This is an archive of the discontinued LLVM Phabricator instance.

LGTM, with the caveat that these docs seem completely outdated (for example, the whole "Updating analysis results for transformations" section just isn't a thing anymore), so probably this needs a larger overhaul to be useful.

This revision is now accepted and ready to land.Jan 26 2021, 1:07 PM

Closed by commit rGe04c058798e4: [Docs] Remove `no-aa` from the alias analysis documentation (authored by jdoerfert). · Explain WhyMar 3 2021, 10:36 PM

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jdoerfert added a commit: rGe04c058798e4: [Docs] Remove `no-aa` from the alias analysis documentation.

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AliasAnalysis.rst

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llvm/docs/AliasAnalysis.rst

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	respectively). Depending on the capabilities of the analysis you are			respectively). Depending on the capabilities of the analysis you are
	implementing, you just override the interfaces you can improve.			implementing, you just override the interfaces you can improve.

	.. _aliasanalysis-chaining:			.. _aliasanalysis-chaining:

	``AliasAnalysis`` chaining behavior			``AliasAnalysis`` chaining behavior
	-----------------------------------			-----------------------------------

	With only one special exception (the :ref:`-no-aa <aliasanalysis-no-aa>` pass)			Every alias analysis pass chains to another alias analysis implementation (for
	every alias analysis pass chains to another alias analysis implementation (for
	example, the user can specify "``-basic-aa -ds-aa -licm``" to get the maximum			example, the user can specify "``-basic-aa -ds-aa -licm``" to get the maximum
	benefit from both alias analyses). The alias analysis class automatically			benefit from both alias analyses). The alias analysis class automatically
	takes care of most of this for methods that you don't override. For methods			takes care of most of this for methods that you don't override. For methods
	that you do override, in code paths that return a conservative MayAlias or			that you do override, in code paths that return a conservative MayAlias or
	Mod/Ref result, simply return whatever the superclass computes. For example:			Mod/Ref result, simply return whatever the superclass computes. For example:

	.. code-block:: c++			.. code-block:: c++

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	implementations.			implementations.

	.. _various alias analysis implementations:			.. _various alias analysis implementations:

	Available ``AliasAnalysis`` implementations			Available ``AliasAnalysis`` implementations
	-------------------------------------------			-------------------------------------------

	This section lists the various implementations of the ``AliasAnalysis``			This section lists the various implementations of the ``AliasAnalysis``
	interface. With the exception of the :ref:`-no-aa <aliasanalysis-no-aa>`			interface. All of these :ref:`chain <aliasanalysis-chaining>` to other
	implementation, all of these :ref:`chain <aliasanalysis-chaining>` to other
	alias analysis implementations.			alias analysis implementations.

	.. _aliasanalysis-no-aa:

	The ``-no-aa`` pass
	^^^^^^^^^^^^^^^^^^^

	The ``-no-aa`` pass is just like what it sounds: an alias analysis that never
	returns any useful information. This pass can be useful if you think that alias
	analysis is doing something wrong and are trying to narrow down a problem.

	The ``-basic-aa`` pass			The ``-basic-aa`` pass
	^^^^^^^^^^^^^^^^^^^^^^			^^^^^^^^^^^^^^^^^^^^^^

	The ``-basic-aa`` pass is an aggressive local analysis that knows many			The ``-basic-aa`` pass is an aggressive local analysis that knows many
	important facts:			important facts:

	* Distinct globals, stack allocations, and heap allocations can never alias.			* Distinct globals, stack allocations, and heap allocations can never alias.
	* Globals, stack allocations, and heap allocations never alias the null pointer.			* Globals, stack allocations, and heap allocations never alias the null pointer.
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This is an archive of the discontinued LLVM Phabricator instance.

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[Docs] Remove `no-aa` from the alias analysis documentation
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