[llvm] r330590 - [doc] Removed obsolete -count-aa from AliasAnalysis documentation
Marianne Mailhot-Sarrasin via llvm-commits
llvm-commits at lists.llvm.org
Mon Apr 23 06:45:28 PDT 2018
Author: mamai
Date: Mon Apr 23 06:45:28 2018
New Revision: 330590
URL: http://llvm.org/viewvc/llvm-project?rev=330590&view=rev
Log:
[doc] Removed obsolete -count-aa from AliasAnalysis documentation
Summary:
This patch removes references to AliasAnalysisCounter pass from the AliasAnalysis documentation. That pass have been eliminated in 2015, at revision trunk at 247167.
Reviewed By: hfinkel
Differential Revision: https://reviews.llvm.org/D45876
Modified:
llvm/trunk/docs/AliasAnalysis.rst
Modified: llvm/trunk/docs/AliasAnalysis.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/AliasAnalysis.rst?rev=330590&r1=330589&r2=330590&view=diff
==============================================================================
--- llvm/trunk/docs/AliasAnalysis.rst (original)
+++ llvm/trunk/docs/AliasAnalysis.rst Mon Apr 23 06:45:28 2018
@@ -389,11 +389,6 @@ in its ``getAnalysisUsage`` that it does
``AU.addPreserved<AliasAnalysis>``, however this doesn't actually have any
effect.
-``AliasAnalysisCounter`` (``-count-aa``) are implemented as ``ModulePass``
-classes, so if your alias analysis uses ``FunctionPass``, it won't be able to
-use these utilities. If you try to use them, the pass manager will silently
-route alias analysis queries directly to ``BasicAliasAnalysis`` instead.
-
Similarly, the ``opt -p`` option introduces ``ModulePass`` passes between each
pass, which prevents the use of ``FunctionPass`` alias analysis passes.
@@ -408,17 +403,10 @@ before it appears in an alias query. How
don't support this, and are known to trigger errors when run with the
``AliasAnalysisDebugger``.
-Due to several of the above limitations, the most obvious use for the
-``AliasAnalysisCounter`` utility, collecting stats on all alias queries in a
-compilation, doesn't work, even if the ``AliasAnalysis`` implementations don't
-use ``FunctionPass``. There's no way to set a default, much less a default
-sequence, and there's no way to preserve it.
-
The ``AliasSetTracker`` class (which is used by ``LICM``) makes a
-non-deterministic number of alias queries. This can cause stats collected by
-``AliasAnalysisCounter`` to have fluctuations among identical runs, for
-example. Another consequence is that debugging techniques involving pausing
-execution after a predetermined number of queries can be unreliable.
+non-deterministic number of alias queries. This can cause debugging techniques
+involving pausing execution after a predetermined number of queries to be
+unreliable.
Many alias queries can be reformulated in terms of other alias queries. When
multiple ``AliasAnalysis`` queries are chained together, it would make sense to
@@ -676,21 +664,6 @@ you're using the ``AliasSetTracker`` cla
% opt -ds-aa -print-alias-sets -disable-output
-The ``-count-aa`` pass
-^^^^^^^^^^^^^^^^^^^^^^
-
-The ``-count-aa`` pass is useful to see how many queries a particular pass is
-making and what responses are returned by the alias analysis. As an example:
-
-.. code-block:: bash
-
- % opt -basicaa -count-aa -ds-aa -count-aa -licm
-
-will print out how many queries (and what responses are returned) by the
-``-licm`` pass (of the ``-ds-aa`` pass) and how many queries are made of the
-``-basicaa`` pass by the ``-ds-aa`` pass. This can be useful when debugging a
-transformation or an alias analysis implementation.
-
The ``-aa-eval`` pass
^^^^^^^^^^^^^^^^^^^^^
More information about the llvm-commits
mailing list