[turbofan] initial framework for unittesting of register allocator

test/unittests/compiler/register-allocator-unittest.cc

+// Copyright 2014 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/base/utils/random-number-generator.h"
+#include "src/compiler/register-allocator.h"
+#include "test/unittests/test-utils.h"
+#include "testing/gmock/include/gmock/gmock.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+typedef BasicBlock::RpoNumber Rpo;
+
+namespace {
+
+static const char* general_register_names_[kMaxGeneralRegisters];
+static const char* double_register_names_[kMaxDoubleRegisters];
+static char register_names_[10 * (kMaxGeneralRegisters + kMaxDoubleRegisters)];
+
+
+static const char* GeneralRegisterName(int allocation_index) {
+  return general_register_names_[allocation_index];
+}
+
+
+static const char* DoubleRegisterName(int allocation_index) {
+  return double_register_names_[allocation_index];
+}
+
+
+static void InitializeRegisterNames() {
+  char* loc = register_names_;
+  for (int i = 0; i < kMaxGeneralRegisters; ++i) {
+    general_register_names_[i] = loc;
+    loc += base::OS::SNPrintF(loc, 100, "gp_%d", i);
+    *loc++ = 0;
+  }
+  for (int i = 0; i < kMaxDoubleRegisters; ++i) {
+    double_register_names_[i] = loc;
+    loc += base::OS::SNPrintF(loc, 100, "fp_%d", i) + 1;
+    *loc++ = 0;
+  }
+}
+
+}  // namespace
+
+
+// TODO(dcarney): fake opcodes.
+// TODO(dcarney): fix printing of sequence w.r.t fake opcodes and registers.
+class RegisterAllocatorTest : public TestWithZone {
+ public:
+  static const int kDefaultNRegs = 4;
+
+  RegisterAllocatorTest()
+      : basic_blocks_(zone()),
+        instruction_blocks_(zone()),
+        current_block_(NULL) {
+    InitializeRegisterNames();
+    config_.num_general_registers_ = kDefaultNRegs;
+    config_.num_double_registers_ = kDefaultNRegs;
+    config_.num_aliased_double_registers_ = kDefaultNRegs;
+    config_.GeneralRegisterName = GeneralRegisterName;
+    config_.DoubleRegisterName = DoubleRegisterName;
+  }
+
+  Frame* frame() {
+    if (frame_.is_empty()) {
+      frame_.Reset(new Frame());
+    }
+    return frame_.get();
+  }
+
+  InstructionSequence* sequence() {
+    if (sequence_.is_empty()) {
+      sequence_.Reset(new InstructionSequence(zone(), &instruction_blocks_));
+    }
+    return sequence_.get();
+  }
+
+  RegisterAllocator* allocator() {
+    if (allocator_.is_empty()) {
+      allocator_.Reset(
+          new RegisterAllocator(config_, zone(), frame(), sequence()));
+    }
+    return allocator_.get();
+  }
+
+  InstructionBlock* StartBlock(Rpo loop_header = Rpo::Invalid(),
+                               Rpo loop_end = Rpo::Invalid()) {
+    CHECK(current_block_ == NULL);
+    BasicBlock::Id block_id =
+        BasicBlock::Id::FromSize(instruction_blocks_.size());
+    BasicBlock* basic_block = new (zone()) BasicBlock(zone(), block_id);
+    basic_block->set_rpo_number(block_id.ToInt());
+    basic_block->set_ao_number(block_id.ToInt());
+    if (loop_header.IsValid()) {
+      basic_block->set_loop_depth(1);
+      basic_block->set_loop_header(basic_blocks_[loop_header.ToSize()]);
+      basic_block->set_loop_end(loop_end.ToInt());
+    }
+    InstructionBlock* instruction_block =
+        new (zone()) InstructionBlock(zone(), basic_block);
+    basic_blocks_.push_back(basic_block);
+    instruction_blocks_.push_back(instruction_block);
+    current_block_ = instruction_block;
+    sequence()->StartBlock(basic_block);
+    return instruction_block;
+  }
+
+  void EndBlock() {
+    CHECK(current_block_ != NULL);
+    sequence()->EndBlock(basic_blocks_[current_block_->rpo_number().ToSize()]);
+    current_block_ = NULL;
+  }
+
+  void Allocate() {
+    if (FLAG_trace_alloc) {
+      OFStream os(stdout);
+      os << "Before: " << std::endl << *sequence() << std::endl;
+    }
+    allocator()->Allocate();
+    if (FLAG_trace_alloc) {
+      OFStream os(stdout);
+      os << "After: " << std::endl << *sequence() << std::endl;
+    }
+  }
+
+  int NewReg() { return sequence()->NextVirtualRegister(); }
+
+  int Parameter() {
+    // TODO(dcarney): assert parameters before other instructions.
+    int vreg = NewReg();
+    InstructionOperand* outputs[1]{
+        Unallocated(UnallocatedOperand::MUST_HAVE_REGISTER, vreg)};
+    sequence()->AddInstruction(
+        Instruction::New(zone(), kArchNop, 1, outputs, 0, NULL, 0, NULL));
+    return vreg;
+  }
+
+  void Return(int vreg) {
+    InstructionOperand* inputs[1]{
+        Unallocated(UnallocatedOperand::MUST_HAVE_REGISTER, vreg)};
+    sequence()->AddInstruction(
+        Instruction::New(zone(), kArchNop, 0, NULL, 1, inputs, 0, NULL));
+  }
+
+  Instruction* Emit(int output_vreg, int input_vreg_0, int input_vreg_1) {
+    InstructionOperand* outputs[1]{
+        Unallocated(UnallocatedOperand::MUST_HAVE_REGISTER, output_vreg)};
+    InstructionOperand* inputs[2]{
+        Unallocated(UnallocatedOperand::MUST_HAVE_REGISTER, input_vreg_0),
+        Unallocated(UnallocatedOperand::MUST_HAVE_REGISTER, input_vreg_1)};
+    Instruction* instruction =
+        Instruction::New(zone(), kArchNop, 1, outputs, 2, inputs, 0, NULL);
+    sequence()->AddInstruction(instruction);
+    return instruction;
+  }
+
+ private:
+  InstructionOperand* Unallocated(UnallocatedOperand::ExtendedPolicy policy,
+                                  int vreg) {
+    UnallocatedOperand* op =
+        new (zone()) UnallocatedOperand(UnallocatedOperand::MUST_HAVE_REGISTER);
+    op->set_virtual_register(vreg);
+    return op;
+  }
+
+  RegisterAllocator::Config config_;
+  ZoneVector<BasicBlock*> basic_blocks_;
+  InstructionBlocks instruction_blocks_;
+  InstructionBlock* current_block_;
+  SmartPointer<Frame> frame_;
+  SmartPointer<RegisterAllocator> allocator_;
+  SmartPointer<InstructionSequence> sequence_;
+};
+
+
+TEST_F(RegisterAllocatorTest, CanAllocateThreeRegisters) {
+  StartBlock();
+  int a_reg = Parameter();
+  int b_reg = Parameter();
+  int c_reg = NewReg();
+  Instruction* res = Emit(c_reg, a_reg, b_reg);
+  Return(c_reg);
+  EndBlock();
+
+  Allocate();
+
+  ASSERT_TRUE(res->OutputAt(0)->IsRegister());
+}
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8