node.cc 12.2 KB
Newer Older
1 2 3 4
// Copyright 2013 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.

5
#include "src/compiler/node.h"
6

7 8 9 10
namespace v8 {
namespace internal {
namespace compiler {

11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51
Node::OutOfLineInputs* Node::OutOfLineInputs::New(Zone* zone, int capacity) {
  size_t size =
      sizeof(OutOfLineInputs) + capacity * (sizeof(Node*) + sizeof(Use));
  intptr_t raw_buffer = reinterpret_cast<intptr_t>(zone->New(size));
  Node::OutOfLineInputs* outline =
      reinterpret_cast<OutOfLineInputs*>(raw_buffer + capacity * sizeof(Use));
  outline->capacity_ = capacity;
  outline->count_ = 0;
  return outline;
}


void Node::OutOfLineInputs::ExtractFrom(Use* old_use_ptr, Node** old_input_ptr,
                                        int count) {
  // Extract the inputs from the old use and input pointers and copy them
  // to this out-of-line-storage.
  Use* new_use_ptr = reinterpret_cast<Use*>(this) - 1;
  Node** new_input_ptr = inputs_;
  for (int current = 0; current < count; current++) {
    new_use_ptr->bit_field_ =
        Use::InputIndexField::encode(current) | Use::InlineField::encode(false);
    DCHECK_EQ(old_input_ptr, old_use_ptr->input_ptr());
    DCHECK_EQ(new_input_ptr, new_use_ptr->input_ptr());
    Node* old_to = *old_input_ptr;
    if (old_to) {
      *old_input_ptr = nullptr;
      old_to->RemoveUse(old_use_ptr);
      *new_input_ptr = old_to;
      old_to->AppendUse(new_use_ptr);
    } else {
      *new_input_ptr = nullptr;
    }
    old_input_ptr++;
    new_input_ptr++;
    old_use_ptr--;
    new_use_ptr--;
  }
  this->count_ = count;
}


52
Node* Node::New(Zone* zone, NodeId id, const Operator* op, int input_count,
53
                Node* const* inputs, bool has_extensible_inputs) {
54 55 56 57 58
  Node** input_ptr;
  Use* use_ptr;
  Node* node;
  bool is_inline;

59 60 61 62
#if DEBUG
  // Verify that none of the inputs are {nullptr}.
  for (int i = 0; i < input_count; i++) {
    if (inputs[i] == nullptr) {
63 64
      V8_Fatal(__FILE__, __LINE__, "Node::New() Error: #%d:%s[%d] is nullptr",
               static_cast<int>(id), op->mnemonic(), i);
65 66 67 68
    }
  }
#endif

69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
  if (input_count > kMaxInlineCapacity) {
    // Allocate out-of-line inputs.
    int capacity =
        has_extensible_inputs ? input_count + kMaxInlineCapacity : input_count;
    OutOfLineInputs* outline = OutOfLineInputs::New(zone, capacity);

    // Allocate node.
    void* node_buffer = zone->New(sizeof(Node));
    node = new (node_buffer) Node(id, op, kOutlineMarker, 0);
    node->inputs_.outline_ = outline;

    outline->node_ = node;
    outline->count_ = input_count;

    input_ptr = outline->inputs_;
    use_ptr = reinterpret_cast<Use*>(outline);
    is_inline = false;
  } else {
    // Allocate node with inline inputs.
    int capacity = input_count;
    if (has_extensible_inputs) {
      const int max = kMaxInlineCapacity;
      capacity = std::min(input_count + 3, max);
    }

    size_t size = sizeof(Node) + capacity * (sizeof(Node*) + sizeof(Use));
    intptr_t raw_buffer = reinterpret_cast<intptr_t>(zone->New(size));
    void* node_buffer =
        reinterpret_cast<void*>(raw_buffer + capacity * sizeof(Use));
98

99 100 101 102 103 104 105
    node = new (node_buffer) Node(id, op, input_count, capacity);
    input_ptr = node->inputs_.inline_;
    use_ptr = reinterpret_cast<Use*>(node);
    is_inline = true;
  }

  // Initialize the input pointers and the uses.
106 107
  for (int current = 0; current < input_count; ++current) {
    Node* to = *inputs++;
108 109 110 111
    input_ptr[current] = to;
    Use* use = use_ptr - 1 - current;
    use->bit_field_ = Use::InputIndexField::encode(current) |
                      Use::InlineField::encode(is_inline);
112 113
    to->AppendUse(use);
  }
114 115
  node->Verify();
  return node;
116 117 118
}


119 120 121 122 123 124
Node* Node::Clone(Zone* zone, NodeId id, const Node* node) {
  int const input_count = node->InputCount();
  Node* const* const inputs = node->has_inline_inputs()
                                  ? node->inputs_.inline_
                                  : node->inputs_.outline_->inputs_;
  Node* const clone = New(zone, id, node->op(), input_count, inputs, false);
125
  clone->set_type(node->type());
126 127 128 129
  return clone;
}


130 131
void Node::Kill() {
  DCHECK_NOT_NULL(op());
132
  NullAllInputs();
133 134 135 136
  DCHECK(uses().empty());
}


137 138 139
void Node::AppendInput(Zone* zone, Node* new_to) {
  DCHECK_NOT_NULL(zone);
  DCHECK_NOT_NULL(new_to);
140 141 142 143 144 145 146 147 148 149 150

  int inline_count = InlineCountField::decode(bit_field_);
  int inline_capacity = InlineCapacityField::decode(bit_field_);
  if (inline_count < inline_capacity) {
    // Append inline input.
    bit_field_ = InlineCountField::update(bit_field_, inline_count + 1);
    *GetInputPtr(inline_count) = new_to;
    Use* use = GetUsePtr(inline_count);
    use->bit_field_ = Use::InputIndexField::encode(inline_count) |
                      Use::InlineField::encode(true);
    new_to->AppendUse(use);
151
  } else {
152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178
    // Append out-of-line input.
    int input_count = InputCount();
    OutOfLineInputs* outline = nullptr;
    if (inline_count != kOutlineMarker) {
      // switch to out of line inputs.
      outline = OutOfLineInputs::New(zone, input_count * 2 + 3);
      outline->node_ = this;
      outline->ExtractFrom(GetUsePtr(0), GetInputPtr(0), input_count);
      bit_field_ = InlineCountField::update(bit_field_, kOutlineMarker);
      inputs_.outline_ = outline;
    } else {
      // use current out of line inputs.
      outline = inputs_.outline_;
      if (input_count >= outline->capacity_) {
        // out of space in out-of-line inputs.
        outline = OutOfLineInputs::New(zone, input_count * 2 + 3);
        outline->node_ = this;
        outline->ExtractFrom(GetUsePtr(0), GetInputPtr(0), input_count);
        inputs_.outline_ = outline;
      }
    }
    outline->count_++;
    *GetInputPtr(input_count) = new_to;
    Use* use = GetUsePtr(input_count);
    use->bit_field_ = Use::InputIndexField::encode(input_count) |
                      Use::InlineField::encode(false);
    new_to->AppendUse(use);
179
  }
180
  Verify();
181 182 183 184 185 186 187 188 189 190
}


void Node::InsertInput(Zone* zone, int index, Node* new_to) {
  DCHECK_NOT_NULL(zone);
  DCHECK_LE(0, index);
  DCHECK_LT(index, InputCount());
  AppendInput(zone, InputAt(InputCount() - 1));
  for (int i = InputCount() - 1; i > index; --i) {
    ReplaceInput(i, InputAt(i - 1));
191
  }
192
  ReplaceInput(index, new_to);
193
  Verify();
194 195
}

196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211
void Node::InsertInputs(Zone* zone, int index, int count) {
  DCHECK_NOT_NULL(zone);
  DCHECK_LE(0, index);
  DCHECK_LT(0, count);
  DCHECK_LT(index, InputCount());
  for (int i = 0; i < count; i++) {
    AppendInput(zone, InputAt(Max(InputCount() - count, 0)));
  }
  for (int i = InputCount() - count - 1; i >= Max(index, count); --i) {
    ReplaceInput(i, InputAt(i - count));
  }
  for (int i = 0; i < count; i++) {
    ReplaceInput(index + i, nullptr);
  }
  Verify();
}
212

213 214 215 216 217 218 219
void Node::RemoveInput(int index) {
  DCHECK_LE(0, index);
  DCHECK_LT(index, InputCount());
  for (; index < InputCount() - 1; ++index) {
    ReplaceInput(index, InputAt(index + 1));
  }
  TrimInputCount(InputCount() - 1);
220
  Verify();
221 222 223
}


224 225 226 227 228 229 230 231 232 233 234 235
void Node::ClearInputs(int start, int count) {
  Node** input_ptr = GetInputPtr(start);
  Use* use_ptr = GetUsePtr(start);
  while (count-- > 0) {
    DCHECK_EQ(input_ptr, use_ptr->input_ptr());
    Node* input = *input_ptr;
    *input_ptr = nullptr;
    if (input) input->RemoveUse(use_ptr);
    input_ptr++;
    use_ptr--;
  }
  Verify();
236 237 238
}


239 240 241
void Node::NullAllInputs() { ClearInputs(0, InputCount()); }


242
void Node::TrimInputCount(int new_input_count) {
243 244 245 246 247 248
  int current_count = InputCount();
  DCHECK_LE(new_input_count, current_count);
  if (new_input_count == current_count) return;  // Nothing to do.
  ClearInputs(new_input_count, current_count - new_input_count);
  if (has_inline_inputs()) {
    bit_field_ = InlineCountField::update(bit_field_, new_input_count);
249
  } else {
250
    inputs_.outline_->count_ = new_input_count;
251 252 253 254
  }
}


255 256 257 258 259 260 261 262 263
int Node::UseCount() const {
  int use_count = 0;
  for (const Use* use = first_use_; use; use = use->next) {
    ++use_count;
  }
  return use_count;
}


264 265 266 267 268 269 270
void Node::ReplaceUses(Node* that) {
  DCHECK(this->first_use_ == nullptr || this->first_use_->prev == nullptr);
  DCHECK(that->first_use_ == nullptr || that->first_use_->prev == nullptr);

  // Update the pointers to {this} to point to {that}.
  Use* last_use = nullptr;
  for (Use* use = this->first_use_; use; use = use->next) {
271
    *use->input_ptr() = that;
272 273 274 275 276 277 278
    last_use = use;
  }
  if (last_use) {
    // Concat the use list of {this} and {that}.
    last_use->next = that->first_use_;
    if (that->first_use_) that->first_use_->prev = last_use;
    that->first_use_ = this->first_use_;
279 280 281 282 283
  }
  first_use_ = nullptr;
}


284 285 286
bool Node::OwnedBy(Node const* owner1, Node const* owner2) const {
  unsigned mask = 0;
  for (Use* use = first_use_; use; use = use->next) {
287 288
    Node* from = use->from();
    if (from == owner1) {
289
      mask |= 1;
290
    } else if (from == owner2) {
291 292 293 294 295 296 297 298 299
      mask |= 2;
    } else {
      return false;
    }
  }
  return mask == 3;
}


300 301 302 303 304 305
void Node::Print() const {
  OFStream os(stdout);
  os << *this << std::endl;
}


306
Node::Node(NodeId id, const Operator* op, int inline_count, int inline_capacity)
307
    : op_(op),
308
      type_(nullptr),
309
      mark_(0),
310 311 312 313 314 315
      bit_field_(IdField::encode(id) | InlineCountField::encode(inline_count) |
                 InlineCapacityField::encode(inline_capacity)),
      first_use_(nullptr) {
  // Inputs must either be out of line or within the inline capacity.
  DCHECK(inline_capacity <= kMaxInlineCapacity);
  DCHECK(inline_count == kOutlineMarker || inline_count <= inline_capacity);
316 317 318
}


319
void Node::AppendUse(Use* use) {
320
  DCHECK(first_use_ == nullptr || first_use_->prev == nullptr);
321
  DCHECK_EQ(this, *use->input_ptr());
322 323 324 325
  use->next = first_use_;
  use->prev = nullptr;
  if (first_use_) first_use_->prev = use;
  first_use_ = use;
326 327 328
}


329
void Node::RemoveUse(Use* use) {
330
  DCHECK(first_use_ == nullptr || first_use_->prev == nullptr);
331
  if (use->prev) {
332
    DCHECK_NE(first_use_, use);
333 334
    use->prev->next = use->next;
  } else {
335
    DCHECK_EQ(first_use_, use);
336 337 338 339
    first_use_ = use->next;
  }
  if (use->next) {
    use->next->prev = use->prev;
340 341 342 343
  }
}


344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381
#if DEBUG
void Node::Verify() {
  // Check basic sanity of input data structures.
  fflush(stdout);
  int count = this->InputCount();
  // Avoid quadratic explosion for mega nodes; only verify if the input
  // count is less than 200 or is a round number of 100s.
  if (count > 200 && count % 100) return;

  for (int i = 0; i < count; i++) {
    CHECK_EQ(i, this->GetUsePtr(i)->input_index());
    CHECK_EQ(this->GetInputPtr(i), this->GetUsePtr(i)->input_ptr());
    CHECK_EQ(count, this->InputCount());
  }
  {  // Direct input iteration.
    int index = 0;
    for (Node* input : this->inputs()) {
      CHECK_EQ(this->InputAt(index), input);
      index++;
    }
    CHECK_EQ(count, index);
    CHECK_EQ(this->InputCount(), index);
  }
  {  // Input edge iteration.
    int index = 0;
    for (Edge edge : this->input_edges()) {
      CHECK_EQ(edge.from(), this);
      CHECK_EQ(index, edge.index());
      CHECK_EQ(this->InputAt(index), edge.to());
      index++;
    }
    CHECK_EQ(count, index);
    CHECK_EQ(this->InputCount(), index);
  }
}
#endif


382
std::ostream& operator<<(std::ostream& os, const Node& n) {
383
  os << n.id() << ": " << *n.op();
384
  if (n.InputCount() > 0) {
385
    os << "(";
386
    for (int i = 0; i < n.InputCount(); ++i) {
387
      if (i != 0) os << ", ";
388 389 390 391 392
      if (n.InputAt(i)) {
        os << n.InputAt(i)->id();
      } else {
        os << "null";
      }
393 394 395 396 397
    }
    os << ")";
  }
  return os;
}
398

399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438

Node::InputEdges::iterator Node::InputEdges::iterator::operator++(int n) {
  iterator result(*this);
  ++(*this);
  return result;
}


bool Node::InputEdges::empty() const { return begin() == end(); }


Node::Inputs::const_iterator Node::Inputs::const_iterator::operator++(int n) {
  const_iterator result(*this);
  ++(*this);
  return result;
}


bool Node::Inputs::empty() const { return begin() == end(); }


Node::UseEdges::iterator Node::UseEdges::iterator::operator++(int n) {
  iterator result(*this);
  ++(*this);
  return result;
}


bool Node::UseEdges::empty() const { return begin() == end(); }


Node::Uses::const_iterator Node::Uses::const_iterator::operator++(int n) {
  const_iterator result(*this);
  ++(*this);
  return result;
}


bool Node::Uses::empty() const { return begin() == end(); }

439 440 441
}  // namespace compiler
}  // namespace internal
}  // namespace v8