llvm/docs
Tim Northover 8f2a85e099 IR: add "cmpxchg weak" variant to support permitted failure.
This commit adds a weak variant of the cmpxchg operation, as described
in C++11. A cmpxchg instruction with this modifier is permitted to
fail to store, even if the comparison indicated it should.

As a result, cmpxchg instructions must return a flag indicating
success in addition to their original iN value loaded. Thus, for
uniformity *all* cmpxchg instructions now return "{ iN, i1 }". The
second flag is 1 when the store succeeded.

At the DAG level, a new ATOMIC_CMP_SWAP_WITH_SUCCESS node has been
added as the natural representation for the new cmpxchg instructions.
It is a strong cmpxchg.

By default this gets Expanded to the existing ATOMIC_CMP_SWAP during
Legalization, so existing backends should see no change in behaviour.
If they wish to deal with the enhanced node instead, they can call
setOperationAction on it. Beware: as a node with 2 results, it cannot
be selected from TableGen.

Currently, no use is made of the extra information provided in this
patch. Test updates are almost entirely adapting the input IR to the
new scheme.

Summary for out of tree users:
------------------------------

+ Legacy Bitcode files are upgraded during read.
+ Legacy assembly IR files will be invalid.
+ Front-ends must adapt to different type for "cmpxchg".
+ Backends should be unaffected by default.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210903 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-13 14:24:07 +00:00
..
_static [docs] Update HTML pages to refer to CSS in a way that works locally and with Sphinx. 2012-04-19 20:20:34 +00:00
_templates [docs] Convert docs index page into Sphinx. 2012-04-19 16:31:37 +00:00
_themes/llvm-theme Sphinx CSS: remove negative letter-spacing, it makes some fonts look really 2012-09-30 20:43:24 +00:00
CommandGuide docs: Remove documentation for legacy PGO options 2014-06-04 06:29:38 +00:00
HistoricalNotes [typo] An LLVM. 2013-08-16 23:30:19 +00:00
TableGen [tablegen] Add !listconcat operator with the similar semantics as !strconcat 2014-05-07 10:13:19 +00:00
tutorial [docs] Clean up some more llvm-gcc stuff 2014-02-19 00:12:34 +00:00
AliasAnalysis.rst Update some AliasAnalysis pass docs for getAdjustedAnalysisPointer. 2014-05-22 19:38:25 +00:00
ARM-BE-bitcastfail.png [ARM64-BE] Add sphinx documentation for the ARM64 NEON implementation. 2014-05-12 15:13:39 +00:00
ARM-BE-bitcastsuccess.png [ARM64-BE] Add sphinx documentation for the ARM64 NEON implementation. 2014-05-12 15:13:39 +00:00
ARM-BE-ld1.png [ARM64-BE] Add sphinx documentation for the ARM64 NEON implementation. 2014-05-12 15:13:39 +00:00
ARM-BE-ldr.png [ARM64-BE] Add sphinx documentation for the ARM64 NEON implementation. 2014-05-12 15:13:39 +00:00
Atomics.rst IR: add "cmpxchg weak" variant to support permitted failure. 2014-06-13 14:24:07 +00:00
BigEndianNEON.rst Fix typos 2014-05-15 01:52:21 +00:00
BitCodeFormat.rst Revert "[ms-cxxabi] Add a new calling convention that swaps 'this' and 'sret'" 2014-05-09 22:56:42 +00:00
BlockFrequencyTerminology.rst Fix typos 2014-05-15 01:52:21 +00:00
BranchWeightMetadata.rst blockfreq: Document BlockFrequencyInfo terminology 2014-04-11 23:21:07 +00:00
Bugpoint.rst [docs] Fix up some links to the preferred style. 2014-04-08 21:06:22 +00:00
CMake.rst fixed a few typos 2014-05-28 20:07:37 +00:00
CMakeLists.txt Added Sphinx documentation generation to CMake build system. 2014-04-18 21:45:25 +00:00
CodeGenerator.rst Fix strange typo in markup. 2014-05-14 08:10:16 +00:00
CodingStandards.rst Update programmers manual to cover llvm::function_ref, and add a note to the 2014-05-06 07:45:39 +00:00
CommandLine.rst Correct word hyphenations 2013-12-05 05:44:44 +00:00
CompilerWriterInfo.rst Fix some doc and comment typos 2014-04-09 14:47:27 +00:00
conf.py Update the copyright credits -- Happy new year 2014! 2014-01-01 08:27:31 +00:00
DebuggingJITedCode.rst docs: Fix long standing linking antipattern. 2013-01-11 02:28:08 +00:00
DeveloperPolicy.rst Clean up language and grammar. 2014-05-20 17:11:11 +00:00
doxygen.cfg.in [docs] Teach CMake docs build how to generate Qt Creator help/documentation files. 2014-03-07 19:19:28 +00:00
doxygen.css [docs] Update Makefile for images removal. 2012-04-20 17:27:12 +00:00
doxygen.footer Update the copyright credits -- Happy new year 2014! 2014-01-01 08:27:31 +00:00
doxygen.header Tidy up. s/Low Level Virtual Machine/LLVM/. 2012-01-25 22:00:23 +00:00
doxygen.intro Tidy up. s/Low Level Virtual Machine/LLVM/. 2012-01-25 22:00:23 +00:00
Dummy.html Add a dummy documentation file to unbreak 'make install'. We need to find how 2012-12-13 13:37:35 +00:00
ExceptionHandling.rst Exception handling docs: Clarify how the llvm.eh.* intrinsics are used 2014-03-28 17:08:57 +00:00
ExtendedIntegerResults.txt Revert r103213. It broke several sections of live website. 2010-05-07 00:28:04 +00:00
ExtendingLLVM.rst Fix documentation on the path to Bitcode reader/writer 2013-06-11 18:09:21 +00:00
Extensions.rst ARM: add VLA extension for WoA Itanium ABI 2014-06-09 20:18:42 +00:00
FAQ.rst remove an old entry whose link is broken anyway 2014-03-02 06:37:03 +00:00
GarbageCollection.rst Remove projects/sample. 2014-03-12 22:40:22 +00:00
gcc-loops.png Update the gcc-loops benchmark 2013-01-20 07:01:04 +00:00
GetElementPtr.rst [docs] Clean up some more llvm-gcc stuff 2014-02-19 00:12:34 +00:00
GettingStarted.rst fixed more typos 2014-05-30 21:18:13 +00:00
GettingStartedVS.rst Document how to select build configuration with Visual C++ IDE or command line. 2014-06-05 16:42:26 +00:00
GoldPlugin.rst Update the LTO GoldPlugin documentation 2013-12-02 07:15:33 +00:00
HowToAddABuilder.rst docs: Fix long standing linking antipattern. 2013-01-11 02:28:08 +00:00
HowToBuildOnARM.rst Adding some info about stability of ARM boards 2013-11-15 08:42:14 +00:00
HowToCrossCompileLLVM.rst [docs] Some typographical fixes. 2013-09-09 19:05:03 +00:00
HowToReleaseLLVM.rst [docs] Fix some Sphinx warnings. 2014-03-02 00:21:42 +00:00
HowToSetUpLLVMStyleRTTI.rst [C++11] Replace LLVM-style type traits with C++11 standard ones. 2014-03-07 14:42:25 +00:00
HowToSubmitABug.rst [docs] Nuke some references to llvm-gcc 2014-02-18 23:56:43 +00:00
HowToUseAttributes.rst Documentation: HowToUseAttributes: formatting (use monospaced font) 2013-02-12 18:26:08 +00:00
HowToUseInstrMappings.rst docs: Fix long standing linking antipattern. 2013-01-11 02:28:08 +00:00
InAlloca.rst inalloca: *Really* fix the docs 2014-03-27 01:38:48 +00:00
index.rst [ARM64-BE] Add sphinx documentation for the ARM64 NEON implementation. 2014-05-12 15:13:39 +00:00
LangRef.rst IR: add "cmpxchg weak" variant to support permitted failure. 2014-06-13 14:24:07 +00:00
Lexicon.rst [docs] PR15254: Add "AST" to the lexicon. 2013-02-13 21:17:20 +00:00
LinkTimeOptimization.rst docs: Fix long standing linking antipattern. 2013-01-11 02:28:08 +00:00
linpack-pc.png Update the linpack benchmark with different array sizes. 2013-01-20 06:52:47 +00:00
LLVMBuild.rst [docs] Fix some links 2014-04-07 22:46:40 +00:00
LLVMBuild.txt LLVMBuild: Remove trailing newline, which irked me. 2011-12-12 19:48:00 +00:00
make.bat [docs] Stub out structure for Sphinx-based docs. 2012-04-19 16:31:19 +00:00
Makefile docs: Remove incompatibility with Solaris shell 2013-10-15 08:30:07 +00:00
Makefile.sphinx Makefile.sphinx: reST conversion is complete! 2012-12-12 21:35:43 +00:00
MakefileGuide.rst Remove projects/sample. 2014-03-12 22:40:22 +00:00
MarkedUpDisassembly.rst docs: Fix long standing linking antipattern. 2013-01-11 02:28:08 +00:00
MCJIT-creation.png Adding a document to describe the MCJIT execution engine implementation. 2013-08-21 22:15:09 +00:00
MCJIT-dyld-load.png Adding a document to describe the MCJIT execution engine implementation. 2013-08-21 22:15:09 +00:00
MCJIT-engine-builder.png Adding a document to describe the MCJIT execution engine implementation. 2013-08-21 22:15:09 +00:00
MCJIT-load-object.png Adding a document to describe the MCJIT execution engine implementation. 2013-08-21 22:15:09 +00:00
MCJIT-load.png Adding a document to describe the MCJIT execution engine implementation. 2013-08-21 22:15:09 +00:00
MCJIT-resolve-relocations.png Adding a document to describe the MCJIT execution engine implementation. 2013-08-21 22:15:09 +00:00
MCJITDesignAndImplementation.rst Adding a document to describe the MCJIT execution engine implementation. 2013-08-21 22:15:09 +00:00
NVPTXUsage.rst Fix documentation typos 2013-12-20 00:33:39 +00:00
Packaging.rst docs: Fix long standing linking antipattern. 2013-01-11 02:28:08 +00:00
Passes.rst docs: Remove documentation for legacy PGO options 2014-06-04 06:29:38 +00:00
Phabricator.rst Update of the documentation: I think we are now happy with Phabricator 2014-05-14 09:22:15 +00:00
ProgrammersManual.rst Fix a typo made in Programmer's Manual made in r210354. Spotted 2014-06-06 18:44:21 +00:00
Projects.rst Remove projects/sample. 2014-03-12 22:40:22 +00:00
re_format.7 Revert r103213. It broke several sections of live website. 2010-05-07 00:28:04 +00:00
README.txt [docs] Add a note to docs/README.txt 2014-04-22 21:47:53 +00:00
ReleaseNotes.rst Be a bit more specific in the release notes. 2014-05-05 17:53:29 +00:00
ReleaseProcess.rst Update Release Process doc 2013-06-12 11:35:33 +00:00
SegmentedStacks.rst Move the segmented stack switch to a function attribute 2014-04-10 22:58:43 +00:00
SourceLevelDebugging.rst [docs] Fix typo, align comments, fix syntax highlighting 2014-06-09 10:12:29 +00:00
SphinxQuickstartTemplate.rst [docs] Provide pointer for building Sphinx docs. 2013-02-27 18:33:21 +00:00
StackMaps.rst Stack map docs. Remove some stray markup. 2014-04-03 07:08:21 +00:00
SystemLibrary.rst remove the rest of the "written by" lines in the documentation. It is 2013-01-10 21:24:04 +00:00
TableGenFundamentals.rst Recover TableGen/LangRef, make it official 2014-04-01 09:51:49 +00:00
TestingGuide.rst Reduce verbiage of lit.local.cfg files 2014-06-09 22:42:55 +00:00
TestSuiteMakefileGuide.rst remove the rest of the "written by" lines in the documentation. It is 2013-01-10 21:24:04 +00:00
Vectorizers.rst Fix whitespace in vectorizer example 2014-03-12 23:58:07 +00:00
WritingAnLLVMBackend.rst [docs] Fix some links 2014-04-07 22:46:40 +00:00
WritingAnLLVMPass.rst docs: Remove documentation for legacy PGO options 2014-06-04 06:29:38 +00:00
yaml2obj.rst Object: rename ARMV7 to ARMNT 2014-03-11 03:08:37 +00:00
YamlIO.rst [YAML] Add an optional argument EnumMask to the yaml::IO::bitSetCase(). 2014-05-23 08:07:09 +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 docs/
    make -f Makefile.sphinx
    $BROWSER _build/html/index.html

The mapping between reStructuredText files and generated documentation is
`docs/Foo.rst` <-> `_build/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/man/`.

    cd docs/
    make -f Makefile.sphinx man
    man -l _build/man/FileCheck.1

The correspondence between .rst files and man pages is
`docs/CommandGuide/Foo.rst` <-> `_build/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 reachibility of external links in the documentation can be checked by
running:

    cd docs/
    make -f Makefile.sphinx linkcheck