[Python-checkins] cpython (3.5): document --with-optimizations in the README for issue26359.

[gregory.p.smith]

https://hg.python.org/cpython/rev/e1987bf14148
changeset:   103334:e1987bf14148
branch:      3.5
parent:      103312:4f6fef83cd0c
user:        Gregory P. Smith <greg at krypto.org> [Google Inc.]
date:        Thu Sep 08 18:33:00 2016 +0000
summary:
  document --with-optimizations in the README for issue26359.

files:
  README |  17 +++++++++++++----
  1 files changed, 13 insertions(+), 4 deletions(-)


diff --git a/README b/README
--- a/README
+++ b/README
@@ -46,16 +46,17 @@
 (This will fail if you *also* built at the top-level directory.
 You should do a "make clean" at the toplevel first.)
 
-If you need an optimized version of Python, you type "make profile-opt" in the
-top level directory. This will rebuild the interpreter executable using Profile
-Guided Optimization (PGO). For more details, see the section bellow.
+To get an optimized build of Python, "configure --with-optimizations" before
+you run make.  This sets the default make targets up to enable Profile Guided
+Optimization (PGO) and Link Time Optimization (LTO) on most platforms.
+For more details, see the sections bellow.
 
 
 Profile Guided Optimization
 ---------------------------
 
 PGO takes advantage of recent versions of the GCC or Clang compilers.
-If ran, the "profile-opt" rule will do several steps.
+If ran, "make profile-opt" will do several steps.
 
 First, the entire Python directory is cleaned of temporary files that
 may have resulted in a previous compilation.
@@ -75,6 +76,14 @@
 that is optimized and suitable for distribution or production installation.
 
 
+Link Time Optimization
+----------------------
+
+LTO takes advantages of recent compiler toolchains ability to optimize across
+the otherwise arbitrary .o file boundary when building final executables or
+shared libraries for additional performance gains.
+
+
 What's New
 ----------
 

-- 
Repository URL: https://hg.python.org/cpython