[interpreter] Add fast path for dynamic global lookups

test/cctest/compiler/test-run-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 <utility>
 
 #include "src/compilation-info.h"
 #include "src/compiler/pipeline.h"
 #include "src/execution.h"
 #include "src/handles.h"
@@ skipping 1099 matching lines @@
              outer_eval_prologue, outer_eval_snippets[i].code_snippet,
              outer_eval_epilogue, kFunctionName);
 
     BytecodeGraphTester tester(isolate, zone, script.start());
     auto callable = tester.GetCallable<>();
     Handle<Object> return_value = callable().ToHandleChecked();
     CHECK(return_value->SameValue(*outer_eval_snippets[i].return_value()));
   }
 }
 
+TEST(BytecodeGraphBuilderLookupGlobalSlot) {
+  HandleAndZoneScope scope;
+  Isolate* isolate = scope.main_isolate();
+  Zone* zone = scope.main_zone();
+  Factory* factory = isolate->factory();
+
+  // Testing with eval called in the current context.
+  const char* inner_eval_prologue = "x = 0; function inner() {";
+  const char* inner_eval_epilogue = "}; return inner();";
+
+  ExpectedSnippet<0> inner_eval_snippets[] = {
+      {"eval(''); return x;", {factory->NewNumber(0)}},
+      {"eval('var x = 1'); return x;", {factory->NewNumber(1)}},
+      {"'use strict'; eval('var x = 1'); return x;", {factory->NewNumber(0)}}};
+
+  for (size_t i = 0; i < arraysize(inner_eval_snippets); i++) {
+    ScopedVector<char> script(1024);
+    SNPrintF(script, "function %s(p1) { %s %s %s } ; %s() ;", kFunctionName,

[rmcilroy, 2016/09/19 09:04:29]

(optional) you could just use std::string to construct this string. like some
other tests.

[Leszek Swirski, 2016/09/19 10:34:51]

Hm, the surrounding code uses SNPrintF so I wanted to keep it consistent.

+             inner_eval_prologue, inner_eval_snippets[i].code_snippet,
+             inner_eval_epilogue, kFunctionName);
+
+    BytecodeGraphTester tester(isolate, zone, script.start());
+    auto callable = tester.GetCallable<>();
+    Handle<Object> return_value = callable().ToHandleChecked();
+    CHECK(return_value->SameValue(*inner_eval_snippets[i].return_value()));
+  }
+
+  // Testing with eval called in a parent context.
+  const char* outer_eval_prologue = "";
+  const char* outer_eval_epilogue =
+      "function inner() { return x; }; return inner();";
+
+  ExpectedSnippet<0> outer_eval_snippets[] = {
+      {"x = 0; eval('');", {factory->NewNumber(0)}},
+      {"x = 0; eval('var x = 1');", {factory->NewNumber(1)}},
+      {"'use strict'; x = 0; eval('var x = 1');", {factory->NewNumber(0)}}};
+
+  for (size_t i = 0; i < arraysize(outer_eval_snippets); i++) {
+    ScopedVector<char> script(1024);
+    SNPrintF(script, "function %s() { %s %s %s } ; %s() ;", kFunctionName,

[rmcilroy, 2016/09/19 09:04:29]

ditto

[Leszek Swirski, 2016/09/19 10:34:51]

As above

+             outer_eval_prologue, outer_eval_snippets[i].code_snippet,
+             outer_eval_epilogue, kFunctionName);
+
+    BytecodeGraphTester tester(isolate, zone, script.start());
+    auto callable = tester.GetCallable<>();
+    Handle<Object> return_value = callable().ToHandleChecked();
+    CHECK(return_value->SameValue(*outer_eval_snippets[i].return_value()));
+  }
+}
+
 TEST(BytecodeGraphBuilderLookupSlotWide) {
   HandleAndZoneScope scope;
   Isolate* isolate = scope.main_isolate();
   Zone* zone = scope.main_zone();
   Factory* factory = isolate->factory();
 
   const char* function_prologue =
       "var f;"
       "var x = 12;"
       "y = 10;"
@@ skipping 1876 matching lines @@
 
   BytecodeGraphTester tester(isolate, zone, script.start());
   auto callable = tester.GetCallable<>();
   Handle<Object> return_value = callable().ToHandleChecked();
   CHECK(return_value->SameValue(*snippet.return_value()));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8