[Interpreter] Bytecode graph builder

test/cctest/compiler/test-bytecode-graph-builder.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 <iostream>
+
+#include "src/compiler/bytecode-graph-builder.h"
+#include "src/compiler/common-operator.h"
+#include "src/compiler/graph-visualizer.h"
+#include "src/compiler/instruction.h"
+#include "src/compiler/instruction-selector.h"
+#include "src/compiler/js-graph.h"
+#include "src/compiler/js-operator.h"
+#include "src/interpreter/bytecodes.h"
+#include "test/cctest/cctest.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+
+struct BytecodeSnippet {
+  const char* body;
+  int frame_size;
+  int parameter_count;
+  int bytecode_length;
+  const uint8_t bytecode[16];
+};
+
+
+// Helper macros for handcrafting bytecode sequences.
+#define B(x) static_cast<uint8_t>(interpreter::Bytecode::k##x)
+#define U8(x) static_cast<uint8_t>(x & 0xff)
+#define R(x) static_cast<uint8_t>(-x & 0xff)
+
+
+static const int kLastParamIndex =
+    -InterpreterFrameConstants::kLastParamFromRegisterPointer / kPointerSize;
+
+
+const BytecodeSnippet kBytecodeSnippets[] = {
+    {"var x = 0; return x;",
+     kPointerSize,
+     0,
+     6,
+     {
+         B(LdaZero),     //
+         B(Star), R(0),  //
+         B(Ldar), R(0),  //
+         B(Return)       //
+     }},
+    {"var x = 0; return x + 3;",
+     2 * kPointerSize,
+     0,
+     12,
+     {
+         B(LdaZero),         //
+         B(Star), R(0),      //
+         B(Ldar), R(0),      // Easy to spot r1 not really needed here.
+         B(Star), R(1),      // Dead store.
+         B(LdaSmi8), U8(3),  //
+         B(Add), R(1),       //
+         B(Return)           //
+     }},
+    {"function f(arg1, arg2, arg3, arg4, arg5, arg6, arg7) { return arg4; }",
+     0,
+     8,
+     3,
+     {
+         B(Ldar),                 //
+         R(kLastParamIndex - 3),  //
+         B(Return)                //
+     }},
+};
+
+
+TEST(BytecodeGraphBuilder) {
+  i::FLAG_ignition = true;
+  i::FLAG_always_opt = true;
+
+  HandleAndZoneScope test_scope;
+
+  size_t snippet_count =
+      sizeof(kBytecodeSnippets) / sizeof(kBytecodeSnippets[0]);
+  for (size_t i = 0; i < snippet_count; i++) {
+    Graph* graph = new (test_scope.main_zone()) Graph(test_scope.main_zone());
+    MachineOperatorBuilder* machine =
+        new (test_scope.main_zone()) MachineOperatorBuilder(
+            test_scope.main_zone(), kMachPtr,
+            InstructionSelector::SupportedMachineOperatorFlags());
+    CommonOperatorBuilder* common = new (test_scope.main_zone())
+        CommonOperatorBuilder(test_scope.main_zone());
+    JSOperatorBuilder* javascript =
+        new (test_scope.main_zone()) JSOperatorBuilder(test_scope.main_zone());
+    JSGraph* jsgraph = new (test_scope.main_zone())
+        JSGraph(test_scope.main_isolate(), graph, common, javascript, machine);
+
+    const BytecodeSnippet& snippet = kBytecodeSnippets[i];
+    Handle<FixedArray> constant_pool =
+        test_scope.main_isolate()->factory()->NewFixedArray(0);
+    Handle<BytecodeArray> bytecode_array =
+        test_scope.main_isolate()->factory()->NewBytecodeArray(
+            snippet.bytecode_length, snippet.bytecode, snippet.frame_size,
+            snippet.parameter_count, constant_pool);
+
+    BytecodeGraphBuilder builder(test_scope.main_zone(), bytecode_array,
+                                 jsgraph);
+    builder.CreateGraphForTest();
+    std::cout << AsDOT(*builder.graph()) << std::endl;
+  }
+}
+
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8