diff -up firefox-99.0/build/moz.configure/lto-pgo.configure.pgo firefox-99.0/build/moz.configure/lto-pgo.configure

--- firefox-99.0/build/moz.configure/lto-pgo.configure.pgo	2022-03-31 01:24:38.000000000 +0200

+++ firefox-99.0/build/moz.configure/lto-pgo.configure	2022-04-04 10:15:45.387694143 +0200

@@ -247,8 +247,8 @@ def lto(

             cflags.append("-flto")

             ldflags.append("-flto")

         else:

-            cflags.append("-flto=thin")

-            ldflags.append("-flto=thin")

+            cflags.append("-flto")

+            ldflags.append("-flto")

         if target.os == "Android" and value == "cross":

             # Work around https://github.com/rust-lang/rust/issues/90088

@@ -264,7 +264,7 @@ def lto(

         if value == "full":

             cflags.append("-flto")

         else:

-            cflags.append("-flto=thin")

+            cflags.append("-flto")

         # With clang-cl, -flto can only be used with -c or -fuse-ld=lld.

         # AC_TRY_LINKs during configure don't have -c, so pass -fuse-ld=lld.

         cflags.append("-fuse-ld=lld")

diff -up firefox-99.0/build/pgo/profileserver.py.pgo firefox-99.0/build/pgo/profileserver.py

--- firefox-99.0/build/pgo/profileserver.py.pgo	2022-03-31 01:24:38.000000000 +0200

+++ firefox-99.0/build/pgo/profileserver.py	2022-04-04 10:15:45.387694143 +0200

@@ -11,7 +11,7 @@ import glob

 import subprocess

 import mozcrash

-from mozbuild.base import MozbuildObject, BinaryNotFoundException

+from mozbuild.base import MozbuildObject, BinaryNotFoundException, BuildEnvironmentNotFoundException

 from mozfile import TemporaryDirectory

 from mozhttpd import MozHttpd

 from mozprofile import FirefoxProfile, Preferences

@@ -87,9 +87,22 @@ if __name__ == "__main__":

     locations = ServerLocations()

     locations.add_host(host="127.0.0.1", port=PORT, options="primary,privileged")

-    old_profraw_files = glob.glob("*.profraw")

-    for f in old_profraw_files:

-        os.remove(f)

+    using_gcc = False

+    try:

+        if build.config_environment.substs.get('CC_TYPE') == 'gcc':

+            using_gcc = True

+    except BuildEnvironmentNotFoundException:

+        pass

+

+    if using_gcc:

+        for dirpath, _, filenames in os.walk('.'):

+            for f in filenames:

+                if f.endswith('.gcda'):

+                    os.remove(os.path.join(dirpath, f))

+    else:

+        old_profraw_files = glob.glob('*.profraw')

+        for f in old_profraw_files:

+            os.remove(f)

     with TemporaryDirectory() as profilePath:

         # TODO: refactor this into mozprofile

@@ -212,6 +225,10 @@ if __name__ == "__main__":

             print("Firefox exited successfully, but produced a crashreport")

             sys.exit(1)

+        print('Copying profile data....')

+        os.system('pwd');

+        os.system('tar cf profdata.tar.gz `find . -name "*.gcda"`; cd ..; tar xf instrumented/profdata.tar.gz;');

+

         llvm_profdata = env.get("LLVM_PROFDATA")

         if llvm_profdata:

             profraw_files = glob.glob("*.profraw")

diff -up firefox-99.0/build/unix/mozconfig.unix.pgo firefox-99.0/build/unix/mozconfig.unix

--- firefox-99.0/build/unix/mozconfig.unix.pgo	2022-03-31 01:24:38.000000000 +0200

+++ firefox-99.0/build/unix/mozconfig.unix	2022-04-04 10:15:45.387694143 +0200

@@ -4,6 +4,15 @@ if [ -n "$FORCE_GCC" ]; then

     CC="$MOZ_FETCHES_DIR/gcc/bin/gcc"

     CXX="$MOZ_FETCHES_DIR/gcc/bin/g++"

+    if [ -n "$MOZ_PGO" ]; then

+        if [ -z "$USE_ARTIFACT" ]; then

+            ac_add_options --enable-lto

+        fi

+        export AR="$topsrcdir/gcc/bin/gcc-ar"

+        export NM="$topsrcdir/gcc/bin/gcc-nm"

+        export RANLIB="$topsrcdir/gcc/bin/gcc-ranlib"

+    fi

+

     # We want to make sure we use binutils and other binaries in the tooltool

     # package.

     mk_add_options "export PATH=$MOZ_FETCHES_DIR/gcc/bin:$PATH"

diff -up firefox-99.0/extensions/spellcheck/src/moz.build.pgo firefox-99.0/extensions/spellcheck/src/moz.build

--- firefox-99.0/extensions/spellcheck/src/moz.build.pgo	2022-03-31 01:24:50.000000000 +0200

+++ firefox-99.0/extensions/spellcheck/src/moz.build	2022-04-04 10:15:45.387694143 +0200

@@ -28,3 +28,5 @@ EXPORTS.mozilla += [

     "mozInlineSpellChecker.h",

     "mozSpellChecker.h",

 ]

+

+CXXFLAGS += ['-fno-devirtualize']

diff -up firefox-99.0/toolkit/components/terminator/nsTerminator.cpp.pgo firefox-99.0/toolkit/components/terminator/nsTerminator.cpp

--- firefox-99.0/toolkit/components/terminator/nsTerminator.cpp.pgo	2022-04-04 10:15:45.387694143 +0200

+++ firefox-99.0/toolkit/components/terminator/nsTerminator.cpp	2022-04-04 10:19:07.022239556 +0200

@@ -466,6 +466,11 @@ void nsTerminator::StartWatchdog() {

   }

 #endif

+  // Disable watchdog for PGO train builds - writting profile information at

+  // exit may take time and it is better to make build hang rather than

+  // silently produce poorly performing binary.

+  crashAfterMS = INT32_MAX;

+

   UniquePtr<Options> options(new Options());

   // crashAfterTicks is guaranteed to be > 0 as

   // crashAfterMS >= ADDITIONAL_WAIT_BEFORE_CRASH_MS >> HEARTBEAT_INTERVAL_MS