commit b1677e2ff07d7cea3cf7ee91d7df202975c11836
author Nicolas Geoffray <ngeoffray@google.com> Fri Dec 16 16:23:16 2016 +0000
committer Nicolas Geoffray <ngeoffray@google.com> Mon Dec 19 09:09:20 2016 +0000
tree 6ed2f535f6e552281f10b0c1357aced68b8e117d
parent 20b66e727a927267bc472958e86f9b4ada42c7fc

Don't unquicken RETURN_VOID_NO_BARRIER with vdex.

The quickening of the RETURN_VOID instruction is based on
local information (no final fields) that doesn't get affected
by a boot image update.

Test: test-art-host, verifier_deps_test
bug:30937355

Change-Id: I12b22d7fcda6dc681a32ff752c3871f6e84f19a1

compiler/dex/dex_to_dex_decompiler.cc

diff --git a/compiler/dex/dex_to_dex_decompiler.cc b/compiler/dex/dex_to_dex_decompiler.cc
index 051125e..bfd485d 100644
--- a/compiler/dex/dex_to_dex_decompiler.cc
+++ b/compiler/dex/dex_to_dex_decompiler.cc
@@ -27,10 +27,13 @@
 
 class DexDecompiler {
  public:
-  DexDecompiler(const DexFile::CodeItem& code_item, const ArrayRef<const uint8_t>& quickened_info)
+  DexDecompiler(const DexFile::CodeItem& code_item,
+                const ArrayRef<const uint8_t>& quickened_info,
+                bool decompile_return_instruction)
     : code_item_(code_item),
       quickened_info_ptr_(quickened_info.data()),
-      quickened_info_end_(quickened_info.data() + quickened_info.size()) {}
+      quickened_info_end_(quickened_info.data() + quickened_info.size()),
+      decompile_return_instruction_(decompile_return_instruction) {}
 
   bool Decompile();
 
@@ -87,6 +90,7 @@
   const DexFile::CodeItem& code_item_;
   const uint8_t* quickened_info_ptr_;
   const uint8_t* const quickened_info_end_;
+  const bool decompile_return_instruction_;
 
   DISALLOW_COPY_AND_ASSIGN(DexDecompiler);
 };
@@ -102,7 +106,9 @@
 
     switch (inst->Opcode()) {
       case Instruction::RETURN_VOID_NO_BARRIER:
-        inst->SetOpcode(Instruction::RETURN_VOID);
+        if (decompile_return_instruction_) {
+          inst->SetOpcode(Instruction::RETURN_VOID);
+        }
         break;
 
       case Instruction::NOP:
@@ -189,8 +195,12 @@
 }
 
 bool ArtDecompileDEX(const DexFile::CodeItem& code_item,
-                     const ArrayRef<const uint8_t>& quickened_info) {
-  DexDecompiler decompiler(code_item, quickened_info);
+                     const ArrayRef<const uint8_t>& quickened_info,
+                     bool decompile_return_instruction) {
+  if (quickened_info.size() == 0 && !decompile_return_instruction) {
+    return true;
+  }
+  DexDecompiler decompiler(code_item, quickened_info, decompile_return_instruction);
   return decompiler.Decompile();
 }
 

compiler/dex/dex_to_dex_decompiler.h

diff --git a/compiler/dex/dex_to_dex_decompiler.h b/compiler/dex/dex_to_dex_decompiler.h
index 5502ca2..b5d5b91 100644
--- a/compiler/dex/dex_to_dex_decompiler.h
+++ b/compiler/dex/dex_to_dex_decompiler.h
@@ -30,7 +30,8 @@
 // consistent with DexToDexCompiler, but we should really change it to
 // DexFile::CodeItem*.
 bool ArtDecompileDEX(const DexFile::CodeItem& code_item,
-                     const ArrayRef<const uint8_t>& quickened_data);
+                     const ArrayRef<const uint8_t>& quickened_data,
+                     bool decompile_return_instruction);
 
 }  // namespace optimizer
 }  // namespace art

compiler/dex/dex_to_dex_decompiler_test.cc

diff --git a/compiler/dex/dex_to_dex_decompiler_test.cc b/compiler/dex/dex_to_dex_decompiler_test.cc
index ea6c7a2..9a8d27c 100644
--- a/compiler/dex/dex_to_dex_decompiler_test.cc
+++ b/compiler/dex/dex_to_dex_decompiler_test.cc
@@ -102,7 +102,8 @@
         if (compiled_method != nullptr) {
           table = compiled_method->GetVmapTable();
         }
-        optimizer::ArtDecompileDEX(*it.GetMethodCodeItem(), table);
+        optimizer::ArtDecompileDEX(
+            *it.GetMethodCodeItem(), table, /* decompile_return_instruction */ true);
         it.Next();
       }
       while (it.HasNextVirtualMethod()) {
@@ -113,7 +114,8 @@
         if (compiled_method != nullptr) {
           table = compiled_method->GetVmapTable();
         }
-        optimizer::ArtDecompileDEX(*it.GetMethodCodeItem(), table);
+        optimizer::ArtDecompileDEX(
+            *it.GetMethodCodeItem(), table, /* decompile_return_instruction */ true);
         it.Next();
       }
       DCHECK(!it.HasNext());