[ignition] Rewrite reverse iterator as random iterator

test/unittests/interpreter/bytecode-array-random-iterator-unittest.cc

 // Copyright 2015 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-reverse-iterator.h"
+#include "src/interpreter/bytecode-array-random-iterator.h"
 #include "test/unittests/test-utils.h"
 
 namespace v8 {
 namespace internal {
 namespace interpreter {
 
-class BytecodeArrayReverseIteratorTest : public TestWithIsolateAndZone {
+class BytecodeArrayRandomIteratorTest : public TestWithIsolateAndZone {
  public:
-  BytecodeArrayReverseIteratorTest() {}
-  ~BytecodeArrayReverseIteratorTest() override {}
+  BytecodeArrayRandomIteratorTest() {}
+  ~BytecodeArrayRandomIteratorTest() override {}
 };
 
-TEST_F(BytecodeArrayReverseIteratorTest, IteratesBytecodeArray) {
+TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
   // Use a builder to create an array with containing multiple bytecodes
   // with 0, 1 and 2 operands.
   BytecodeArrayBuilder builder(isolate(), zone(), 3, 3, 0);
   Factory* factory = isolate()->factory();
   Handle<HeapObject> heap_num_0 = factory->NewHeapNumber(2.718);
   Handle<HeapObject> heap_num_1 = factory->NewHeapNumber(2147483647);
   Smi* zero = Smi::kZero;
   Smi* smi_0 = Smi::FromInt(64);
   Smi* smi_1 = Smi::FromInt(-65536);
   Register reg_0(0);
@@ skipping 25 matching lines @@
       .StoreAccumulatorInRegister(param)
       .CallRuntimeForPair(Runtime::kLoadLookupSlotForCall, param, pair)
       .ForInPrepare(reg_0, triple)
       .CallRuntime(Runtime::kLoadIC_Miss, reg_0)
       .Debugger()
       .LoadGlobal(name, 0x10000000, TypeofMode::NOT_INSIDE_TYPEOF)
       .Return();
 
   // Test iterator sees the expected output from the builder.
   Handle<BytecodeArray> bytecodeArray = builder.ToBytecodeArray(isolate());
-  BytecodeArrayReverseIterator iterator(bytecodeArray, zone());
+  BytecodeArrayRandomIterator iterator(bytecodeArray, zone());
   const int kPrefixByteSize = 1;
   int offset = bytecodeArray->length();
 
+  iterator.GoToEnd();
+
   offset -= Bytecodes::Size(Bytecode::kReturn, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kReturn);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kLdaGlobal, OperandScale::kQuadruple) +
             kPrefixByteSize;
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kLdaGlobal);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kQuadruple);
   CHECK_EQ(iterator.current_bytecode_size(), 10);
   CHECK_EQ(iterator.GetIndexOperand(1), 0x10000000u);
-  iterator.Advance();
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kDebugger, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kDebugger);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kCallRuntime, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kCallRuntime);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRuntimeIdOperand(0), Runtime::kLoadIC_Miss);
   CHECK_EQ(iterator.GetRegisterOperand(1).index(), reg_0.index());
   CHECK_EQ(iterator.GetRegisterCountOperand(2), 1u);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kForInPrepare, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kForInPrepare);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
   CHECK_EQ(iterator.GetRegisterOperandRange(0), 1);
   CHECK_EQ(iterator.GetRegisterOperand(1).index(), reg_0.index());
   CHECK_EQ(iterator.GetRegisterOperandRange(1), 3);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -=
       Bytecodes::Size(Bytecode::kCallRuntimeForPair, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kCallRuntimeForPair);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRuntimeIdOperand(0), Runtime::kLoadLookupSlotForCall);
   CHECK_EQ(iterator.GetRegisterOperand(1).index(), param.index());
   CHECK_EQ(iterator.GetRegisterOperandRange(1), 1);
   CHECK_EQ(iterator.GetRegisterCountOperand(2), 1u);
   CHECK_EQ(iterator.GetRegisterOperand(3).index(), reg_0.index());
   CHECK_EQ(iterator.GetRegisterOperandRange(3), 2);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kStar);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRegisterOperand(0).index(), param.index());
   CHECK_EQ(iterator.GetRegisterOperandRange(0), 1);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kAdd, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kAdd);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
   CHECK_EQ(iterator.GetRegisterOperandRange(0), 1);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kLdaNamedProperty, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kLdaNamedProperty);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRegisterOperand(0).index(), reg_1.index());
   CHECK_EQ(iterator.GetIndexOperand(1), name_index);
   CHECK_EQ(iterator.GetIndexOperand(2), feedback_slot);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kStar);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRegisterOperand(0).index(), reg_1.index());
   CHECK_EQ(iterator.GetRegisterOperandRange(0), 1);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kAdd, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kAdd);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
   CHECK_EQ(iterator.GetRegisterOperandRange(0), 1);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kLdar, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kLdar);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kStar);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRegisterOperand(0).index(), reg_1.index());
   CHECK_EQ(iterator.GetRegisterOperandRange(0), 1);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kStackCheck, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kStackCheck);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(Bytecodes::NumberOfOperands(iterator.current_bytecode()), 0);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kLdaSmi, OperandScale::kQuadruple) +
             kPrefixByteSize;
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kLdaSmi);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kQuadruple);
   CHECK_EQ(Smi::FromInt(iterator.GetImmediateOperand(0)), smi_1);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kStar);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
   CHECK_EQ(iterator.GetRegisterOperandRange(0), 1);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kStackCheck, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kStackCheck);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(Bytecodes::NumberOfOperands(iterator.current_bytecode()), 0);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kLdaSmi, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kLdaSmi);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(Smi::FromInt(iterator.GetImmediateOperand(0)), smi_0);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kStar);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
   CHECK_EQ(iterator.GetRegisterOperandRange(0), 1);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kLdaZero, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kLdaZero);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kStar);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
   CHECK_EQ(iterator.GetRegisterOperandRange(0), 1);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kLdaConstant, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kLdaConstant);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK(iterator.GetConstantForIndexOperand(0).is_identical_to(heap_num_1));
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kStar);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
   CHECK_EQ(iterator.GetRegisterOperandRange(0), 1);
-  CHECK(!iterator.done());
-  iterator.Advance();
+  CHECK(iterator.Valid());
+  --iterator;
 
   offset -= Bytecodes::Size(Bytecode::kLdaConstant, OperandScale::kSingle);
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kLdaConstant);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK(iterator.GetConstantForIndexOperand(0).is_identical_to(heap_num_0));
-  CHECK(!iterator.done());
-  iterator.Advance();
-  CHECK(iterator.done());
+  CHECK(iterator.Valid());
+  --iterator;
+  CHECK(!iterator.Valid());
 }
 

[rmcilroy, 2016/11/29 12:09:32]

nit - could you add a random access iteration test please

[Leszek Swirski, 2016/11/29 15:05:35]

Done. I went a bit mad with tests here, the Ctrl, C and V keys on my keyboard
are worn out now.

 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8