diff options
| author | Eric Christopher <echristo@gmail.com> | 2018-01-31 19:52:58 +0000 |
|---|---|---|
| committer | Eric Christopher <echristo@gmail.com> | 2018-01-31 19:52:58 +0000 |
| commit | c61c9b6147ef05b3c53aec135e4196fa8e51a592 (patch) | |
| tree | 468f3a315e3500ae5fd63d279f063cc196525b5d /clang/docs/UsersManual.rst | |
| parent | 6e7f1826c58932c0e987d8eca5b9055439161b13 (diff) | |
| download | bcm5719-llvm-c61c9b6147ef05b3c53aec135e4196fa8e51a592.tar.gz bcm5719-llvm-c61c9b6147ef05b3c53aec135e4196fa8e51a592.zip | |
Clarify that optimization levels -O2 and above are recommended for use of PGO.
llvm-svn: 323902
Diffstat (limited to 'clang/docs/UsersManual.rst')
| -rw-r--r-- | clang/docs/UsersManual.rst | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst index 48ea714304b..84dfe9fc3d7 100644 --- a/clang/docs/UsersManual.rst +++ b/clang/docs/UsersManual.rst @@ -1375,7 +1375,8 @@ Profile Guided Optimization Profile information enables better optimization. For example, knowing that a branch is taken very frequently helps the compiler make better decisions when ordering basic blocks. Knowing that a function ``foo`` is called more -frequently than another function ``bar`` helps the inliner. +frequently than another function ``bar`` helps the inliner. Optimization +levels ``-O2`` and above are recommended for use of profile guided optimization. Clang supports profile guided optimization with two different kinds of profiling. A sampling profiler can generate a profile with very low runtime |
