diff --git a/cc/object.go b/cc/object.go
index b9c5742..c9ca07a 100644
--- a/cc/object.go
+++ b/cc/object.go
@@ -33,6 +33,9 @@
 	Properties ObjectLinkerProperties
 }
 
+// cc_object runs the compiler without running the linker. It is rarely
+// necessary, but sometimes used to generate .s files from .c files to use as
+// input to a cc_genrule module.
 func ObjectFactory() android.Module {
 	module := newBaseModule(android.HostAndDeviceSupported, android.MultilibBoth)
 	module.linker = &objectLinker{
diff --git a/cc/pgo.go b/cc/pgo.go
index 9363916..7334ea2 100644
--- a/cc/pgo.go
+++ b/cc/pgo.go
@@ -27,8 +27,11 @@
 
 var (
 	// Add flags to ignore warnings that profiles are old or missing for
-	// some functions
-	profileUseOtherFlags = []string{"-Wno-backend-plugin"}
+	// some functions, and turn on the experimental new pass manager.
+	profileUseOtherFlags = []string{
+		"-Wno-backend-plugin",
+		"-fexperimental-new-pass-manager",
+	}
 
 	globalPgoProfileProjects = []string{
 		"toolchain/pgo-profiles",