Revert^2 "Reduce the number of calls to Jit::AddSamples."

The method is called for every invoke which is expensive.
Add samples, but don't check the consequences every time.

This reduces its cost from 3.5% to 1% (maps on device).

This reverts commit 0402f4b019c1d6c567b1c56589f1ea9170ab5dcc
and fixes 667-jit-jni-stub which relied on being able to set
the sample count to exactly one below the compilation threshold,
and then expected the compilation to happen on the next sample.

Test: ./art/test.py -b --host -r --ndebug
Test: ./art/test.py -b -r -t 570
Change-Id: I99c6d03f565f17fe6539ed89632d8f8bbda68107
diff --git a/runtime/jit/jit-inl.h b/runtime/jit/jit-inl.h
new file mode 100644
index 0000000..80324ad
--- /dev/null
+++ b/runtime/jit/jit-inl.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_RUNTIME_JIT_JIT_INL_H_
+#define ART_RUNTIME_JIT_JIT_INL_H_
+
+#include "jit/jit.h"
+
+#include "art_method.h"
+#include "base/bit_utils.h"
+#include "thread.h"
+#include "runtime-inl.h"
+
+namespace art {
+namespace jit {
+
+inline bool Jit::ShouldUsePriorityThreadWeight(Thread* self) {
+  return self->IsJitSensitiveThread() && Runtime::Current()->InJankPerceptibleProcessState();
+}
+
+inline void Jit::AddSamples(Thread* self,
+                            ArtMethod* method,
+                            uint16_t samples,
+                            bool with_backedges) {
+  if (Jit::ShouldUsePriorityThreadWeight(self)) {
+    samples *= PriorityThreadWeight();
+  }
+  uint32_t old_count = method->GetCounter();
+  uint32_t new_count = old_count + samples;
+
+  // The full check is fairly expensive so we just add to hotness most of the time,
+  // and we do the full check only when some of the higher bits of the count change.
+  // NB: The method needs to see the transitions of the counter past the thresholds.
+  uint32_t old_batch = RoundDown(old_count, kJitSamplesBatchSize);  // Clear lower bits.
+  uint32_t new_batch = RoundDown(new_count, kJitSamplesBatchSize);  // Clear lower bits.
+  if (UNLIKELY(old_batch == 0)) {
+    // For low sample counts, we check every time (which is important for tests).
+    if (!MaybeCompileMethod(self, method, old_count, new_count, with_backedges)) {
+      // Tests may check that the counter is 0 for methods that we never compile.
+      return;  // Ignore the samples for now and retry later.
+    }
+  } else if (UNLIKELY(old_batch != new_batch)) {
+    // For high sample counts, we check only when we move past the batch boundary.
+    if (!MaybeCompileMethod(self, method, old_batch, new_batch, with_backedges)) {
+      // OSR compilation will ignore the samples if they don't have backedges.
+      return;  // Ignore the samples for now and retry later.
+    }
+  }
+
+  method->SetCounter(new_count);
+}
+
+}  // namespace jit
+}  // namespace art
+
+#endif  // ART_RUNTIME_JIT_JIT_INL_H_