[Interpreter] Basic flow control.

test/unittests/interpreter/bytecode-array-builder-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/v8.h"
 
 #include "src/interpreter/bytecode-array-builder.h"
+#include "src/interpreter/bytecode-array-iterator.h"
 #include "test/unittests/test-utils.h"
 
 namespace v8 {
 namespace internal {
 namespace interpreter {
 
 class BytecodeArrayBuilderTest : public TestWithIsolateAndZone {
  public:
   BytecodeArrayBuilderTest() {}
   ~BytecodeArrayBuilderTest() override {}
@@ skipping 30 matching lines @@
   // Call operations.
   builder.Call(reg, reg, 0);
 
   // Emit binary operators invocations.
   builder.BinaryOperation(Token::Value::ADD, reg)
       .BinaryOperation(Token::Value::SUB, reg)
       .BinaryOperation(Token::Value::MUL, reg)
       .BinaryOperation(Token::Value::DIV, reg)
       .BinaryOperation(Token::Value::MOD, reg);
 
+  // Emit test operators invocations.
+  builder.CompareOperation(Token::Value::EQ, reg)
+      .CompareOperation(Token::Value::NE, reg)
+      .CompareOperation(Token::Value::EQ_STRICT, reg)
+      .CompareOperation(Token::Value::NE_STRICT, reg)
+      .CompareOperation(Token::Value::LT, reg)
+      .CompareOperation(Token::Value::GT, reg)
+      .CompareOperation(Token::Value::LTE, reg)
+      .CompareOperation(Token::Value::GTE, reg)
+      .CompareOperation(Token::Value::INSTANCEOF, reg)
+      .CompareOperation(Token::Value::IN, reg);
+
   // Emit control flow. Return must be the last instruction.
+  BytecodeLabel start;
+  builder.Bind(&start);
+  // Short jumps with Imm8 operands
+  builder.Jump(&start).JumpIfTrue(&start).JumpIfFalse(&start);
+  // Insert dummy ops to force longer jumps
+  for (int i = 0; i < 128; i++) {
+    builder.LoadTrue();
+  }
+  // Longer jumps requiring Constant operand
+  builder.Jump(&start).JumpIfTrue(&start).JumpIfFalse(&start);
   builder.Return();
 
   // Generate BytecodeArray.
   Handle<BytecodeArray> the_array = builder.ToBytecodeArray();
   CHECK_EQ(the_array->frame_size(), builder.locals_count() * kPointerSize);
 
   // Build scorecard of bytecodes encountered in the BytecodeArray.
   std::vector<int> scorecard(Bytecodes::ToByte(Bytecode::kLast) + 1);
   Bytecode final_bytecode = Bytecode::kLdaZero;
   for (int i = 0; i < the_array->length(); i++) {
@@ skipping 104 matching lines @@
       .LoadLiteral(large_smi)
       .LoadLiteral(heap_num_1)
       .LoadLiteral(heap_num_1)
       .LoadLiteral(heap_num_2_copy);
 
   Handle<BytecodeArray> array = builder.ToBytecodeArray();
   // Should only have one entry for each identical constant.
   CHECK_EQ(array->constant_pool()->length(), 3);
 }
 
+
+TEST_F(BytecodeArrayBuilderTest, ForwardJumps) {
+  static const int kFarJumpDistance = 256;
+
+  BytecodeArrayBuilder builder(isolate(), zone());
+  builder.set_parameter_count(0);
+  builder.set_locals_count(0);
+
+  BytecodeLabel far0, far1, far2;
+  BytecodeLabel near0, near1, near2;
+
+  builder.Jump(&near0)
+      .JumpIfTrue(&near1)
+      .JumpIfFalse(&near2)
+      .Bind(&near0)
+      .Bind(&near1)
+      .Bind(&near2)
+      .Jump(&far0)
+      .JumpIfTrue(&far1)
+      .JumpIfFalse(&far2);
+  for (int i = 0; i < kFarJumpDistance - 6; i++) {
+    builder.LoadUndefined();
+  }
+  builder.Bind(&far0).Bind(&far1).Bind(&far2);
+  builder.Return();
+
+  Handle<BytecodeArray> array = builder.ToBytecodeArray();
+  DCHECK_EQ(array->length(), 12 + kFarJumpDistance - 6 + 1);
+
+  BytecodeArrayIterator iterator(array);
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpSmi8);
+  CHECK_EQ(iterator.GetSmi8Operand(0), 6);
+  iterator.Advance();
+
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpIfTrueSmi8);
+  CHECK_EQ(iterator.GetSmi8Operand(0), 4);
+  iterator.Advance();
+
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpIfFalseSmi8);
+  CHECK_EQ(iterator.GetSmi8Operand(0), 2);
+  iterator.Advance();
+
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpConstant);
+  CHECK_EQ(*iterator.GetConstantForIndexOperand(0),
+           Smi::FromInt(kFarJumpDistance));
+  CHECK_EQ(
+      array->get(iterator.current_offset() +
+                 Smi::cast(*iterator.GetConstantForIndexOperand(0))->value()),
+      Bytecodes::ToByte(Bytecode::kReturn));
+  iterator.Advance();
+
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpIfTrueConstant);
+  CHECK_EQ(*iterator.GetConstantForIndexOperand(0),
+           Smi::FromInt(kFarJumpDistance - 2));
+  CHECK_EQ(
+      array->get(iterator.current_offset() +
+                 Smi::cast(*iterator.GetConstantForIndexOperand(0))->value()),
+      Bytecodes::ToByte(Bytecode::kReturn));
+  iterator.Advance();
+
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpIfFalseConstant);
+  CHECK_EQ(*iterator.GetConstantForIndexOperand(0),
+           Smi::FromInt(kFarJumpDistance - 4));
+  CHECK_EQ(
+      array->get(iterator.current_offset() +
+                 Smi::cast(*iterator.GetConstantForIndexOperand(0))->value()),
+      Bytecodes::ToByte(Bytecode::kReturn));
+  iterator.Advance();
+}
+
+
+TEST_F(BytecodeArrayBuilderTest, BackwardJumps) {
+  BytecodeArrayBuilder builder(isolate(), zone());
+  builder.set_parameter_count(0);
+  builder.set_locals_count(0);
+
+  BytecodeLabel label0, label1, label2;
+  builder.Bind(&label0)
+      .Jump(&label0)
+      .Bind(&label1)
+      .JumpIfTrue(&label1)
+      .Bind(&label2)
+      .JumpIfFalse(&label2);
+  for (int i = 0; i < 64; i++) {
+    builder.Jump(&label2);
+  }
+  builder.JumpIfFalse(&label2);
+  builder.JumpIfTrue(&label1);
+  builder.Jump(&label0);
+  builder.Return();
+
+  Handle<BytecodeArray> array = builder.ToBytecodeArray();
+  BytecodeArrayIterator iterator(array);
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpSmi8);
+  CHECK_EQ(iterator.GetSmi8Operand(0), 0);
+  iterator.Advance();
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpIfTrueSmi8);
+  CHECK_EQ(iterator.GetSmi8Operand(0), 0);
+  iterator.Advance();
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpIfFalseSmi8);
+  CHECK_EQ(iterator.GetSmi8Operand(0), 0);
+  iterator.Advance();
+  for (int i = 0; i < 64; i++) {
+    CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpSmi8);
+    CHECK_EQ(iterator.GetSmi8Operand(0), -i * 2 - 2);
+    iterator.Advance();
+  }
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpIfFalseConstant);
+  CHECK_EQ(Smi::cast(*iterator.GetConstantForIndexOperand(0))->value(), -130);
+  iterator.Advance();
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpIfTrueConstant);
+  CHECK_EQ(Smi::cast(*iterator.GetConstantForIndexOperand(0))->value(), -134);
+  iterator.Advance();
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpConstant);
+  CHECK_EQ(Smi::cast(*iterator.GetConstantForIndexOperand(0))->value(), -138);
+  iterator.Advance();
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kReturn);
+  iterator.Advance();
+  CHECK(iterator.done());
+}
+
+
+TEST_F(BytecodeArrayBuilderTest, LabelReuse) {
+  BytecodeArrayBuilder builder(isolate(), zone());
+  builder.set_parameter_count(0);
+  builder.set_locals_count(0);
+
+  // Labels can only have 1 forward reference, but
+  // can be referred to mulitple times once bound.
+  BytecodeLabel label;
+
+  builder.Jump(&label).Bind(&label).Jump(&label).Jump(&label).Return();
+
+  Handle<BytecodeArray> array = builder.ToBytecodeArray();
+  BytecodeArrayIterator iterator(array);
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpSmi8);
+  CHECK_EQ(iterator.GetSmi8Operand(0), 2);
+  iterator.Advance();
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpSmi8);
+  CHECK_EQ(iterator.GetSmi8Operand(0), 0);
+  iterator.Advance();
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpSmi8);
+  CHECK_EQ(iterator.GetSmi8Operand(0), -2);
+  iterator.Advance();
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kReturn);
+  iterator.Advance();
+  CHECK(iterator.done());
+}
+
+
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8