diff --git a/llvm/docs/TestingGuide.rst b/llvm/docs/TestingGuide.rst
--- a/llvm/docs/TestingGuide.rst
+++ b/llvm/docs/TestingGuide.rst
@@ -47,6 +47,9 @@
 Unit tests are written using `Google Test <https://github.com/google/googletest/blob/master/googletest/docs/primer.md>`_
 and `Google Mock <https://github.com/google/googletest/blob/master/googlemock/docs/for_dummies.md>`_
 and are located in the ``llvm/unittests`` directory.
+In general unit tests are reserved to test targeting the support library and
+generic data structure, we prefer relying on regression tests for testing
+transformations and analysis on the IR.
 
 Regression tests
 ----------------
@@ -62,6 +65,17 @@
 somewhere underneath this directory. For example, it can be a small
 piece of LLVM IR distilled from an actual application or benchmark.
 
+Testing Analysis
+----------------
+
+Analysis are passes that are inferring properties on some part of the IR and not
+transforming it. They are tested in general using the same infrastructure as the
+regression tests, by creating a separate "Printer" pass to consume the analysis
+result and print it on the standard output in a textual format suitable for
+FileCheck.
+See `llvm/test/Analysis/BranchProbabilityInfo/loop.ll <https://github.com/llvm/llvm-project/blob/master/llvm/test/Analysis/BranchProbabilityInfo/loop.ll>`_
+for an example of such test.
+
 ``test-suite``
 --------------
 
@@ -184,7 +198,7 @@
 ----------------------------
 
 The regression test structure is very simple, but does require some
-information to be set. This information is gathered via ``configure``
+information to be set. This information is gathered via ``cmake``
 and is written to a file, ``test/lit.site.cfg`` in the build directory.
 The ``llvm/test`` Makefile does this work for you.