diff --git a/polly/docs/TipsAndTricks.rst b/polly/docs/TipsAndTricks.rst index 30efd02b8d0e..71758891c73a 100644 --- a/polly/docs/TipsAndTricks.rst +++ b/polly/docs/TipsAndTricks.rst @@ -37,3 +37,16 @@ Understanding which pass makes a particular change - ``$ opt -O3 -polly -debug-pass=Arguments`` to get all passes that are run by default. ``-debug-pass=Arguments`` will list all passes that have run. - Bisect down to the pass that changes it. + +Debugging regressions introduced at some unknown earlier point +-------------------------------------------------------------- + +In case of a regression in performance or correctness (e.g., an earlier version +of Polly behaved as expected and a later version does not), bisecting over the +version history is the standard approach to identify the commit that introduced +the regression. + +LLVM has a single repository that contains all projects. It can be cloned at: +``_. How to bisect on a +git repository is explained here +`