Index: TipsAndTricks.rst
===================================================================
--- TipsAndTricks.rst
+++ TipsAndTricks.rst
@@ -13,15 +13,35 @@
     If you know the ``opt`` invocation and have a large ``.ll`` file that causes
     an error, ``bugpoint`` allows one to reduce the size of test cases.
 
-    The general calling pattern is:
+    The general calling pattern of ``bugpoint`` to reduce a .ll file on which Polly crashes is:
 
-    - ``$ bugpoint <file.ll> <pass that causes the crash> -opt-args <opt option flags>``
+    - ``$ bugpoint <file.ll> -safe-auto -compile-custom -compile-command=<opt cmd line>``
+
+                   ``-opt-command=<opt file with path> -opt-args=<opt option flags>``
+
+
+    By doing so we avoid testing ``llc``, which is another component ``bugpoint`` can test, since it can give errors like: <<Initializing execution environment: bugpoint: [...] Assertion `!Name.empty() && "Must have a name!"' failed.>> .
+
+    We advise the user to give all these arguments: compile-command, opt-command, although they repeat the information.
 
     An example invocation is:
 
-    - ``$ bugpoint crash.ll -polly-codegen -opt-args  -polly-canonicalize -polly-process-unprofitable``
+    - ``$ clang -O3 -mllvm -disable-llvm-optzns -emit-llvm -S -o file_noopt.ll -g file.c``
+    - ``$ bugpoint file_noopt.ll -safe-auto  -compile-custom``
+
+                   ``-compile-command="/llvm/bin/opt -O3 -polly -S"``
+
+                   ``-opt-command=/llvm/bin/opt -opt-args="-polly -S"``
+
+
+    For more documentation on bugpoint, `Visit the LLVM manual <http://llvm.org/docs/Bugpoint.html>`_, the `Command Guide <https://llvm.org/docs/CommandGuide/bugpoint.html>`_ and also the `LLVM blog <http://blog.llvm.org/2015/11/reduce-your-testcases-with-bugpoint-and.html>`_ .
+
+    It is worth mentioning that bugpoint can take a long time to finish, for example 39 hours running on 1 core of a workstation.
+    Note that running a release build of LLVM reduces the total runtime to 5.22 hours.
+
+    Note that since the ``bugpoint`` tool can be a bit tricky to use with Polly, if you have problems you can best check the source code of the bugpoint tool.
+    For example, to avoid the error "Sorry, I can't automatically select a safe interpreter!" we had to get inspired directly from the source code file: https://github.com/llvm-mirror/llvm/blob/master/tools/bugpoint/ExecutionDriver.cpp in order to use a command line as indicated above, with arguments compile-command, opt-command, opt-args.
 
-    For more documentation on bugpoint, `Visit the LLVM manual <http://llvm.org/docs/Bugpoint.html>`_
 
 
 Understanding which pass makes a particular change