Small optimization improvements.
- Tune CanBeNull for HBoundType.
- Remove LoadClass when we know the class is loaded.
- Tune CanBeNull for StringInit.
Change-Id: I564ed33a506d65e991a514342bdfd1610bed0cf5
diff --git a/compiler/optimizing/instruction_simplifier.cc b/compiler/optimizing/instruction_simplifier.cc
index 931a1c3..df6e550 100644
--- a/compiler/optimizing/instruction_simplifier.cc
+++ b/compiler/optimizing/instruction_simplifier.cc
@@ -238,12 +238,19 @@
}
bool outcome;
- if (TypeCheckHasKnownOutcome(check_cast->InputAt(1)->AsLoadClass(), object, &outcome)) {
+ HLoadClass* load_class = check_cast->InputAt(1)->AsLoadClass();
+ if (TypeCheckHasKnownOutcome(load_class, object, &outcome)) {
if (outcome) {
check_cast->GetBlock()->RemoveInstruction(check_cast);
if (stats_ != nullptr) {
stats_->RecordStat(MethodCompilationStat::kRemovedCheckedCast);
}
+ if (!load_class->HasUses()) {
+ // We cannot rely on DCE to remove the class because the `HLoadClass` thinks it can throw.
+ // However, here we know that it cannot because the checkcast was successfull, hence
+ // the class was already loaded.
+ load_class->GetBlock()->RemoveInstruction(load_class);
+ }
} else {
// Don't do anything for exceptional cases for now. Ideally we should remove
// all instructions and blocks this instruction dominates.
@@ -268,7 +275,8 @@
}
bool outcome;
- if (TypeCheckHasKnownOutcome(instruction->InputAt(1)->AsLoadClass(), object, &outcome)) {
+ HLoadClass* load_class = instruction->InputAt(1)->AsLoadClass();
+ if (TypeCheckHasKnownOutcome(load_class, object, &outcome)) {
if (outcome && can_be_null) {
// Type test will succeed, we just need a null test.
HNotEqual* test = new (graph->GetArena()) HNotEqual(graph->GetNullConstant(), object);
@@ -280,6 +288,12 @@
}
RecordSimplification();
instruction->GetBlock()->RemoveInstruction(instruction);
+ if (outcome && !load_class->HasUses()) {
+ // We cannot rely on DCE to remove the class because the `HLoadClass` thinks it can throw.
+ // However, here we know that it cannot because the instanceof check was successfull, hence
+ // the class was already loaded.
+ load_class->GetBlock()->RemoveInstruction(load_class);
+ }
}
}