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Remove -simplify-libcalls pass form Passes documentation
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This pass was removed in r184459.

Also added note that the InstCombine pass does library call
simplification.

Patch slightly modified from one by Daniel Liew
<[email protected]>!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206650 91177308-0d34-0410-b5e6-96231b3b80d8
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rnk committed Apr 18, 2014
1 parent 904f8dc commit ed56048
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19 changes: 10 additions & 9 deletions docs/Passes.rst
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Expand Up @@ -540,6 +540,8 @@ instructions that are obviously dead.
A trivial dead store elimination that only considers basic-block local
redundant stores.

.. _passes-functionattrs:

``-functionattrs``: Deduce function attributes
----------------------------------------------

Expand Down Expand Up @@ -648,7 +650,7 @@ program, and is used for a wide variety of program transformations.
------------------------------------------------

Combine instructions to form fewer, simple instructions. This pass does not
modify the CFG This pass is where algebraic simplification happens.
modify the CFG. This pass is where algebraic simplification happens.

This pass combines things like:

Expand Down Expand Up @@ -681,6 +683,13 @@ program:
shifts.
#. … etc.

This pass can also simplify calls to specific well-known function calls (e.g.
runtime library functions). For example, a call ``exit(3)`` that occurs within
the ``main()`` function can be transformed into simply ``return 3``. Whether or
not library calls are simplified is controlled by the
:ref:`-functionattrs <passes-functionattrs>` pass and LLVM's knowledge of
library calls on different targets.

``-internalize``: Internalize Global Symbols
--------------------------------------------

Expand Down Expand Up @@ -1011,14 +1020,6 @@ as:
Note that this pass has a habit of making definitions be dead. It is a good
idea to run a :ref:`DCE <passes-dce>` pass sometime after running this pass.

``-simplify-libcalls``: Simplify well-known library calls
---------------------------------------------------------

Applies a variety of small optimizations for calls to specific well-known
function calls (e.g. runtime library functions). For example, a call
``exit(3)`` that occurs within the ``main()`` function can be transformed into
simply ``return 3``.

.. _passes-simplifycfg:

``-simplifycfg``: Simplify the CFG
Expand Down

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