commit 3aaa37bba53d6df0265793de48b4b0b57327e57a
author jessicahandojo <jessicahandojo@google.com> Fri Jul 29 14:46:37 2016 -0700
committer jessicahandojo <jessicahandojo@google.com> Tue Aug 23 15:12:26 2016 -0700
tree ce795803f0f10003eb3d96d9348da620937675b3
parent 792c98bb773c8c2390f9cbf774f85be9d9a75332

creating workflow for mirror::String compression

All-ASCII String characters are stored in 8-bit blocks
instead of 16-bit. The compression has not taken place, but all
workflow are in the code already (changing kUseStringCompression in
string.h file to TRUE will enable the feature)

Notes: Feature works on interpreter only without optimizing

Test art: m ART_TEST_INTERPRETER=true ART_TEST_OPTIMIZING=false
          test-art-host

Also tested with String tests from libcore/:
1. libcore.java.lang.StringTest
2. libcore.java.lang.StringBufferTest
3. libcore.java.lang.StringBuilderTest
4. libcore.java.lang.OldStringTest
5. libcore.java.lang.OldStringBufferTest

Memory improvement is 33% (from 6.03% to 4.03%, total String memory
from all apps per total memory of all apps) measured on Angler
with Hprof tools

Bug: 31040547
Change-Id: I9cc92c265ebf1305fc06b5fc33efd83797660cce

runtime/interpreter/unstarted_runtime_test.cc

diff --git a/runtime/interpreter/unstarted_runtime_test.cc b/runtime/interpreter/unstarted_runtime_test.cc
index 7e1f795..c324600 100644
--- a/runtime/interpreter/unstarted_runtime_test.cc
+++ b/runtime/interpreter/unstarted_runtime_test.cc
@@ -401,8 +401,23 @@
   interpreter::DoCall<false, false>(method, self, *shadow_frame, inst, inst_data[0], &result);
   mirror::String* string_result = reinterpret_cast<mirror::String*>(result.GetL());
   EXPECT_EQ(string_arg->GetLength(), string_result->GetLength());
-  EXPECT_EQ(memcmp(string_arg->GetValue(), string_result->GetValue(),
-                   string_arg->GetLength() * sizeof(uint16_t)), 0);
+
+  if (string_arg->IsCompressed() && string_result->IsCompressed()) {
+    EXPECT_EQ(memcmp(string_arg->GetValueCompressed(), string_result->GetValueCompressed(),
+                     string_arg->GetLength() * sizeof(uint8_t)), 0);
+  } else if (!string_arg->IsCompressed() && !string_result->IsCompressed()) {
+    EXPECT_EQ(memcmp(string_arg->GetValue(), string_result->GetValue(),
+                     string_arg->GetLength() * sizeof(uint16_t)), 0);
+  } else {
+    bool equal = true;
+    for (int i = 0; i < string_arg->GetLength(); ++i) {
+      if (string_arg->CharAt(i) != string_result->CharAt(i)) {
+        equal = false;
+        break;
+      }
+    }
+    EXPECT_EQ(equal, true);
+  }
 
   ShadowFrame::DeleteDeoptimizedFrame(shadow_frame);
 }