Peephole the type of a source of a move-object before instance-of.
In relation to dx's Bug:9316546 we need to look through move-objects to see
where the original register comes from.
This increases the number of check-casts removed in boot.oat by ~0.5%.
Change-Id: I0c8e94978f522d840764fa675e805496a3ff08b8
diff --git a/src/verifier/method_verifier.cc b/src/verifier/method_verifier.cc
index 5eec58b..1bb163a 100644
--- a/src/verifier/method_verifier.cc
+++ b/src/verifier/method_verifier.cc
@@ -1767,18 +1767,18 @@
}
// Find previous instruction - its existence is a precondition to peephole optimization.
- uint32_t prev_idx = 0;
+ uint32_t instance_of_idx = 0;
if (0 != work_insn_idx_) {
- prev_idx = work_insn_idx_ - 1;
- while(0 != prev_idx && !insn_flags_[prev_idx].IsOpcode()) {
- prev_idx--;
+ instance_of_idx = work_insn_idx_ - 1;
+ while(0 != instance_of_idx && !insn_flags_[instance_of_idx].IsOpcode()) {
+ instance_of_idx--;
}
- CHECK(insn_flags_[prev_idx].IsOpcode());
+ CHECK(insn_flags_[instance_of_idx].IsOpcode());
} else {
break;
}
- const Instruction* prev_inst = Instruction::At(code_item_->insns_+prev_idx);
+ const Instruction* instance_of_inst = Instruction::At(code_item_->insns_ + instance_of_idx);
/* Check for peep-hole pattern of:
* ...;
@@ -1793,22 +1793,51 @@
* - when vX == vY.
*/
if (!CurrentInsnFlags()->IsBranchTarget() &&
- (Instruction::INSTANCE_OF == prev_inst->Opcode()) &&
- (inst->VRegA_21t() == prev_inst->VRegA_22c()) &&
- (prev_inst->VRegA_22c() != prev_inst->VRegB_22c())) {
+ (Instruction::INSTANCE_OF == instance_of_inst->Opcode()) &&
+ (inst->VRegA_21t() == instance_of_inst->VRegA_22c()) &&
+ (instance_of_inst->VRegA_22c() != instance_of_inst->VRegB_22c())) {
// Check that the we are not attempting conversion to interface types,
// which is not done because of the multiple inheritance implications.
- const RegType& cast_type = ResolveClassAndCheckAccess(prev_inst->VRegC_22c());
+ const RegType& cast_type = ResolveClassAndCheckAccess(instance_of_inst->VRegC_22c());
if(!cast_type.IsUnresolvedTypes() && !cast_type.GetClass()->IsInterface()) {
+ RegisterLine* update_line = new RegisterLine(code_item_->registers_size_, this);
if (inst->Opcode() == Instruction::IF_EQZ) {
- fallthrough_line.reset(new RegisterLine(code_item_->registers_size_, this));
- fallthrough_line->CopyFromLine(work_line_.get());
- fallthrough_line->SetRegisterType(prev_inst->VRegB_22c(), cast_type);
+ fallthrough_line.reset(update_line);
} else {
- branch_line.reset(new RegisterLine(code_item_->registers_size_, this));
- branch_line->CopyFromLine(work_line_.get());
- branch_line->SetRegisterType(prev_inst->VRegB_22c(), cast_type);
+ branch_line.reset(update_line);
+ }
+ update_line->CopyFromLine(work_line_.get());
+ update_line->SetRegisterType(instance_of_inst->VRegB_22c(), cast_type);
+ if (!insn_flags_[instance_of_idx].IsBranchTarget() && 0 != instance_of_idx) {
+ // See if instance-of was preceded by a move-object operation, common due to the small
+ // register encoding space of instance-of, and propagate type information to the source
+ // of the move-object.
+ uint32_t move_idx = instance_of_idx - 1;
+ while(0 != move_idx && !insn_flags_[move_idx].IsOpcode()) {
+ move_idx--;
+ }
+ CHECK(insn_flags_[move_idx].IsOpcode());
+ const Instruction* move_inst = Instruction::At(code_item_->insns_ + move_idx);
+ switch (move_inst->Opcode()) {
+ case Instruction::MOVE_OBJECT:
+ if (move_inst->VRegA_12x() == instance_of_inst->VRegB_22c()) {
+ update_line->SetRegisterType(move_inst->VRegB_12x(), cast_type);
+ }
+ break;
+ case Instruction::MOVE_OBJECT_FROM16:
+ if (move_inst->VRegA_22x() == instance_of_inst->VRegB_22c()) {
+ update_line->SetRegisterType(move_inst->VRegB_22x(), cast_type);
+ }
+ break;
+ case Instruction::MOVE_OBJECT_16:
+ if (move_inst->VRegA_32x() == instance_of_inst->VRegB_22c()) {
+ update_line->SetRegisterType(move_inst->VRegB_32x(), cast_type);
+ }
+ break;
+ default:
+ break;
+ }
}
}
}
