The intrinsic implements the checks made by C standard library functions `isnan`, `isinf`, `isfinite`, `isnormal`, `issubnormal`, `issignaling` and corresponding IEEE-754 operations. The primary motivation for this intrinsic is the support of strict FP mode. In this mode using compare instructions or other FP operations is not possible, because if the value is a signaling NaN, floating-point exception `Invalid` is raised, but the aforementioned functions must never raise exceptions. Currently there are two solutions for this problem, both are implemented partially. One of them is using integer operations to implement the check. It was implemented in https://reviews.llvm.org/D95948 for `isnan`. It solves the problem of exceptions, but offers one solution for all targets, although some can do the check in more efficient way. The other, implemented in https://reviews.llvm.org/D96568, introduced a hook 'clang::TargetCodeGenInfo::testFPKind', which injects a target specific code into IR to implement `isnan` and some other functions. It is convenient for targets that have dedicated instruction to determine FP data class. However using target-specific intrinsic complicates analysis and can prevent some optimizations. A special intrinsic for value class checks allows representing data class tests with enough flexibility. During IR transformations it represents the check in target-independent way and saves it from undesired transformations. In the instruction selector it allows efficient lowering depending on the used target and mode. This implementation is an extended variant of `llvm.isnan` introduced in https://reviews.llvm.org/D104854. It is limited to minimal intrinsic support. Target-specific treatment will be implemented in separate patches. Differential Revision: https://reviews.llvm.org/D112025 |
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| AMDGPU | ||
| AMDGPUDwarfExtensionAllowLocationDescriptionOnTheDwarfExpressionStack | ||
| CommandGuide | ||
| DependenceGraphs | ||
| Frontend | ||
| GlobalISel | ||
| HistoricalNotes | ||
| PDB | ||
| Proposals | ||
| TableGen | ||
| _ocamldoc | ||
| _static | ||
| _templates | ||
| _themes/llvm-theme | ||
| tutorial | ||
| AMDGPUDwarfExtensionsForHeterogeneousDebugging.rst | ||
| AMDGPUInstructionNotation.rst | ||
| AMDGPUInstructionSyntax.rst | ||
| AMDGPUModifierSyntax.rst | ||
| AMDGPUOperandSyntax.rst | ||
| AMDGPUUsage.rst | ||
| ARM-BE-bitcastfail.png | ||
| ARM-BE-bitcastsuccess.png | ||
| ARM-BE-ld1.png | ||
| ARM-BE-ldr.png | ||
| AddingConstrainedIntrinsics.rst | ||
| AdvancedBuilds.rst | ||
| AliasAnalysis.rst | ||
| Atomics.rst | ||
| Benchmarking.rst | ||
| BigEndianNEON.rst | ||
| BitCodeFormat.rst | ||
| BlockFrequencyTerminology.rst | ||
| BranchWeightMetadata.rst | ||
| BugLifeCycle.rst | ||
| Bugpoint.rst | ||
| BugpointRedesign.md | ||
| BuildingADistribution.rst | ||
| CFIVerify.rst | ||
| CMake.rst | ||
| CMakeLists.txt | ||
| CMakePrimer.rst | ||
| CodeGenerator.rst | ||
| CodeOfConduct.rst | ||
| CodeReview.rst | ||
| CodingStandards.rst | ||
| CommandLine.rst | ||
| CompileCudaWithLLVM.rst | ||
| CompilerWriterInfo.rst | ||
| Contributing.rst | ||
| Coroutines.rst | ||
| CoverageMappingFormat.rst | ||
| CycleTerminology.rst | ||
| DebuggingJITedCode.rst | ||
| DeveloperPolicy.rst | ||
| DiscourseMigrationGuide.md | ||
| Docker.rst | ||
| ExceptionHandling.rst | ||
| ExtendedIntegerResults.txt | ||
| ExtendingLLVM.rst | ||
| Extensions.rst | ||
| FAQ.rst | ||
| FaultMaps.rst | ||
| FuzzingLLVM.rst | ||
| GarbageCollection.rst | ||
| GetElementPtr.rst | ||
| GettingInvolved.rst | ||
| GettingStarted.rst | ||
| GettingStartedTutorials.rst | ||
| GettingStartedVS.rst | ||
| GitBisecting.rst | ||
| GitHub.rst | ||
| GitRepositoryPolicy.md | ||
| GoldPlugin.rst | ||
| GwpAsan.rst | ||
| HowToAddABuilder.rst | ||
| HowToBuildOnARM.rst | ||
| HowToBuildWindowsItaniumPrograms.rst | ||
| HowToBuildWithPGO.rst | ||
| HowToCrossCompileBuiltinsOnArm.rst | ||
| HowToCrossCompileLLVM.rst | ||
| HowToReleaseLLVM.rst | ||
| HowToSetUpLLVMStyleRTTI.rst | ||
| HowToSubmitABug.rst | ||
| HowToUpdateDebugInfo.rst | ||
| HowToUseAttributes.rst | ||
| HowToUseInstrMappings.rst | ||
| InAlloca.rst | ||
| JITLink.rst | ||
| LangRef.rst | ||
| Lexicon.rst | ||
| LibFuzzer.rst | ||
| LinkTimeOptimization.rst | ||
| LoopTerminology.rst | ||
| MCJIT-creation.png | ||
| MCJIT-dyld-load.png | ||
| MCJIT-engine-builder.png | ||
| MCJIT-load-object.png | ||
| MCJIT-load.png | ||
| MCJIT-resolve-relocations.png | ||
| MCJITDesignAndImplementation.rst | ||
| MIRLangRef.rst | ||
| MarkdownQuickstartTemplate.md | ||
| MarkedUpDisassembly.rst | ||
| MeetupGuidelines.rst | ||
| MemTagSanitizer.rst | ||
| MemorySSA.rst | ||
| MergeFunctions.rst | ||
| MisExpect.rst | ||
| MyFirstTypoFix.rst | ||
| NVPTXUsage.rst | ||
| NewPassManager.rst | ||
| ORCv2.rst | ||
| OpaquePointers.rst | ||
| OptBisect.rst | ||
| Packaging.rst | ||
| Passes.rst | ||
| Phabricator.rst | ||
| Phabricator_premerge_results.png | ||
| Phabricator_premerge_unit_tests.png | ||
| PointerAuth.md | ||
| ProgrammersManual.rst | ||
| Projects.rst | ||
| README.txt | ||
| Reference.rst | ||
| ReleaseNotes.rst | ||
| ReleaseProcess.rst | ||
| Remarks.rst | ||
| ReportingGuide.rst | ||
| ResponseGuide.rst | ||
| ScudoHardenedAllocator.rst | ||
| Security.rst | ||
| SecurityTransparencyReports.rst | ||
| SegmentedStacks.rst | ||
| SourceLevelDebugging.rst | ||
| SpeculativeLoadHardening.md | ||
| SphinxQuickstartTemplate.rst | ||
| StackMaps.rst | ||
| StackSafetyAnalysis.rst | ||
| Statepoints.rst | ||
| SupportLibrary.rst | ||
| SupportPolicy.rst | ||
| SystemLibrary.rst | ||
| TableGenFundamentals.rst | ||
| TestSuiteGuide.md | ||
| TestSuiteMakefileGuide.rst | ||
| TestingGuide.rst | ||
| TransformMetadata.rst | ||
| TypeMetadata.rst | ||
| UserGuides.rst | ||
| Vectorizers.rst | ||
| WritingAnLLVMBackend.rst | ||
| WritingAnLLVMNewPMPass.rst | ||
| WritingAnLLVMPass.rst | ||
| XRay.rst | ||
| XRayExample.rst | ||
| XRayFDRFormat.rst | ||
| YamlIO.rst | ||
| buildbot_worker_contact.png | ||
| conf.py | ||
| cycle-1.png | ||
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| doxygen-mainpage.dox | ||
| doxygen.cfg.in | ||
| epilogue-vectorization-cfg.png | ||
| gcc-loops.png | ||
| index.rst | ||
| linpack-pc.png | ||
| llvm-objdump.1 | ||
| loop-guard.svg | ||
| loop-irreducible.svg | ||
| loop-merge.svg | ||
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| loop-single.svg | ||
| loop-terminology-guarded-loop.png | ||
| loop-terminology-initial-loop.png | ||
| loop-terminology-rotated-loop.png | ||
| loop-terminology.svg | ||
| make.bat | ||
| re_format.7 | ||
| speculative_load_hardening_microbenchmarks.png | ||
| yaml2obj.rst | ||
README.txt
LLVM Documentation
==================
LLVM's documentation is written in reStructuredText, a lightweight
plaintext markup language (file extension `.rst`). While the
reStructuredText documentation should be quite readable in source form, it
is mostly meant to be processed by the Sphinx documentation generation
system to create HTML pages which are hosted on <https://llvm.org/docs/> and
updated after every commit. Manpage output is also supported, see below.
If you instead would like to generate and view the HTML locally, install
Sphinx <http://sphinx-doc.org/> and then do:
cd <build-dir>
cmake -DLLVM_ENABLE_SPHINX=true -DSPHINX_OUTPUT_HTML=true <src-dir>
make -j3 docs-llvm-html
$BROWSER <build-dir>/docs/html/index.html
The mapping between reStructuredText files and generated documentation is
`docs/Foo.rst` <-> `<build-dir>/docs//html/Foo.html` <-> `https://llvm.org/docs/Foo.html`.
If you are interested in writing new documentation, you will want to read
`SphinxQuickstartTemplate.rst` which will get you writing documentation
very fast and includes examples of the most important reStructuredText
markup syntax.
Manpage Output
===============
Building the manpages is similar to building the HTML documentation. The
primary difference is to use the `man` makefile target, instead of the
default (which is `html`). Sphinx then produces the man pages in the
directory `<build-dir>/docs/man/`.
cd <build-dir>
cmake -DLLVM_ENABLE_SPHINX=true -DSPHINX_OUTPUT_MAN=true <src-dir>
make -j3 docs-llvm-man
man -l <build-dir>/docs/man/FileCheck.1
The correspondence between .rst files and man pages is
`docs/CommandGuide/Foo.rst` <-> `<build-dir>/docs//man/Foo.1`.
These .rst files are also included during HTML generation so they are also
viewable online (as noted above) at e.g.
`https://llvm.org/docs/CommandGuide/Foo.html`.
Checking links
==============
The reachability of external links in the documentation can be checked by
running:
cd llvm/docs/
sphinx-build -b linkcheck . _build/lintcheck/
# report will be generated in _build/lintcheck/output.txt
Doxygen page Output
==============
Install doxygen <https://www.doxygen.nl/download.html> and dot2tex <https://dot2tex.readthedocs.io/en/latest>.
cd <build-dir>
cmake -DLLVM_ENABLE_DOXYGEN=On <llvm-top-src-dir>
make doxygen-llvm # for LLVM docs
make doxygen-clang # for clang docs
It will generate html in
<build-dir>/docs/doxygen/html # for LLVM docs
<build-dir>/tools/clang/docs/doxygen/html # for clang docs