excluded_prefices

Summary:
This allows an easy workaround to exclude methods known to have unstable method profiles.

This is a behavior-preserving change.

Reviewed By: beicy

Differential Revision: D51761656

fbshipit-source-id: 6b8a71e8c981717a12d602d9bf6b2abfde4d14ab

opt/outliner/MethodSplitter.cpp

@@ -420,8 +420,23 @@ void split_methods_in_stores(
       dex_states[&dex];
     }
   }
-  walk::parallel::code(
-      scope, [&](DexMethod* method, IRCode&) { methods.insert(method); });
+
+  auto is_excluded = [&](DexMethod* method) {
+    auto name = method->get_deobfuscated_name_or_empty();
+    for (const auto& prefix : config.excluded_prefices) {
+      if (name.substr(0, prefix.size()) == prefix) {
+        return true;
+      }
+    }
+    return false;
+  };
+  walk::parallel::code(scope, [&](DexMethod* method, IRCode&) {
+    if (is_excluded(method)) {
+      stats->excluded_methods++;
+      return;
+    }
+    methods.insert(method);
+  });
 
   size_t iteration{0};
   AtomicMap<std::string, size_t> uniquifiers;

opt/outliner/MethodSplitter.h

@@ -32,6 +32,7 @@ struct Stats {
   std::atomic<size_t> added_code_size{0};
   std::atomic<size_t> split_code_size{0};
   std::unordered_set<DexMethod*> added_methods;
+  std::atomic<size_t> excluded_methods{0};
 };
 
 void split_methods_in_stores(

opt/outliner/MethodSplittingConfig.h

@@ -9,6 +9,8 @@
 
 #include <cstddef>
 #include <cstdint>
+#include <string>
+#include <vector>
 
 namespace method_splitting_impl {
 
@@ -29,6 +31,8 @@ struct Config {
   size_t cost_split_method{16};
   size_t cost_split_switch{6};
   size_t cost_split_switch_case{4};
+
+  std::vector<std::string> excluded_prefices;
 };
 
 } // namespace method_splitting_impl

opt/outliner/MethodSplittingPass.cpp

@@ -54,6 +54,8 @@ void MethodSplittingPass::bind_config() {
        "Maximum number of live-in registers");
   bind("max_iteration", m_config.max_iteration, m_config.max_iteration,
        "Maximum number of top-level iterations");
+  bind("excluded_prefices", m_config.excluded_prefices,
+       m_config.excluded_prefices);
 }
 
 void MethodSplittingPass::run_pass(DexStoresVector& stores,
@@ -96,6 +98,7 @@ void MethodSplittingPass::run_pass(DexStoresVector& stores,
   mgr.set_metric("split_code_size", (size_t)stats.split_code_size);
   mgr.set_metric("new_hot_methods", concurrent_new_hot_methods.size());
   mgr.set_metric("derived_method_profile_stats", derived_method_profile_stats);
+  mgr.set_metric("excluded_methods", (size_t)stats.excluded_methods);
   TRACE(MS, 1, "Split out %zu methods", stats.added_methods.size());
 
   for (auto [method, size] : concurrent_splittable_no_optimizations_methods) {