Merge "Fix load store elimination bug in the presence of null[i]."

2 files changed, 18 insertions, 0 deletions

diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 9acaa1d000..3b643a3c4f 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -4796,6 +4796,7 @@ void InstructionCodeGeneratorX86::HandleFieldSet(HInstruction* instruction,
         int32_t v = CodeGenerator::GetInt32ValueOf(value.GetConstant());
         __ movl(Address(base, offset), Immediate(v));
       } else {
+        DCHECK(value.IsRegister()) << value;
         __ movl(Address(base, offset), value.AsRegister<Register>());
       }
       break;
diff --git a/compiler/optimizing/load_store_elimination.cc b/compiler/optimizing/load_store_elimination.cc
index 8eaac0bbd3..561dcfbb1f 100644
--- a/compiler/optimizing/load_store_elimination.cc
+++ b/compiler/optimizing/load_store_elimination.cc
@@ -728,6 +728,23 @@ class LSEVisitor : public HGraphVisitor {
       // This acts like GVN but with better aliasing analysis.
       heap_values[idx] = instruction;
     } else {
+      if (Primitive::PrimitiveKind(heap_value->GetType())
+              != Primitive::PrimitiveKind(instruction->GetType())) {
+        // The only situation where the same heap location has different type is when
+        // we do an array get from a null constant. In order to stay properly typed
+        // we do not merge the array gets.
+        if (kIsDebugBuild) {
+          DCHECK(heap_value->IsArrayGet()) << heap_value->DebugName();
+          DCHECK(instruction->IsArrayGet()) << instruction->DebugName();
+          HInstruction* array = instruction->AsArrayGet()->GetArray();
+          DCHECK(array->IsNullCheck()) << array->DebugName();
+          DCHECK(array->InputAt(0)->IsNullConstant()) << array->InputAt(0)->DebugName();
+          array = heap_value->AsArrayGet()->GetArray();
+          DCHECK(array->IsNullCheck()) << array->DebugName();
+          DCHECK(array->InputAt(0)->IsNullConstant()) << array->InputAt(0)->DebugName();
+        }
+        return;
+      }
       removed_loads_.push_back(instruction);
       substitute_instructions_for_loads_.push_back(heap_value);
       TryRemovingNullCheck(instruction);