From 93f9a8a5afb58b1d2e4f27bb46d3d4e0fa8c08f0 Mon Sep 17 00:00:00 2001 From: "Gregory P. Smith" Date: Wed, 16 May 2018 10:34:47 -0500 Subject: [PATCH] bpo-24318: Rewrite the README PGO section. (#6863) * bpo-24318: Rewrite the README PGO section. Merged from a phone on an airplane. :) --- README.rst | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/README.rst b/README.rst index 5420558f0dc..d30b237a011 100644 --- a/README.rst +++ b/README.rst @@ -93,25 +93,26 @@ Profile Guided Optimization ^^^^^^^^^^^^^^^^^^^^^^^^^^^ PGO takes advantage of recent versions of the GCC or Clang compilers. If used, -either via ``configure --enable-optimizations`` above or by manually running -``make profile-opt`` regardless of configure flags it will do several steps. +either via ``configure --enable-optimizations`` or by manually running +``make profile-opt`` regardless of configure flags, the optimized build +process will perform the following steps: -First, the entire Python directory is cleaned of temporary files that may have -resulted in a previous compilation. +The entire Python directory is cleaned of temporary files that may have +resulted from a previous compilation. -Then, an instrumented version of the interpreter is built, using suitable -compiler flags for each flavour. Note that this is just an intermediary step. -The binary resulting from this step is not good for real life workloads as -it has profiling instructions embedded inside. +An instrumented version of the interpreter is built, using suitable compiler +flags for each flavour. Note that this is just an intermediary step. The +binary resulting from this step is not good for real life workloads as it has +profiling instructions embedded inside. -After this instrumented version of the interpreter is built, the Makefile will -automatically run a training workload. This is necessary in order to profile -the interpreter execution. Note also that any output, both stdout and stderr, -that may appear at this step is suppressed. +After the instrumented interpreter is built, the Makefile will run a training +workload. This is necessary in order to profile the interpreter execution. +Note also that any output, both stdout and stderr, that may appear at this step +is suppressed. -Finally, the last step is to rebuild the interpreter, using the information -collected in the previous one. The end result will be a Python binary that is -optimized and suitable for distribution or production installation. +The final step is to build the actual interpreter, using the information +collected from the instrumented one. The end result will be a Python binary +that is optimized; suitable for distribution or production installation. Link Time Optimization