This change seeks to add support for vendor flavoured SPIRV - more
specifically, AMDGCN flavoured SPIRV. The aim is to generate SPIRV that
carries some extra bits of information that are only usable by AMDGCN
targets, forfeiting absolute genericity to obtain greater expressiveness
for target features:
- AMDGCN inline ASM is allowed/supported, under the assumption that the
[SPV_INTEL_inline_assembly](https://github.com/intel/llvm/blob/sycl/sycl/doc/design/spirv-extensions/SPV_INTEL_inline_assembly.asciidoc)
extension is enabled/used
- AMDGCN target specific builtins are allowed/supported, under the
assumption that e.g. the `--spirv-allow-unknown-intrinsics` option is
enabled when using the downstream translator
- the featureset matches the union of AMDGCN targets' features
- the datalayout string is overspecified to affix both the program
address space and the alloca address space, the latter under the
assumption that the
[SPV_INTEL_function_pointers](https://github.com/intel/llvm/blob/sycl/sycl/doc/design/spirv-extensions/SPV_INTEL_function_pointers.asciidoc)
extension is enabled/used, case in which the extant SPIRV datalayout
string would lead to pointers to function pointing to the private
address space, which would be wrong.
Existing AMDGCN tests are extended to cover this new target. It is
currently dormant / will require some additional changes, but I thought
I'd rather put it up for review to get feedback as early as possible. I
will note that an alternative option is to place this under AMDGPU, but
that seems slightly less natural, since this is still SPIRV, albeit
relaxed in terms of preconditions & constrained in terms of
postconditions, and only guaranteed to be usable on AMDGCN targets (it
is still possible to obtain pristine portable SPIRV through usage of the
flavoured target, though).
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
88e2bb4092
