1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-26 04:32:44 +01:00
llvm-mirror/docs
Michael Kruse a9ec994652 Introduce llvm.loop.parallel_accesses and llvm.access.group metadata.
The current llvm.mem.parallel_loop_access metadata has a problem in that
it uses LoopIDs. LoopID unfortunately is not loop identifier. It is
neither unique (there's even a regression test assigning the some LoopID
to multiple loops; can otherwise happen if passes such as LoopVersioning
make copies of entire loops) nor persistent (every time a property is
removed/added from a LoopID's MDNode, it will also receive a new LoopID;
this happens e.g. when calling Loop::setLoopAlreadyUnrolled()).
Since most loop transformation passes change the loop attributes (even
if it just to mark that a loop should not be processed again as
llvm.loop.isvectorized does, for the versioned and unversioned loop),
the parallel access information is lost for any subsequent pass.

This patch unlinks LoopIDs and parallel accesses.
llvm.mem.parallel_loop_access metadata on instruction is replaced by
llvm.access.group metadata. llvm.access.group points to a distinct
MDNode with no operands (avoiding the problem to ever need to add/remove
operands), called "access group". Alternatively, it can point to a list
of access groups. The LoopID then has an attribute
llvm.loop.parallel_accesses with all the access groups that are parallel
(no dependencies carries by this loop).

This intentionally avoid any kind of "ID". Loops that are clones/have
their attributes modifies retain the llvm.loop.parallel_accesses
attribute. Access instructions that a cloned point to the same access
group. It is not necessary for each access to have it's own "ID" MDNode,
but those memory access instructions with the same behavior can be
grouped together.

The behavior of llvm.mem.parallel_loop_access is not changed by this
patch, but should be considered deprecated.

Differential Revision: https://reviews.llvm.org/D52116

llvm-svn: 349725
2018-12-20 04:58:07 +00:00
..
_ocamldoc
_static
_templates
_themes/llvm-theme
AMDGPU [AMDGPU][MC][DOC] A fix for build failure in r349370 2018-12-17 18:53:10 +00:00
CommandGuide [FileCheck] Annotate input dump (1/7) 2018-12-18 00:01:39 +00:00
Frontend
HistoricalNotes
PDB
Proposals [docs] Add C++ Performance Benchmark to test-suite proposals. 2018-11-21 00:34:02 +00:00
TableGen [TableGen] Preprocessing support 2018-11-27 18:57:43 +00:00
tutorial [BuildingAJIT] Clang-format chapters 1 and 2. 2018-11-13 01:26:25 +00:00
AdvancedBuilds.rst Use backquotes to avoid a sphinx unexpected error: 2018-12-16 14:19:39 +00:00
AliasAnalysis.rst
AMDGPUInstructionNotation.rst [AMDGPU][MC][DOC] A fix for build failure in r349370 2018-12-17 18:53:10 +00:00
AMDGPUInstructionSyntax.rst [AMDGPU][MC][DOC] A fix for build failure in r349370 2018-12-17 18:53:10 +00:00
AMDGPUModifierSyntax.rst [AMDGPU][MC][DOC] A fix for build failure in r349370 2018-12-17 18:53:10 +00:00
AMDGPUOperandSyntax.rst [AMDGPU][MC][DOC] A fix for build failure in r349370 2018-12-17 18:53:10 +00:00
AMDGPUUsage.rst [AMDGPU][MC][DOC] Updated AMD GPU assembler description 2018-12-17 17:38:11 +00:00
ARM-BE-bitcastfail.png
ARM-BE-bitcastsuccess.png
ARM-BE-ld1.png
ARM-BE-ldr.png
Atomics.rst [docs][AtomicExpandPass] Document the alternate lowering strategy for part-word atomicrmw/cmpxchg 2018-11-30 09:23:24 +00:00
Benchmarking.rst
BigEndianNEON.rst
BitCodeFormat.rst
BlockFrequencyTerminology.rst
BranchWeightMetadata.rst [TI removal] Remove discussion of TerminatorInst from the LLVM 2018-10-18 07:40:24 +00:00
BugLifeCycle.rst Introduce bug life cycle documentation. 2018-11-07 08:49:36 +00:00
Bugpoint.rst
CFIVerify.rst [cfi-verify] Abort on unsupported targets 2018-07-16 15:26:44 +00:00
CMake.rst [benchmark] Re-enable benchmarks on all platforms including Windows 2018-09-07 21:47:00 +00:00
CMakeLists.txt
CMakePrimer.rst
CodeGenerator.rst [NFC] fix trivial typos in documents 2018-06-15 05:10:09 +00:00
CodeOfConduct.rst
CodingStandards.rst Document how to comment an actual parameter. 2018-11-14 13:43:19 +00:00
CommandLine.rst
CompileCudaWithLLVM.rst Added missing whitespace in the link. 2018-11-16 01:23:12 +00:00
CompilerWriterInfo.rst [docs] Update CompilerWriterInfo.rst for MIPS 2018-06-14 15:16:37 +00:00
conf.py Add a CommandGuide for llvm-objdump 2018-08-08 14:39:22 +00:00
Contributing.rst
Coroutines.rst
CoverageMappingFormat.rst
DebuggingJITedCode.rst
DeveloperPolicy.rst fix an out of date paragraph noticed by Bryce Lelbach 2018-10-16 16:54:10 +00:00
Docker.rst
doxygen-mainpage.dox
doxygen.cfg.in
ExceptionHandling.rst
ExtendedIntegerResults.txt
ExtendingLLVM.rst
Extensions.rst MC: Implement support for new .addrsig and .addrsig_sym directives. 2018-07-17 22:17:18 +00:00
FAQ.rst
FaultMaps.rst
FuzzingLLVM.rst [docs] Try to clarify the FuzzingLLVM docs 2018-08-16 21:55:09 +00:00
GarbageCollection.rst [GC docs] Update the gcroot documentation to reflect recent simplifcations to GCStrategy configurability 2018-11-12 20:30:50 +00:00
gcc-loops.png
GetElementPtr.rst
GettingStarted.rst [docs] Remove reference to makellvm which was removed in rL329041 2018-09-27 03:48:04 +00:00
GettingStartedVS.rst
GlobalISel.rst
GoldPlugin.rst [docs][gold] Fix a typo 2018-08-21 21:00:54 +00:00
HowToAddABuilder.rst
HowToBuildOnARM.rst
HowToBuildWithPGO.rst HowToBuildWithPGO.rst: Fix a few details in the manual steps 2018-12-05 08:35:30 +00:00
HowToCrossCompileBuiltinsOnArm.rst [docs] Improve HowToCrossCompilerBuiltinsOnArm 2018-12-18 12:40:19 +00:00
HowToCrossCompileLLVM.rst
HowToReleaseLLVM.rst
HowToSetUpLLVMStyleRTTI.rst
HowToSubmitABug.rst
HowToUseAttributes.rst
HowToUseInstrMappings.rst
InAlloca.rst
index.rst [Unroll/UnrollAndJam/Vectorizer/Distribute] Add followup loop attributes. 2018-12-12 17:32:52 +00:00
LangRef.rst Introduce llvm.loop.parallel_accesses and llvm.access.group metadata. 2018-12-20 04:58:07 +00:00
Lexicon.rst Update the coding standards and developer policy documentation surrounding whitespace. 2018-08-10 17:26:07 +00:00
LibFuzzer.rst [libFuzzer] Update documentation regarding MSan. 2018-07-19 17:59:11 +00:00
LinkTimeOptimization.rst
linpack-pc.png
llvm-objdump.1 Add llvm-objdump man page 2018-12-19 01:26:55 +00:00
LLVMBuild.rst
LLVMBuild.txt
make.bat
Makefile.sphinx
MarkdownQuickstartTemplate.md [docs] Reinstate r337730 - Add support for Markdown documentation in 2018-08-06 00:38:31 +00:00
MarkedUpDisassembly.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
MemorySSA.rst
MergeFunctions.rst Updating MergeFunctions.rst 2018-08-18 20:17:19 +00:00
MIRLangRef.rst MIR: Add method to stop after specific runs of passes 2018-12-04 17:45:12 +00:00
NVPTXUsage.rst
OptBisect.rst [Docs] Remove hard tab character from code block in optbisect documentation 2018-07-27 06:54:13 +00:00
Packaging.rst
Passes.rst [Unroll/UnrollAndJam/Vectorizer/Distribute] Add followup loop attributes. 2018-12-12 17:32:52 +00:00
Phabricator.rst Introduce bug life cycle documentation. 2018-11-07 08:49:36 +00:00
ProgrammersManual.rst [TI removal] Remove discussion of TerminatorInst from the LLVM 2018-10-18 07:40:24 +00:00
Projects.rst
re_format.7
README.txt
ReleaseNotes.rst [llvm-cov] Add lcov tracefile export format. 2018-11-09 16:10:44 +00:00
ReleaseProcess.rst
ReportingGuide.rst
ScudoHardenedAllocator.rst
SegmentedStacks.rst
SourceLevelDebugging.rst It's its 2018-11-19 22:53:42 +00:00
speculative_load_hardening_microbenchmarks.png [x86/SLH] Add the design document for Speculative Load Hardening, 2018-07-18 14:05:14 +00:00
SpeculativeLoadHardening.md [x86/SLH] Teach SLH to harden against the "ret2spec" attack by 2018-09-04 10:59:10 +00:00
SphinxQuickstartTemplate.rst
StackMaps.rst [docs] Clarify ELF section naming for StackMaps and fix a typo 2018-11-08 17:20:35 +00:00
StackSafetyAnalysis.rst Remove trailing empty line 2018-11-26 23:17:52 +00:00
Statepoints.rst [docs][statepoints] Reformulate open issues list 2018-11-09 17:09:16 +00:00
SupportLibrary.rst [Docs] [Support] Correct a missed reference and use up to date .inc examples. 2018-09-21 01:53:51 +00:00
SystemLibrary.rst [Docs] [Support] System Library to Support Library transition along with minor corrections to reflect it. 2018-09-18 18:05:38 +00:00
TableGenFundamentals.rst
TestingGuide.rst Revamp test-suite documentation 2018-08-31 21:47:01 +00:00
TestSuiteGuide.md Revamp test-suite documentation 2018-08-31 21:47:01 +00:00
TestSuiteMakefileGuide.rst Revamp test-suite documentation 2018-08-31 21:47:01 +00:00
TransformMetadata.rst [Unroll/UnrollAndJam/Vectorizer/Distribute] Add followup loop attributes. 2018-12-12 17:32:52 +00:00
TypeMetadata.rst
Vectorizers.rst
WritingAnLLVMBackend.rst
WritingAnLLVMPass.rst
XRay.rst [Docs] Update of Xray page 2018-07-26 04:44:31 +00:00
XRayExample.rst [XRay][docs] Chrome Trace Viewer Instructions 2018-08-28 17:36:30 +00:00
XRayFDRFormat.rst Tidy some language in the xray documentation. 2018-05-27 09:19:03 +00:00
yaml2obj.rst
YamlIO.rst [Docs] Fix LLVM_YAML_IS_DOCUMENT_LIST_VECTOR 2018-07-23 14:17:43 +00:00

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 <http://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` <-> `http://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.
`http://llvm.org/docs/CommandGuide/Foo.html`.

Checking links
==============

The reachability of external links in the documentation can be checked by
running:

    cd docs/
    make -f Makefile.sphinx linkcheck

Doxygen page Output
==============

Install doxygen <http://www.stack.nl/~dimitri/doxygen/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