ART: Skip compiler-driver compile loop for VerifyAtRuntime

We don't compile (not even dex-to-dex) anyways, so skip iterating
over all methods. Shows a ~10% improvement of boot image compile
time on Nexus 9. Shows a ~40% improvement for a common large app
on the same device. Most of the remaining time is unzipping dex
files.

Bug: 24103765
Change-Id: I00931fd062a0a2297d1c7b90794302cb664571cc

1 files changed, 11 insertions, 1 deletions

diff --git a/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index 4c1408a177..750e912da3 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -490,8 +490,18 @@ void CompilerDriver::CompileAll(jobject class_loader,
   std::unique_ptr<ThreadPool> thread_pool(
       new ThreadPool("Compiler driver thread pool", thread_count_ - 1));
   VLOG(compiler) << "Before precompile " << GetMemoryUsageString(false);
+  // Precompile:
+  // 1) Load image classes
+  // 2) Resolve all classes
+  // 3) Attempt to verify all classes
+  // 4) Attempt to initialize image classes, and trivially initialized classes
   PreCompile(class_loader, dex_files, thread_pool.get(), timings);
-  Compile(class_loader, dex_files, thread_pool.get(), timings);
+  // Compile:
+  // 1) Compile all classes and methods enabled for compilation. May fall back to dex-to-dex
+  //    compilation.
+  if (!GetCompilerOptions().VerifyAtRuntime()) {
+    Compile(class_loader, dex_files, thread_pool.get(), timings);
+  }
   if (dump_stats_) {
     stats_->Dump();
   }