From: Diego Novillo <dnovillo@google.com>
Date: Fri, 14 Aug 2015 15:46:59 +0000 (+0000)
Subject: Add release notes for PGO flag changes.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ab4c20f1f6deacb6c700b88aeff837b4821b5139;p=clang

Add release notes for PGO flag changes.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_37@245061 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index bfd33d71be..8af1e7e6d3 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -136,6 +136,20 @@ OpenCL C Language Changes in Clang
 
 ...
 
+Profile Guided Optimization
+---------------------------
+
+Clang now accepts GCC-compatible flags for profile guided optimization (PGO).
+You can now use ``-fprofile-generate=<dir>``, ``-fprofile-use=<dir>``,
+``-fno-profile-generate`` and ``-fno-profile-use``. These flags have the
+same semantics as their GCC counterparts. However, the generated profile
+is still LLVM-specific. PGO profiles generated with Clang cannot be used
+by GCC and vice-versa.
+
+Clang now emits function entry counts in profile-instrumented binaries.
+This has improved the computation of weights and frequencies in
+profile analysis.
+
 OpenMP Support
 --------------
 OpenMP 3.1 is fully supported, but disabled by default. To enable it, please use