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-rw-r--r--compiler/optimizing/code_generator_x86.cc83
-rw-r--r--compiler/optimizing/code_generator_x86_64.cc81
2 files changed, 86 insertions, 78 deletions
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 2e8170ecc4..952b00fce9 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -317,6 +317,13 @@ class TypeCheckSlowPathX86 : public SlowPathCode {
CodeGeneratorX86* x86_codegen = down_cast<CodeGeneratorX86*>(codegen);
__ Bind(GetEntryLabel());
+ if (kPoisonHeapReferences &&
+ instruction_->IsCheckCast() &&
+ instruction_->AsCheckCast()->GetTypeCheckKind() == TypeCheckKind::kInterfaceCheck) {
+ // First, unpoison the `cls` reference that was poisoned for direct memory comparison.
+ __ UnpoisonHeapReference(locations->InAt(1).AsRegister<Register>());
+ }
+
if (!is_fatal_) {
SaveLiveRegisters(codegen, locations);
}
@@ -6369,7 +6376,7 @@ static size_t NumberOfInstanceOfTemps(TypeCheckKind type_check_kind) {
// interface pointer, one for loading the current interface.
// The other checks have one temp for loading the object's class.
static size_t NumberOfCheckCastTemps(TypeCheckKind type_check_kind) {
- if (type_check_kind == TypeCheckKind::kInterfaceCheck && !kPoisonHeapReferences) {
+ if (type_check_kind == TypeCheckKind::kInterfaceCheck) {
return 2;
}
return 1 + NumberOfInstanceOfTemps(type_check_kind);
@@ -6638,7 +6645,7 @@ static bool IsTypeCheckSlowPathFatal(TypeCheckKind type_check_kind, bool throws_
case TypeCheckKind::kArrayObjectCheck:
return !throws_into_catch && !kEmitCompilerReadBarrier;
case TypeCheckKind::kInterfaceCheck:
- return !throws_into_catch && !kEmitCompilerReadBarrier && !kPoisonHeapReferences;
+ return !throws_into_catch && !kEmitCompilerReadBarrier;
case TypeCheckKind::kArrayCheck:
case TypeCheckKind::kUnresolvedCheck:
return false;
@@ -6849,44 +6856,40 @@ void InstructionCodeGeneratorX86::VisitCheckCast(HCheckCast* instruction) {
break;
case TypeCheckKind::kInterfaceCheck: {
- // Fast path for the interface check. Since we compare with a memory location in the inner
- // loop we would need to have cls poisoned. However unpoisoning cls would reset the
- // conditional flags and cause the conditional jump to be incorrect. Therefore we just jump
- // to the slow path if we are running under poisoning.
- if (!kPoisonHeapReferences) {
- // Try to avoid read barriers to improve the fast path. We can not get false positives by
- // doing this.
- // /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction,
- temp_loc,
- obj_loc,
- class_offset,
- kWithoutReadBarrier);
-
- // /* HeapReference<Class> */ temp = temp->iftable_
- GenerateReferenceLoadTwoRegisters(instruction,
- temp_loc,
- temp_loc,
- iftable_offset,
- kWithoutReadBarrier);
- // Iftable is never null.
- __ movl(maybe_temp2_loc.AsRegister<Register>(), Address(temp, array_length_offset));
- // Loop through the iftable and check if any class matches.
- NearLabel start_loop;
- __ Bind(&start_loop);
- // Need to subtract first to handle the empty array case.
- __ subl(maybe_temp2_loc.AsRegister<Register>(), Immediate(2));
- __ j(kNegative, type_check_slow_path->GetEntryLabel());
- // Go to next interface if the classes do not match.
- __ cmpl(cls.AsRegister<Register>(),
- CodeGeneratorX86::ArrayAddress(temp,
- maybe_temp2_loc,
- TIMES_4,
- object_array_data_offset));
- __ j(kNotEqual, &start_loop);
- } else {
- __ jmp(type_check_slow_path->GetEntryLabel());
- }
+ // Fast path for the interface check. Try to avoid read barriers to improve the fast path.
+ // We can not get false positives by doing this.
+ // /* HeapReference<Class> */ temp = obj->klass_
+ GenerateReferenceLoadTwoRegisters(instruction,
+ temp_loc,
+ obj_loc,
+ class_offset,
+ kWithoutReadBarrier);
+
+ // /* HeapReference<Class> */ temp = temp->iftable_
+ GenerateReferenceLoadTwoRegisters(instruction,
+ temp_loc,
+ temp_loc,
+ iftable_offset,
+ kWithoutReadBarrier);
+ // Iftable is never null.
+ __ movl(maybe_temp2_loc.AsRegister<Register>(), Address(temp, array_length_offset));
+ // Maybe poison the `cls` for direct comparison with memory.
+ __ MaybePoisonHeapReference(cls.AsRegister<Register>());
+ // Loop through the iftable and check if any class matches.
+ NearLabel start_loop;
+ __ Bind(&start_loop);
+ // Need to subtract first to handle the empty array case.
+ __ subl(maybe_temp2_loc.AsRegister<Register>(), Immediate(2));
+ __ j(kNegative, type_check_slow_path->GetEntryLabel());
+ // Go to next interface if the classes do not match.
+ __ cmpl(cls.AsRegister<Register>(),
+ CodeGeneratorX86::ArrayAddress(temp,
+ maybe_temp2_loc,
+ TIMES_4,
+ object_array_data_offset));
+ __ j(kNotEqual, &start_loop);
+ // If `cls` was poisoned above, unpoison it.
+ __ MaybeUnpoisonHeapReference(cls.AsRegister<Register>());
break;
}
}
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index e25688c9a3..106531cd27 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -337,6 +337,13 @@ class TypeCheckSlowPathX86_64 : public SlowPathCode {
CodeGeneratorX86_64* x86_64_codegen = down_cast<CodeGeneratorX86_64*>(codegen);
__ Bind(GetEntryLabel());
+ if (kPoisonHeapReferences &&
+ instruction_->IsCheckCast() &&
+ instruction_->AsCheckCast()->GetTypeCheckKind() == TypeCheckKind::kInterfaceCheck) {
+ // First, unpoison the `cls` reference that was poisoned for direct memory comparison.
+ __ UnpoisonHeapReference(locations->InAt(1).AsRegister<CpuRegister>());
+ }
+
if (!is_fatal_) {
SaveLiveRegisters(codegen, locations);
}
@@ -5729,7 +5736,7 @@ void InstructionCodeGeneratorX86_64::VisitThrow(HThrow* instruction) {
}
static bool CheckCastTypeCheckNeedsATemporary(TypeCheckKind type_check_kind) {
- if (type_check_kind == TypeCheckKind::kInterfaceCheck && !kPoisonHeapReferences) {
+ if (type_check_kind == TypeCheckKind::kInterfaceCheck) {
// We need a temporary for holding the iftable length.
return true;
}
@@ -6019,7 +6026,7 @@ static bool IsTypeCheckSlowPathFatal(TypeCheckKind type_check_kind, bool throws_
case TypeCheckKind::kArrayObjectCheck:
return !throws_into_catch && !kEmitCompilerReadBarrier;
case TypeCheckKind::kInterfaceCheck:
- return !throws_into_catch && !kEmitCompilerReadBarrier && !kPoisonHeapReferences;
+ return !throws_into_catch && !kEmitCompilerReadBarrier;
case TypeCheckKind::kArrayCheck:
case TypeCheckKind::kUnresolvedCheck:
return false;
@@ -6233,42 +6240,40 @@ void InstructionCodeGeneratorX86_64::VisitCheckCast(HCheckCast* instruction) {
}
case TypeCheckKind::kInterfaceCheck:
- // Fast path for the interface check. We always go slow path for heap poisoning since
- // unpoisoning cls would require an extra temp.
- if (!kPoisonHeapReferences) {
- // Try to avoid read barriers to improve the fast path. We can not get false positives by
- // doing this.
- // /* HeapReference<Class> */ temp = obj->klass_
- GenerateReferenceLoadTwoRegisters(instruction,
- temp_loc,
- obj_loc,
- class_offset,
- kWithoutReadBarrier);
-
- // /* HeapReference<Class> */ temp = temp->iftable_
- GenerateReferenceLoadTwoRegisters(instruction,
- temp_loc,
- temp_loc,
- iftable_offset,
- kWithoutReadBarrier);
- // Iftable is never null.
- __ movl(maybe_temp2_loc.AsRegister<CpuRegister>(), Address(temp, array_length_offset));
- // Loop through the iftable and check if any class matches.
- NearLabel start_loop;
- __ Bind(&start_loop);
- // Need to subtract first to handle the empty array case.
- __ subl(maybe_temp2_loc.AsRegister<CpuRegister>(), Immediate(2));
- __ j(kNegative, type_check_slow_path->GetEntryLabel());
- // Go to next interface if the classes do not match.
- __ cmpl(cls.AsRegister<CpuRegister>(),
- CodeGeneratorX86_64::ArrayAddress(temp,
- maybe_temp2_loc,
- TIMES_4,
- object_array_data_offset));
- __ j(kNotEqual, &start_loop); // Return if same class.
- } else {
- __ jmp(type_check_slow_path->GetEntryLabel());
- }
+ // Fast path for the interface check. Try to avoid read barriers to improve the fast path.
+ // We can not get false positives by doing this.
+ // /* HeapReference<Class> */ temp = obj->klass_
+ GenerateReferenceLoadTwoRegisters(instruction,
+ temp_loc,
+ obj_loc,
+ class_offset,
+ kWithoutReadBarrier);
+
+ // /* HeapReference<Class> */ temp = temp->iftable_
+ GenerateReferenceLoadTwoRegisters(instruction,
+ temp_loc,
+ temp_loc,
+ iftable_offset,
+ kWithoutReadBarrier);
+ // Iftable is never null.
+ __ movl(maybe_temp2_loc.AsRegister<CpuRegister>(), Address(temp, array_length_offset));
+ // Maybe poison the `cls` for direct comparison with memory.
+ __ MaybePoisonHeapReference(cls.AsRegister<CpuRegister>());
+ // Loop through the iftable and check if any class matches.
+ NearLabel start_loop;
+ __ Bind(&start_loop);
+ // Need to subtract first to handle the empty array case.
+ __ subl(maybe_temp2_loc.AsRegister<CpuRegister>(), Immediate(2));
+ __ j(kNegative, type_check_slow_path->GetEntryLabel());
+ // Go to next interface if the classes do not match.
+ __ cmpl(cls.AsRegister<CpuRegister>(),
+ CodeGeneratorX86_64::ArrayAddress(temp,
+ maybe_temp2_loc,
+ TIMES_4,
+ object_array_data_offset));
+ __ j(kNotEqual, &start_loop); // Return if same class.
+ // If `cls` was poisoned above, unpoison it.
+ __ MaybeUnpoisonHeapReference(cls.AsRegister<CpuRegister>());
break;
}
generated by cgit v1.2.3-59-g8ed1b (git 2.39.0) at 2025-10-21 14:20:26 +0000