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test-code-generator.cc
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// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/assembler-inl.h"
#include "src/base/utils/random-number-generator.h"
#include "src/code-stub-assembler.h"
#include "src/codegen.h"
#include "src/compiler/code-generator.h"
#include "src/compiler/instruction.h"
#include "src/compiler/linkage.h"
#include "src/isolate.h"
#include "src/objects-inl.h"
#include "src/optimized-compilation-info.h"
#include "test/cctest/cctest.h"
#include "test/cctest/compiler/code-assembler-tester.h"
#include "test/cctest/compiler/function-tester.h"
namespace v8 {
namespace internal {
namespace compiler {
#define __ assembler.
namespace {
int GetSlotSizeInBytes(MachineRepresentation rep) {
switch (rep) {
case MachineRepresentation::kTagged:
case MachineRepresentation::kFloat32:
return kPointerSize;
case MachineRepresentation::kFloat64:
return kDoubleSize;
case MachineRepresentation::kSimd128:
return kSimd128Size;
default:
break;
}
UNREACHABLE();
}
// Forward declaration.
Handle<Code> BuildTeardownFunction(Isolate* isolate,
CallDescriptor* call_descriptor,
std::vector<AllocatedOperand> parameters);
// Build the `setup` function. It takes a code object and a FixedArray as
// parameters and calls the former while passing it each element of the array as
// arguments:
// ~~~
// FixedArray setup(CodeObject* test, FixedArray state_in) {
// FixedArray state_out = AllocateFixedArray(state_in.length());
// // `test` will tail-call to its first parameter which will be `teardown`.
// return test(teardown, state_out, state_in[0], state_in[1],
// state_in[2], ...);
// }
// ~~~
//
// This function needs to convert each element of the FixedArray to raw unboxed
// values to pass to the `test` function. The array will have been created using
// `GenerateInitialState()` and needs to be converted in the following way:
//
// | Parameter type | FixedArray element | Conversion |
// |----------------+---------------------+------------------------------------|
// | kTagged | Smi | None. |
// | kFloat32 | HeapNumber | Load value and convert to Float32. |
// | kFloat64 | HeapNumber | Load value. |
// | kSimd128 | FixedArray<Smi>[4] | Untag each Smi and write the |
// | | | results into lanes of a new |
// | | | 128-bit vector. |
//
Handle<Code> BuildSetupFunction(Isolate* isolate,
CallDescriptor* call_descriptor,
std::vector<AllocatedOperand> parameters) {
CodeAssemblerTester tester(isolate, 2, Code::BUILTIN, "setup");
CodeStubAssembler assembler(tester.state());
std::vector<Node*> params;
// The first parameter is always the callee.
params.push_back(__ Parameter(0));
params.push_back(__ HeapConstant(
BuildTeardownFunction(isolate, call_descriptor, parameters)));
// First allocate the FixedArray which will hold the final results. Here we
// should take care of all allocations, meaning we allocate HeapNumbers and
// FixedArrays representing Simd128 values.
TNode<FixedArray> state_out = __ Cast(__ AllocateFixedArray(
PACKED_ELEMENTS, __ IntPtrConstant(parameters.size())));
for (int i = 0; i < static_cast<int>(parameters.size()); i++) {
switch (parameters[i].representation()) {
case MachineRepresentation::kTagged:
break;
case MachineRepresentation::kFloat32:
case MachineRepresentation::kFloat64:
__ StoreFixedArrayElement(state_out, i, __ AllocateHeapNumber());
break;
case MachineRepresentation::kSimd128: {
TNode<FixedArray> vector = __ Cast(
__ AllocateFixedArray(PACKED_SMI_ELEMENTS, __ IntPtrConstant(4)));
for (int lane = 0; lane < 4; lane++) {
__ StoreFixedArrayElement(vector, lane, __ SmiConstant(0));
}
__ StoreFixedArrayElement(state_out, i, vector);
break;
}
default:
UNREACHABLE();
break;
}
}
params.push_back(state_out);
// Then take each element of the initial state and pass them as arguments.
TNode<FixedArray> state_in = __ Cast(__ Parameter(1));
for (int i = 0; i < static_cast<int>(parameters.size()); i++) {
Node* element = __ LoadFixedArrayElement(state_in, __ IntPtrConstant(i));
// Unbox all elements before passing them as arguments.
switch (parameters[i].representation()) {
// Tagged parameters are Smis, they do not need unboxing.
case MachineRepresentation::kTagged:
break;
case MachineRepresentation::kFloat32:
element = __ TruncateFloat64ToFloat32(__ LoadHeapNumberValue(element));
break;
case MachineRepresentation::kFloat64:
element = __ LoadHeapNumberValue(element);
break;
case MachineRepresentation::kSimd128: {
Node* vector = tester.raw_assembler_for_testing()->AddNode(
tester.raw_assembler_for_testing()->machine()->I32x4Splat(),
__ Int32Constant(0));
for (int lane = 0; lane < 4; lane++) {
TNode<Int32T> lane_value = __ LoadAndUntagToWord32FixedArrayElement(
element, __ IntPtrConstant(lane));
vector = tester.raw_assembler_for_testing()->AddNode(
tester.raw_assembler_for_testing()->machine()->I32x4ReplaceLane(
lane),
vector, lane_value);
}
element = vector;
break;
}
default:
UNREACHABLE();
break;
}
params.push_back(element);
}
__ Return(tester.raw_assembler_for_testing()->AddNode(
tester.raw_assembler_for_testing()->common()->Call(call_descriptor),
static_cast<int>(params.size()), params.data()));
return tester.GenerateCodeCloseAndEscape();
}
// Build the `teardown` function. It takes a FixedArray as argument, fills it
// with the rest of its parameters and returns it. The parameters need to be
// consistent with `parameters`.
// ~~~
// FixedArray teardown(CodeObject* /* unused */, FixedArray result,
// // Tagged registers.
// Object* r0, Object* r1, ...,
// // FP registers.
// Float32 s0, Float64 d1, ...,
// // Mixed stack slots.
// Float64 mem0, Object* mem1, Float32 mem2, ...) {
// result[0] = r0;
// result[1] = r1;
// ...
// result[..] = s0;
// ...
// result[..] = mem0;
// ...
// return result;
// }
// ~~~
//
// This function needs to convert its parameters into values fit for a
// FixedArray, essentially reverting what the `setup` function did:
//
// | Parameter type | Parameter value | Conversion |
// |----------------+-------------------+--------------------------------------|
// | kTagged | Smi or HeapNumber | None. |
// | kFloat32 | Raw Float32 | Convert to Float64. |
// | kFloat64 | Raw Float64 | None. |
// | kSimd128 | Raw Simd128 | Split into 4 Word32 values and tag |
// | | | them. |
//
// Note that it is possible for a `kTagged` value to go from a Smi to a
// HeapNumber. This is because `AssembleMove` will allocate a new HeapNumber if
// it is asked to move a FP constant to a tagged register or slot.
//
// Finally, it is important that this function does not call `RecordWrite` which
// is why "setup" is in charge of all allocations and we are using
// SKIP_WRITE_BARRIER. The reason for this is that `RecordWrite` may clobber the
// top 64 bits of Simd128 registers. This is the case on x64, ia32 and Arm64 for
// example.
Handle<Code> BuildTeardownFunction(Isolate* isolate,
CallDescriptor* call_descriptor,
std::vector<AllocatedOperand> parameters) {
CodeAssemblerTester tester(isolate, call_descriptor, "teardown");
CodeStubAssembler assembler(tester.state());
TNode<FixedArray> result_array = __ Cast(__ Parameter(1));
for (int i = 0; i < static_cast<int>(parameters.size()); i++) {
// The first argument is not used and the second is "result_array".
Node* param = __ Parameter(i + 2);
switch (parameters[i].representation()) {
case MachineRepresentation::kTagged:
__ StoreFixedArrayElement(result_array, i, param, SKIP_WRITE_BARRIER);
break;
// Box FP values into HeapNumbers.
case MachineRepresentation::kFloat32:
param =
tester.raw_assembler_for_testing()->ChangeFloat32ToFloat64(param);
V8_FALLTHROUGH;
case MachineRepresentation::kFloat64:
__ StoreObjectFieldNoWriteBarrier(
__ LoadFixedArrayElement(result_array, i), HeapNumber::kValueOffset,
param, MachineRepresentation::kFloat64);
break;
case MachineRepresentation::kSimd128: {
TNode<FixedArray> vector =
__ Cast(__ LoadFixedArrayElement(result_array, i));
for (int lane = 0; lane < 4; lane++) {
Node* lane_value =
__ SmiFromInt32(tester.raw_assembler_for_testing()->AddNode(
tester.raw_assembler_for_testing()
->machine()
->I32x4ExtractLane(lane),
param));
__ StoreFixedArrayElement(vector, lane, lane_value,
SKIP_WRITE_BARRIER);
}
break;
}
default:
UNREACHABLE();
break;
}
}
__ Return(result_array);
return tester.GenerateCodeCloseAndEscape();
}
// Print the content of `value`, representing the register or stack slot
// described by `operand`.
void PrintStateValue(std::ostream& os, Isolate* isolate, Handle<Object> value,
AllocatedOperand operand) {
switch (operand.representation()) {
case MachineRepresentation::kTagged:
if (value->IsSmi()) {
os << Smi::cast(*value)->value();
} else {
os << value->Number();
}
break;
case MachineRepresentation::kFloat32:
case MachineRepresentation::kFloat64:
os << value->Number();
break;
case MachineRepresentation::kSimd128: {
FixedArray* vector = FixedArray::cast(*value);
os << "[";
for (int lane = 0; lane < 4; lane++) {
os << Smi::cast(*vector->GetValueChecked<Smi>(isolate, lane))->value();
if (lane < 3) {
os << ", ";
}
}
os << "]";
break;
}
default:
UNREACHABLE();
break;
}
os << " (" << operand.representation() << " ";
if (operand.location_kind() == AllocatedOperand::REGISTER) {
os << "register";
} else {
DCHECK_EQ(operand.location_kind(), AllocatedOperand::STACK_SLOT);
os << "stack slot";
}
os << ")";
}
bool TestSimd128Moves() {
return CpuFeatures::SupportsWasmSimd128();
}
} // namespace
#undef __
// Representation of a test environment. It describes a set of registers, stack
// slots and constants available to the CodeGeneratorTester to perform moves
// with. It has the ability to randomly generate lists of moves and run the code
// generated by the CodeGeneratorTester.
//
// The following representations are tested:
// - kTagged
// - kFloat32
// - kFloat64
// - kSimd128 (if supported)
// There is no need to test using Word32 or Word64 as they are the same as
// Tagged as far as the code generator is concerned.
//
// Testing the generated code is achieved by wrapping it around `setup` and
// `teardown` functions, written using the CodeStubAssembler. The key idea here
// is that `teardown` and the generated code share the same custom
// CallDescriptor. This descriptor assigns parameters to either registers or
// stack slot of a given representation and therefore essentially describes the
// environment.
//
// What happens is the following:
//
// - The `setup` function receives a FixedArray as the initial state. It
// unpacks it and passes each element as arguments to the generated code
// `test`. We also pass the `teardown` function as a first argument as well
// as a newly allocated FixedArray as a second argument which will hold the
// final results. Thanks to the custom CallDescriptor, registers and stack
// slots get initialised according to the content of the initial FixedArray.
//
// - The `test` function performs the list of moves on its parameters and
// eventually tail-calls to its first parameter, which is the `teardown`
// function.
//
// - The `teardown` function receives the final results as a FixedArray, fills
// it with the rest of its arguments and returns it. Thanks to the
// tail-call, this is as if the `setup` function called `teardown` directly,
// except now moves were performed!
//
// .----------------setup--------------------------.
// | Take a FixedArray as parameters with |
// | all the initial values of registers |
// | and stack slots. | <- CodeStubAssembler
// | |
// | Allocate a new FixedArray `result` with |
// | initial values. |
// | |
// | Call test(teardown, result, state[0], |
// | state[1], state[2], ...); |
// '-----------------------------------------------'
// |
// V
// .----------------test-------------------------------.
// | - Move(param3, param42); |
// | - Swap(param64, param4); |
// | - Move(param2, param6); | <- CodeGeneratorTester
// | ... |
// | |
// | // "teardown" is the first parameter as well as |
// | // the callee. |
// | TailCall teardown(teardown, result, param2, ...); |
// '---------------------------------------------------'
// |
// V
// .----------------teardown---------------------------.
// | Fill in the incoming `result` FixedArray with all |
// | parameters and return it. | <- CodeStubAssembler
// '---------------------------------------------------'
class TestEnvironment : public HandleAndZoneScope {
public:
// These constants may be tuned to experiment with different environments.
static constexpr int kGeneralRegisterCount = 4;
static constexpr int kDoubleRegisterCount = 6;
static constexpr int kTaggedSlotCount = 64;
static constexpr int kFloat32SlotCount = 64;
static constexpr int kFloat64SlotCount = 64;
static constexpr int kSimd128SlotCount = 16;
// TODO(all): Test all types of constants (e.g. ExternalReference and
// HeapObject).
static constexpr int kSmiConstantCount = 4;
static constexpr int kFloatConstantCount = 4;
static constexpr int kDoubleConstantCount = 4;
TestEnvironment()
: blocks_(1, main_zone()),
code_(main_isolate(), main_zone(), &blocks_),
rng_(CcTest::random_number_generator()),
supported_reps_({MachineRepresentation::kTagged,
MachineRepresentation::kFloat32,
MachineRepresentation::kFloat64}) {
// Create and initialize a single empty block in blocks_.
InstructionBlock* block = new (main_zone()) InstructionBlock(
main_zone(), RpoNumber::FromInt(0), RpoNumber::Invalid(),
RpoNumber::Invalid(), false, false);
block->set_ao_number(RpoNumber::FromInt(0));
blocks_[0] = block;
stack_slot_count_ =
kTaggedSlotCount + kFloat32SlotCount + kFloat64SlotCount;
if (TestSimd128Moves()) {
stack_slot_count_ += kSimd128SlotCount;
supported_reps_.push_back(MachineRepresentation::kSimd128);
}
// The "teardown" and "test" functions share the same descriptor with the
// following signature:
// ~~~
// FixedArray f(CodeObject* teardown, FixedArray preallocated_result,
// // Tagged registers.
// Object*, Object*, ...,
// // FP registers.
// Float32, Float64, Simd128, ...,
// // Mixed stack slots.
// Float64, Object*, Float32, Simd128, ...);
// ~~~
LocationSignature::Builder test_signature(
main_zone(), 1,
2 + kGeneralRegisterCount + kDoubleRegisterCount + stack_slot_count_);
// The first parameter will be the code object of the "teardown"
// function. This way, the "test" function can tail-call to it.
test_signature.AddParam(LinkageLocation::ForRegister(
kReturnRegister0.code(), MachineType::AnyTagged()));
// The second parameter will be a pre-allocated FixedArray that the
// "teardown" function will fill with result and then return. We place this
// parameter on the first stack argument slot which is always -1. And
// therefore slots to perform moves on start at -2.
test_signature.AddParam(
LinkageLocation::ForCallerFrameSlot(-1, MachineType::AnyTagged()));
int slot_parameter_n = -2;
const int kTotalStackParameterCount = stack_slot_count_ + 1;
// Initialise registers.
// Make sure that the target has enough general purpose registers to
// generate a call to a CodeObject using this descriptor. We have reserved
// kReturnRegister0 as the first parameter, and the call will need a
// register to hold the CodeObject address. So the maximum number of
// registers left to test with is the number of available registers minus 2.
DCHECK_LE(
kGeneralRegisterCount,
RegisterConfiguration::Default()->num_allocatable_general_registers() -
2);
int32_t general_mask =
RegisterConfiguration::Default()->allocatable_general_codes_mask();
// kReturnRegister0 is used to hold the "teardown" code object, do not
// generate moves using it.
std::unique_ptr<const RegisterConfiguration> registers(
RegisterConfiguration::RestrictGeneralRegisters(
general_mask & ~kReturnRegister0.bit()));
for (int i = 0; i < kGeneralRegisterCount; i++) {
int code = registers->GetAllocatableGeneralCode(i);
AddRegister(&test_signature, MachineRepresentation::kTagged, code);
}
// We assume that Double, Float and Simd128 registers alias, depending on
// kSimpleFPAliasing. For this reason, we allocate a Float, Double and
// Simd128 together, hence the reason why `kDoubleRegisterCount` should be a
// multiple of 3 and 2 in case Simd128 is not supported.
static_assert(
((kDoubleRegisterCount % 2) == 0) && ((kDoubleRegisterCount % 3) == 0),
"kDoubleRegisterCount should be a multiple of two and three.");
for (int i = 0; i < kDoubleRegisterCount; i += 2) {
if (kSimpleFPAliasing) {
// Allocate three registers at once if kSimd128 is supported, else
// allocate in pairs.
AddRegister(&test_signature, MachineRepresentation::kFloat32,
registers->GetAllocatableFloatCode(i));
AddRegister(&test_signature, MachineRepresentation::kFloat64,
registers->GetAllocatableDoubleCode(i + 1));
if (TestSimd128Moves()) {
AddRegister(&test_signature, MachineRepresentation::kSimd128,
registers->GetAllocatableSimd128Code(i + 2));
i++;
}
} else {
// Make sure we do not allocate FP registers which alias. To do this, we
// allocate three 128-bit registers and then convert two of them to a
// float and a double. With this aliasing scheme, a Simd128 register
// aliases two Double registers and four Float registers, so we need to
// scale indexes accordingly:
//
// Simd128 register: q0, q1, q2, q3, q4, q5
// | | | |
// V V V V
// Aliases: s0, d2, q2, s12, d8, q5
//
// This isn't space efficient at all but suits our need.
static_assert(
kDoubleRegisterCount < 8,
"Arm has a q8 and a d16 register but no overlapping s32 register.");
int first_simd128 = registers->GetAllocatableSimd128Code(i);
int second_simd128 = registers->GetAllocatableSimd128Code(i + 1);
AddRegister(&test_signature, MachineRepresentation::kFloat32,
first_simd128 * 4);
AddRegister(&test_signature, MachineRepresentation::kFloat64,
second_simd128 * 2);
if (TestSimd128Moves()) {
int third_simd128 = registers->GetAllocatableSimd128Code(i + 2);
AddRegister(&test_signature, MachineRepresentation::kSimd128,
third_simd128);
i++;
}
}
}
// Initialise stack slots.
std::map<MachineRepresentation, int> slots = {
{MachineRepresentation::kTagged, kTaggedSlotCount},
{MachineRepresentation::kFloat32, kFloat32SlotCount},
{MachineRepresentation::kFloat64, kFloat64SlotCount}};
if (TestSimd128Moves()) {
slots.emplace(MachineRepresentation::kSimd128, kSimd128SlotCount);
}
// Allocate new slots until we run out of them.
while (std::any_of(slots.cbegin(), slots.cend(),
[](const std::pair<MachineRepresentation, int>& entry) {
// True if there are slots left to allocate for this
// representation.
return entry.second > 0;
})) {
// Pick a random MachineRepresentation from supported_reps_.
MachineRepresentation rep = CreateRandomMachineRepresentation();
auto entry = slots.find(rep);
DCHECK(entry != slots.end());
// We may have picked a representation for which all slots have already
// been allocated.
if (entry->second > 0) {
// Keep a map of (MachineRepresentation . std::vector<int>) with
// allocated slots to pick from for each representation.
int slot = slot_parameter_n;
slot_parameter_n -= (GetSlotSizeInBytes(rep) / kPointerSize);
AddStackSlot(&test_signature, rep, slot);
entry->second--;
}
}
// Initialise random constants.
// While constants do not know about Smis, we need to be able to
// differentiate between a pointer to a HeapNumber and a integer. For this
// reason, we make sure all integers are Smis, including constants.
for (int i = 0; i < kSmiConstantCount; i++) {
intptr_t smi_value = reinterpret_cast<intptr_t>(
Smi::FromInt(rng_->NextInt(Smi::kMaxValue)));
Constant constant = kPointerSize == 8
? Constant(static_cast<int64_t>(smi_value))
: Constant(static_cast<int32_t>(smi_value));
AddConstant(MachineRepresentation::kTagged, AllocateConstant(constant));
}
// Float and Double constants can be moved to both Tagged and FP registers
// or slots. Register them as compatible with both FP and Tagged
// destinations.
for (int i = 0; i < kFloatConstantCount; i++) {
int virtual_register =
AllocateConstant(Constant(DoubleToFloat32(rng_->NextDouble())));
AddConstant(MachineRepresentation::kTagged, virtual_register);
AddConstant(MachineRepresentation::kFloat32, virtual_register);
}
for (int i = 0; i < kDoubleConstantCount; i++) {
int virtual_register = AllocateConstant(Constant(rng_->NextDouble()));
AddConstant(MachineRepresentation::kTagged, virtual_register);
AddConstant(MachineRepresentation::kFloat64, virtual_register);
}
// The "teardown" function returns a FixedArray with the resulting state.
test_signature.AddReturn(LinkageLocation::ForRegister(
kReturnRegister0.code(), MachineType::AnyTagged()));
test_descriptor_ = new (main_zone())
CallDescriptor(CallDescriptor::kCallCodeObject, // kind
MachineType::AnyTagged(), // target MachineType
LinkageLocation::ForAnyRegister(
MachineType::AnyTagged()), // target location
test_signature.Build(), // location_sig
kTotalStackParameterCount, // stack_parameter_count
Operator::kNoProperties, // properties
kNoCalleeSaved, // callee-saved registers
kNoCalleeSaved, // callee-saved fp
CallDescriptor::kNoFlags); // flags
}
int AllocateConstant(Constant constant) {
int virtual_register = code_.NextVirtualRegister();
code_.AddConstant(virtual_register, constant);
return virtual_register;
}
// Register a constant referenced by `virtual_register` as compatible with
// `rep`.
void AddConstant(MachineRepresentation rep, int virtual_register) {
auto entry = allocated_constants_.find(rep);
if (entry == allocated_constants_.end()) {
allocated_constants_.emplace(
rep, std::vector<ConstantOperand>{ConstantOperand(virtual_register)});
} else {
entry->second.emplace_back(virtual_register);
}
}
// Register a new register or stack slot as compatible with `rep`. As opposed
// to constants, registers and stack slots are written to on `setup` and read
// from on `teardown`. Therefore they are part of the environment's layout,
// and are parameters of the `test` function.
void AddRegister(LocationSignature::Builder* test_signature,
MachineRepresentation rep, int code) {
AllocatedOperand operand(AllocatedOperand::REGISTER, rep, code);
layout_.push_back(operand);
test_signature->AddParam(LinkageLocation::ForRegister(
code, MachineType::TypeForRepresentation(rep)));
auto entry = allocated_registers_.find(rep);
if (entry == allocated_registers_.end()) {
allocated_registers_.emplace(rep, std::vector<AllocatedOperand>{operand});
} else {
entry->second.push_back(operand);
}
}
void AddStackSlot(LocationSignature::Builder* test_signature,
MachineRepresentation rep, int slot) {
AllocatedOperand operand(AllocatedOperand::STACK_SLOT, rep, slot);
layout_.push_back(operand);
test_signature->AddParam(LinkageLocation::ForCallerFrameSlot(
slot, MachineType::TypeForRepresentation(rep)));
auto entry = allocated_slots_.find(rep);
if (entry == allocated_slots_.end()) {
allocated_slots_.emplace(rep, std::vector<AllocatedOperand>{operand});
} else {
entry->second.push_back(operand);
}
}
// Generate a random initial state to test moves against. A "state" is a
// packed FixedArray with Smis and HeapNumbers, according to the layout of the
// environment.
Handle<FixedArray> GenerateInitialState() {
Handle<FixedArray> state = main_isolate()->factory()->NewFixedArray(
static_cast<int>(layout_.size()));
for (int i = 0; i < state->length(); i++) {
switch (layout_[i].representation()) {
case MachineRepresentation::kTagged:
state->set(i, Smi::FromInt(rng_->NextInt(Smi::kMaxValue)));
break;
case MachineRepresentation::kFloat32:
// HeapNumbers are Float64 values. However, we will convert it to a
// Float32 and back inside `setup` and `teardown`. Make sure the value
// we pick fits in a Float32.
state->set(
i, *main_isolate()->factory()->NewHeapNumber(
static_cast<double>(DoubleToFloat32(rng_->NextDouble()))));
break;
case MachineRepresentation::kFloat64:
state->set(
i, *main_isolate()->factory()->NewHeapNumber(rng_->NextDouble()));
break;
case MachineRepresentation::kSimd128: {
Handle<FixedArray> vector =
main_isolate()->factory()->NewFixedArray(4);
for (int lane = 0; lane < 4; lane++) {
vector->set(lane, Smi::FromInt(rng_->NextInt(Smi::kMaxValue)));
}
state->set(i, *vector);
break;
}
default:
UNREACHABLE();
break;
}
}
return state;
}
// Run the code generated by a CodeGeneratorTester against `state_in` and
// return a new resulting state.
Handle<FixedArray> Run(Handle<Code> test, Handle<FixedArray> state_in) {
Handle<FixedArray> state_out = main_isolate()->factory()->NewFixedArray(
static_cast<int>(layout_.size()));
{
#ifdef ENABLE_SLOW_DCHECKS
// The "setup" and "teardown" functions are relatively big, and with
// runtime assertions enabled they get so big that memory during register
// allocation becomes a problem. Temporarily disable such assertions.
bool old_enable_slow_asserts = FLAG_enable_slow_asserts;
FLAG_enable_slow_asserts = false;
#endif
Handle<Code> setup =
BuildSetupFunction(main_isolate(), test_descriptor_, layout_);
#ifdef ENABLE_SLOW_DCHECKS
FLAG_enable_slow_asserts = old_enable_slow_asserts;
#endif
// FunctionTester maintains its own HandleScope which means that its
// return value will be freed along with it. Copy the result into
// state_out.
FunctionTester ft(setup, 2);
Handle<FixedArray> result = ft.CallChecked<FixedArray>(test, state_in);
CHECK_EQ(result->length(), state_in->length());
result->CopyTo(0, *state_out, 0, result->length());
}
return state_out;
}
// For a given operand representing either a register or a stack slot, return
// what position it should live in inside a FixedArray state.
int OperandToStatePosition(const AllocatedOperand& operand) const {
// Search `layout_` for `operand`.
auto it = std::find_if(layout_.cbegin(), layout_.cend(),
[operand](const AllocatedOperand& this_operand) {
return this_operand.Equals(operand);
});
DCHECK_NE(it, layout_.cend());
return static_cast<int>(std::distance(layout_.cbegin(), it));
}
// Perform the given list of moves on `state_in` and return a newly allocated
// state with the results.
Handle<FixedArray> SimulateMoves(ParallelMove* moves,
Handle<FixedArray> state_in) {
Handle<FixedArray> state_out = main_isolate()->factory()->NewFixedArray(
static_cast<int>(layout_.size()));
// We do not want to modify `state_in` in place so perform the moves on a
// copy.
state_in->CopyTo(0, *state_out, 0, state_in->length());
for (auto move : *moves) {
int to_index =
OperandToStatePosition(AllocatedOperand::cast(move->destination()));
InstructionOperand from = move->source();
if (from.IsConstant()) {
Constant constant =
code_.GetConstant(ConstantOperand::cast(from).virtual_register());
Handle<Object> constant_value;
switch (constant.type()) {
case Constant::kInt32:
constant_value =
Handle<Smi>(reinterpret_cast<Smi*>(
static_cast<intptr_t>(constant.ToInt32())),
main_isolate());
break;
case Constant::kInt64:
constant_value =
Handle<Smi>(reinterpret_cast<Smi*>(
static_cast<intptr_t>(constant.ToInt64())),
main_isolate());
break;
case Constant::kFloat32:
constant_value = main_isolate()->factory()->NewHeapNumber(
static_cast<double>(constant.ToFloat32()));
break;
case Constant::kFloat64:
constant_value = main_isolate()->factory()->NewHeapNumber(
constant.ToFloat64().value());
break;
default:
UNREACHABLE();
break;
}
state_out->set(to_index, *constant_value);
} else {
int from_index = OperandToStatePosition(AllocatedOperand::cast(from));
state_out->set(to_index, *state_out->GetValueChecked<Object>(
main_isolate(), from_index));
}
}
return state_out;
}
// Perform the given list of swaps on `state_in` and return a newly allocated
// state with the results.
Handle<FixedArray> SimulateSwaps(ParallelMove* swaps,
Handle<FixedArray> state_in) {
Handle<FixedArray> state_out = main_isolate()->factory()->NewFixedArray(
static_cast<int>(layout_.size()));
// We do not want to modify `state_in` in place so perform the swaps on a
// copy.
state_in->CopyTo(0, *state_out, 0, state_in->length());
for (auto swap : *swaps) {
int lhs_index =
OperandToStatePosition(AllocatedOperand::cast(swap->destination()));
int rhs_index =
OperandToStatePosition(AllocatedOperand::cast(swap->source()));
Handle<Object> lhs =
state_out->GetValueChecked<Object>(main_isolate(), lhs_index);
Handle<Object> rhs =
state_out->GetValueChecked<Object>(main_isolate(), rhs_index);
state_out->set(lhs_index, *rhs);
state_out->set(rhs_index, *lhs);
}
return state_out;
}
// Compare the given state with a reference.
void CheckState(Handle<FixedArray> actual, Handle<FixedArray> expected) {
for (int i = 0; i < static_cast<int>(layout_.size()); i++) {
Handle<Object> actual_value =
actual->GetValueChecked<Object>(main_isolate(), i);
Handle<Object> expected_value =
expected->GetValueChecked<Object>(main_isolate(), i);
if (!CompareValues(actual_value, expected_value,
layout_[i].representation())) {
std::ostringstream expected_str;
PrintStateValue(expected_str, main_isolate(), expected_value,
layout_[i]);
std::ostringstream actual_str;
PrintStateValue(actual_str, main_isolate(), actual_value, layout_[i]);
V8_Fatal(__FILE__, __LINE__, "Expected: '%s' but got '%s'",
expected_str.str().c_str(), actual_str.str().c_str());
}
}
}
bool CompareValues(Handle<Object> actual, Handle<Object> expected,
MachineRepresentation rep) {
switch (rep) {
case MachineRepresentation::kTagged:
case MachineRepresentation::kFloat32:
case MachineRepresentation::kFloat64:
return actual->StrictEquals(*expected);
case MachineRepresentation::kSimd128:
for (int lane = 0; lane < 4; lane++) {
Handle<Smi> actual_lane =
FixedArray::cast(*actual)->GetValueChecked<Smi>(main_isolate(),
lane);
Handle<Smi> expected_lane =
FixedArray::cast(*expected)->GetValueChecked<Smi>(main_isolate(),
lane);
if (!actual_lane->StrictEquals(*expected_lane)) {
return false;
}
}
return true;
default:
UNREACHABLE();
break;
}
}
enum OperandConstraint {
kNone,
// Restrict operands to non-constants. This is useful when generating a
// destination.
kCannotBeConstant
};
// Generate parallel moves at random. Note that they may not be compatible
// between each other as this doesn't matter to the code generator.
ParallelMove* GenerateRandomMoves(int size) {
ParallelMove* parallel_move = new (main_zone()) ParallelMove(main_zone());
for (int i = 0; i < size;) {
MachineRepresentation rep = CreateRandomMachineRepresentation();
MoveOperands mo(CreateRandomOperand(kNone, rep),
CreateRandomOperand(kCannotBeConstant, rep));
// It isn't valid to call `AssembleMove` and `AssembleSwap` with redundant
// moves.
if (mo.IsRedundant()) continue;
parallel_move->AddMove(mo.source(), mo.destination());
// Iterate only when a move was created.
i++;
}
return parallel_move;
}
ParallelMove* GenerateRandomSwaps(int size) {
ParallelMove* parallel_move = new (main_zone()) ParallelMove(main_zone());
for (int i = 0; i < size;) {
MachineRepresentation rep = CreateRandomMachineRepresentation();
InstructionOperand lhs = CreateRandomOperand(kCannotBeConstant, rep);
InstructionOperand rhs = CreateRandomOperand(kCannotBeConstant, rep);
MoveOperands mo(lhs, rhs);
// It isn't valid to call `AssembleMove` and `AssembleSwap` with redundant
// moves.
if (mo.IsRedundant()) continue;
// Canonicalize the swap: the register operand has to be the left hand
// side.
if (lhs.IsStackSlot() || lhs.IsFPStackSlot()) {
std::swap(lhs, rhs);
}
parallel_move->AddMove(lhs, rhs);
// Iterate only when a swap was created.
i++;
}
return parallel_move;
}
MachineRepresentation CreateRandomMachineRepresentation() {
int index = rng_->NextInt(static_cast<int>(supported_reps_.size()));
return supported_reps_[index];
}
InstructionOperand CreateRandomOperand(OperandConstraint constraint,
MachineRepresentation rep) {
// Only generate a Constant if the operand is a source and we have a
// constant with a compatible representation in stock.
bool generate_constant =
(constraint != kCannotBeConstant) &&
(allocated_constants_.find(rep) != allocated_constants_.end());
switch (rng_->NextInt(generate_constant ? 3 : 2)) {
case 0:
return CreateRandomStackSlotOperand(rep);
case 1:
return CreateRandomRegisterOperand(rep);
case 2:
return CreateRandomConstant(rep);
}
UNREACHABLE();
}
AllocatedOperand CreateRandomRegisterOperand(MachineRepresentation rep) {
int index =
rng_->NextInt(static_cast<int>(allocated_registers_[rep].size()));
return allocated_registers_[rep][index];
}
AllocatedOperand CreateRandomStackSlotOperand(MachineRepresentation rep) {
int index = rng_->NextInt(static_cast<int>(allocated_slots_[rep].size()));
return allocated_slots_[rep][index];
}
ConstantOperand CreateRandomConstant(MachineRepresentation rep) {
int index =
rng_->NextInt(static_cast<int>(allocated_constants_[rep].size()));
return allocated_constants_[rep][index];
}
v8::base::RandomNumberGenerator* rng() const { return rng_; }
InstructionSequence* code() { return &code_; }
CallDescriptor* test_descriptor() { return test_descriptor_; }
int stack_slot_count() const { return stack_slot_count_; }
private:
ZoneVector<InstructionBlock*> blocks_;
InstructionSequence code_;
v8::base::RandomNumberGenerator* rng_;
// The layout describes the type of each element in the environment, in order.
std::vector<AllocatedOperand> layout_;
CallDescriptor* test_descriptor_;
// Allocated constants, registers and stack slots that we can generate moves
// with. Each per compatible representation.
std::vector<MachineRepresentation> supported_reps_;
std::map<MachineRepresentation, std::vector<ConstantOperand>>
allocated_constants_;
std::map<MachineRepresentation, std::vector<AllocatedOperand>>
allocated_registers_;
std::map<MachineRepresentation, std::vector<AllocatedOperand>>
allocated_slots_;
int stack_slot_count_;
};
// static
constexpr int TestEnvironment::kGeneralRegisterCount;
constexpr int TestEnvironment::kDoubleRegisterCount;
constexpr int TestEnvironment::kTaggedSlotCount;
constexpr int TestEnvironment::kFloat32SlotCount;
constexpr int TestEnvironment::kFloat64SlotCount;
constexpr int TestEnvironment::kSimd128SlotCount;
constexpr int TestEnvironment::kSmiConstantCount;
constexpr int TestEnvironment::kFloatConstantCount;
constexpr int TestEnvironment::kDoubleConstantCount;
// Wrapper around the CodeGenerator. Code generated by this can only be called
// using the given `TestEnvironment`.
class CodeGeneratorTester {
public:
explicit CodeGeneratorTester(TestEnvironment* environment,
int extra_stack_space = 0)
: zone_(environment->main_zone()),
info_(ArrayVector("test"), environment->main_zone(), Code::STUB),
linkage_(environment->test_descriptor()),
frame_(environment->test_descriptor()->CalculateFixedFrameSize()) {
// Pick half of the stack parameters at random and move them into spill
// slots, seperated by `extra_stack_space` bytes.
// When testing a move with stack slots using CheckAssembleMove or
// CheckAssembleSwap, we'll transparently make use of local spill slots
// instead of stack parameters for those that were picked. This allows us to
// test negative, positive, far and near ranges.
for (int i = 0; i < (environment->stack_slot_count() / 2);) {
MachineRepresentation rep =
environment->CreateRandomMachineRepresentation();
LocationOperand old_slot =
LocationOperand::cast(environment->CreateRandomStackSlotOperand(rep));
// Do not pick the same slot twice.
if (GetSpillSlot(&old_slot) != spill_slots_.end()) {
continue;
}
LocationOperand new_slot =
AllocatedOperand(LocationOperand::STACK_SLOT, rep,
frame_.AllocateSpillSlot(GetSlotSizeInBytes(rep)));
// Artificially create space on the stack by allocating a new slot.
if (extra_stack_space > 0) {
frame_.AllocateSpillSlot(extra_stack_space);
}
spill_slots_.emplace_back(old_slot, new_slot);
i++;
}
generator_ = new CodeGenerator(
environment->main_zone(), &frame_, &linkage_, environment->code(),
&info_, environment->main_isolate(), base::Optional<OsrHelper>(),
kNoSourcePosition, nullptr, PoisoningMitigationLevel::kDontPoison,
AssemblerOptions::Default(environment->main_isolate()),