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/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "intrinsics_arm_vixl.h"
#include "arch/arm/instruction_set_features_arm.h"
#include "art_method.h"
#include "code_generator_arm_vixl.h"
#include "common_arm.h"
#include "heap_poisoning.h"
#include "lock_word.h"
#include "mirror/array-inl.h"
#include "mirror/object_array-inl.h"
#include "mirror/reference.h"
#include "mirror/string-inl.h"
#include "scoped_thread_state_change-inl.h"
#include "thread-current-inl.h"
#include "aarch32/constants-aarch32.h"
namespace art {
namespace arm {
#define __ assembler->GetVIXLAssembler()->
using helpers::DRegisterFrom;
using helpers::HighRegisterFrom;
using helpers::InputDRegisterAt;
using helpers::InputRegisterAt;
using helpers::InputSRegisterAt;
using helpers::Int32ConstantFrom;
using helpers::LocationFrom;
using helpers::LowRegisterFrom;
using helpers::LowSRegisterFrom;
using helpers::HighSRegisterFrom;
using helpers::OutputDRegister;
using helpers::OutputRegister;
using helpers::RegisterFrom;
using helpers::SRegisterFrom;
using namespace vixl::aarch32; // NOLINT(build/namespaces)
using vixl::ExactAssemblyScope;
using vixl::CodeBufferCheckScope;
ArmVIXLAssembler* IntrinsicCodeGeneratorARMVIXL::GetAssembler() {
return codegen_->GetAssembler();
}
ArenaAllocator* IntrinsicCodeGeneratorARMVIXL::GetAllocator() {
return codegen_->GetGraph()->GetAllocator();
}
// Default slow-path for fallback (calling the managed code to handle the intrinsic) in an
// intrinsified call. This will copy the arguments into the positions for a regular call.
//
// Note: The actual parameters are required to be in the locations given by the invoke's location
// summary. If an intrinsic modifies those locations before a slowpath call, they must be
// restored!
//
// Note: If an invoke wasn't sharpened, we will put down an invoke-virtual here. That's potentially
// sub-optimal (compared to a direct pointer call), but this is a slow-path.
class IntrinsicSlowPathARMVIXL : public SlowPathCodeARMVIXL {
public:
explicit IntrinsicSlowPathARMVIXL(HInvoke* invoke)
: SlowPathCodeARMVIXL(invoke), invoke_(invoke) {}
Location MoveArguments(CodeGenerator* codegen) {
InvokeDexCallingConventionVisitorARMVIXL calling_convention_visitor;
IntrinsicVisitor::MoveArguments(invoke_, codegen, &calling_convention_visitor);
return calling_convention_visitor.GetMethodLocation();
}
void EmitNativeCode(CodeGenerator* codegen) override {
ArmVIXLAssembler* assembler = down_cast<ArmVIXLAssembler*>(codegen->GetAssembler());
__ Bind(GetEntryLabel());
SaveLiveRegisters(codegen, invoke_->GetLocations());
Location method_loc = MoveArguments(codegen);
if (invoke_->IsInvokeStaticOrDirect()) {
codegen->GenerateStaticOrDirectCall(invoke_->AsInvokeStaticOrDirect(), method_loc, this);
} else {
codegen->GenerateVirtualCall(invoke_->AsInvokeVirtual(), method_loc, this);
}
// Copy the result back to the expected output.
Location out = invoke_->GetLocations()->Out();
if (out.IsValid()) {
DCHECK(out.IsRegister()); // TODO: Replace this when we support output in memory.
DCHECK(!invoke_->GetLocations()->GetLiveRegisters()->ContainsCoreRegister(out.reg()));
codegen->MoveFromReturnRegister(out, invoke_->GetType());
}
RestoreLiveRegisters(codegen, invoke_->GetLocations());
__ B(GetExitLabel());
}
const char* GetDescription() const override { return "IntrinsicSlowPath"; }
private:
// The instruction where this slow path is happening.
HInvoke* const invoke_;
DISALLOW_COPY_AND_ASSIGN(IntrinsicSlowPathARMVIXL);
};
// Compute base address for the System.arraycopy intrinsic in `base`.
static void GenSystemArrayCopyBaseAddress(ArmVIXLAssembler* assembler,
DataType::Type type,
const vixl32::Register& array,
const Location& pos,
const vixl32::Register& base) {
// This routine is only used by the SystemArrayCopy intrinsic at the
// moment. We can allow DataType::Type::kReference as `type` to implement
// the SystemArrayCopyChar intrinsic.
DCHECK_EQ(type, DataType::Type::kReference);
const int32_t element_size = DataType::Size(type);
const uint32_t element_size_shift = DataType::SizeShift(type);
const uint32_t data_offset = mirror::Array::DataOffset(element_size).Uint32Value();
if (pos.IsConstant()) {
int32_t constant = Int32ConstantFrom(pos);
__ Add(base, array, element_size * constant + data_offset);
} else {
__ Add(base, array, Operand(RegisterFrom(pos), vixl32::LSL, element_size_shift));
__ Add(base, base, data_offset);
}
}
// Compute end address for the System.arraycopy intrinsic in `end`.
static void GenSystemArrayCopyEndAddress(ArmVIXLAssembler* assembler,
DataType::Type type,
const Location& copy_length,
const vixl32::Register& base,
const vixl32::Register& end) {
// This routine is only used by the SystemArrayCopy intrinsic at the
// moment. We can allow DataType::Type::kReference as `type` to implement
// the SystemArrayCopyChar intrinsic.
DCHECK_EQ(type, DataType::Type::kReference);
const int32_t element_size = DataType::Size(type);
const uint32_t element_size_shift = DataType::SizeShift(type);
if (copy_length.IsConstant()) {
int32_t constant = Int32ConstantFrom(copy_length);
__ Add(end, base, element_size * constant);
} else {
__ Add(end, base, Operand(RegisterFrom(copy_length), vixl32::LSL, element_size_shift));
}
}
// Slow path implementing the SystemArrayCopy intrinsic copy loop with read barriers.
class ReadBarrierSystemArrayCopySlowPathARMVIXL : public SlowPathCodeARMVIXL {
public:
explicit ReadBarrierSystemArrayCopySlowPathARMVIXL(HInstruction* instruction)
: SlowPathCodeARMVIXL(instruction) {
DCHECK(kEmitCompilerReadBarrier);
DCHECK(kUseBakerReadBarrier);
}
void EmitNativeCode(CodeGenerator* codegen) override {
CodeGeneratorARMVIXL* arm_codegen = down_cast<CodeGeneratorARMVIXL*>(codegen);
ArmVIXLAssembler* assembler = arm_codegen->GetAssembler();
LocationSummary* locations = instruction_->GetLocations();
DCHECK(locations->CanCall());
DCHECK(instruction_->IsInvokeStaticOrDirect())
<< "Unexpected instruction in read barrier arraycopy slow path: "
<< instruction_->DebugName();
DCHECK(instruction_->GetLocations()->Intrinsified());
DCHECK_EQ(instruction_->AsInvoke()->GetIntrinsic(), Intrinsics::kSystemArrayCopy);
DataType::Type type = DataType::Type::kReference;
const int32_t element_size = DataType::Size(type);
vixl32::Register dest = InputRegisterAt(instruction_, 2);
Location dest_pos = locations->InAt(3);
vixl32::Register src_curr_addr = RegisterFrom(locations->GetTemp(0));
vixl32::Register dst_curr_addr = RegisterFrom(locations->GetTemp(1));
vixl32::Register src_stop_addr = RegisterFrom(locations->GetTemp(2));
vixl32::Register tmp = RegisterFrom(locations->GetTemp(3));
__ Bind(GetEntryLabel());
// Compute the base destination address in `dst_curr_addr`.
GenSystemArrayCopyBaseAddress(assembler, type, dest, dest_pos, dst_curr_addr);
vixl32::Label loop;
__ Bind(&loop);
__ Ldr(tmp, MemOperand(src_curr_addr, element_size, PostIndex));
assembler->MaybeUnpoisonHeapReference(tmp);
// TODO: Inline the mark bit check before calling the runtime?
// tmp = ReadBarrier::Mark(tmp);
// No need to save live registers; it's taken care of by the
// entrypoint. Also, there is no need to update the stack mask,
// as this runtime call will not trigger a garbage collection.
// (See ReadBarrierMarkSlowPathARM::EmitNativeCode for more
// explanations.)
DCHECK(!tmp.IsSP());
DCHECK(!tmp.IsLR());
DCHECK(!tmp.IsPC());
// IP is used internally by the ReadBarrierMarkRegX entry point
// as a temporary (and not preserved). It thus cannot be used by
// any live register in this slow path.
DCHECK(!src_curr_addr.Is(ip));
DCHECK(!dst_curr_addr.Is(ip));
DCHECK(!src_stop_addr.Is(ip));
DCHECK(!tmp.Is(ip));
DCHECK(tmp.IsRegister()) << tmp;
// TODO: Load the entrypoint once before the loop, instead of
// loading it at every iteration.
int32_t entry_point_offset =
Thread::ReadBarrierMarkEntryPointsOffset<kArmPointerSize>(tmp.GetCode());
// This runtime call does not require a stack map.
arm_codegen->InvokeRuntimeWithoutRecordingPcInfo(entry_point_offset, instruction_, this);
assembler->MaybePoisonHeapReference(tmp);
__ Str(tmp, MemOperand(dst_curr_addr, element_size, PostIndex));
__ Cmp(src_curr_addr, src_stop_addr);
__ B(ne, &loop, /* far_target */ false);
__ B(GetExitLabel());
}
const char* GetDescription() const override {
return "ReadBarrierSystemArrayCopySlowPathARMVIXL";
}
private:
DISALLOW_COPY_AND_ASSIGN(ReadBarrierSystemArrayCopySlowPathARMVIXL);
};
IntrinsicLocationsBuilderARMVIXL::IntrinsicLocationsBuilderARMVIXL(CodeGeneratorARMVIXL* codegen)
: allocator_(codegen->GetGraph()->GetAllocator()),
codegen_(codegen),
assembler_(codegen->GetAssembler()),
features_(codegen->GetInstructionSetFeatures()) {}
bool IntrinsicLocationsBuilderARMVIXL::TryDispatch(HInvoke* invoke) {
Dispatch(invoke);
LocationSummary* res = invoke->GetLocations();
if (res == nullptr) {
return false;
}
return res->Intrinsified();
}
static void CreateFPToIntLocations(ArenaAllocator* allocator, HInvoke* invoke) {
LocationSummary* locations =
new (allocator) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
locations->SetInAt(0, Location::RequiresFpuRegister());
locations->SetOut(Location::RequiresRegister());
}
static void CreateIntToFPLocations(ArenaAllocator* allocator, HInvoke* invoke) {
LocationSummary* locations =
new (allocator) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
locations->SetInAt(0, Location::RequiresRegister());
locations->SetOut(Location::RequiresFpuRegister());
}
static void MoveFPToInt(LocationSummary* locations, bool is64bit, ArmVIXLAssembler* assembler) {
Location input = locations->InAt(0);
Location output = locations->Out();
if (is64bit) {
__ Vmov(LowRegisterFrom(output), HighRegisterFrom(output), DRegisterFrom(input));
} else {
__ Vmov(RegisterFrom(output), SRegisterFrom(input));
}
}
static void MoveIntToFP(LocationSummary* locations, bool is64bit, ArmVIXLAssembler* assembler) {
Location input = locations->InAt(0);
Location output = locations->Out();
if (is64bit) {
__ Vmov(DRegisterFrom(output), LowRegisterFrom(input), HighRegisterFrom(input));
} else {
__ Vmov(SRegisterFrom(output), RegisterFrom(input));
}
}
void IntrinsicLocationsBuilderARMVIXL::VisitDoubleDoubleToRawLongBits(HInvoke* invoke) {
CreateFPToIntLocations(allocator_, invoke);
}
void IntrinsicLocationsBuilderARMVIXL::VisitDoubleLongBitsToDouble(HInvoke* invoke) {
CreateIntToFPLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitDoubleDoubleToRawLongBits(HInvoke* invoke) {
MoveFPToInt(invoke->GetLocations(), /* is64bit */ true, GetAssembler());
}
void IntrinsicCodeGeneratorARMVIXL::VisitDoubleLongBitsToDouble(HInvoke* invoke) {
MoveIntToFP(invoke->GetLocations(), /* is64bit */ true, GetAssembler());
}
void IntrinsicLocationsBuilderARMVIXL::VisitFloatFloatToRawIntBits(HInvoke* invoke) {
CreateFPToIntLocations(allocator_, invoke);
}
void IntrinsicLocationsBuilderARMVIXL::VisitFloatIntBitsToFloat(HInvoke* invoke) {
CreateIntToFPLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitFloatFloatToRawIntBits(HInvoke* invoke) {
MoveFPToInt(invoke->GetLocations(), /* is64bit */ false, GetAssembler());
}
void IntrinsicCodeGeneratorARMVIXL::VisitFloatIntBitsToFloat(HInvoke* invoke) {
MoveIntToFP(invoke->GetLocations(), /* is64bit */ false, GetAssembler());
}
static void CreateIntToIntLocations(ArenaAllocator* allocator, HInvoke* invoke) {
LocationSummary* locations =
new (allocator) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
locations->SetInAt(0, Location::RequiresRegister());
locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
}
static void CreateLongToLongLocationsWithOverlap(ArenaAllocator* allocator, HInvoke* invoke) {
LocationSummary* locations =
new (allocator) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
locations->SetInAt(0, Location::RequiresRegister());
locations->SetOut(Location::RequiresRegister(), Location::kOutputOverlap);
}
static void CreateFPToFPLocations(ArenaAllocator* allocator, HInvoke* invoke) {
LocationSummary* locations =
new (allocator) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
locations->SetInAt(0, Location::RequiresFpuRegister());
locations->SetOut(Location::RequiresFpuRegister(), Location::kNoOutputOverlap);
}
static void GenNumberOfLeadingZeros(HInvoke* invoke,
DataType::Type type,
CodeGeneratorARMVIXL* codegen) {
ArmVIXLAssembler* assembler = codegen->GetAssembler();
LocationSummary* locations = invoke->GetLocations();
Location in = locations->InAt(0);
vixl32::Register out = RegisterFrom(locations->Out());
DCHECK((type == DataType::Type::kInt32) || (type == DataType::Type::kInt64));
if (type == DataType::Type::kInt64) {
vixl32::Register in_reg_lo = LowRegisterFrom(in);
vixl32::Register in_reg_hi = HighRegisterFrom(in);
vixl32::Label end;
vixl32::Label* final_label = codegen->GetFinalLabel(invoke, &end);
__ Clz(out, in_reg_hi);
__ CompareAndBranchIfNonZero(in_reg_hi, final_label, /* far_target */ false);
__ Clz(out, in_reg_lo);
__ Add(out, out, 32);
if (end.IsReferenced()) {
__ Bind(&end);
}
} else {
__ Clz(out, RegisterFrom(in));
}
}
void IntrinsicLocationsBuilderARMVIXL::VisitIntegerNumberOfLeadingZeros(HInvoke* invoke) {
CreateIntToIntLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitIntegerNumberOfLeadingZeros(HInvoke* invoke) {
GenNumberOfLeadingZeros(invoke, DataType::Type::kInt32, codegen_);
}
void IntrinsicLocationsBuilderARMVIXL::VisitLongNumberOfLeadingZeros(HInvoke* invoke) {
CreateLongToLongLocationsWithOverlap(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitLongNumberOfLeadingZeros(HInvoke* invoke) {
GenNumberOfLeadingZeros(invoke, DataType::Type::kInt64, codegen_);
}
static void GenNumberOfTrailingZeros(HInvoke* invoke,
DataType::Type type,
CodeGeneratorARMVIXL* codegen) {
DCHECK((type == DataType::Type::kInt32) || (type == DataType::Type::kInt64));
ArmVIXLAssembler* assembler = codegen->GetAssembler();
LocationSummary* locations = invoke->GetLocations();
vixl32::Register out = RegisterFrom(locations->Out());
if (type == DataType::Type::kInt64) {
vixl32::Register in_reg_lo = LowRegisterFrom(locations->InAt(0));
vixl32::Register in_reg_hi = HighRegisterFrom(locations->InAt(0));
vixl32::Label end;
vixl32::Label* final_label = codegen->GetFinalLabel(invoke, &end);
__ Rbit(out, in_reg_lo);
__ Clz(out, out);
__ CompareAndBranchIfNonZero(in_reg_lo, final_label, /* far_target */ false);
__ Rbit(out, in_reg_hi);
__ Clz(out, out);
__ Add(out, out, 32);
if (end.IsReferenced()) {
__ Bind(&end);
}
} else {
vixl32::Register in = RegisterFrom(locations->InAt(0));
__ Rbit(out, in);
__ Clz(out, out);
}
}
void IntrinsicLocationsBuilderARMVIXL::VisitIntegerNumberOfTrailingZeros(HInvoke* invoke) {
CreateIntToIntLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitIntegerNumberOfTrailingZeros(HInvoke* invoke) {
GenNumberOfTrailingZeros(invoke, DataType::Type::kInt32, codegen_);
}
void IntrinsicLocationsBuilderARMVIXL::VisitLongNumberOfTrailingZeros(HInvoke* invoke) {
CreateLongToLongLocationsWithOverlap(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitLongNumberOfTrailingZeros(HInvoke* invoke) {
GenNumberOfTrailingZeros(invoke, DataType::Type::kInt64, codegen_);
}
void IntrinsicLocationsBuilderARMVIXL::VisitMathSqrt(HInvoke* invoke) {
CreateFPToFPLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitMathSqrt(HInvoke* invoke) {
ArmVIXLAssembler* assembler = GetAssembler();
__ Vsqrt(OutputDRegister(invoke), InputDRegisterAt(invoke, 0));
}
void IntrinsicLocationsBuilderARMVIXL::VisitMathRint(HInvoke* invoke) {
if (features_.HasARMv8AInstructions()) {
CreateFPToFPLocations(allocator_, invoke);
}
}
void IntrinsicCodeGeneratorARMVIXL::VisitMathRint(HInvoke* invoke) {
DCHECK(codegen_->GetInstructionSetFeatures().HasARMv8AInstructions());
ArmVIXLAssembler* assembler = GetAssembler();
__ Vrintn(F64, OutputDRegister(invoke), InputDRegisterAt(invoke, 0));
}
void IntrinsicLocationsBuilderARMVIXL::VisitMathRoundFloat(HInvoke* invoke) {
if (features_.HasARMv8AInstructions()) {
LocationSummary* locations =
new (allocator_) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
locations->SetInAt(0, Location::RequiresFpuRegister());
locations->SetOut(Location::RequiresRegister());
locations->AddTemp(Location::RequiresFpuRegister());
}
}
void IntrinsicCodeGeneratorARMVIXL::VisitMathRoundFloat(HInvoke* invoke) {
DCHECK(codegen_->GetInstructionSetFeatures().HasARMv8AInstructions());
ArmVIXLAssembler* assembler = GetAssembler();
vixl32::SRegister in_reg = InputSRegisterAt(invoke, 0);
vixl32::Register out_reg = OutputRegister(invoke);
vixl32::SRegister temp1 = LowSRegisterFrom(invoke->GetLocations()->GetTemp(0));
vixl32::SRegister temp2 = HighSRegisterFrom(invoke->GetLocations()->GetTemp(0));
vixl32::Label done;
vixl32::Label* final_label = codegen_->GetFinalLabel(invoke, &done);
// Round to nearest integer, ties away from zero.
__ Vcvta(S32, F32, temp1, in_reg);
__ Vmov(out_reg, temp1);
// For positive, zero or NaN inputs, rounding is done.
__ Cmp(out_reg, 0);
__ B(ge, final_label, /* far_target */ false);
// Handle input < 0 cases.
// If input is negative but not a tie, previous result (round to nearest) is valid.
// If input is a negative tie, change rounding direction to positive infinity, out_reg += 1.
__ Vrinta(F32, temp1, in_reg);
__ Vmov(temp2, 0.5);
__ Vsub(F32, temp1, in_reg, temp1);
__ Vcmp(F32, temp1, temp2);
__ Vmrs(RegisterOrAPSR_nzcv(kPcCode), FPSCR);
{
// Use ExactAsemblyScope here because we are using IT.
ExactAssemblyScope it_scope(assembler->GetVIXLAssembler(),
2 * kMaxInstructionSizeInBytes,
CodeBufferCheckScope::kMaximumSize);
__ it(eq);
__ add(eq, out_reg, out_reg, 1);
}
if (done.IsReferenced()) {
__ Bind(&done);
}
}
void IntrinsicLocationsBuilderARMVIXL::VisitMemoryPeekByte(HInvoke* invoke) {
CreateIntToIntLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitMemoryPeekByte(HInvoke* invoke) {
ArmVIXLAssembler* assembler = GetAssembler();
// Ignore upper 4B of long address.
__ Ldrsb(OutputRegister(invoke), MemOperand(LowRegisterFrom(invoke->GetLocations()->InAt(0))));
}
void IntrinsicLocationsBuilderARMVIXL::VisitMemoryPeekIntNative(HInvoke* invoke) {
CreateIntToIntLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitMemoryPeekIntNative(HInvoke* invoke) {
ArmVIXLAssembler* assembler = GetAssembler();
// Ignore upper 4B of long address.
__ Ldr(OutputRegister(invoke), MemOperand(LowRegisterFrom(invoke->GetLocations()->InAt(0))));
}
void IntrinsicLocationsBuilderARMVIXL::VisitMemoryPeekLongNative(HInvoke* invoke) {
CreateIntToIntLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitMemoryPeekLongNative(HInvoke* invoke) {
ArmVIXLAssembler* assembler = GetAssembler();
// Ignore upper 4B of long address.
vixl32::Register addr = LowRegisterFrom(invoke->GetLocations()->InAt(0));
// Worst case: Control register bit SCTLR.A = 0. Then unaligned accesses throw a processor
// exception. So we can't use ldrd as addr may be unaligned.
vixl32::Register lo = LowRegisterFrom(invoke->GetLocations()->Out());
vixl32::Register hi = HighRegisterFrom(invoke->GetLocations()->Out());
if (addr.Is(lo)) {
__ Ldr(hi, MemOperand(addr, 4));
__ Ldr(lo, MemOperand(addr));
} else {
__ Ldr(lo, MemOperand(addr));
__ Ldr(hi, MemOperand(addr, 4));
}
}
void IntrinsicLocationsBuilderARMVIXL::VisitMemoryPeekShortNative(HInvoke* invoke) {
CreateIntToIntLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitMemoryPeekShortNative(HInvoke* invoke) {
ArmVIXLAssembler* assembler = GetAssembler();
// Ignore upper 4B of long address.
__ Ldrsh(OutputRegister(invoke), MemOperand(LowRegisterFrom(invoke->GetLocations()->InAt(0))));
}
static void CreateIntIntToVoidLocations(ArenaAllocator* allocator, HInvoke* invoke) {
LocationSummary* locations =
new (allocator) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
locations->SetInAt(0, Location::RequiresRegister());
locations->SetInAt(1, Location::RequiresRegister());
}
void IntrinsicLocationsBuilderARMVIXL::VisitMemoryPokeByte(HInvoke* invoke) {
CreateIntIntToVoidLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitMemoryPokeByte(HInvoke* invoke) {
ArmVIXLAssembler* assembler = GetAssembler();
__ Strb(InputRegisterAt(invoke, 1), MemOperand(LowRegisterFrom(invoke->GetLocations()->InAt(0))));
}
void IntrinsicLocationsBuilderARMVIXL::VisitMemoryPokeIntNative(HInvoke* invoke) {
CreateIntIntToVoidLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitMemoryPokeIntNative(HInvoke* invoke) {
ArmVIXLAssembler* assembler = GetAssembler();
__ Str(InputRegisterAt(invoke, 1), MemOperand(LowRegisterFrom(invoke->GetLocations()->InAt(0))));
}
void IntrinsicLocationsBuilderARMVIXL::VisitMemoryPokeLongNative(HInvoke* invoke) {
CreateIntIntToVoidLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitMemoryPokeLongNative(HInvoke* invoke) {
ArmVIXLAssembler* assembler = GetAssembler();
// Ignore upper 4B of long address.
vixl32::Register addr = LowRegisterFrom(invoke->GetLocations()->InAt(0));
// Worst case: Control register bit SCTLR.A = 0. Then unaligned accesses throw a processor
// exception. So we can't use ldrd as addr may be unaligned.
__ Str(LowRegisterFrom(invoke->GetLocations()->InAt(1)), MemOperand(addr));
__ Str(HighRegisterFrom(invoke->GetLocations()->InAt(1)), MemOperand(addr, 4));
}
void IntrinsicLocationsBuilderARMVIXL::VisitMemoryPokeShortNative(HInvoke* invoke) {
CreateIntIntToVoidLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitMemoryPokeShortNative(HInvoke* invoke) {
ArmVIXLAssembler* assembler = GetAssembler();
__ Strh(InputRegisterAt(invoke, 1), MemOperand(LowRegisterFrom(invoke->GetLocations()->InAt(0))));
}
void IntrinsicLocationsBuilderARMVIXL::VisitThreadCurrentThread(HInvoke* invoke) {
LocationSummary* locations =
new (allocator_) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
locations->SetOut(Location::RequiresRegister());
}
void IntrinsicCodeGeneratorARMVIXL::VisitThreadCurrentThread(HInvoke* invoke) {
ArmVIXLAssembler* assembler = GetAssembler();
__ Ldr(OutputRegister(invoke),
MemOperand(tr, Thread::PeerOffset<kArmPointerSize>().Int32Value()));
}
static void GenUnsafeGet(HInvoke* invoke,
DataType::Type type,
bool is_volatile,
CodeGeneratorARMVIXL* codegen) {
LocationSummary* locations = invoke->GetLocations();
ArmVIXLAssembler* assembler = codegen->GetAssembler();
Location base_loc = locations->InAt(1);
vixl32::Register base = InputRegisterAt(invoke, 1); // Object pointer.
Location offset_loc = locations->InAt(2);
vixl32::Register offset = LowRegisterFrom(offset_loc); // Long offset, lo part only.
Location trg_loc = locations->Out();
switch (type) {
case DataType::Type::kInt32: {
vixl32::Register trg = RegisterFrom(trg_loc);
__ Ldr(trg, MemOperand(base, offset));
if (is_volatile) {
__ Dmb(vixl32::ISH);
}
break;
}
case DataType::Type::kReference: {
vixl32::Register trg = RegisterFrom(trg_loc);
if (kEmitCompilerReadBarrier) {
if (kUseBakerReadBarrier) {
Location temp = locations->GetTemp(0);
// Piggy-back on the field load path using introspection for the Baker read barrier.
__ Add(RegisterFrom(temp), base, Operand(offset));
MemOperand src(RegisterFrom(temp), 0);
codegen->GenerateFieldLoadWithBakerReadBarrier(
invoke, trg_loc, base, src, /* needs_null_check */ false);
if (is_volatile) {
__ Dmb(vixl32::ISH);
}
} else {
__ Ldr(trg, MemOperand(base, offset));
if (is_volatile) {
__ Dmb(vixl32::ISH);
}
codegen->GenerateReadBarrierSlow(invoke, trg_loc, trg_loc, base_loc, 0U, offset_loc);
}
} else {
__ Ldr(trg, MemOperand(base, offset));
if (is_volatile) {
__ Dmb(vixl32::ISH);
}
assembler->MaybeUnpoisonHeapReference(trg);
}
break;
}
case DataType::Type::kInt64: {
vixl32::Register trg_lo = LowRegisterFrom(trg_loc);
vixl32::Register trg_hi = HighRegisterFrom(trg_loc);
if (is_volatile && !codegen->GetInstructionSetFeatures().HasAtomicLdrdAndStrd()) {
UseScratchRegisterScope temps(assembler->GetVIXLAssembler());
const vixl32::Register temp_reg = temps.Acquire();
__ Add(temp_reg, base, offset);
__ Ldrexd(trg_lo, trg_hi, MemOperand(temp_reg));
} else {
__ Ldrd(trg_lo, trg_hi, MemOperand(base, offset));
}
if (is_volatile) {
__ Dmb(vixl32::ISH);
}
break;
}
default:
LOG(FATAL) << "Unexpected type " << type;
UNREACHABLE();
}
}
static void CreateIntIntIntToIntLocations(ArenaAllocator* allocator,
HInvoke* invoke,
DataType::Type type) {
bool can_call = kEmitCompilerReadBarrier &&
(invoke->GetIntrinsic() == Intrinsics::kUnsafeGetObject ||
invoke->GetIntrinsic() == Intrinsics::kUnsafeGetObjectVolatile);
LocationSummary* locations =
new (allocator) LocationSummary(invoke,
can_call
? LocationSummary::kCallOnSlowPath
: LocationSummary::kNoCall,
kIntrinsified);
if (can_call && kUseBakerReadBarrier) {
locations->SetCustomSlowPathCallerSaves(RegisterSet::Empty()); // No caller-save registers.
}
locations->SetInAt(0, Location::NoLocation()); // Unused receiver.
locations->SetInAt(1, Location::RequiresRegister());
locations->SetInAt(2, Location::RequiresRegister());
locations->SetOut(Location::RequiresRegister(),
(can_call ? Location::kOutputOverlap : Location::kNoOutputOverlap));
if (type == DataType::Type::kReference && kEmitCompilerReadBarrier && kUseBakerReadBarrier) {
// We need a temporary register for the read barrier marking slow
// path in CodeGeneratorARMVIXL::GenerateReferenceLoadWithBakerReadBarrier.
locations->AddTemp(Location::RequiresRegister());
}
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafeGet(HInvoke* invoke) {
CreateIntIntIntToIntLocations(allocator_, invoke, DataType::Type::kInt32);
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafeGetVolatile(HInvoke* invoke) {
CreateIntIntIntToIntLocations(allocator_, invoke, DataType::Type::kInt32);
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafeGetLong(HInvoke* invoke) {
CreateIntIntIntToIntLocations(allocator_, invoke, DataType::Type::kInt64);
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafeGetLongVolatile(HInvoke* invoke) {
CreateIntIntIntToIntLocations(allocator_, invoke, DataType::Type::kInt64);
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafeGetObject(HInvoke* invoke) {
CreateIntIntIntToIntLocations(allocator_, invoke, DataType::Type::kReference);
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafeGetObjectVolatile(HInvoke* invoke) {
CreateIntIntIntToIntLocations(allocator_, invoke, DataType::Type::kReference);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafeGet(HInvoke* invoke) {
GenUnsafeGet(invoke, DataType::Type::kInt32, /* is_volatile */ false, codegen_);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafeGetVolatile(HInvoke* invoke) {
GenUnsafeGet(invoke, DataType::Type::kInt32, /* is_volatile */ true, codegen_);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafeGetLong(HInvoke* invoke) {
GenUnsafeGet(invoke, DataType::Type::kInt64, /* is_volatile */ false, codegen_);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafeGetLongVolatile(HInvoke* invoke) {
GenUnsafeGet(invoke, DataType::Type::kInt64, /* is_volatile */ true, codegen_);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafeGetObject(HInvoke* invoke) {
GenUnsafeGet(invoke, DataType::Type::kReference, /* is_volatile */ false, codegen_);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafeGetObjectVolatile(HInvoke* invoke) {
GenUnsafeGet(invoke, DataType::Type::kReference, /* is_volatile */ true, codegen_);
}
static void CreateIntIntIntIntToVoid(ArenaAllocator* allocator,
const ArmInstructionSetFeatures& features,
DataType::Type type,
bool is_volatile,
HInvoke* invoke) {
LocationSummary* locations =
new (allocator) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
locations->SetInAt(0, Location::NoLocation()); // Unused receiver.
locations->SetInAt(1, Location::RequiresRegister());
locations->SetInAt(2, Location::RequiresRegister());
locations->SetInAt(3, Location::RequiresRegister());
if (type == DataType::Type::kInt64) {
// Potentially need temps for ldrexd-strexd loop.
if (is_volatile && !features.HasAtomicLdrdAndStrd()) {
locations->AddTemp(Location::RequiresRegister()); // Temp_lo.
locations->AddTemp(Location::RequiresRegister()); // Temp_hi.
}
} else if (type == DataType::Type::kReference) {
// Temps for card-marking.
locations->AddTemp(Location::RequiresRegister()); // Temp.
locations->AddTemp(Location::RequiresRegister()); // Card.
}
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafePut(HInvoke* invoke) {
CreateIntIntIntIntToVoid(
allocator_, features_, DataType::Type::kInt32, /* is_volatile */ false, invoke);
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafePutOrdered(HInvoke* invoke) {
CreateIntIntIntIntToVoid(
allocator_, features_, DataType::Type::kInt32, /* is_volatile */ false, invoke);
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafePutVolatile(HInvoke* invoke) {
CreateIntIntIntIntToVoid(
allocator_, features_, DataType::Type::kInt32, /* is_volatile */ true, invoke);
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafePutObject(HInvoke* invoke) {
CreateIntIntIntIntToVoid(
allocator_, features_, DataType::Type::kReference, /* is_volatile */ false, invoke);
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafePutObjectOrdered(HInvoke* invoke) {
CreateIntIntIntIntToVoid(
allocator_, features_, DataType::Type::kReference, /* is_volatile */ false, invoke);
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafePutObjectVolatile(HInvoke* invoke) {
CreateIntIntIntIntToVoid(
allocator_, features_, DataType::Type::kReference, /* is_volatile */ true, invoke);
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafePutLong(HInvoke* invoke) {
CreateIntIntIntIntToVoid(
allocator_, features_, DataType::Type::kInt64, /* is_volatile */ false, invoke);
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafePutLongOrdered(HInvoke* invoke) {
CreateIntIntIntIntToVoid(
allocator_, features_, DataType::Type::kInt64, /* is_volatile */ false, invoke);
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafePutLongVolatile(HInvoke* invoke) {
CreateIntIntIntIntToVoid(
allocator_, features_, DataType::Type::kInt64, /* is_volatile */ true, invoke);
}
static void GenUnsafePut(LocationSummary* locations,
DataType::Type type,
bool is_volatile,
bool is_ordered,
CodeGeneratorARMVIXL* codegen) {
ArmVIXLAssembler* assembler = codegen->GetAssembler();
vixl32::Register base = RegisterFrom(locations->InAt(1)); // Object pointer.
vixl32::Register offset = LowRegisterFrom(locations->InAt(2)); // Long offset, lo part only.
vixl32::Register value;
if (is_volatile || is_ordered) {
__ Dmb(vixl32::ISH);
}
if (type == DataType::Type::kInt64) {
vixl32::Register value_lo = LowRegisterFrom(locations->InAt(3));
vixl32::Register value_hi = HighRegisterFrom(locations->InAt(3));
value = value_lo;
if (is_volatile && !codegen->GetInstructionSetFeatures().HasAtomicLdrdAndStrd()) {
vixl32::Register temp_lo = RegisterFrom(locations->GetTemp(0));
vixl32::Register temp_hi = RegisterFrom(locations->GetTemp(1));
UseScratchRegisterScope temps(assembler->GetVIXLAssembler());
const vixl32::Register temp_reg = temps.Acquire();
__ Add(temp_reg, base, offset);
vixl32::Label loop_head;
__ Bind(&loop_head);
__ Ldrexd(temp_lo, temp_hi, MemOperand(temp_reg));
__ Strexd(temp_lo, value_lo, value_hi, MemOperand(temp_reg));
__ Cmp(temp_lo, 0);
__ B(ne, &loop_head, /* far_target */ false);
} else {
__ Strd(value_lo, value_hi, MemOperand(base, offset));
}
} else {
value = RegisterFrom(locations->InAt(3));
vixl32::Register source = value;
if (kPoisonHeapReferences && type == DataType::Type::kReference) {
vixl32::Register temp = RegisterFrom(locations->GetTemp(0));
__ Mov(temp, value);
assembler->PoisonHeapReference(temp);
source = temp;
}
__ Str(source, MemOperand(base, offset));
}
if (is_volatile) {
__ Dmb(vixl32::ISH);
}
if (type == DataType::Type::kReference) {
vixl32::Register temp = RegisterFrom(locations->GetTemp(0));
vixl32::Register card = RegisterFrom(locations->GetTemp(1));
bool value_can_be_null = true; // TODO: Worth finding out this information?
codegen->MarkGCCard(temp, card, base, value, value_can_be_null);
}
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafePut(HInvoke* invoke) {
GenUnsafePut(invoke->GetLocations(),
DataType::Type::kInt32,
/* is_volatile */ false,
/* is_ordered */ false,
codegen_);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafePutOrdered(HInvoke* invoke) {
GenUnsafePut(invoke->GetLocations(),
DataType::Type::kInt32,
/* is_volatile */ false,
/* is_ordered */ true,
codegen_);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafePutVolatile(HInvoke* invoke) {
GenUnsafePut(invoke->GetLocations(),
DataType::Type::kInt32,
/* is_volatile */ true,
/* is_ordered */ false,
codegen_);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafePutObject(HInvoke* invoke) {
GenUnsafePut(invoke->GetLocations(),
DataType::Type::kReference,
/* is_volatile */ false,
/* is_ordered */ false,
codegen_);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafePutObjectOrdered(HInvoke* invoke) {
GenUnsafePut(invoke->GetLocations(),
DataType::Type::kReference,
/* is_volatile */ false,
/* is_ordered */ true,
codegen_);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafePutObjectVolatile(HInvoke* invoke) {
GenUnsafePut(invoke->GetLocations(),
DataType::Type::kReference,
/* is_volatile */ true,
/* is_ordered */ false,
codegen_);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafePutLong(HInvoke* invoke) {
GenUnsafePut(invoke->GetLocations(),
DataType::Type::kInt64,
/* is_volatile */ false,
/* is_ordered */ false,
codegen_);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafePutLongOrdered(HInvoke* invoke) {
GenUnsafePut(invoke->GetLocations(),
DataType::Type::kInt64,
/* is_volatile */ false,
/* is_ordered */ true,
codegen_);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafePutLongVolatile(HInvoke* invoke) {
GenUnsafePut(invoke->GetLocations(),
DataType::Type::kInt64,
/* is_volatile */ true,
/* is_ordered */ false,
codegen_);
}
static void CreateIntIntIntIntIntToIntPlusTemps(ArenaAllocator* allocator, HInvoke* invoke) {
bool can_call = kEmitCompilerReadBarrier &&
kUseBakerReadBarrier &&
(invoke->GetIntrinsic() == Intrinsics::kUnsafeCASObject);
LocationSummary* locations =
new (allocator) LocationSummary(invoke,
can_call
? LocationSummary::kCallOnSlowPath
: LocationSummary::kNoCall,
kIntrinsified);
if (can_call) {
locations->SetCustomSlowPathCallerSaves(RegisterSet::Empty()); // No caller-save registers.
}
locations->SetInAt(0, Location::NoLocation()); // Unused receiver.
locations->SetInAt(1, Location::RequiresRegister());
locations->SetInAt(2, Location::RequiresRegister());
locations->SetInAt(3, Location::RequiresRegister());
locations->SetInAt(4, Location::RequiresRegister());
locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
// Temporary registers used in CAS. In the object case
// (UnsafeCASObject intrinsic), these are also used for
// card-marking, and possibly for (Baker) read barrier.
locations->AddTemp(Location::RequiresRegister()); // Pointer.
locations->AddTemp(Location::RequiresRegister()); // Temp 1.
}
class BakerReadBarrierCasSlowPathARMVIXL : public SlowPathCodeARMVIXL {
public:
explicit BakerReadBarrierCasSlowPathARMVIXL(HInvoke* invoke)
: SlowPathCodeARMVIXL(invoke) {}
const char* GetDescription() const override { return "BakerReadBarrierCasSlowPathARMVIXL"; }
void EmitNativeCode(CodeGenerator* codegen) override {
CodeGeneratorARMVIXL* arm_codegen = down_cast<CodeGeneratorARMVIXL*>(codegen);
ArmVIXLAssembler* assembler = arm_codegen->GetAssembler();
__ Bind(GetEntryLabel());
LocationSummary* locations = instruction_->GetLocations();
vixl32::Register base = InputRegisterAt(instruction_, 1); // Object pointer.
vixl32::Register offset = LowRegisterFrom(locations->InAt(2)); // Offset (discard high 4B).
vixl32::Register expected = InputRegisterAt(instruction_, 3); // Expected.
vixl32::Register value = InputRegisterAt(instruction_, 4); // Value.
vixl32::Register tmp_ptr = RegisterFrom(locations->GetTemp(0)); // Pointer to actual memory.
vixl32::Register tmp = RegisterFrom(locations->GetTemp(1)); // Temporary.
// The `tmp` is initialized to `[tmp_ptr] - expected` in the main path. Reconstruct
// and mark the old value and compare with `expected`. We clobber `tmp_ptr` in the
// process due to lack of other temps suitable for the read barrier.
arm_codegen->GenerateUnsafeCasOldValueAddWithBakerReadBarrier(tmp_ptr, tmp, expected);
__ Cmp(tmp_ptr, expected);
__ B(ne, GetExitLabel());
// The old value we have read did not match `expected` (which is always a to-space reference)
// but after the read barrier in GenerateUnsafeCasOldValueAddWithBakerReadBarrier() the marked
// to-space value matched, so the old value must be a from-space reference to the same object.
// Do the same CAS loop as the main path but check for both `expected` and the unmarked
// old value representing the to-space and from-space references for the same object.
UseScratchRegisterScope temps(assembler->GetVIXLAssembler());
vixl32::Register adjusted_old_value = temps.Acquire(); // For saved `tmp` from main path.
// Recalculate the `tmp_ptr` clobbered above and store the `adjusted_old_value`, i.e. IP.
__ Add(tmp_ptr, base, offset);
__ Mov(adjusted_old_value, tmp);
// do {
// tmp = [r_ptr] - expected;
// } while ((tmp == 0 || tmp == adjusted_old_value) && failure([r_ptr] <- r_new_value));
// result = (tmp == 0 || tmp == adjusted_old_value);
vixl32::Label loop_head;
__ Bind(&loop_head);
__ Ldrex(tmp, MemOperand(tmp_ptr)); // This can now load null stored by another thread.
assembler->MaybeUnpoisonHeapReference(tmp);
__ Subs(tmp, tmp, expected); // Use SUBS to get non-zero value if both compares fail.
{
// If the newly loaded value did not match `expected`, compare with `adjusted_old_value`.
ExactAssemblyScope aas(assembler->GetVIXLAssembler(), 2 * k16BitT32InstructionSizeInBytes);
__ it(ne);
__ cmp(ne, tmp, adjusted_old_value);
}
__ B(ne, GetExitLabel());
assembler->MaybePoisonHeapReference(value);
__ Strex(tmp, value, MemOperand(tmp_ptr));
assembler->MaybeUnpoisonHeapReference(value);
__ Cmp(tmp, 0);
__ B(ne, &loop_head, /* far_target */ false);
__ B(GetExitLabel());
}
};
static void GenCas(HInvoke* invoke, DataType::Type type, CodeGeneratorARMVIXL* codegen) {
DCHECK_NE(type, DataType::Type::kInt64);
ArmVIXLAssembler* assembler = codegen->GetAssembler();
LocationSummary* locations = invoke->GetLocations();
vixl32::Register out = OutputRegister(invoke); // Boolean result.
vixl32::Register base = InputRegisterAt(invoke, 1); // Object pointer.
vixl32::Register offset = LowRegisterFrom(locations->InAt(2)); // Offset (discard high 4B).
vixl32::Register expected = InputRegisterAt(invoke, 3); // Expected.
vixl32::Register value = InputRegisterAt(invoke, 4); // Value.
vixl32::Register tmp_ptr = RegisterFrom(locations->GetTemp(0)); // Pointer to actual memory.
vixl32::Register tmp = RegisterFrom(locations->GetTemp(1)); // Temporary.
vixl32::Label loop_exit_label;
vixl32::Label* loop_exit = &loop_exit_label;
vixl32::Label* failure = &loop_exit_label;
if (type == DataType::Type::kReference) {
// The only read barrier implementation supporting the
// UnsafeCASObject intrinsic is the Baker-style read barriers.
DCHECK(!kEmitCompilerReadBarrier || kUseBakerReadBarrier);
// Mark card for object assuming new value is stored. Worst case we will mark an unchanged
// object and scan the receiver at the next GC for nothing.
bool value_can_be_null = true; // TODO: Worth finding out this information?
codegen->MarkGCCard(tmp_ptr, tmp, base, value, value_can_be_null);
if (kEmitCompilerReadBarrier && kUseBakerReadBarrier) {
// If marking, check if the stored reference is a from-space reference to the same
// object as the to-space reference `expected`. If so, perform a custom CAS loop.
BakerReadBarrierCasSlowPathARMVIXL* slow_path =
new (codegen->GetScopedAllocator()) BakerReadBarrierCasSlowPathARMVIXL(invoke);
codegen->AddSlowPath(slow_path);
failure = slow_path->GetEntryLabel();
loop_exit = slow_path->GetExitLabel();
}
}
// Prevent reordering with prior memory operations.
// Emit a DMB ISH instruction instead of an DMB ISHST one, as the
// latter allows a preceding load to be delayed past the STREX
// instruction below.
__ Dmb(vixl32::ISH);
__ Add(tmp_ptr, base, offset);
// do {
// tmp = [r_ptr] - expected;
// } while (tmp == 0 && failure([r_ptr] <- r_new_value));
// result = tmp == 0;
vixl32::Label loop_head;
__ Bind(&loop_head);
__ Ldrex(tmp, MemOperand(tmp_ptr));
if (type == DataType::Type::kReference) {
assembler->MaybeUnpoisonHeapReference(tmp);
}
__ Subs(tmp, tmp, expected);
static_cast<vixl32::MacroAssembler*>(assembler->GetVIXLAssembler())->
B(ne, failure, /* hint= */ (failure == loop_exit) ? kNear : kBranchWithoutHint);
if (type == DataType::Type::kReference) {
assembler->MaybePoisonHeapReference(value);
}
__ Strex(tmp, value, MemOperand(tmp_ptr));
if (type == DataType::Type::kReference) {
assembler->MaybeUnpoisonHeapReference(value);
}
__ Cmp(tmp, 0);
__ B(ne, &loop_head, /* far_target */ false);
__ Bind(loop_exit);
__ Dmb(vixl32::ISH);
// out = tmp == 0.
__ Clz(out, tmp);
__ Lsr(out, out, WhichPowerOf2(out.GetSizeInBits()));
if (type == DataType::Type::kReference) {
codegen->MaybeGenerateMarkingRegisterCheck(/* code */ 128);
}
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafeCASInt(HInvoke* invoke) {
CreateIntIntIntIntIntToIntPlusTemps(allocator_, invoke);
}
void IntrinsicLocationsBuilderARMVIXL::VisitUnsafeCASObject(HInvoke* invoke) {
// The only read barrier implementation supporting the
// UnsafeCASObject intrinsic is the Baker-style read barriers.
if (kEmitCompilerReadBarrier && !kUseBakerReadBarrier) {
return;
}
CreateIntIntIntIntIntToIntPlusTemps(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafeCASInt(HInvoke* invoke) {
GenCas(invoke, DataType::Type::kInt32, codegen_);
}
void IntrinsicCodeGeneratorARMVIXL::VisitUnsafeCASObject(HInvoke* invoke) {
// The only read barrier implementation supporting the
// UnsafeCASObject intrinsic is the Baker-style read barriers.
DCHECK(!kEmitCompilerReadBarrier || kUseBakerReadBarrier);
GenCas(invoke, DataType::Type::kReference, codegen_);
}
void IntrinsicLocationsBuilderARMVIXL::VisitStringCompareTo(HInvoke* invoke) {
// The inputs plus one temp.
LocationSummary* locations =
new (allocator_) LocationSummary(invoke,
invoke->InputAt(1)->CanBeNull()
? LocationSummary::kCallOnSlowPath
: LocationSummary::kNoCall,
kIntrinsified);
locations->SetInAt(0, Location::RequiresRegister());
locations->SetInAt(1, Location::RequiresRegister());
locations->AddTemp(Location::RequiresRegister());
locations->AddTemp(Location::RequiresRegister());
locations->AddTemp(Location::RequiresRegister());
// Need temporary registers for String compression's feature.
if (mirror::kUseStringCompression) {
locations->AddTemp(Location::RequiresRegister());
}
locations->SetOut(Location::RequiresRegister(), Location::kOutputOverlap);
}
// Forward declaration.
//
// ART build system imposes a size limit (deviceFrameSizeLimit) on the stack frames generated
// by the compiler for every C++ function, and if this function gets inlined in
// IntrinsicCodeGeneratorARMVIXL::VisitStringCompareTo, the limit will be exceeded, resulting in a
// build failure. That is the reason why NO_INLINE attribute is used.
static void NO_INLINE GenerateStringCompareToLoop(ArmVIXLAssembler* assembler,
HInvoke* invoke,
vixl32::Label* end,
vixl32::Label* different_compression);
void IntrinsicCodeGeneratorARMVIXL::VisitStringCompareTo(HInvoke* invoke) {
ArmVIXLAssembler* assembler = GetAssembler();
LocationSummary* locations = invoke->GetLocations();
const vixl32::Register str = InputRegisterAt(invoke, 0);
const vixl32::Register arg = InputRegisterAt(invoke, 1);
const vixl32::Register out = OutputRegister(invoke);
const vixl32::Register temp0 = RegisterFrom(locations->GetTemp(0));
const vixl32::Register temp1 = RegisterFrom(locations->GetTemp(1));
const vixl32::Register temp2 = RegisterFrom(locations->GetTemp(2));
vixl32::Register temp3;
if (mirror::kUseStringCompression) {
temp3 = RegisterFrom(locations->GetTemp(3));
}
vixl32::Label end;
vixl32::Label different_compression;
// Get offsets of count and value fields within a string object.
const int32_t count_offset = mirror::String::CountOffset().Int32Value();
// Note that the null check must have been done earlier.
DCHECK(!invoke->CanDoImplicitNullCheckOn(invoke->InputAt(0)));
// Take slow path and throw if input can be and is null.
SlowPathCodeARMVIXL* slow_path = nullptr;
const bool can_slow_path = invoke->InputAt(1)->CanBeNull();
if (can_slow_path) {
slow_path = new (codegen_->GetScopedAllocator()) IntrinsicSlowPathARMVIXL(invoke);
codegen_->AddSlowPath(slow_path);
__ CompareAndBranchIfZero(arg, slow_path->GetEntryLabel());
}
// Reference equality check, return 0 if same reference.
__ Subs(out, str, arg);
__ B(eq, &end);
if (mirror::kUseStringCompression) {
// Load `count` fields of this and argument strings.
__ Ldr(temp3, MemOperand(str, count_offset));
__ Ldr(temp2, MemOperand(arg, count_offset));
// Extract lengths from the `count` fields.
__ Lsr(temp0, temp3, 1u);
__ Lsr(temp1, temp2, 1u);
} else {
// Load lengths of this and argument strings.
__ Ldr(temp0, MemOperand(str, count_offset));
__ Ldr(temp1, MemOperand(arg, count_offset));
}
// out = length diff.
__ Subs(out, temp0, temp1);
// temp0 = min(len(str), len(arg)).
{
ExactAssemblyScope aas(assembler->GetVIXLAssembler(),
2 * kMaxInstructionSizeInBytes,
CodeBufferCheckScope::kMaximumSize);
__ it(gt);
__ mov(gt, temp0, temp1);
}
// Shorter string is empty?
// Note that mirror::kUseStringCompression==true introduces lots of instructions,
// which makes &end label far away from this branch and makes it not 'CBZ-encodable'.
__ CompareAndBranchIfZero(temp0, &end, mirror::kUseStringCompression);
if (mirror::kUseStringCompression) {
// Check if both strings using same compression style to use this comparison loop.
__ Eors(temp2, temp2, temp3);
__ Lsrs(temp2, temp2, 1u);
__ B(cs, &different_compression);
// For string compression, calculate the number of bytes to compare (not chars).
// This could in theory exceed INT32_MAX, so treat temp0 as unsigned.
__ Lsls(temp3, temp3, 31u); // Extract purely the compression flag.
ExactAssemblyScope aas(assembler->GetVIXLAssembler(),
2 * kMaxInstructionSizeInBytes,
CodeBufferCheckScope::kMaximumSize);
__ it(ne);
__ add(ne, temp0, temp0, temp0);
}
GenerateStringCompareToLoop(assembler, invoke, &end, &different_compression);
__ Bind(&end);
if (can_slow_path) {
__ Bind(slow_path->GetExitLabel());
}
}
static void GenerateStringCompareToLoop(ArmVIXLAssembler* assembler,
HInvoke* invoke,
vixl32::Label* end,
vixl32::Label* different_compression) {
LocationSummary* locations = invoke->GetLocations();
const vixl32::Register str = InputRegisterAt(invoke, 0);
const vixl32::Register arg = InputRegisterAt(invoke, 1);
const vixl32::Register out = OutputRegister(invoke);
const vixl32::Register temp0 = RegisterFrom(locations->GetTemp(0));
const vixl32::Register temp1 = RegisterFrom(locations->GetTemp(1));
const vixl32::Register temp2 = RegisterFrom(locations->GetTemp(2));
vixl32::Register temp3;
if (mirror::kUseStringCompression) {
temp3 = RegisterFrom(locations->GetTemp(3));
}
vixl32::Label loop;
vixl32::Label find_char_diff;
const int32_t value_offset = mirror::String::ValueOffset().Int32Value();
// Store offset of string value in preparation for comparison loop.
__ Mov(temp1, value_offset);
// Assertions that must hold in order to compare multiple characters at a time.
CHECK_ALIGNED(value_offset, 8);
static_assert(IsAligned<8>(kObjectAlignment),
"String data must be 8-byte aligned for unrolled CompareTo loop.");
const unsigned char_size = DataType::Size(DataType::Type::kUint16);
DCHECK_EQ(char_size, 2u);
UseScratchRegisterScope temps(assembler->GetVIXLAssembler());
vixl32::Label find_char_diff_2nd_cmp;
// Unrolled loop comparing 4x16-bit chars per iteration (ok because of string data alignment).
__ Bind(&loop);
vixl32::Register temp_reg = temps.Acquire();
__ Ldr(temp_reg, MemOperand(str, temp1));
__ Ldr(temp2, MemOperand(arg, temp1));
__ Cmp(temp_reg, temp2);
__ B(ne, &find_char_diff, /* far_target */ false);
__ Add(temp1, temp1, char_size * 2);
__ Ldr(temp_reg, MemOperand(str, temp1));
__ Ldr(temp2, MemOperand(arg, temp1));
__ Cmp(temp_reg, temp2);
__ B(ne, &find_char_diff_2nd_cmp, /* far_target */ false);
__ Add(temp1, temp1, char_size * 2);
// With string compression, we have compared 8 bytes, otherwise 4 chars.
__ Subs(temp0, temp0, (mirror::kUseStringCompression ? 8 : 4));
__ B(hi, &loop, /* far_target */ false);
__ B(end);
__ Bind(&find_char_diff_2nd_cmp);
if (mirror::kUseStringCompression) {
__ Subs(temp0, temp0, 4); // 4 bytes previously compared.
__ B(ls, end, /* far_target */ false); // Was the second comparison fully beyond the end?
} else {
// Without string compression, we can start treating temp0 as signed
// and rely on the signed comparison below.
__ Sub(temp0, temp0, 2);
}
// Find the single character difference.
__ Bind(&find_char_diff);
// Get the bit position of the first character that differs.
__ Eor(temp1, temp2, temp_reg);
__ Rbit(temp1, temp1);
__ Clz(temp1, temp1);
// temp0 = number of characters remaining to compare.
// (Without string compression, it could be < 1 if a difference is found by the second CMP
// in the comparison loop, and after the end of the shorter string data).
// Without string compression (temp1 >> 4) = character where difference occurs between the last
// two words compared, in the interval [0,1].
// (0 for low half-word different, 1 for high half-word different).
// With string compression, (temp1 << 3) = byte where the difference occurs,
// in the interval [0,3].
// If temp0 <= (temp1 >> (kUseStringCompression ? 3 : 4)), the difference occurs outside
// the remaining string data, so just return length diff (out).
// The comparison is unsigned for string compression, otherwise signed.
__ Cmp(temp0, Operand(temp1, vixl32::LSR, (mirror::kUseStringCompression ? 3 : 4)));
__ B((mirror::kUseStringCompression ? ls : le), end, /* far_target */ false);
// Extract the characters and calculate the difference.
if (mirror::kUseStringCompression) {
// For compressed strings we need to clear 0x7 from temp1, for uncompressed we need to clear
// 0xf. We also need to prepare the character extraction mask `uncompressed ? 0xffffu : 0xffu`.
// The compression flag is now in the highest bit of temp3, so let's play some tricks.
__ Orr(temp3, temp3, 0xffu << 23); // uncompressed ? 0xff800000u : 0x7ff80000u
__ Bic(temp1, temp1, Operand(temp3, vixl32::LSR, 31 - 3)); // &= ~(uncompressed ? 0xfu : 0x7u)
__ Asr(temp3, temp3, 7u); // uncompressed ? 0xffff0000u : 0xff0000u.
__ Lsr(temp2, temp2, temp1); // Extract second character.
__ Lsr(temp3, temp3, 16u); // uncompressed ? 0xffffu : 0xffu
__ Lsr(out, temp_reg, temp1); // Extract first character.
__ And(temp2, temp2, temp3);
__ And(out, out, temp3);
} else {
__ Bic(temp1, temp1, 0xf);
__ Lsr(temp2, temp2, temp1);
__ Lsr(out, temp_reg, temp1);
__ Movt(temp2, 0);
__ Movt(out, 0);
}
__ Sub(out, out, temp2);
temps.Release(temp_reg);
if (mirror::kUseStringCompression) {
__ B(end);
__ Bind(different_compression);
// Comparison for different compression style.
const size_t c_char_size = DataType::Size(DataType::Type::kInt8);
DCHECK_EQ(c_char_size, 1u);
// We want to free up the temp3, currently holding `str.count`, for comparison.
// So, we move it to the bottom bit of the iteration count `temp0` which we tnen
// need to treat as unsigned. Start by freeing the bit with an ADD and continue
// further down by a LSRS+SBC which will flip the meaning of the flag but allow
// `subs temp0, #2; bhi different_compression_loop` to serve as the loop condition.
__ Add(temp0, temp0, temp0); // Unlike LSL, this ADD is always 16-bit.
// `temp1` will hold the compressed data pointer, `temp2` the uncompressed data pointer.
__ Mov(temp1, str);
__ Mov(temp2, arg);
__ Lsrs(temp3, temp3, 1u); // Continue the move of the compression flag.
{
ExactAssemblyScope aas(assembler->GetVIXLAssembler(),
3 * kMaxInstructionSizeInBytes,
CodeBufferCheckScope::kMaximumSize);
__ itt(cs); // Interleave with selection of temp1 and temp2.
__ mov(cs, temp1, arg); // Preserves flags.
__ mov(cs, temp2, str); // Preserves flags.
}
__ Sbc(temp0, temp0, 0); // Complete the move of the compression flag.
// Adjust temp1 and temp2 from string pointers to data pointers.
__ Add(temp1, temp1, value_offset);
__ Add(temp2, temp2, value_offset);
vixl32::Label different_compression_loop;
vixl32::Label different_compression_diff;
// Main loop for different compression.
temp_reg = temps.Acquire();
__ Bind(&different_compression_loop);
__ Ldrb(temp_reg, MemOperand(temp1, c_char_size, PostIndex));
__ Ldrh(temp3, MemOperand(temp2, char_size, PostIndex));
__ Cmp(temp_reg, temp3);
__ B(ne, &different_compression_diff, /* far_target */ false);
__ Subs(temp0, temp0, 2);
__ B(hi, &different_compression_loop, /* far_target */ false);
__ B(end);
// Calculate the difference.
__ Bind(&different_compression_diff);
__ Sub(out, temp_reg, temp3);
temps.Release(temp_reg);
// Flip the difference if the `arg` is compressed.
// `temp0` contains inverted `str` compression flag, i.e the same as `arg` compression flag.
__ Lsrs(temp0, temp0, 1u);
static_assert(static_cast<uint32_t>(mirror::StringCompressionFlag::kCompressed) == 0u,
"Expecting 0=compressed, 1=uncompressed");
ExactAssemblyScope aas(assembler->GetVIXLAssembler(),
2 * kMaxInstructionSizeInBytes,
CodeBufferCheckScope::kMaximumSize);
__ it(cc);
__ rsb(cc, out, out, 0);
}
}
// The cut off for unrolling the loop in String.equals() intrinsic for const strings.
// The normal loop plus the pre-header is 9 instructions (18-26 bytes) without string compression
// and 12 instructions (24-32 bytes) with string compression. We can compare up to 4 bytes in 4
// instructions (LDR+LDR+CMP+BNE) and up to 8 bytes in 6 instructions (LDRD+LDRD+CMP+BNE+CMP+BNE).
// Allow up to 12 instructions (32 bytes) for the unrolled loop.
constexpr size_t kShortConstStringEqualsCutoffInBytes = 16;
static const char* GetConstString(HInstruction* candidate, uint32_t* utf16_length) {
if (candidate->IsLoadString()) {
HLoadString* load_string = candidate->AsLoadString();
const DexFile& dex_file = load_string->GetDexFile();
return dex_file.StringDataAndUtf16LengthByIdx(load_string->GetStringIndex(), utf16_length);
}
return nullptr;
}
void IntrinsicLocationsBuilderARMVIXL::VisitStringEquals(HInvoke* invoke) {
LocationSummary* locations =
new (allocator_) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
InvokeRuntimeCallingConventionARMVIXL calling_convention;
locations->SetInAt(0, Location::RequiresRegister());
locations->SetInAt(1, Location::RequiresRegister());
// Temporary registers to store lengths of strings and for calculations.
// Using instruction cbz requires a low register, so explicitly set a temp to be R0.
locations->AddTemp(LocationFrom(r0));
// For the generic implementation and for long const strings we need an extra temporary.
// We do not need it for short const strings, up to 4 bytes, see code generation below.
uint32_t const_string_length = 0u;
const char* const_string = GetConstString(invoke->InputAt(0), &const_string_length);
if (const_string == nullptr) {
const_string = GetConstString(invoke->InputAt(1), &const_string_length);
}
bool is_compressed =
mirror::kUseStringCompression &&
const_string != nullptr &&
mirror::String::DexFileStringAllASCII(const_string, const_string_length);
if (const_string == nullptr || const_string_length > (is_compressed ? 4u : 2u)) {
locations->AddTemp(Location::RequiresRegister());
}
// TODO: If the String.equals() is used only for an immediately following HIf, we can
// mark it as emitted-at-use-site and emit branches directly to the appropriate blocks.
// Then we shall need an extra temporary register instead of the output register.
locations->SetOut(Location::RequiresRegister());
}
void IntrinsicCodeGeneratorARMVIXL::VisitStringEquals(HInvoke* invoke) {
ArmVIXLAssembler* assembler = GetAssembler();
LocationSummary* locations = invoke->GetLocations();
vixl32::Register str = InputRegisterAt(invoke, 0);
vixl32::Register arg = InputRegisterAt(invoke, 1);
vixl32::Register out = OutputRegister(invoke);
vixl32::Register temp = RegisterFrom(locations->GetTemp(0));
vixl32::Label loop;
vixl32::Label end;
vixl32::Label return_true;
vixl32::Label return_false;
vixl32::Label* final_label = codegen_->GetFinalLabel(invoke, &end);
// Get offsets of count, value, and class fields within a string object.
const uint32_t count_offset = mirror::String::CountOffset().Uint32Value();
const uint32_t value_offset = mirror::String::ValueOffset().Uint32Value();
const uint32_t class_offset = mirror::Object::ClassOffset().Uint32Value();
// Note that the null check must have been done earlier.
DCHECK(!invoke->CanDoImplicitNullCheckOn(invoke->InputAt(0)));
StringEqualsOptimizations optimizations(invoke);
if (!optimizations.GetArgumentNotNull()) {
// Check if input is null, return false if it is.
__ CompareAndBranchIfZero(arg, &return_false, /* far_target */ false);
}
// Reference equality check, return true if same reference.
__ Cmp(str, arg);
__ B(eq, &return_true, /* far_target */ false);
if (!optimizations.GetArgumentIsString()) {
// Instanceof check for the argument by comparing class fields.
// All string objects must have the same type since String cannot be subclassed.
// Receiver must be a string object, so its class field is equal to all strings' class fields.
// If the argument is a string object, its class field must be equal to receiver's class field.
__ Ldr(temp, MemOperand(str, class_offset));
__ Ldr(out, MemOperand(arg, class_offset));
__ Cmp(temp, out);
__ B(ne, &return_false, /* far_target */ false);
}
// Check if one of the inputs is a const string. Do not special-case both strings
// being const, such cases should be handled by constant folding if needed.
uint32_t const_string_length = 0u;
const char* const_string = GetConstString(invoke->InputAt(0), &const_string_length);
if (const_string == nullptr) {
const_string = GetConstString(invoke->InputAt(1), &const_string_length);
if (const_string != nullptr) {
std::swap(str, arg); // Make sure the const string is in `str`.
}
}
bool is_compressed =
mirror::kUseStringCompression &&
const_string != nullptr &&
mirror::String::DexFileStringAllASCII(const_string, const_string_length);
if (const_string != nullptr) {
// Load `count` field of the argument string and check if it matches the const string.
// Also compares the compression style, if differs return false.
__ Ldr(temp, MemOperand(arg, count_offset));
__ Cmp(temp, Operand(mirror::String::GetFlaggedCount(const_string_length, is_compressed)));
__ B(ne, &return_false, /* far_target */ false);
} else {
// Load `count` fields of this and argument strings.
__ Ldr(temp, MemOperand(str, count_offset));
__ Ldr(out, MemOperand(arg, count_offset));
// Check if `count` fields are equal, return false if they're not.
// Also compares the compression style, if differs return false.
__ Cmp(temp, out);
__ B(ne, &return_false, /* far_target */ false);
}
// Assertions that must hold in order to compare strings 4 bytes at a time.
// Ok to do this because strings are zero-padded to kObjectAlignment.
DCHECK_ALIGNED(value_offset, 4);
static_assert(IsAligned<4>(kObjectAlignment), "String data must be aligned for fast compare.");
if (const_string != nullptr &&
const_string_length <= (is_compressed ? kShortConstStringEqualsCutoffInBytes
: kShortConstStringEqualsCutoffInBytes / 2u)) {
// Load and compare the contents. Though we know the contents of the short const string
// at compile time, materializing constants may be more code than loading from memory.
int32_t offset = value_offset;
size_t remaining_bytes =
RoundUp(is_compressed ? const_string_length : const_string_length * 2u, 4u);
while (remaining_bytes > sizeof(uint32_t)) {
vixl32::Register temp1 = RegisterFrom(locations->GetTemp(1));
UseScratchRegisterScope scratch_scope(assembler->GetVIXLAssembler());
vixl32::Register temp2 = scratch_scope.Acquire();
__ Ldrd(temp, temp1, MemOperand(str, offset));
__ Ldrd(temp2, out, MemOperand(arg, offset));
__ Cmp(temp, temp2);
__ B(ne, &return_false, /* far_label */ false);
__ Cmp(temp1, out);
__ B(ne, &return_false, /* far_label */ false);
offset += 2u * sizeof(uint32_t);
remaining_bytes -= 2u * sizeof(uint32_t);
}
if (remaining_bytes != 0u) {
__ Ldr(temp, MemOperand(str, offset));
__ Ldr(out, MemOperand(arg, offset));
__ Cmp(temp, out);
__ B(ne, &return_false, /* far_label */ false);
}
} else {
// Return true if both strings are empty. Even with string compression `count == 0` means empty.
static_assert(static_cast<uint32_t>(mirror::StringCompressionFlag::kCompressed) == 0u,
"Expecting 0=compressed, 1=uncompressed");
__ CompareAndBranchIfZero(temp, &return_true, /* far_target */ false);
if (mirror::kUseStringCompression) {
// For string compression, calculate the number of bytes to compare (not chars).
// This could in theory exceed INT32_MAX, so treat temp as unsigned.
__ Lsrs(temp, temp, 1u); // Extract length and check compression flag.
ExactAssemblyScope aas(assembler->GetVIXLAssembler(),
2 * kMaxInstructionSizeInBytes,
CodeBufferCheckScope::kMaximumSize);
__ it(cs); // If uncompressed,
__ add(cs, temp, temp, temp); // double the byte count.
}
vixl32::Register temp1 = RegisterFrom(locations->GetTemp(1));
UseScratchRegisterScope scratch_scope(assembler->GetVIXLAssembler());
vixl32::Register temp2 = scratch_scope.Acquire();
// Store offset of string value in preparation for comparison loop.
__ Mov(temp1, value_offset);
// Loop to compare strings 4 bytes at a time starting at the front of the string.
__ Bind(&loop);
__ Ldr(out, MemOperand(str, temp1));
__ Ldr(temp2, MemOperand(arg, temp1));
__ Add(temp1, temp1, Operand::From(sizeof(uint32_t)));
__ Cmp(out, temp2);
__ B(ne, &return_false, /* far_target */ false);
// With string compression, we have compared 4 bytes, otherwise 2 chars.
__ Subs(temp, temp, mirror::kUseStringCompression ? 4 : 2);
__ B(hi, &loop, /* far_target */ false);
}
// Return true and exit the function.
// If loop does not result in returning false, we return true.
__ Bind(&return_true);
__ Mov(out, 1);
__ B(final_label);
// Return false and exit the function.
__ Bind(&return_false);
__ Mov(out, 0);
if (end.IsReferenced()) {
__ Bind(&end);
}
}
static void GenerateVisitStringIndexOf(HInvoke* invoke,
ArmVIXLAssembler* assembler,
CodeGeneratorARMVIXL* codegen,
bool start_at_zero) {
LocationSummary* locations = invoke->GetLocations();
// Note that the null check must have been done earlier.
DCHECK(!invoke->CanDoImplicitNullCheckOn(invoke->InputAt(0)));
// Check for code points > 0xFFFF. Either a slow-path check when we don't know statically,
// or directly dispatch for a large constant, or omit slow-path for a small constant or a char.
SlowPathCodeARMVIXL* slow_path = nullptr;
HInstruction* code_point = invoke->InputAt(1);
if (code_point->IsIntConstant()) {
if (static_cast<uint32_t>(Int32ConstantFrom(code_point)) >
std::numeric_limits<uint16_t>::max()) {
// Always needs the slow-path. We could directly dispatch to it, but this case should be
// rare, so for simplicity just put the full slow-path down and branch unconditionally.
slow_path = new (codegen->GetScopedAllocator()) IntrinsicSlowPathARMVIXL(invoke);
codegen->AddSlowPath(slow_path);
__ B(slow_path->GetEntryLabel());
__ Bind(slow_path->GetExitLabel());
return;
}
} else if (code_point->GetType() != DataType::Type::kUint16) {
vixl32::Register char_reg = InputRegisterAt(invoke, 1);
// 0xffff is not modified immediate but 0x10000 is, so use `>= 0x10000` instead of `> 0xffff`.
__ Cmp(char_reg, static_cast<uint32_t>(std::numeric_limits<uint16_t>::max()) + 1);
slow_path = new (codegen->GetScopedAllocator()) IntrinsicSlowPathARMVIXL(invoke);
codegen->AddSlowPath(slow_path);
__ B(hs, slow_path->GetEntryLabel());
}
if (start_at_zero) {
vixl32::Register tmp_reg = RegisterFrom(locations->GetTemp(0));
DCHECK(tmp_reg.Is(r2));
// Start-index = 0.
__ Mov(tmp_reg, 0);
}
codegen->InvokeRuntime(kQuickIndexOf, invoke, invoke->GetDexPc(), slow_path);
CheckEntrypointTypes<kQuickIndexOf, int32_t, void*, uint32_t, uint32_t>();
if (slow_path != nullptr) {
__ Bind(slow_path->GetExitLabel());
}
}
void IntrinsicLocationsBuilderARMVIXL::VisitStringIndexOf(HInvoke* invoke) {
LocationSummary* locations = new (allocator_) LocationSummary(
invoke, LocationSummary::kCallOnMainAndSlowPath, kIntrinsified);
// We have a hand-crafted assembly stub that follows the runtime calling convention. So it's
// best to align the inputs accordingly.
InvokeRuntimeCallingConventionARMVIXL calling_convention;
locations->SetInAt(0, LocationFrom(calling_convention.GetRegisterAt(0)));
locations->SetInAt(1, LocationFrom(calling_convention.GetRegisterAt(1)));
locations->SetOut(LocationFrom(r0));
// Need to send start-index=0.
locations->AddTemp(LocationFrom(calling_convention.GetRegisterAt(2)));
}
void IntrinsicCodeGeneratorARMVIXL::VisitStringIndexOf(HInvoke* invoke) {
GenerateVisitStringIndexOf(invoke, GetAssembler(), codegen_, /* start_at_zero */ true);
}
void IntrinsicLocationsBuilderARMVIXL::VisitStringIndexOfAfter(HInvoke* invoke) {
LocationSummary* locations = new (allocator_) LocationSummary(
invoke, LocationSummary::kCallOnMainAndSlowPath, kIntrinsified);
// We have a hand-crafted assembly stub that follows the runtime calling convention. So it's
// best to align the inputs accordingly.
InvokeRuntimeCallingConventionARMVIXL calling_convention;
locations->SetInAt(0, LocationFrom(calling_convention.GetRegisterAt(0)));
locations->SetInAt(1, LocationFrom(calling_convention.GetRegisterAt(1)));
locations->SetInAt(2, LocationFrom(calling_convention.GetRegisterAt(2)));
locations->SetOut(LocationFrom(r0));
}
void IntrinsicCodeGeneratorARMVIXL::VisitStringIndexOfAfter(HInvoke* invoke) {
GenerateVisitStringIndexOf(invoke, GetAssembler(), codegen_, /* start_at_zero */ false);
}
void IntrinsicLocationsBuilderARMVIXL::VisitStringNewStringFromBytes(HInvoke* invoke) {
LocationSummary* locations = new (allocator_) LocationSummary(
invoke, LocationSummary::kCallOnMainAndSlowPath, kIntrinsified);
InvokeRuntimeCallingConventionARMVIXL calling_convention;
locations->SetInAt(0, LocationFrom(calling_convention.GetRegisterAt(0)));
locations->SetInAt(1, LocationFrom(calling_convention.GetRegisterAt(1)));
locations->SetInAt(2, LocationFrom(calling_convention.GetRegisterAt(2)));
locations->SetInAt(3, LocationFrom(calling_convention.GetRegisterAt(3)));
locations->SetOut(LocationFrom(r0));
}
void IntrinsicCodeGeneratorARMVIXL::VisitStringNewStringFromBytes(HInvoke* invoke) {
ArmVIXLAssembler* assembler = GetAssembler();
vixl32::Register byte_array = InputRegisterAt(invoke, 0);
__ Cmp(byte_array, 0);
SlowPathCodeARMVIXL* slow_path =
new (codegen_->GetScopedAllocator()) IntrinsicSlowPathARMVIXL(invoke);
codegen_->AddSlowPath(slow_path);
__ B(eq, slow_path->GetEntryLabel());
codegen_->InvokeRuntime(kQuickAllocStringFromBytes, invoke, invoke->GetDexPc(), slow_path);
CheckEntrypointTypes<kQuickAllocStringFromBytes, void*, void*, int32_t, int32_t, int32_t>();
__ Bind(slow_path->GetExitLabel());
}
void IntrinsicLocationsBuilderARMVIXL::VisitStringNewStringFromChars(HInvoke* invoke) {
LocationSummary* locations =
new (allocator_) LocationSummary(invoke, LocationSummary::kCallOnMainOnly, kIntrinsified);
InvokeRuntimeCallingConventionARMVIXL calling_convention;
locations->SetInAt(0, LocationFrom(calling_convention.GetRegisterAt(0)));
locations->SetInAt(1, LocationFrom(calling_convention.GetRegisterAt(1)));
locations->SetInAt(2, LocationFrom(calling_convention.GetRegisterAt(2)));
locations->SetOut(LocationFrom(r0));
}
void IntrinsicCodeGeneratorARMVIXL::VisitStringNewStringFromChars(HInvoke* invoke) {
// No need to emit code checking whether `locations->InAt(2)` is a null
// pointer, as callers of the native method
//
// java.lang.StringFactory.newStringFromChars(int offset, int charCount, char[] data)
//
// all include a null check on `data` before calling that method.
codegen_->InvokeRuntime(kQuickAllocStringFromChars, invoke, invoke->GetDexPc());
CheckEntrypointTypes<kQuickAllocStringFromChars, void*, int32_t, int32_t, void*>();
}
void IntrinsicLocationsBuilderARMVIXL::VisitStringNewStringFromString(HInvoke* invoke) {
LocationSummary* locations = new (allocator_) LocationSummary(
invoke, LocationSummary::kCallOnMainAndSlowPath, kIntrinsified);
InvokeRuntimeCallingConventionARMVIXL calling_convention;
locations->SetInAt(0, LocationFrom(calling_convention.GetRegisterAt(0)));
locations->SetOut(LocationFrom(r0));
}
void IntrinsicCodeGeneratorARMVIXL::VisitStringNewStringFromString(HInvoke* invoke) {
ArmVIXLAssembler* assembler = GetAssembler();
vixl32::Register string_to_copy = InputRegisterAt(invoke, 0);
__ Cmp(string_to_copy, 0);
SlowPathCodeARMVIXL* slow_path =
new (codegen_->GetScopedAllocator()) IntrinsicSlowPathARMVIXL(invoke);
codegen_->AddSlowPath(slow_path);
__ B(eq, slow_path->GetEntryLabel());
codegen_->InvokeRuntime(kQuickAllocStringFromString, invoke, invoke->GetDexPc(), slow_path);
CheckEntrypointTypes<kQuickAllocStringFromString, void*, void*>();
__ Bind(slow_path->GetExitLabel());
}
void IntrinsicLocationsBuilderARMVIXL::VisitSystemArrayCopy(HInvoke* invoke) {
// The only read barrier implementation supporting the
// SystemArrayCopy intrinsic is the Baker-style read barriers.
if (kEmitCompilerReadBarrier && !kUseBakerReadBarrier) {
return;
}
CodeGenerator::CreateSystemArrayCopyLocationSummary(invoke);
LocationSummary* locations = invoke->GetLocations();
if (locations == nullptr) {
return;
}
HIntConstant* src_pos = invoke->InputAt(1)->AsIntConstant();
HIntConstant* dest_pos = invoke->InputAt(3)->AsIntConstant();
HIntConstant* length = invoke->InputAt(4)->AsIntConstant();
if (src_pos != nullptr && !assembler_->ShifterOperandCanAlwaysHold(src_pos->GetValue())) {
locations->SetInAt(1, Location::RequiresRegister());
}
if (dest_pos != nullptr && !assembler_->ShifterOperandCanAlwaysHold(dest_pos->GetValue())) {
locations->SetInAt(3, Location::RequiresRegister());
}
if (length != nullptr && !assembler_->ShifterOperandCanAlwaysHold(length->GetValue())) {
locations->SetInAt(4, Location::RequiresRegister());
}
if (kEmitCompilerReadBarrier && kUseBakerReadBarrier) {
// Temporary register IP cannot be used in
// ReadBarrierSystemArrayCopySlowPathARM (because that register
// is clobbered by ReadBarrierMarkRegX entry points). Get an extra
// temporary register from the register allocator.
locations->AddTemp(Location::RequiresRegister());
}
}
static void CheckPosition(ArmVIXLAssembler* assembler,
Location pos,
vixl32::Register input,
Location length,
SlowPathCodeARMVIXL* slow_path,
vixl32::Register temp,
bool length_is_input_length = false) {
// Where is the length in the Array?
const uint32_t length_offset = mirror::Array::LengthOffset().Uint32Value();
if (pos.IsConstant()) {
int32_t pos_const = Int32ConstantFrom(pos);
if (pos_const == 0) {
if (!length_is_input_length) {
// Check that length(input) >= length.
__ Ldr(temp, MemOperand(input, length_offset));
if (length.IsConstant()) {
__ Cmp(temp, Int32ConstantFrom(length));
} else {
__ Cmp(temp, RegisterFrom(length));
}
__ B(lt, slow_path->GetEntryLabel());
}
} else {
// Check that length(input) >= pos.
__ Ldr(temp, MemOperand(input, length_offset));
__ Subs(temp, temp, pos_const);
__ B(lt, slow_path->GetEntryLabel());
// Check that (length(input) - pos) >= length.
if (length.IsConstant()) {
__ Cmp(temp, Int32ConstantFrom(length));
} else {
__ Cmp(temp, RegisterFrom(length));
}
__ B(lt, slow_path->GetEntryLabel());
}
} else if (length_is_input_length) {
// The only way the copy can succeed is if pos is zero.
vixl32::Register pos_reg = RegisterFrom(pos);
__ CompareAndBranchIfNonZero(pos_reg, slow_path->GetEntryLabel());
} else {
// Check that pos >= 0.
vixl32::Register pos_reg = RegisterFrom(pos);
__ Cmp(pos_reg, 0);
__ B(lt, slow_path->GetEntryLabel());
// Check that pos <= length(input).
__ Ldr(temp, MemOperand(input, length_offset));
__ Subs(temp, temp, pos_reg);
__ B(lt, slow_path->GetEntryLabel());
// Check that (length(input) - pos) >= length.
if (length.IsConstant()) {
__ Cmp(temp, Int32ConstantFrom(length));
} else {
__ Cmp(temp, RegisterFrom(length));
}
__ B(lt, slow_path->GetEntryLabel());
}
}
void IntrinsicCodeGeneratorARMVIXL::VisitSystemArrayCopy(HInvoke* invoke) {
// The only read barrier implementation supporting the
// SystemArrayCopy intrinsic is the Baker-style read barriers.
DCHECK(!kEmitCompilerReadBarrier || kUseBakerReadBarrier);
ArmVIXLAssembler* assembler = GetAssembler();
LocationSummary* locations = invoke->GetLocations();
uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
uint32_t super_offset = mirror::Class::SuperClassOffset().Int32Value();
uint32_t component_offset = mirror::Class::ComponentTypeOffset().Int32Value();
uint32_t primitive_offset = mirror::Class::PrimitiveTypeOffset().Int32Value();
uint32_t monitor_offset = mirror::Object::MonitorOffset().Int32Value();
vixl32::Register src = InputRegisterAt(invoke, 0);
Location src_pos = locations->InAt(1);
vixl32::Register dest = InputRegisterAt(invoke, 2);
Location dest_pos = locations->InAt(3);
Location length = locations->InAt(4);
Location temp1_loc = locations->GetTemp(0);
vixl32::Register temp1 = RegisterFrom(temp1_loc);
Location temp2_loc = locations->GetTemp(1);
vixl32::Register temp2 = RegisterFrom(temp2_loc);
Location temp3_loc = locations->GetTemp(2);
vixl32::Register temp3 = RegisterFrom(temp3_loc);
SlowPathCodeARMVIXL* intrinsic_slow_path =
new (codegen_->GetScopedAllocator()) IntrinsicSlowPathARMVIXL(invoke);
codegen_->AddSlowPath(intrinsic_slow_path);
vixl32::Label conditions_on_positions_validated;
SystemArrayCopyOptimizations optimizations(invoke);
// If source and destination are the same, we go to slow path if we need to do
// forward copying.
if (src_pos.IsConstant()) {
int32_t src_pos_constant = Int32ConstantFrom(src_pos);
if (dest_pos.IsConstant()) {
int32_t dest_pos_constant = Int32ConstantFrom(dest_pos);
if (optimizations.GetDestinationIsSource()) {
// Checked when building locations.
DCHECK_GE(src_pos_constant, dest_pos_constant);
} else if (src_pos_constant < dest_pos_constant) {
__ Cmp(src, dest);
__ B(eq, intrinsic_slow_path->GetEntryLabel());
}
// Checked when building locations.
DCHECK(!optimizations.GetDestinationIsSource()
|| (src_pos_constant >= Int32ConstantFrom(dest_pos)));
} else {
if (!optimizations.GetDestinationIsSource()) {
__ Cmp(src, dest);
__ B(ne, &conditions_on_positions_validated, /* far_target */ false);
}
__ Cmp(RegisterFrom(dest_pos), src_pos_constant);
__ B(gt, intrinsic_slow_path->GetEntryLabel());
}
} else {
if (!optimizations.GetDestinationIsSource()) {
__ Cmp(src, dest);
__ B(ne, &conditions_on_positions_validated, /* far_target */ false);
}
if (dest_pos.IsConstant()) {
int32_t dest_pos_constant = Int32ConstantFrom(dest_pos);
__ Cmp(RegisterFrom(src_pos), dest_pos_constant);
} else {
__ Cmp(RegisterFrom(src_pos), RegisterFrom(dest_pos));
}
__ B(lt, intrinsic_slow_path->GetEntryLabel());
}
__ Bind(&conditions_on_positions_validated);
if (!optimizations.GetSourceIsNotNull()) {
// Bail out if the source is null.
__ CompareAndBranchIfZero(src, intrinsic_slow_path->GetEntryLabel());
}
if (!optimizations.GetDestinationIsNotNull() && !optimizations.GetDestinationIsSource()) {
// Bail out if the destination is null.
__ CompareAndBranchIfZero(dest, intrinsic_slow_path->GetEntryLabel());
}
// If the length is negative, bail out.
// We have already checked in the LocationsBuilder for the constant case.
if (!length.IsConstant() &&
!optimizations.GetCountIsSourceLength() &&
!optimizations.GetCountIsDestinationLength()) {
__ Cmp(RegisterFrom(length), 0);
__ B(lt, intrinsic_slow_path->GetEntryLabel());
}
// Validity checks: source.
CheckPosition(assembler,
src_pos,
src,
length,
intrinsic_slow_path,
temp1,
optimizations.GetCountIsSourceLength());
// Validity checks: dest.
CheckPosition(assembler,
dest_pos,
dest,
length,
intrinsic_slow_path,
temp1,
optimizations.GetCountIsDestinationLength());
if (!optimizations.GetDoesNotNeedTypeCheck()) {
// Check whether all elements of the source array are assignable to the component
// type of the destination array. We do two checks: the classes are the same,
// or the destination is Object[]. If none of these checks succeed, we go to the
// slow path.
if (kEmitCompilerReadBarrier && kUseBakerReadBarrier) {
if (!optimizations.GetSourceIsNonPrimitiveArray()) {
// /* HeapReference<Class> */ temp1 = src->klass_
codegen_->GenerateFieldLoadWithBakerReadBarrier(
invoke, temp1_loc, src, class_offset, temp2_loc, /* needs_null_check */ false);
// Bail out if the source is not a non primitive array.
// /* HeapReference<Class> */ temp1 = temp1->component_type_
codegen_->GenerateFieldLoadWithBakerReadBarrier(
invoke, temp1_loc, temp1, component_offset, temp2_loc, /* needs_null_check */ false);
__ CompareAndBranchIfZero(temp1, intrinsic_slow_path->GetEntryLabel());
// If heap poisoning is enabled, `temp1` has been unpoisoned
// by the the previous call to GenerateFieldLoadWithBakerReadBarrier.
// /* uint16_t */ temp1 = static_cast<uint16>(temp1->primitive_type_);
__ Ldrh(temp1, MemOperand(temp1, primitive_offset));
static_assert(Primitive::kPrimNot == 0, "Expected 0 for kPrimNot");
__ CompareAndBranchIfNonZero(temp1, intrinsic_slow_path->GetEntryLabel());
}
// /* HeapReference<Class> */ temp1 = dest->klass_
codegen_->GenerateFieldLoadWithBakerReadBarrier(
invoke, temp1_loc, dest, class_offset, temp2_loc, /* needs_null_check */ false);
if (!optimizations.GetDestinationIsNonPrimitiveArray()) {
// Bail out if the destination is not a non primitive array.
//
// Register `temp1` is not trashed by the read barrier emitted
// by GenerateFieldLoadWithBakerReadBarrier below, as that
// method produces a call to a ReadBarrierMarkRegX entry point,
// which saves all potentially live registers, including
// temporaries such a `temp1`.
// /* HeapReference<Class> */ temp2 = temp1->component_type_
codegen_->GenerateFieldLoadWithBakerReadBarrier(
invoke, temp2_loc, temp1, component_offset, temp3_loc, /* needs_null_check */ false);
__ CompareAndBranchIfZero(temp2, intrinsic_slow_path->GetEntryLabel());
// If heap poisoning is enabled, `temp2` has been unpoisoned
// by the the previous call to GenerateFieldLoadWithBakerReadBarrier.
// /* uint16_t */ temp2 = static_cast<uint16>(temp2->primitive_type_);
__ Ldrh(temp2, MemOperand(temp2, primitive_offset));
static_assert(Primitive::kPrimNot == 0, "Expected 0 for kPrimNot");
__ CompareAndBranchIfNonZero(temp2, intrinsic_slow_path->GetEntryLabel());
}
// For the same reason given earlier, `temp1` is not trashed by the
// read barrier emitted by GenerateFieldLoadWithBakerReadBarrier below.
// /* HeapReference<Class> */ temp2 = src->klass_
codegen_->GenerateFieldLoadWithBakerReadBarrier(
invoke, temp2_loc, src, class_offset, temp3_loc, /* needs_null_check */ false);
// Note: if heap poisoning is on, we are comparing two unpoisoned references here.
__ Cmp(temp1, temp2);
if (optimizations.GetDestinationIsTypedObjectArray()) {
vixl32::Label do_copy;
__ B(eq, &do_copy, /* far_target */ false);
// /* HeapReference<Class> */ temp1 = temp1->component_type_
codegen_->GenerateFieldLoadWithBakerReadBarrier(
invoke, temp1_loc, temp1, component_offset, temp2_loc, /* needs_null_check */ false);
// /* HeapReference<Class> */ temp1 = temp1->super_class_
// We do not need to emit a read barrier for the following
// heap reference load, as `temp1` is only used in a
// comparison with null below, and this reference is not
// kept afterwards.
__ Ldr(temp1, MemOperand(temp1, super_offset));
__ CompareAndBranchIfNonZero(temp1, intrinsic_slow_path->GetEntryLabel());
__ Bind(&do_copy);
} else {
__ B(ne, intrinsic_slow_path->GetEntryLabel());
}
} else {
// Non read barrier code.
// /* HeapReference<Class> */ temp1 = dest->klass_
__ Ldr(temp1, MemOperand(dest, class_offset));
// /* HeapReference<Class> */ temp2 = src->klass_
__ Ldr(temp2, MemOperand(src, class_offset));
bool did_unpoison = false;
if (!optimizations.GetDestinationIsNonPrimitiveArray() ||
!optimizations.GetSourceIsNonPrimitiveArray()) {
// One or two of the references need to be unpoisoned. Unpoison them
// both to make the identity check valid.
assembler->MaybeUnpoisonHeapReference(temp1);
assembler->MaybeUnpoisonHeapReference(temp2);
did_unpoison = true;
}
if (!optimizations.GetDestinationIsNonPrimitiveArray()) {
// Bail out if the destination is not a non primitive array.
// /* HeapReference<Class> */ temp3 = temp1->component_type_
__ Ldr(temp3, MemOperand(temp1, component_offset));
__ CompareAndBranchIfZero(temp3, intrinsic_slow_path->GetEntryLabel());
assembler->MaybeUnpoisonHeapReference(temp3);
// /* uint16_t */ temp3 = static_cast<uint16>(temp3->primitive_type_);
__ Ldrh(temp3, MemOperand(temp3, primitive_offset));
static_assert(Primitive::kPrimNot == 0, "Expected 0 for kPrimNot");
__ CompareAndBranchIfNonZero(temp3, intrinsic_slow_path->GetEntryLabel());
}
if (!optimizations.GetSourceIsNonPrimitiveArray()) {
// Bail out if the source is not a non primitive array.
// /* HeapReference<Class> */ temp3 = temp2->component_type_
__ Ldr(temp3, MemOperand(temp2, component_offset));
__ CompareAndBranchIfZero(temp3, intrinsic_slow_path->GetEntryLabel());
assembler->MaybeUnpoisonHeapReference(temp3);
// /* uint16_t */ temp3 = static_cast<uint16>(temp3->primitive_type_);
__ Ldrh(temp3, MemOperand(temp3, primitive_offset));
static_assert(Primitive::kPrimNot == 0, "Expected 0 for kPrimNot");
__ CompareAndBranchIfNonZero(temp3, intrinsic_slow_path->GetEntryLabel());
}
__ Cmp(temp1, temp2);
if (optimizations.GetDestinationIsTypedObjectArray()) {
vixl32::Label do_copy;
__ B(eq, &do_copy, /* far_target */ false);
if (!did_unpoison) {
assembler->MaybeUnpoisonHeapReference(temp1);
}
// /* HeapReference<Class> */ temp1 = temp1->component_type_
__ Ldr(temp1, MemOperand(temp1, component_offset));
assembler->MaybeUnpoisonHeapReference(temp1);
// /* HeapReference<Class> */ temp1 = temp1->super_class_
__ Ldr(temp1, MemOperand(temp1, super_offset));
// No need to unpoison the result, we're comparing against null.
__ CompareAndBranchIfNonZero(temp1, intrinsic_slow_path->GetEntryLabel());
__ Bind(&do_copy);
} else {
__ B(ne, intrinsic_slow_path->GetEntryLabel());
}
}
} else if (!optimizations.GetSourceIsNonPrimitiveArray()) {
DCHECK(optimizations.GetDestinationIsNonPrimitiveArray());
// Bail out if the source is not a non primitive array.
if (kEmitCompilerReadBarrier && kUseBakerReadBarrier) {
// /* HeapReference<Class> */ temp1 = src->klass_
codegen_->GenerateFieldLoadWithBakerReadBarrier(
invoke, temp1_loc, src, class_offset, temp2_loc, /* needs_null_check */ false);
// /* HeapReference<Class> */ temp3 = temp1->component_type_
codegen_->GenerateFieldLoadWithBakerReadBarrier(
invoke, temp3_loc, temp1, component_offset, temp2_loc, /* needs_null_check */ false);
__ CompareAndBranchIfZero(temp3, intrinsic_slow_path->GetEntryLabel());
// If heap poisoning is enabled, `temp3` has been unpoisoned
// by the the previous call to GenerateFieldLoadWithBakerReadBarrier.
} else {
// /* HeapReference<Class> */ temp1 = src->klass_
__ Ldr(temp1, MemOperand(src, class_offset));
assembler->MaybeUnpoisonHeapReference(temp1);
// /* HeapReference<Class> */ temp3 = temp1->component_type_
__ Ldr(temp3, MemOperand(temp1, component_offset));
__ CompareAndBranchIfZero(temp3, intrinsic_slow_path->GetEntryLabel());
assembler->MaybeUnpoisonHeapReference(temp3);
}
// /* uint16_t */ temp3 = static_cast<uint16>(temp3->primitive_type_);
__ Ldrh(temp3, MemOperand(temp3, primitive_offset));
static_assert(Primitive::kPrimNot == 0, "Expected 0 for kPrimNot");
__ CompareAndBranchIfNonZero(temp3, intrinsic_slow_path->GetEntryLabel());
}
if (length.IsConstant() && Int32ConstantFrom(length) == 0) {
// Null constant length: not need to emit the loop code at all.
} else {
vixl32::Label done;
const DataType::Type type = DataType::Type::kReference;
const int32_t element_size = DataType::Size(type);
if (length.IsRegister()) {
// Don't enter the copy loop if the length is null.
__ CompareAndBranchIfZero(RegisterFrom(length), &done, /* is_far_target */ false);
}
if (kEmitCompilerReadBarrier && kUseBakerReadBarrier) {
// TODO: Also convert this intrinsic to the IsGcMarking strategy?
// SystemArrayCopy implementation for Baker read barriers (see
// also CodeGeneratorARMVIXL::GenerateReferenceLoadWithBakerReadBarrier):
//
// uint32_t rb_state = Lockword(src->monitor_).ReadBarrierState();
// lfence; // Load fence or artificial data dependency to prevent load-load reordering
// bool is_gray = (rb_state == ReadBarrier::GrayState());
// if (is_gray) {
// // Slow-path copy.
// do {
// *dest_ptr++ = MaybePoison(ReadBarrier::Mark(MaybeUnpoison(*src_ptr++)));
// } while (src_ptr != end_ptr)
// } else {
// // Fast-path copy.
// do {
// *dest_ptr++ = *src_ptr++;
// } while (src_ptr != end_ptr)
// }
// /* int32_t */ monitor = src->monitor_
__ Ldr(temp2, MemOperand(src, monitor_offset));
// /* LockWord */ lock_word = LockWord(monitor)
static_assert(sizeof(LockWord) == sizeof(int32_t),
"art::LockWord and int32_t have different sizes.");
// Introduce a dependency on the lock_word including the rb_state,
// which shall prevent load-load reordering without using
// a memory barrier (which would be more expensive).
// `src` is unchanged by this operation, but its value now depends
// on `temp2`.
__ Add(src, src, Operand(temp2, vixl32::LSR, 32));
// Compute the base source address in `temp1`.
// Note that `temp1` (the base source address) is computed from
// `src` (and `src_pos`) here, and thus honors the artificial
// dependency of `src` on `temp2`.
GenSystemArrayCopyBaseAddress(GetAssembler(), type, src, src_pos, temp1);
// Compute the end source address in `temp3`.
GenSystemArrayCopyEndAddress(GetAssembler(), type, length, temp1, temp3);
// The base destination address is computed later, as `temp2` is
// used for intermediate computations.
// Slow path used to copy array when `src` is gray.
// Note that the base destination address is computed in `temp2`
// by the slow path code.
SlowPathCodeARMVIXL* read_barrier_slow_path =
new (codegen_->GetScopedAllocator()) ReadBarrierSystemArrayCopySlowPathARMVIXL(invoke);
codegen_->AddSlowPath(read_barrier_slow_path);
// Given the numeric representation, it's enough to check the low bit of the
// rb_state. We do that by shifting the bit out of the lock word with LSRS
// which can be a 16-bit instruction unlike the TST immediate.
static_assert(ReadBarrier::NonGrayState() == 0, "Expecting non-gray to have value 0");
static_assert(ReadBarrier::GrayState() == 1, "Expecting gray to have value 1");
__ Lsrs(temp2, temp2, LockWord::kReadBarrierStateShift + 1);
// Carry flag is the last bit shifted out by LSRS.
__ B(cs, read_barrier_slow_path->GetEntryLabel());
// Fast-path copy.
// Compute the base destination address in `temp2`.
GenSystemArrayCopyBaseAddress(GetAssembler(), type, dest, dest_pos, temp2);
// Iterate over the arrays and do a raw copy of the objects. We don't need to
// poison/unpoison.
vixl32::Label loop;
__ Bind(&loop);
{
UseScratchRegisterScope temps(assembler->GetVIXLAssembler());
const vixl32::Register temp_reg = temps.Acquire();
__ Ldr(temp_reg, MemOperand(temp1, element_size, PostIndex));
__ Str(temp_reg, MemOperand(temp2, element_size, PostIndex));
}
__ Cmp(temp1, temp3);
__ B(ne, &loop, /* far_target */ false);
__ Bind(read_barrier_slow_path->GetExitLabel());
} else {
// Non read barrier code.
// Compute the base source address in `temp1`.
GenSystemArrayCopyBaseAddress(GetAssembler(), type, src, src_pos, temp1);
// Compute the base destination address in `temp2`.
GenSystemArrayCopyBaseAddress(GetAssembler(), type, dest, dest_pos, temp2);
// Compute the end source address in `temp3`.
GenSystemArrayCopyEndAddress(GetAssembler(), type, length, temp1, temp3);
// Iterate over the arrays and do a raw copy of the objects. We don't need to
// poison/unpoison.
vixl32::Label loop;
__ Bind(&loop);
{
UseScratchRegisterScope temps(assembler->GetVIXLAssembler());
const vixl32::Register temp_reg = temps.Acquire();
__ Ldr(temp_reg, MemOperand(temp1, element_size, PostIndex));
__ Str(temp_reg, MemOperand(temp2, element_size, PostIndex));
}
__ Cmp(temp1, temp3);
__ B(ne, &loop, /* far_target */ false);
}
__ Bind(&done);
}
// We only need one card marking on the destination array.
codegen_->MarkGCCard(temp1, temp2, dest, NoReg, /* value_can_be_null */ false);
__ Bind(intrinsic_slow_path->GetExitLabel());
}
static void CreateFPToFPCallLocations(ArenaAllocator* allocator, HInvoke* invoke) {
// If the graph is debuggable, all callee-saved floating-point registers are blocked by
// the code generator. Furthermore, the register allocator creates fixed live intervals
// for all caller-saved registers because we are doing a function call. As a result, if
// the input and output locations are unallocated, the register allocator runs out of
// registers and fails; however, a debuggable graph is not the common case.
if (invoke->GetBlock()->GetGraph()->IsDebuggable()) {
return;
}
DCHECK_EQ(invoke->GetNumberOfArguments(), 1U);
DCHECK_EQ(invoke->InputAt(0)->GetType(), DataType::Type::kFloat64);
DCHECK_EQ(invoke->GetType(), DataType::Type::kFloat64);
LocationSummary* const locations =
new (allocator) LocationSummary(invoke, LocationSummary::kCallOnMainOnly, kIntrinsified);
const InvokeRuntimeCallingConventionARMVIXL calling_convention;
locations->SetInAt(0, Location::RequiresFpuRegister());
locations->SetOut(Location::RequiresFpuRegister());
// Native code uses the soft float ABI.
locations->AddTemp(LocationFrom(calling_convention.GetRegisterAt(0)));
locations->AddTemp(LocationFrom(calling_convention.GetRegisterAt(1)));
}
static void CreateFPFPToFPCallLocations(ArenaAllocator* allocator, HInvoke* invoke) {
// If the graph is debuggable, all callee-saved floating-point registers are blocked by
// the code generator. Furthermore, the register allocator creates fixed live intervals
// for all caller-saved registers because we are doing a function call. As a result, if
// the input and output locations are unallocated, the register allocator runs out of
// registers and fails; however, a debuggable graph is not the common case.
if (invoke->GetBlock()->GetGraph()->IsDebuggable()) {
return;
}
DCHECK_EQ(invoke->GetNumberOfArguments(), 2U);
DCHECK_EQ(invoke->InputAt(0)->GetType(), DataType::Type::kFloat64);
DCHECK_EQ(invoke->InputAt(1)->GetType(), DataType::Type::kFloat64);
DCHECK_EQ(invoke->GetType(), DataType::Type::kFloat64);
LocationSummary* const locations =
new (allocator) LocationSummary(invoke, LocationSummary::kCallOnMainOnly, kIntrinsified);
const InvokeRuntimeCallingConventionARMVIXL calling_convention;
locations->SetInAt(0, Location::RequiresFpuRegister());
locations->SetInAt(1, Location::RequiresFpuRegister());
locations->SetOut(Location::RequiresFpuRegister());
// Native code uses the soft float ABI.
locations->AddTemp(LocationFrom(calling_convention.GetRegisterAt(0)));
locations->AddTemp(LocationFrom(calling_convention.GetRegisterAt(1)));
locations->AddTemp(LocationFrom(calling_convention.GetRegisterAt(2)));
locations->AddTemp(LocationFrom(calling_convention.GetRegisterAt(3)));
}
static void GenFPToFPCall(HInvoke* invoke,
ArmVIXLAssembler* assembler,
CodeGeneratorARMVIXL* codegen,
QuickEntrypointEnum entry) {
LocationSummary* const locations = invoke->GetLocations();
DCHECK_EQ(invoke->GetNumberOfArguments(), 1U);
DCHECK(locations->WillCall() && locations->Intrinsified());
// Native code uses the soft float ABI.
__ Vmov(RegisterFrom(locations->GetTemp(0)),
RegisterFrom(locations->GetTemp(1)),
InputDRegisterAt(invoke, 0));
codegen->InvokeRuntime(entry, invoke, invoke->GetDexPc());
__ Vmov(OutputDRegister(invoke),
RegisterFrom(locations->GetTemp(0)),
RegisterFrom(locations->GetTemp(1)));
}
static void GenFPFPToFPCall(HInvoke* invoke,
ArmVIXLAssembler* assembler,
CodeGeneratorARMVIXL* codegen,
QuickEntrypointEnum entry) {
LocationSummary* const locations = invoke->GetLocations();
DCHECK_EQ(invoke->GetNumberOfArguments(), 2U);
DCHECK(locations->WillCall() && locations->Intrinsified());
// Native code uses the soft float ABI.
__ Vmov(RegisterFrom(locations->GetTemp(0)),
RegisterFrom(locations->GetTemp(1)),
InputDRegisterAt(invoke, 0));
__ Vmov(RegisterFrom(locations->GetTemp(2)),
RegisterFrom(locations->GetTemp(3)),
InputDRegisterAt(invoke, 1));
codegen->InvokeRuntime(entry, invoke, invoke->GetDexPc());
__ Vmov(OutputDRegister(invoke),
RegisterFrom(locations->GetTemp(0)),
RegisterFrom(locations->GetTemp(1)));
}
void IntrinsicLocationsBuilderARMVIXL::VisitMathCos(HInvoke* invoke) {
CreateFPToFPCallLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitMathCos(HInvoke* invoke) {
GenFPToFPCall(invoke, GetAssembler(), codegen_, kQuickCos);
}
void IntrinsicLocationsBuilderARMVIXL::VisitMathSin(HInvoke* invoke) {
CreateFPToFPCallLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitMathSin(HInvoke* invoke) {
GenFPToFPCall(invoke, GetAssembler(), codegen_, kQuickSin);
}
void IntrinsicLocationsBuilderARMVIXL::VisitMathAcos(HInvoke* invoke) {
CreateFPToFPCallLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitMathAcos(HInvoke* invoke) {
GenFPToFPCall(invoke, GetAssembler(), codegen_, kQuickAcos);
}
void IntrinsicLocationsBuilderARMVIXL::VisitMathAsin(HInvoke* invoke) {
CreateFPToFPCallLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitMathAsin(HInvoke* invoke) {
GenFPToFPCall(invoke, GetAssembler(), codegen_, kQuickAsin);
}
void IntrinsicLocationsBuilderARMVIXL::VisitMathAtan(HInvoke* invoke) {
CreateFPToFPCallLocations(allocator_, invoke);
}
void IntrinsicCodeGeneratorARMVIXL::VisitMathAtan(HInvoke* invoke) {
GenFPToFPCall(invoke, GetAssembler(), codegen_, kQuickAtan);