Remove unnecessary null checks in CheckCast and InstanceOf
Change-Id: I6fd81cabd8673be360f369e6318df0de8b18b634
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 0cc377c..b48a4d5 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -4225,9 +4225,11 @@
SlowPathCodeX86* slow_path = nullptr;
// Return 0 if `obj` is null.
- // TODO: avoid this check if we know obj is not null.
- __ testl(obj, obj);
- __ j(kEqual, &zero);
+ // Avoid null check if we know obj is not null.
+ if (instruction->MustDoNullCheck()) {
+ __ testl(obj, obj);
+ __ j(kEqual, &zero);
+ }
__ movl(out, Address(obj, class_offset));
// Compare the class of `obj` with `cls`.
if (cls.IsRegister()) {
@@ -4252,8 +4254,12 @@
__ movl(out, Immediate(1));
__ jmp(&done);
}
- __ Bind(&zero);
- __ movl(out, Immediate(0));
+
+ if (instruction->MustDoNullCheck() || instruction->IsClassFinal()) {
+ __ Bind(&zero);
+ __ movl(out, Immediate(0));
+ }
+
if (slow_path != nullptr) {
__ Bind(slow_path->GetExitLabel());
}
@@ -4278,11 +4284,13 @@
instruction, locations->InAt(1), locations->GetTemp(0), instruction->GetDexPc());
codegen_->AddSlowPath(slow_path);
- // TODO: avoid this check if we know obj is not null.
- __ testl(obj, obj);
- __ j(kEqual, slow_path->GetExitLabel());
- __ movl(temp, Address(obj, class_offset));
+ // Avoid null check if we know obj is not null.
+ if (instruction->MustDoNullCheck()) {
+ __ testl(obj, obj);
+ __ j(kEqual, slow_path->GetExitLabel());
+ }
+ __ movl(temp, Address(obj, class_offset));
// Compare the class of `obj` with `cls`.
if (cls.IsRegister()) {
__ cmpl(temp, cls.AsRegister<Register>());