This commit adds a new target-independent calling convention for C++ TLS
access functions. It aims to minimize overhead in the caller by perserving as
many registers as possible.
The target-specific implementation for X86-64 is defined as following:
Arguments are passed as for the default C calling convention
The same applies for the return value(s)
The callee preserves all GPRs - except RAX and RDI
The access function makes C-style TLS function calls in the entry and exit
block, C-style TLS functions save a lot more registers than normal calls.
The added calling convention ties into the existing implementation of the
C-style TLS functions, so we can't simply use existing calling conventions
such as preserve_mostcc.
rdar://9001553
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254737 91177308-0d34-0410-b5e6-96231b3b80d8
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
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`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
cd2103de5a
