1// Copyright 2014 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "src/compiler/js-context-specialization.h"
6#include "src/compiler/js-operator.h"
7#include "src/compiler/node-matchers.h"
8#include "src/compiler/node-properties-inl.h"
9#include "src/compiler/source-position.h"
10#include "src/compiler/typer.h"
11#include "test/cctest/cctest.h"
12#include "test/cctest/compiler/function-tester.h"
13#include "test/cctest/compiler/graph-builder-tester.h"
14
15using namespace v8::internal;
16using namespace v8::internal::compiler;
17
18class ContextSpecializationTester : public HandleAndZoneScope,
19                                    public DirectGraphBuilder {
20 public:
21  ContextSpecializationTester()
22      : DirectGraphBuilder(new (main_zone()) Graph(main_zone())),
23        common_(main_zone()),
24        javascript_(main_zone()),
25        machine_(),
26        simplified_(main_zone()),
27        typer_(main_zone()),
28        jsgraph_(graph(), common(), &javascript_, &typer_, &machine_),
29        info_(main_isolate(), main_zone()) {}
30
31  Factory* factory() { return main_isolate()->factory(); }
32  CommonOperatorBuilder* common() { return &common_; }
33  JSOperatorBuilder* javascript() { return &javascript_; }
34  SimplifiedOperatorBuilder* simplified() { return &simplified_; }
35  JSGraph* jsgraph() { return &jsgraph_; }
36  CompilationInfo* info() { return &info_; }
37
38 private:
39  CommonOperatorBuilder common_;
40  JSOperatorBuilder javascript_;
41  MachineOperatorBuilder machine_;
42  SimplifiedOperatorBuilder simplified_;
43  Typer typer_;
44  JSGraph jsgraph_;
45  CompilationInfo info_;
46};
47
48
49TEST(ReduceJSLoadContext) {
50  ContextSpecializationTester t;
51
52  Node* start = t.NewNode(t.common()->Start(0));
53  t.graph()->SetStart(start);
54
55  // Make a context and initialize it a bit for this test.
56  Handle<Context> native = t.factory()->NewNativeContext();
57  Handle<Context> subcontext1 = t.factory()->NewNativeContext();
58  Handle<Context> subcontext2 = t.factory()->NewNativeContext();
59  subcontext2->set_previous(*subcontext1);
60  subcontext1->set_previous(*native);
61  Handle<Object> expected = t.factory()->InternalizeUtf8String("gboy!");
62  const int slot = Context::GLOBAL_OBJECT_INDEX;
63  native->set(slot, *expected);
64
65  Node* const_context = t.jsgraph()->Constant(native);
66  Node* deep_const_context = t.jsgraph()->Constant(subcontext2);
67  Node* param_context = t.NewNode(t.common()->Parameter(0), start);
68  JSContextSpecializer spec(t.info(), t.jsgraph(), const_context);
69
70  {
71    // Mutable slot, constant context, depth = 0 => do nothing.
72    Node* load = t.NewNode(t.javascript()->LoadContext(0, 0, false),
73                           const_context, const_context, start);
74    Reduction r = spec.ReduceJSLoadContext(load);
75    CHECK(!r.Changed());
76  }
77
78  {
79    // Mutable slot, non-constant context, depth = 0 => do nothing.
80    Node* load = t.NewNode(t.javascript()->LoadContext(0, 0, false),
81                           param_context, param_context, start);
82    Reduction r = spec.ReduceJSLoadContext(load);
83    CHECK(!r.Changed());
84  }
85
86  {
87    // Mutable slot, constant context, depth > 0 => fold-in parent context.
88    Node* load = t.NewNode(
89        t.javascript()->LoadContext(2, Context::GLOBAL_EVAL_FUN_INDEX, false),
90        deep_const_context, deep_const_context, start);
91    Reduction r = spec.ReduceJSLoadContext(load);
92    CHECK(r.Changed());
93    Node* new_context_input = NodeProperties::GetValueInput(r.replacement(), 0);
94    CHECK_EQ(IrOpcode::kHeapConstant, new_context_input->opcode());
95    HeapObjectMatcher<Context> match(new_context_input);
96    CHECK_EQ(*native, *match.Value().handle());
97    ContextAccess access = OpParameter<ContextAccess>(r.replacement());
98    CHECK_EQ(Context::GLOBAL_EVAL_FUN_INDEX, access.index());
99    CHECK_EQ(0, access.depth());
100    CHECK_EQ(false, access.immutable());
101  }
102
103  {
104    // Immutable slot, constant context, depth = 0 => specialize.
105    Node* load = t.NewNode(t.javascript()->LoadContext(0, slot, true),
106                           const_context, const_context, start);
107    Reduction r = spec.ReduceJSLoadContext(load);
108    CHECK(r.Changed());
109    CHECK(r.replacement() != load);
110
111    HeapObjectMatcher<Object> match(r.replacement());
112    CHECK(match.HasValue());
113    CHECK_EQ(*expected, *match.Value().handle());
114  }
115
116  // TODO(titzer): test with other kinds of contexts, e.g. a function context.
117  // TODO(sigurds): test that loads below create context are not optimized
118}
119
120
121TEST(ReduceJSStoreContext) {
122  ContextSpecializationTester t;
123
124  Node* start = t.NewNode(t.common()->Start(0));
125  t.graph()->SetStart(start);
126
127  // Make a context and initialize it a bit for this test.
128  Handle<Context> native = t.factory()->NewNativeContext();
129  Handle<Context> subcontext1 = t.factory()->NewNativeContext();
130  Handle<Context> subcontext2 = t.factory()->NewNativeContext();
131  subcontext2->set_previous(*subcontext1);
132  subcontext1->set_previous(*native);
133  Handle<Object> expected = t.factory()->InternalizeUtf8String("gboy!");
134  const int slot = Context::GLOBAL_OBJECT_INDEX;
135  native->set(slot, *expected);
136
137  Node* const_context = t.jsgraph()->Constant(native);
138  Node* deep_const_context = t.jsgraph()->Constant(subcontext2);
139  Node* param_context = t.NewNode(t.common()->Parameter(0), start);
140  JSContextSpecializer spec(t.info(), t.jsgraph(), const_context);
141
142  {
143    // Mutable slot, constant context, depth = 0 => do nothing.
144    Node* load = t.NewNode(t.javascript()->StoreContext(0, 0), const_context,
145                           const_context, start);
146    Reduction r = spec.ReduceJSStoreContext(load);
147    CHECK(!r.Changed());
148  }
149
150  {
151    // Mutable slot, non-constant context, depth = 0 => do nothing.
152    Node* load = t.NewNode(t.javascript()->StoreContext(0, 0), param_context,
153                           param_context, start);
154    Reduction r = spec.ReduceJSStoreContext(load);
155    CHECK(!r.Changed());
156  }
157
158  {
159    // Immutable slot, constant context, depth = 0 => do nothing.
160    Node* load = t.NewNode(t.javascript()->StoreContext(0, slot), const_context,
161                           const_context, start);
162    Reduction r = spec.ReduceJSStoreContext(load);
163    CHECK(!r.Changed());
164  }
165
166  {
167    // Mutable slot, constant context, depth > 0 => fold-in parent context.
168    Node* load = t.NewNode(
169        t.javascript()->StoreContext(2, Context::GLOBAL_EVAL_FUN_INDEX),
170        deep_const_context, deep_const_context, start);
171    Reduction r = spec.ReduceJSStoreContext(load);
172    CHECK(r.Changed());
173    Node* new_context_input = NodeProperties::GetValueInput(r.replacement(), 0);
174    CHECK_EQ(IrOpcode::kHeapConstant, new_context_input->opcode());
175    HeapObjectMatcher<Context> match(new_context_input);
176    CHECK_EQ(*native, *match.Value().handle());
177    ContextAccess access = OpParameter<ContextAccess>(r.replacement());
178    CHECK_EQ(Context::GLOBAL_EVAL_FUN_INDEX, access.index());
179    CHECK_EQ(0, access.depth());
180    CHECK_EQ(false, access.immutable());
181  }
182}
183
184
185// TODO(titzer): factor out common code with effects checking in typed lowering.
186static void CheckEffectInput(Node* effect, Node* use) {
187  CHECK_EQ(effect, NodeProperties::GetEffectInput(use));
188}
189
190
191TEST(SpecializeToContext) {
192  ContextSpecializationTester t;
193
194  Node* start = t.NewNode(t.common()->Start(0));
195  t.graph()->SetStart(start);
196
197  // Make a context and initialize it a bit for this test.
198  Handle<Context> native = t.factory()->NewNativeContext();
199  Handle<Object> expected = t.factory()->InternalizeUtf8String("gboy!");
200  const int slot = Context::GLOBAL_OBJECT_INDEX;
201  native->set(slot, *expected);
202  t.info()->SetContext(native);
203
204  Node* const_context = t.jsgraph()->Constant(native);
205  Node* param_context = t.NewNode(t.common()->Parameter(0), start);
206  JSContextSpecializer spec(t.info(), t.jsgraph(), const_context);
207
208  {
209    // Check that SpecializeToContext() replaces values and forwards effects
210    // correctly, and folds values from constant and non-constant contexts
211    Node* effect_in = start;
212    Node* load = t.NewNode(t.javascript()->LoadContext(0, slot, true),
213                           const_context, const_context, effect_in);
214
215
216    Node* value_use = t.NewNode(t.simplified()->ChangeTaggedToInt32(), load);
217    Node* other_load = t.NewNode(t.javascript()->LoadContext(0, slot, true),
218                                 param_context, param_context, load);
219    Node* effect_use = other_load;
220    Node* other_use =
221        t.NewNode(t.simplified()->ChangeTaggedToInt32(), other_load);
222
223    Node* add = t.NewNode(t.javascript()->Add(), value_use, other_use,
224                          param_context, other_load, start);
225
226    Node* ret = t.NewNode(t.common()->Return(), add, effect_use, start);
227    Node* end = t.NewNode(t.common()->End(), ret);
228    USE(end);
229    t.graph()->SetEnd(end);
230
231    // Double check the above graph is what we expect, or the test is broken.
232    CheckEffectInput(effect_in, load);
233    CheckEffectInput(load, effect_use);
234
235    // Perform the substitution on the entire graph.
236    spec.SpecializeToContext();
237
238    // Effects should have been forwarded (not replaced with a value).
239    CheckEffectInput(effect_in, effect_use);
240
241    // Use of {other_load} should not have been replaced.
242    CHECK_EQ(other_load, other_use->InputAt(0));
243
244    Node* replacement = value_use->InputAt(0);
245    HeapObjectMatcher<Object> match(replacement);
246    CHECK(match.HasValue());
247    CHECK_EQ(*expected, *match.Value().handle());
248  }
249  // TODO(titzer): clean up above test and test more complicated effects.
250}
251
252
253TEST(SpecializeJSFunction_ToConstant1) {
254  FunctionTester T(
255      "(function() { var x = 1; function inc(a)"
256      " { return a + x; } return inc; })()");
257
258  T.CheckCall(1.0, 0.0, 0.0);
259  T.CheckCall(2.0, 1.0, 0.0);
260  T.CheckCall(2.1, 1.1, 0.0);
261}
262
263
264TEST(SpecializeJSFunction_ToConstant2) {
265  FunctionTester T(
266      "(function() { var x = 1.5; var y = 2.25; var z = 3.75;"
267      " function f(a) { return a - x + y - z; } return f; })()");
268
269  T.CheckCall(-3.0, 0.0, 0.0);
270  T.CheckCall(-2.0, 1.0, 0.0);
271  T.CheckCall(-1.9, 1.1, 0.0);
272}
273
274
275TEST(SpecializeJSFunction_ToConstant3) {
276  FunctionTester T(
277      "(function() { var x = -11.5; function inc()"
278      " { return (function(a) { return a + x; }); }"
279      " return inc(); })()");
280
281  T.CheckCall(-11.5, 0.0, 0.0);
282  T.CheckCall(-10.5, 1.0, 0.0);
283  T.CheckCall(-10.4, 1.1, 0.0);
284}
285
286
287TEST(SpecializeJSFunction_ToConstant_uninit) {
288  {
289    FunctionTester T(
290        "(function() { if (false) { var x = 1; } function inc(a)"
291        " { return x; } return inc; })()");  // x is undefined!
292
293    CHECK(T.Call(T.Val(0.0), T.Val(0.0)).ToHandleChecked()->IsUndefined());
294    CHECK(T.Call(T.Val(2.0), T.Val(0.0)).ToHandleChecked()->IsUndefined());
295    CHECK(T.Call(T.Val(-2.1), T.Val(0.0)).ToHandleChecked()->IsUndefined());
296  }
297
298  {
299    FunctionTester T(
300        "(function() { if (false) { var x = 1; } function inc(a)"
301        " { return a + x; } return inc; })()");  // x is undefined!
302
303    CHECK(T.Call(T.Val(0.0), T.Val(0.0)).ToHandleChecked()->IsNaN());
304    CHECK(T.Call(T.Val(2.0), T.Val(0.0)).ToHandleChecked()->IsNaN());
305    CHECK(T.Call(T.Val(-2.1), T.Val(0.0)).ToHandleChecked()->IsNaN());
306  }
307}
308