commit ff484b95b25a5181a6a8a191cbd11da501c97651
author Nicolas Geoffray <ngeoffray@google.com> Wed Jul 13 14:13:48 2016 +0100
committer Nicolas Geoffray <ngeoffray@google.com> Wed Jul 13 16:13:03 2016 +0100
tree a14875e1a28afd1c5f7bd6a0a80414674253e593
parent 1fd347303275a424d114c9833f954e8e27812554

Fix a bug in ClassTableGet code generation for IMTs.

Introduced by:
  https://android-review.googlesource.com/#/c/244980/

test:566-polymorphic-inling for fixing x86 crash. Also
fixes a performance regression.
bug:29188168

Change-Id: Id90cb819c88e7ba3db1cb3c50c517a112ab7d784

compiler/optimizing/code_generator_x86.cc

diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 2ded562..96c2857 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -4073,20 +4073,21 @@
 
 void InstructionCodeGeneratorX86::VisitClassTableGet(HClassTableGet* instruction) {
   LocationSummary* locations = instruction->GetLocations();
-  uint32_t method_offset = 0;
   if (instruction->GetTableKind() == HClassTableGet::TableKind::kVTable) {
-    method_offset = mirror::Class::EmbeddedVTableEntryOffset(
+    uint32_t method_offset = mirror::Class::EmbeddedVTableEntryOffset(
         instruction->GetIndex(), kX86PointerSize).SizeValue();
+    __ movl(locations->Out().AsRegister<Register>(),
+            Address(locations->InAt(0).AsRegister<Register>(), method_offset));
   } else {
-    __ movl(locations->InAt(0).AsRegister<Register>(),
-        Address(locations->InAt(0).AsRegister<Register>(),
-        mirror::Class::ImtPtrOffset(kX86PointerSize).Uint32Value()));
-    // temp = temp->GetImtEntryAt(method_offset);
-    method_offset = static_cast<uint32_t>(ImTable::OffsetOfElement(
+    uint32_t method_offset = static_cast<uint32_t>(ImTable::OffsetOfElement(
         instruction->GetIndex() % ImTable::kSize, kX86PointerSize));
+    __ movl(locations->Out().AsRegister<Register>(),
+            Address(locations->InAt(0).AsRegister<Register>(),
+                    mirror::Class::ImtPtrOffset(kX86PointerSize).Uint32Value()));
+    // temp = temp->GetImtEntryAt(method_offset);
+    __ movl(locations->Out().AsRegister<Register>(),
+            Address(locations->Out().AsRegister<Register>(), method_offset));
   }
-  __ movl(locations->Out().AsRegister<Register>(),
-          Address(locations->InAt(0).AsRegister<Register>(), method_offset));
 }
 
 void LocationsBuilderX86::VisitNot(HNot* not_) {