Sanjay Patel 2c5adb18ba [InstCombine] fix wrong undef handling when converting select to shuffle
As discussed in:
https://bugs.llvm.org/show_bug.cgi?id=32486
...the canonicalization of vector select to shufflevector does not hold up
when undef elements are present in the condition vector. 

Try to make the undef handling clear in the code and the LangRef.

Differential Revision: https://reviews.llvm.org/D31980



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300092 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-12 18:39:53 +00:00
..
2017-04-03 18:21:50 +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
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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
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If you are interested in writing new documentation, you will want to read
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Manpage Output
===============

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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
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These .rst files are also included during HTML generation so they are also
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Checking links
==============

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

    cd docs/
    make -f Makefile.sphinx linkcheck