Improve documentation and assertions of read barrier instrumentation.
For ARM, x86, x86-64 back ends. The case of the ARM64 back
end is already handled in
https://android-review.googlesource.com/#/c/197870/.
Bug: 12687968
Change-Id: I6df1128cc100cbdb89020876e1a54de719508be3
diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 2725792..5f00f0a 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -5381,7 +5381,7 @@
Register cls = locations->InAt(1).AsRegister<Register>();
Location out_loc = locations->Out();
Register out = out_loc.AsRegister<Register>();
- Location temp_loc = TypeCheckNeedsATemporary(type_check_kind) ?
+ Location maybe_temp_loc = TypeCheckNeedsATemporary(type_check_kind) ?
locations->GetTemp(0) :
Location::NoLocation();
uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
@@ -5398,7 +5398,7 @@
}
// /* HeapReference<Class> */ out = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, out_loc, obj_loc, class_offset, temp_loc);
+ GenerateReferenceLoadTwoRegisters(instruction, out_loc, obj_loc, class_offset, maybe_temp_loc);
switch (type_check_kind) {
case TypeCheckKind::kExactCheck: {
@@ -5416,7 +5416,7 @@
Label loop;
__ Bind(&loop);
// /* HeapReference<Class> */ out = out->super_class_
- GenerateReferenceLoadOneRegister(instruction, out_loc, super_offset, temp_loc);
+ GenerateReferenceLoadOneRegister(instruction, out_loc, super_offset, maybe_temp_loc);
// If `out` is null, we use it for the result, and jump to `done`.
__ CompareAndBranchIfZero(out, &done);
__ cmp(out, ShifterOperand(cls));
@@ -5435,7 +5435,7 @@
__ cmp(out, ShifterOperand(cls));
__ b(&success, EQ);
// /* HeapReference<Class> */ out = out->super_class_
- GenerateReferenceLoadOneRegister(instruction, out_loc, super_offset, temp_loc);
+ GenerateReferenceLoadOneRegister(instruction, out_loc, super_offset, maybe_temp_loc);
__ CompareAndBranchIfNonZero(out, &loop);
// If `out` is null, we use it for the result, and jump to `done`.
__ b(&done);
@@ -5454,7 +5454,7 @@
__ b(&exact_check, EQ);
// Otherwise, we need to check that the object's class is a non-primitive array.
// /* HeapReference<Class> */ out = out->component_type_
- GenerateReferenceLoadOneRegister(instruction, out_loc, component_offset, temp_loc);
+ GenerateReferenceLoadOneRegister(instruction, out_loc, component_offset, maybe_temp_loc);
// If `out` is null, we use it for the result, and jump to `done`.
__ CompareAndBranchIfZero(out, &done);
__ LoadFromOffset(kLoadUnsignedHalfword, out, out, primitive_offset);
@@ -5567,7 +5567,7 @@
Register cls = locations->InAt(1).AsRegister<Register>();
Location temp_loc = locations->GetTemp(0);
Register temp = temp_loc.AsRegister<Register>();
- Location temp2_loc = TypeCheckNeedsATemporary(type_check_kind) ?
+ Location maybe_temp2_loc = TypeCheckNeedsATemporary(type_check_kind) ?
locations->GetTemp(1) :
Location::NoLocation();
uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
@@ -5593,7 +5593,7 @@
}
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
switch (type_check_kind) {
case TypeCheckKind::kExactCheck:
@@ -5611,7 +5611,7 @@
Label loop, compare_classes;
__ Bind(&loop);
// /* HeapReference<Class> */ temp = temp->super_class_
- GenerateReferenceLoadOneRegister(instruction, temp_loc, super_offset, temp2_loc);
+ GenerateReferenceLoadOneRegister(instruction, temp_loc, super_offset, maybe_temp2_loc);
// If the class reference currently in `temp` is not null, jump
// to the `compare_classes` label to compare it with the checked
@@ -5623,7 +5623,8 @@
// going into the slow path, as it has been overwritten in the
// meantime.
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(
+ instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
__ b(type_check_slow_path->GetEntryLabel());
__ Bind(&compare_classes);
@@ -5640,7 +5641,7 @@
__ b(&done, EQ);
// /* HeapReference<Class> */ temp = temp->super_class_
- GenerateReferenceLoadOneRegister(instruction, temp_loc, super_offset, temp2_loc);
+ GenerateReferenceLoadOneRegister(instruction, temp_loc, super_offset, maybe_temp2_loc);
// If the class reference currently in `temp` is not null, jump
// back at the beginning of the loop.
@@ -5651,7 +5652,8 @@
// going into the slow path, as it has been overwritten in the
// meantime.
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(
+ instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
__ b(type_check_slow_path->GetEntryLabel());
break;
}
@@ -5664,7 +5666,7 @@
// Otherwise, we need to check that the object's class is a non-primitive array.
// /* HeapReference<Class> */ temp = temp->component_type_
- GenerateReferenceLoadOneRegister(instruction, temp_loc, component_offset, temp2_loc);
+ GenerateReferenceLoadOneRegister(instruction, temp_loc, component_offset, maybe_temp2_loc);
// If the component type is not null (i.e. the object is indeed
// an array), jump to label `check_non_primitive_component_type`
@@ -5677,7 +5679,8 @@
// going into the slow path, as it has been overwritten in the
// meantime.
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(
+ instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
__ b(type_check_slow_path->GetEntryLabel());
__ Bind(&check_non_primitive_component_type);
@@ -5686,7 +5689,8 @@
__ CompareAndBranchIfZero(temp, &done);
// Same comment as above regarding `temp` and the slow path.
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(
+ instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
__ b(type_check_slow_path->GetEntryLabel());
break;
}
@@ -5897,23 +5901,24 @@
void InstructionCodeGeneratorARM::GenerateReferenceLoadOneRegister(HInstruction* instruction,
Location out,
uint32_t offset,
- Location temp) {
+ Location maybe_temp) {
Register out_reg = out.AsRegister<Register>();
if (kEmitCompilerReadBarrier) {
+ DCHECK(maybe_temp.IsRegister()) << maybe_temp;
if (kUseBakerReadBarrier) {
// Load with fast path based Baker's read barrier.
// /* HeapReference<Object> */ out = *(out + offset)
codegen_->GenerateFieldLoadWithBakerReadBarrier(
- instruction, out, out_reg, offset, temp, /* needs_null_check */ false);
+ instruction, out, out_reg, offset, maybe_temp, /* needs_null_check */ false);
} else {
// Load with slow path based read barrier.
- // Save the value of `out` into `temp` before overwriting it
+ // Save the value of `out` into `maybe_temp` before overwriting it
// in the following move operation, as we will need it for the
// read barrier below.
- __ Mov(temp.AsRegister<Register>(), out_reg);
+ __ Mov(maybe_temp.AsRegister<Register>(), out_reg);
// /* HeapReference<Object> */ out = *(out + offset)
__ LoadFromOffset(kLoadWord, out_reg, out_reg, offset);
- codegen_->GenerateReadBarrierSlow(instruction, out, out, temp, offset);
+ codegen_->GenerateReadBarrierSlow(instruction, out, out, maybe_temp, offset);
}
} else {
// Plain load with no read barrier.
@@ -5927,15 +5932,16 @@
Location out,
Location obj,
uint32_t offset,
- Location temp) {
+ Location maybe_temp) {
Register out_reg = out.AsRegister<Register>();
Register obj_reg = obj.AsRegister<Register>();
if (kEmitCompilerReadBarrier) {
if (kUseBakerReadBarrier) {
+ DCHECK(maybe_temp.IsRegister()) << maybe_temp;
// Load with fast path based Baker's read barrier.
// /* HeapReference<Object> */ out = *(obj + offset)
codegen_->GenerateFieldLoadWithBakerReadBarrier(
- instruction, out, obj_reg, offset, temp, /* needs_null_check */ false);
+ instruction, out, obj_reg, offset, maybe_temp, /* needs_null_check */ false);
} else {
// Load with slow path based read barrier.
// /* HeapReference<Object> */ out = *(obj + offset)
diff --git a/compiler/optimizing/code_generator_arm.h b/compiler/optimizing/code_generator_arm.h
index d45ea97..558c9cf 100644
--- a/compiler/optimizing/code_generator_arm.h
+++ b/compiler/optimizing/code_generator_arm.h
@@ -240,23 +240,29 @@
// out <- *(out + offset)
//
// while honoring heap poisoning and/or read barriers (if any).
- // Register `temp` is used when generating a read barrier.
+ //
+ // Location `maybe_temp` is used when generating a read barrier and
+ // shall be a register in that case; it may be an invalid location
+ // otherwise.
void GenerateReferenceLoadOneRegister(HInstruction* instruction,
Location out,
uint32_t offset,
- Location temp);
+ Location maybe_temp);
// Generate a heap reference load using two different registers
// `out` and `obj`:
//
// out <- *(obj + offset)
//
// while honoring heap poisoning and/or read barriers (if any).
- // Register `temp` is used when generating a Baker's read barrier.
+ //
+ // Location `maybe_temp` is used when generating a Baker's (fast
+ // path) read barrier and shall be a register in that case; it may
+ // be an invalid location otherwise.
void GenerateReferenceLoadTwoRegisters(HInstruction* instruction,
Location out,
Location obj,
uint32_t offset,
- Location temp);
+ Location maybe_temp);
// Generate a GC root reference load:
//
// root <- *(obj + offset)
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index f7ccdd8..50c4ba2 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -5878,7 +5878,7 @@
Location cls = locations->InAt(1);
Location out_loc = locations->Out();
Register out = out_loc.AsRegister<Register>();
- Location temp_loc = TypeCheckNeedsATemporary(type_check_kind) ?
+ Location maybe_temp_loc = TypeCheckNeedsATemporary(type_check_kind) ?
locations->GetTemp(0) :
Location::NoLocation();
uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
@@ -5896,7 +5896,7 @@
}
// /* HeapReference<Class> */ out = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, out_loc, obj_loc, class_offset, temp_loc);
+ GenerateReferenceLoadTwoRegisters(instruction, out_loc, obj_loc, class_offset, maybe_temp_loc);
switch (type_check_kind) {
case TypeCheckKind::kExactCheck: {
@@ -5920,7 +5920,7 @@
NearLabel loop;
__ Bind(&loop);
// /* HeapReference<Class> */ out = out->super_class_
- GenerateReferenceLoadOneRegister(instruction, out_loc, super_offset, temp_loc);
+ GenerateReferenceLoadOneRegister(instruction, out_loc, super_offset, maybe_temp_loc);
__ testl(out, out);
// If `out` is null, we use it for the result, and jump to `done`.
__ j(kEqual, &done);
@@ -5950,7 +5950,7 @@
}
__ j(kEqual, &success);
// /* HeapReference<Class> */ out = out->super_class_
- GenerateReferenceLoadOneRegister(instruction, out_loc, super_offset, temp_loc);
+ GenerateReferenceLoadOneRegister(instruction, out_loc, super_offset, maybe_temp_loc);
__ testl(out, out);
__ j(kNotEqual, &loop);
// If `out` is null, we use it for the result, and jump to `done`.
@@ -5975,7 +5975,7 @@
__ j(kEqual, &exact_check);
// Otherwise, we need to check that the object's class is a non-primitive array.
// /* HeapReference<Class> */ out = out->component_type_
- GenerateReferenceLoadOneRegister(instruction, out_loc, component_offset, temp_loc);
+ GenerateReferenceLoadOneRegister(instruction, out_loc, component_offset, maybe_temp_loc);
__ testl(out, out);
// If `out` is null, we use it for the result, and jump to `done`.
__ j(kEqual, &done);
@@ -6091,7 +6091,7 @@
Location cls = locations->InAt(1);
Location temp_loc = locations->GetTemp(0);
Register temp = temp_loc.AsRegister<Register>();
- Location temp2_loc = TypeCheckNeedsATemporary(type_check_kind) ?
+ Location maybe_temp2_loc = TypeCheckNeedsATemporary(type_check_kind) ?
locations->GetTemp(1) :
Location::NoLocation();
uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
@@ -6118,7 +6118,7 @@
}
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
switch (type_check_kind) {
case TypeCheckKind::kExactCheck:
@@ -6141,7 +6141,7 @@
NearLabel loop, compare_classes;
__ Bind(&loop);
// /* HeapReference<Class> */ temp = temp->super_class_
- GenerateReferenceLoadOneRegister(instruction, temp_loc, super_offset, temp2_loc);
+ GenerateReferenceLoadOneRegister(instruction, temp_loc, super_offset, maybe_temp2_loc);
// If the class reference currently in `temp` is not null, jump
// to the `compare_classes` label to compare it with the checked
@@ -6154,7 +6154,8 @@
// going into the slow path, as it has been overwritten in the
// meantime.
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(
+ instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
__ jmp(type_check_slow_path->GetEntryLabel());
__ Bind(&compare_classes);
@@ -6181,7 +6182,7 @@
__ j(kEqual, &done);
// /* HeapReference<Class> */ temp = temp->super_class_
- GenerateReferenceLoadOneRegister(instruction, temp_loc, super_offset, temp2_loc);
+ GenerateReferenceLoadOneRegister(instruction, temp_loc, super_offset, maybe_temp2_loc);
// If the class reference currently in `temp` is not null, jump
// back at the beginning of the loop.
@@ -6193,7 +6194,8 @@
// going into the slow path, as it has been overwritten in the
// meantime.
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(
+ instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
__ jmp(type_check_slow_path->GetEntryLabel());
break;
}
@@ -6211,7 +6213,7 @@
// Otherwise, we need to check that the object's class is a non-primitive array.
// /* HeapReference<Class> */ temp = temp->component_type_
- GenerateReferenceLoadOneRegister(instruction, temp_loc, component_offset, temp2_loc);
+ GenerateReferenceLoadOneRegister(instruction, temp_loc, component_offset, maybe_temp2_loc);
// If the component type is not null (i.e. the object is indeed
// an array), jump to label `check_non_primitive_component_type`
@@ -6225,7 +6227,8 @@
// going into the slow path, as it has been overwritten in the
// meantime.
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(
+ instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
__ jmp(type_check_slow_path->GetEntryLabel());
__ Bind(&check_non_primitive_component_type);
@@ -6233,7 +6236,8 @@
__ j(kEqual, &done);
// Same comment as above regarding `temp` and the slow path.
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(
+ instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
__ jmp(type_check_slow_path->GetEntryLabel());
break;
}
@@ -6421,23 +6425,24 @@
void InstructionCodeGeneratorX86::GenerateReferenceLoadOneRegister(HInstruction* instruction,
Location out,
uint32_t offset,
- Location temp) {
+ Location maybe_temp) {
Register out_reg = out.AsRegister<Register>();
if (kEmitCompilerReadBarrier) {
+ DCHECK(maybe_temp.IsRegister()) << maybe_temp;
if (kUseBakerReadBarrier) {
// Load with fast path based Baker's read barrier.
// /* HeapReference<Object> */ out = *(out + offset)
codegen_->GenerateFieldLoadWithBakerReadBarrier(
- instruction, out, out_reg, offset, temp, /* needs_null_check */ false);
+ instruction, out, out_reg, offset, maybe_temp, /* needs_null_check */ false);
} else {
// Load with slow path based read barrier.
- // Save the value of `out` into `temp` before overwriting it
+ // Save the value of `out` into `maybe_temp` before overwriting it
// in the following move operation, as we will need it for the
// read barrier below.
- __ movl(temp.AsRegister<Register>(), out_reg);
+ __ movl(maybe_temp.AsRegister<Register>(), out_reg);
// /* HeapReference<Object> */ out = *(out + offset)
__ movl(out_reg, Address(out_reg, offset));
- codegen_->GenerateReadBarrierSlow(instruction, out, out, temp, offset);
+ codegen_->GenerateReadBarrierSlow(instruction, out, out, maybe_temp, offset);
}
} else {
// Plain load with no read barrier.
@@ -6451,15 +6456,16 @@
Location out,
Location obj,
uint32_t offset,
- Location temp) {
+ Location maybe_temp) {
Register out_reg = out.AsRegister<Register>();
Register obj_reg = obj.AsRegister<Register>();
if (kEmitCompilerReadBarrier) {
if (kUseBakerReadBarrier) {
+ DCHECK(maybe_temp.IsRegister()) << maybe_temp;
// Load with fast path based Baker's read barrier.
// /* HeapReference<Object> */ out = *(obj + offset)
codegen_->GenerateFieldLoadWithBakerReadBarrier(
- instruction, out, obj_reg, offset, temp, /* needs_null_check */ false);
+ instruction, out, obj_reg, offset, maybe_temp, /* needs_null_check */ false);
} else {
// Load with slow path based read barrier.
// /* HeapReference<Object> */ out = *(obj + offset)
diff --git a/compiler/optimizing/code_generator_x86.h b/compiler/optimizing/code_generator_x86.h
index 43e9543..0aef478 100644
--- a/compiler/optimizing/code_generator_x86.h
+++ b/compiler/optimizing/code_generator_x86.h
@@ -233,23 +233,29 @@
// out <- *(out + offset)
//
// while honoring heap poisoning and/or read barriers (if any).
- // Register `temp` is used when generating a read barrier.
+ //
+ // Location `maybe_temp` is used when generating a read barrier and
+ // shall be a register in that case; it may be an invalid location
+ // otherwise.
void GenerateReferenceLoadOneRegister(HInstruction* instruction,
Location out,
uint32_t offset,
- Location temp);
+ Location maybe_temp);
// Generate a heap reference load using two different registers
// `out` and `obj`:
//
// out <- *(obj + offset)
//
// while honoring heap poisoning and/or read barriers (if any).
- // Register `temp` is used when generating a Baker's read barrier.
+ //
+ // Location `maybe_temp` is used when generating a Baker's (fast
+ // path) read barrier and shall be a register in that case; it may
+ // be an invalid location otherwise.
void GenerateReferenceLoadTwoRegisters(HInstruction* instruction,
Location out,
Location obj,
uint32_t offset,
- Location temp);
+ Location maybe_temp);
// Generate a GC root reference load:
//
// root <- *(obj + offset)
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index 2ce2d91..fd18834 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -5490,7 +5490,7 @@
Location cls = locations->InAt(1);
Location out_loc = locations->Out();
CpuRegister out = out_loc.AsRegister<CpuRegister>();
- Location temp_loc = TypeCheckNeedsATemporary(type_check_kind) ?
+ Location maybe_temp_loc = TypeCheckNeedsATemporary(type_check_kind) ?
locations->GetTemp(0) :
Location::NoLocation();
uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
@@ -5508,7 +5508,7 @@
}
// /* HeapReference<Class> */ out = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, out_loc, obj_loc, class_offset, temp_loc);
+ GenerateReferenceLoadTwoRegisters(instruction, out_loc, obj_loc, class_offset, maybe_temp_loc);
switch (type_check_kind) {
case TypeCheckKind::kExactCheck: {
@@ -5537,7 +5537,7 @@
NearLabel loop, success;
__ Bind(&loop);
// /* HeapReference<Class> */ out = out->super_class_
- GenerateReferenceLoadOneRegister(instruction, out_loc, super_offset, temp_loc);
+ GenerateReferenceLoadOneRegister(instruction, out_loc, super_offset, maybe_temp_loc);
__ testl(out, out);
// If `out` is null, we use it for the result, and jump to `done`.
__ j(kEqual, &done);
@@ -5567,7 +5567,7 @@
}
__ j(kEqual, &success);
// /* HeapReference<Class> */ out = out->super_class_
- GenerateReferenceLoadOneRegister(instruction, out_loc, super_offset, temp_loc);
+ GenerateReferenceLoadOneRegister(instruction, out_loc, super_offset, maybe_temp_loc);
__ testl(out, out);
__ j(kNotEqual, &loop);
// If `out` is null, we use it for the result, and jump to `done`.
@@ -5592,7 +5592,7 @@
__ j(kEqual, &exact_check);
// Otherwise, we need to check that the object's class is a non-primitive array.
// /* HeapReference<Class> */ out = out->component_type_
- GenerateReferenceLoadOneRegister(instruction, out_loc, component_offset, temp_loc);
+ GenerateReferenceLoadOneRegister(instruction, out_loc, component_offset, maybe_temp_loc);
__ testl(out, out);
// If `out` is null, we use it for the result, and jump to `done`.
__ j(kEqual, &done);
@@ -5708,7 +5708,7 @@
Location cls = locations->InAt(1);
Location temp_loc = locations->GetTemp(0);
CpuRegister temp = temp_loc.AsRegister<CpuRegister>();
- Location temp2_loc = TypeCheckNeedsATemporary(type_check_kind) ?
+ Location maybe_temp2_loc = TypeCheckNeedsATemporary(type_check_kind) ?
locations->GetTemp(1) :
Location::NoLocation();
uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
@@ -5735,7 +5735,7 @@
}
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
switch (type_check_kind) {
case TypeCheckKind::kExactCheck:
@@ -5758,7 +5758,7 @@
NearLabel loop, compare_classes;
__ Bind(&loop);
// /* HeapReference<Class> */ temp = temp->super_class_
- GenerateReferenceLoadOneRegister(instruction, temp_loc, super_offset, temp2_loc);
+ GenerateReferenceLoadOneRegister(instruction, temp_loc, super_offset, maybe_temp2_loc);
// If the class reference currently in `temp` is not null, jump
// to the `compare_classes` label to compare it with the checked
@@ -5771,7 +5771,8 @@
// going into the slow path, as it has been overwritten in the
// meantime.
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(
+ instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
__ jmp(type_check_slow_path->GetEntryLabel());
__ Bind(&compare_classes);
@@ -5798,7 +5799,7 @@
__ j(kEqual, &done);
// /* HeapReference<Class> */ temp = temp->super_class_
- GenerateReferenceLoadOneRegister(instruction, temp_loc, super_offset, temp2_loc);
+ GenerateReferenceLoadOneRegister(instruction, temp_loc, super_offset, maybe_temp2_loc);
// If the class reference currently in `temp` is not null, jump
// back at the beginning of the loop.
@@ -5810,7 +5811,8 @@
// going into the slow path, as it has been overwritten in the
// meantime.
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(
+ instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
__ jmp(type_check_slow_path->GetEntryLabel());
break;
}
@@ -5828,7 +5830,7 @@
// Otherwise, we need to check that the object's class is a non-primitive array.
// /* HeapReference<Class> */ temp = temp->component_type_
- GenerateReferenceLoadOneRegister(instruction, temp_loc, component_offset, temp2_loc);
+ GenerateReferenceLoadOneRegister(instruction, temp_loc, component_offset, maybe_temp2_loc);
// If the component type is not null (i.e. the object is indeed
// an array), jump to label `check_non_primitive_component_type`
@@ -5842,7 +5844,8 @@
// going into the slow path, as it has been overwritten in the
// meantime.
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(
+ instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
__ jmp(type_check_slow_path->GetEntryLabel());
__ Bind(&check_non_primitive_component_type);
@@ -5850,7 +5853,8 @@
__ j(kEqual, &done);
// Same comment as above regarding `temp` and the slow path.
// /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction, temp_loc, obj_loc, class_offset, temp2_loc);
+ GenerateReferenceLoadTwoRegisters(
+ instruction, temp_loc, obj_loc, class_offset, maybe_temp2_loc);
__ jmp(type_check_slow_path->GetEntryLabel());
break;
}
@@ -6020,23 +6024,24 @@
void InstructionCodeGeneratorX86_64::GenerateReferenceLoadOneRegister(HInstruction* instruction,
Location out,
uint32_t offset,
- Location temp) {
+ Location maybe_temp) {
CpuRegister out_reg = out.AsRegister<CpuRegister>();
if (kEmitCompilerReadBarrier) {
+ DCHECK(maybe_temp.IsRegister()) << maybe_temp;
if (kUseBakerReadBarrier) {
// Load with fast path based Baker's read barrier.
// /* HeapReference<Object> */ out = *(out + offset)
codegen_->GenerateFieldLoadWithBakerReadBarrier(
- instruction, out, out_reg, offset, temp, /* needs_null_check */ false);
+ instruction, out, out_reg, offset, maybe_temp, /* needs_null_check */ false);
} else {
// Load with slow path based read barrier.
- // Save the value of `out` into `temp` before overwriting it
+ // Save the value of `out` into `maybe_temp` before overwriting it
// in the following move operation, as we will need it for the
// read barrier below.
- __ movl(temp.AsRegister<CpuRegister>(), out_reg);
+ __ movl(maybe_temp.AsRegister<CpuRegister>(), out_reg);
// /* HeapReference<Object> */ out = *(out + offset)
__ movl(out_reg, Address(out_reg, offset));
- codegen_->GenerateReadBarrierSlow(instruction, out, out, temp, offset);
+ codegen_->GenerateReadBarrierSlow(instruction, out, out, maybe_temp, offset);
}
} else {
// Plain load with no read barrier.
@@ -6050,15 +6055,16 @@
Location out,
Location obj,
uint32_t offset,
- Location temp) {
+ Location maybe_temp) {
CpuRegister out_reg = out.AsRegister<CpuRegister>();
CpuRegister obj_reg = obj.AsRegister<CpuRegister>();
if (kEmitCompilerReadBarrier) {
if (kUseBakerReadBarrier) {
+ DCHECK(maybe_temp.IsRegister()) << maybe_temp;
// Load with fast path based Baker's read barrier.
// /* HeapReference<Object> */ out = *(obj + offset)
codegen_->GenerateFieldLoadWithBakerReadBarrier(
- instruction, out, obj_reg, offset, temp, /* needs_null_check */ false);
+ instruction, out, obj_reg, offset, maybe_temp, /* needs_null_check */ false);
} else {
// Load with slow path based read barrier.
// /* HeapReference<Object> */ out = *(obj + offset)
diff --git a/compiler/optimizing/code_generator_x86_64.h b/compiler/optimizing/code_generator_x86_64.h
index 82aabb0..9626590 100644
--- a/compiler/optimizing/code_generator_x86_64.h
+++ b/compiler/optimizing/code_generator_x86_64.h
@@ -227,23 +227,29 @@
// out <- *(out + offset)
//
// while honoring heap poisoning and/or read barriers (if any).
- // Register `temp` is used when generating a read barrier.
+ //
+ // Location `maybe_temp` is used when generating a read barrier and
+ // shall be a register in that case; it may be an invalid location
+ // otherwise.
void GenerateReferenceLoadOneRegister(HInstruction* instruction,
Location out,
uint32_t offset,
- Location temp);
+ Location maybe_temp);
// Generate a heap reference load using two different registers
// `out` and `obj`:
//
// out <- *(obj + offset)
//
// while honoring heap poisoning and/or read barriers (if any).
- // Register `temp` is used when generating a Baker's read barrier.
+ //
+ // Location `maybe_temp` is used when generating a Baker's (fast
+ // path) read barrier and shall be a register in that case; it may
+ // be an invalid location otherwise.
void GenerateReferenceLoadTwoRegisters(HInstruction* instruction,
Location out,
Location obj,
uint32_t offset,
- Location temp);
+ Location maybe_temp);
// Generate a GC root reference load:
//
// root <- *(obj + offset)
